Search

To explore an effective quality evaluation system based on microstructure changes, tilapia samples were preserved at the temperature of −20, −40, and −80°C up to a storage period of 270 days. The porous structure of fish muscle was quantified using the cross‐section area (CA) and fractal dimension (FD) of ice crystals, and the effectiveness of the two was compared. The relationships between microstructure changes and traditional quality parameters, including water‐holding capacity, texture properties, K value, and total volatile basic nitrogen (TVB‐N), were also explored. The results showed that FD dropped by 8.79, 4.53, and 3.03% of fillets at −20, −40, and −80°C after 270 days of storage, respectively. The better fitting on the basis of FD for evaluating quality of tilapia compared with CA. Traditional quality indicators were correlated well with the FD (R2 > 0.94), except for relaxation time (T2). The first‐order kinetic equation FD = exp (0.0895 t exp[−7240.26/RT])/1.8903 was developed, and FD relative errors between predicted and observed values were all less than 3%, which demonstrated that the feasibleness and accuracy of quality evaluation based on FD during frozen storage. Practical applications: Frozen storage inevitably has a negative impact on the tissue, water‐holding capacity, and protein properties of fish. Thus, it is of great urgency to put forward an effective quality evaluation system of frozen fish. Here, tilapia samples were studied over a period of 270 days by measuring their microstructure of muscle fibers and traditional quality parameters. Correlation analysis of each index was also conducted and kinetic model based on FD was established and validated finally. In addition to establishing an effective quality evaluation system based on microstructure changes for tilapia, these results will provide new insights into the quality evaluation and laid a foundation for the application of fractal dimension in tilapia processing and transportation. [ABSTRACT FROM AUTHOR]

Background: Enzyme injection is vital for improving the sensory attributes and processing characteristics of meat products by enhancing proteolysis. However, studies regarding the appropriate dose addition for accelerating protein degradation in grass carp are minimal. This study aimed to investigate the impact of Flavourzyme® on the flavor quality and antioxidant activity of salted grass carp via brine injection and brining. Results: Flavourzyme was added at doses of 0, 5, 10, 20, and 30 leucine aminopeptidase units (LAPU) per kilogram of raw meat. The results indicated that adding Flavourzyme promoted proteolysis, which was reflected by the enhanced total free amino acid content (from 3.7414 g kg−1 to 4.9160 g kg−1 in the brining group and from 3.8039 g kg−1 to 5.4061 g kg−1 in the injection group) and a decrease in salt soluble and insoluble protein (P < 0.05). The antioxidant activity was improved, and the thiobarbituric acid reactive substance value in salted carp decreased due to the higher content of the protein hydrolysis product (P < 0.05). All sensory attributes were improved significantly, especially when using brine injection (P < 0.05). Brine injection was helpful to diffuse the Flavourzyme, resulting in stronger proteolysis. Conclusion: The appropriate Flavourzyme dose was 10 LAPU kg−1 in the injection group and 20 LAPU kg−1 in the brining group. Therefore, moderate Flavourzyme addition was excellent in improving sensory attributes and storage characteristics, whereas injection represented a novel method to obtain a similar fish meat quality in a shorter time and with less added Flavourzyme. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This study investigated the effects of different thawing methods (water immersion thawing [WIT, 25 °C], air thawing [AT, 25 °C] and refrigerator thawing [RT, 25 °C]) on the biochemical properties and microstructure of tilapia (Oreochromis niloticus) fillets during storage at −18 °C for 6 months. The results indicated that the thawing time for WIT, AT and RT were approximately 7, 83 and 616 min, respectively. Thawing and cooking losses in the RT samples were significantly lower than those in WIT and AT samples (P < 0.05). The microstructural integrity of RT samples was less compromised than that of WIT and AT treated samples. Ca2+‐ATPase activity and SH content decreased with increasing storage time and the frozen storage time. Compared with the other two thawing groups during frozen storage, RT had the highest fluorescence, which was significant for the quality of tilapia fillets. However, no significant difference (P < 0.05) was observed in protein secondary structure changes, especially β‐sheets and β‐turns. Therefore, RT is suggested to be an effective thawing method to minimise quality change during frozen storage and the frozen storage time has a greater impact on its quality. These results demonstrate the interaction between frozen storage and thawing processes on selected quality parameters. [ABSTRACT FROM AUTHOR]

BACKGROUND: Glycation is a green processing technology. Based on our previous studies, glycation with l‐arabinose and xylose was beneficial to enhance the texture properties of silver carp mince (SCM) gels. However, the possible enhancement mechanism remained unclear. Therefore, in this study, SCM gels with different types of reducing sugar (glucose, l‐arabinose, and xylose) were prepared based on our previous study. The possible mechanism of texture enhancement of SCM gels was analyzed by investigating the changes in water distribution, protein structures, and microstructure in the gel system. RESULTS: The glycation of l‐arabinose and xylose enhanced the hardness, cohesiveness, chewiness, and resilience of SCM gels. Hardness increased from 1883.04 (control group) to 3624.54 (l‐arabinose group) and 4348.18 (xylose group). Low‐field nuclear magnetic resonance (LF‐NMR) showed that glycation promoted the tight binding of immobilized water to proteins. Raman spectroscopic analysis showed that glycation increased the surface hydrophobicity and promoted the formation of disulfide bonds. Scanning electron microscopy (SEM) showed that glycation promoted the formation of uniform and dense three‐dimensional network structure in SCM gels. CONCLUSION: In summary, glycation enhanced the binding ability of immobilized water to proteins, improved the surface hydrophobicity, promoted the formation of disulfide bonds, and led to a more uniform and dense gel network structure of proteins, thus enhancing the texture properties of SCM gels. This research provided a theoretical basis for a better understanding of the mechanism of the effect of glycation on the quality of gel products and also provided technical support for the application of l‐arabinose and xylose in new functional gel foods. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The research on the quality changes of grass carp during brine salting with 6%, 8%, and 10% salt additions was evaluated by chemical and physical indicators, as well as a sensory assessment and microbiological analysis. The NaCl content was proportional to salt addition and salting time. The increase of salt addition could lead to the increase of hardness and chewiness in which change trends were contrary to the pH within 24 hr. All K values were less than 10% during brine salting. The effect of 8% salt additions on free amino acids was relatively smaller. Higher levels of salt additions could inhibit bacterial growth. Combined with sensory assessment, equivalent umami concentration (EUC), and taste activity value (TAV) to analysis comprehensively, it was suggested that grass carp meat should be eaten at 4–8 hr of brine salting with 8% salt additions or processed for the next step, in which the grass carp meat had a better taste and quality. [ABSTRACT FROM AUTHOR]

This study was aimed at to investigate the quality changes of grass carp during short‐term starvation. The pH, lactic acid, free amino acid, and adenosine triphosphate‐related compounds of dorsal meat, belly meat and red meat in grass carp were measured during starvation for 6 days, and the quality of grass carp was evaluated by K value, equivalent umami concentration (EUC), taste activity value (TAV), and electronic tongue. The pH of three parts meat reached the maximum value on the fourth day, which was closely related to the lactic acid content. Concurrently, the contents of fresh sweet amino acids were higher on the fourth day in all parts. The K values in dorsal meat and belly meat were below 10% during starvation. Considering the overall results of electronic tongue, EUC, and TAV analysis, it is suggested that grass carp should be marketed and eaten with a starvation period of 2–4 days for best taste and quality. [ABSTRACT FROM AUTHOR]

Grass carp is the most important freshwater fish in China, and salting is the main processing method. This study investigated the effect of brine injection on flavor of grass carp muscle compared with brining at low temperature (4°C) and room temperature (20°C) respectively. Salt content, free amino acids, nucleotides, equivalent umami concentration (EUC) and texture were evaluated as flavor indicators during salting. The results showed that brine injection groups reached equilibrium in 3 h and 5 h at 20°C and 4°C, respectively. Brining groups reached equilibrium in 5 h and 7 h at 20°C and 4°C, respectively. The equilibrium salt content was about 1.76%, and there was no significant deterioration in terms of the other indicators mentioned above by two different methods. The results of this research indicate the feasibility and the great economic potential of brine injection, and also provide the theoretical basis to promote this method in processing of aquatic products. [ABSTRACT FROM AUTHOR]

Pacific White Shrimps (Litopenaeus vannamei) are an aquaculture species with global importance. For the purpose of this paper, the quality shelling process of Pacific White Shrimps, freshly harvested from farms and stored in a mixture ice water up to 24 hr, was investigated. Both the differences and correlations between the indexes such as peeling time, shrimp yield, chromatic aberration, texture, K value, TBA value, and microstructure were compared and analyzed. The optimal shell peeling time of Pacific White Shrimps was determined by ice water treatment for 8 hr. The shell peeling time was 1.77 min, the elasticity of the shrimp was 0.51 mm, the hardness was 2,124.58 g, K value was 1.33%, and TBA value was 0.004 mg/100 g. Both the smell and color of the shelled shrimp were normal. This study aims to endorse the mechanical shelling of Pacific White Shrimps. For the purpose of this paper, the quality shelling process of Pacific White Shrimps, freshly harvested from farms and stored in an ice water mixture for up to 24 hr, was investigated. Both the differences and correlations between the indexes such as peeling time, shrimp yield, chromatic aberration, texture, K value, TBA value, and microstructure were compared and analyzed. This study aims to endorse the mechanical shelling of Pacific White Shrimps. [ABSTRACT FROM AUTHOR]

A tandem mass tag technology (TMT), based on the quantitative proteomics approach, was applied to investigate the associations between tilapia (Oreochromis niloticus) fillet quality characteristics (pH, color, texture, ice crystal morphology and protein denaturation) and proteome profiles during a 12-month frozen storage period. When compared with the control group (0 day), a total of 175 differentially abundant proteins (DAPs) were found in tilapia muscle from two frozen storage temperatures (−20 °C and −40 °C). Correlation analysis between the DAPs and the quality traits showed that 80 DAPs were correlated closely with the quality traits. The bioinformatics analysis revealed that 49, 9 and 2 DAPs were involved in binding proteins, metabolic enzymes and protein turnover, respectively, which were mainly closely associated with color traits and protein denaturation. These results provide a further understanding of the proteome changes and mechanisms of the quality decline of tilapia during frozen storage. • A TMT-based strategy was applied to the proteomics of frozen tilapia fillets for 12 months. • Tilapia fillets stored at − 40 °C exhibited satisfactory quality traits. • Tilapia fillets stored at − 20 °C showed greater proteome changes than those stored at − 40 °C. • Twenty-nine and 17 DAPs correlated closely with color trait and protein denaturation. • Four proteins could be potential biomarkers for monitoring the quality of frozen tilapia. [ABSTRACT FROM AUTHOR]

Polymer geosynthetic reinforcements exhibit obvious viscous behaviours depending on the loading strain rate. These behaviours can be accurately described using a nonlinear three-component constitutive model. After implementing this model into the finite element software ABAQUS, it can be widely used for the analysis of geosynthetic-reinforced soil problems. The algorithm for the numerical integration of this elasto-viscoplastic model is explained in detail. Simulations of both in-isolation geosynthetic reinforcement and geosynthetic-reinforced soil specimen are performed to analyse the viscous behaviours of polymer geosynthetics under complex loading histories. The corresponding user subroutines are provided in the supplementary data for potential readers. [ABSTRACT FROM AUTHOR]

The back cover image is based on the Original Article The impact of Flavourzyme on flavor, antioxidant activity and sensory attributes of salted grass carp by brine injection and brining by Shi Wenzheng et al., https://doi.org/10.1002/jsfa.11506. [ABSTRACT FROM AUTHOR]

• The prepared GMP particles have an irregular polyhedral structure. • The O/W type Pickering emulsion can be stabilized by GMP. • The increased concentration of GMP improves the stability of Pickering emulsions. In this study, edible Pickering emulsions stabilized with GMP particles were prepared for the first time using low-value grass carp myofibrillar protein (GMP). To elucidate the emulsion formation mechanism, the grass carp myofibrillar protein particles were first characterized, and the results showed that the lyophilized GMP particles had an irregular polyhedral structure and were amphiphilic nanoparticles. The stability of GMP-based emulsions tended to stabilize with the increase of GMP concentration at an appropriate oil-to-water volume ratio, with a decrease in droplet particle size and an increase in water-holding capacity, storage stability, and rheological stability, whereas the phenomenon of droplet aggregation after storage appeared at 4.0% additive level. Therefore, appropriate concentrations of GMP at a certain oil-to-water volume ratio can stabilize Pickering emulsions, which have an important future as a potential food-grade active substance delivery carrier for biological applications. [ABSTRACT FROM AUTHOR]

Summary: In this study, the effect of different fermenters on the quality and flavour of fermented mandarin fish was investigated via pH, salt content, moisture content, thiobarbituric acid, microbial community, free amino acids and volatile compounds. The results demonstrated that the inoculated fermentation effectively suppressed fish fat oxidation, resulting in significantly higher levels of umami amino acids in mandarin fish compared to the natural fermentation group (P < 0.05). Additionally, certain bitter amino acids were also inhibited. Moreover, the total amino acid content of the mixed inoculated fermentation group was significantly elevated compared to other groups, reaching 300.21 ± 5.37 mg/100 g. The synergistic effect of free amino acids and flavour‐enhancing nucleotides significantly influenced the taste of the fermented fish, with the mixed inoculation fermentation group exhibiting a significantly higher Equivalent umami concentration (EUC) value compared to other groups, reaching 216.06 ± 20.13 mgMSG/100 g on the sixth day of fermentation. A total of 47 volatile compounds were detected by using headspace gas chromatography‐ion mobility spectrometry (HS‐GC‐IMS), and the results demonstrated that inoculated fermentation positively influenced the development of fish flavour, and mixed inoculated fermentation proved to be more effective. This study provides a theoretical foundation for the industrial production of fermented fish products and offers potential avenues for technical enhancement. [ABSTRACT FROM AUTHOR]

Summary The effects of hydrostatic thawing (HT), flowing water thawing (FT), ultrasonic thawing (UT), microwave thawing (MT), and microwave‐combined ultrasonic thawing (MUT) on the quality of yellowtail fillets were investigated via thawing time, physicochemical quality, water retention, microstructure and water migration distribution. The results showed that MUT had a shorter thawing time, second only to microwave thawing (MT) and significantly shorter than other thawing methods. Moreover, MUT could retain a better performance of the samples, such as colour, texture, water retention and moisture distribution, and prevent damage to the microstructure. In addition, freshness analysis showed that pH, total volatile saline nitrogen and K values were optimal for MUT. Therefore, MUT could be a viable thawing method that increases the thawing rate of yellowtail fillets while maintaining their quality characteristics. [ABSTRACT FROM AUTHOR]

The dried black carp was studied based on moisture content, color, aerobic plate count (APC), total volatile basic nitrogen (TVB‐N), peroxide value (POV), thiobarbituric acid reactive substance (TBARS), fatty acids, free amino acids, and nucleotides to explore the physicochemical properties changes. After drying for 12 hr, moisture content dropped to 42.53% and color changed obviously. L* value decreased and a* and b* values increased. APC and TVB‐N results indicated fillets had high food safety. POV and TBA both were on the rise in fillets, reaching the maximum values of 0.08 mg/100 g and 2.33 mg MDA/kg, respectively. Monounsaturated fatty acids and polyunsaturated fatty acids were oxidized and decomposed, which led to the increase of saturated fatty acids absolute content. From the results of equivalent umami concentration, fillets reached the maximum value of 9.04 g MSG/100 g. The longer the drying time, the worse the taste quality in products. Practical applications: In order to investigate the quality changes of black carp during drying, physical properties, lipid oxidation, and nonvolatile flavor substances were analyzed. From this article, it can be found that during the process of drying, the black carp was in a safe state. The results of this article provided theoretical and technical support for black carp. [ABSTRACT FROM AUTHOR]

BACKGROUND: Potentilla anserina L. is rich in various nutrients, active ingredients and unique flavor, comprising a natural nutrition and health food. However, its application in aquatic food has been rarely reported. Therefore, the effects of Potentilla anserina L. powder (PAP) on gel properties and volatile flavor profile of silver carp surimi were investigated. RESULTS: The gel strength and water‐holding capacity of the surimi gels were significantly improved (P < 0.05), and the whiteness and cooking loss of all the samples decreased slightly with the increase in PAP content. The addition of PAP shortened the relaxation time (T2) of the surimi gels and converted some of the free water into immobile or bound water, which resulted in a better immobilization of water in the surimi. Scanning electron microscopy images demonstrated that the network of surimi gels with PAP added was denser and had a smoother surface compared to the control. Volatile components (VCs) analysis showed that 33 VCs were identified in the surimi gel samples with different additions of PAP, among which aldehydes, alcohols and esters were the major VCs, accounting for more than 50% of the VCs in the surimi gels. PAP addition reduced the fishy and rancid flavor compounds in surimi gels, such as 1‐propanol, 1‐octen‐3‐ol, etc., and promoted the production of aldehydes, alcohols, esters and other flavor substances. CONCLUSION: These results of the present study provide theoretical support for the investigation and development of new nutrient‐health‐flavored surimi products. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In this study, adenosine triphosphate (ATP)‐related compounds and free amino acids were determined to study the changes of water‐soluble flavor substances in grass carp meat during steaming for 18 min. Sensory assessment, electronic tongue, equivalent umami concentration (EUC) value, and taste active value (TAV) were also performed to obtain the best quality of steamed grass carp meat. The results showed that the flavor presented by nucleotides in three parts meat was better within 9 min. The bitter amino acids in the dorsal meat and red meat significantly decreased at 6 min (101.33 mg/100 g and 44.64 mg/100 g, respectively). From the sensory analysis, EUC value, and TAV, it can be found that the quality of grass carp meat was the best when steamed for 6–9 min. The electronic tongue indicated that the taste differences were significantly between 6 and 9 min. Therefore, this study suggested that grass carp should be eaten during 6–9 min of steaming. Practical applications: As the main way of meat processing and eating, heating not only endows the product with good color, but also kill microorganisms and improve the product quality. The reasonable heating will make the protein denaturation of the food, so that the protein digestion and absorption rate can be improved, which is conducive to people to obtain more abundant nutrition. The quality changes of grass carp meat during 18 min of steaming were studied by measuring ATP‐related compounds and free amino acids, combining with sensory assessment, electronic tongue analysis, EUC value, and TAV. These results not only provide useful information for the quality control of grass carp in the heating process, but also provide theoretical reference for the improvement of the nutritional value of grass carp. In addition, the mechanism of flavor change in the heating process of grass carp will be further improved, and effective suggestions will be provided for consumers to reasonably eat grass carp. [ABSTRACT FROM AUTHOR]

Chinese mitten crab (Eriocheir sinensis) is widely distributed along the eastern coast of China and is considered one of the most economically important crabs in China. Evaluating its taste substances can help to develop new varieties of Eriocheir sinensis with distinctive flavours to meet the diversified needs of the market. In the current research work, we compared the meat yield and flavour of wild adult male Eriocheir sinensis muscle from five rivers. The results showed that crabs from the Min River had the highest meat yield (32.94 ± 2.93%). The electronic tongue showed that the taste profiles of Min River and Ou River crabs were similar. The Min River crabs had the highest total amino acid content of 1404.01 ± 2.83 mg/100 g, of which sweet amino acids accounted for 64.9%, the highest 5′-inosine phosphate of 14.49 ± 2.11 mg/100 g, and the highest equivalent umami concentration (3.82 gMSG/100 g). Taste activity value analysis showed that crabs in Min River, Ou River, and Yangtze River were more influenced by alanine, arginine, and 5′-guanosine phosphate. Overall, wild male Eriocheir sinensis from Min River enriched the flavour substance, making it a potentially valuable resource for the Eriocheir sinensis industry. • Compared flavour and taste substances of wild Eriocheir sinensis from five rivers. • Significant flavour differences between different geographic populations. • The results help to develop germplasm resources of wild Eriocheir sinensis. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION The taste of fish is highly dependent on the composition of free amino acids (FAAs) and nucleotides. The present study aimed to investigate the effect of long‐term frozen storage periods (−18 °C, up to 6 months) and thawing methods [water thawing (WT, 25 °C), air thawing (AT, 25 °C), and chilled air thawing (CAT, 4 °C)] on the taste quality of tilapia (Oreochromis niloticus) fillets.The results showed that increase in bitter FAAs of CAT samples was 150.57% at 6 months of storage, which was lower than that of AT and WT. Glycine was the most abundant FAA and CAT maintained the highest sweet FAAs (249.90 mg/100 g). Additionally, the inosine monophosphate (IMP) of CAT samples were 1.18 and 1.09 times higher than that of WT and AT, respectively, at a frozen period of 6 months. In particular, the increase in equivalent umami concentration (EUC) values ranged from 24.25% to 103.16% in the three groups during the first 2 months. Data from principal component analysis (PCA) and orthogonal partial least‐squares discrimination analysis (OPLS‐DA) indicated that the taste quality was highly correlated with high levels of FAAs, hypoxanthine inosine (HxR) and hypoxanthine (Hx) as the storage time progressed.In general, CAT is beneficial in maintaining the taste quality of tilapia fillets during frozen storage, and frozen durations for 2 months enhances the umami flavor. This study provides useful information for the preservation of frozen aquatic products during the storage and thawing, and enrich the theoretical knowledge of the flavor chemistry of fish products. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION The present study aimed to investigate the cryoprotective effect of epigallocatechin gallate (EGCG) replacing sucrose on surimi during frozen storage. Substitution or partial substitution of 0.1% EGCG for sucrose (1.5%) was added to surimi, and the surimi samples without and with commercial cryoprotectants (4% sucrose and 4% sorbitol) were used as the control group.The results obtained suggest that, with the increase in frozen storage time, the structural performance of surimi protein gradually weakened (e.g. the decrease in the surface hydrophobicity, the increase in the total sulfhydryl and solubility, and the protein myosin heavy chain bands became shallow) and surimi gel quality gradually deteriorated (e.g. the decrease in water‐holding capacity, gel strength and all texture profile attributes). However, compared with the other three group surimi samples during the frozen period, the surimi proteins with partial replacement of sucrose by EGCG had a higher total sulfhydryl group content and solubility of proteins, as well as lower surface hydrophobicity of protein, suggesting that the addition of EGCG as a partial substitute for sucrose can enhance the antifreeze ability of surimi. Meanwhile, the surimi gel with the partial replacement of sucrose by EGCG had a higher water retention capacity, gel strength and texture attributes (e.g. hardness, springiness, cohesiveness, chewiness, and resilience), indicating that the addition of EGCG as a partial substitute for sucrose can inhibit the deterioration of surimi gel quality.Overall, EGCG partially replacing sucrose can play an alternative cryoprotectant with a lower sweetness to prevent the quality of surimi from deteriorating. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Among various cooking methods, steaming is favored by many because it can cause less damage to nutrient components in muscle, retain the inherent food flavor, and reduce the generation of harmful substances. Steaming conditions are closely related to fish flavor, fat and protein oxidation, and digestibility. RESULTS: The black carp steamed for 4 to 14 min was studied in this article based on sensory assessment, electronic tongue, free amino acids, adenosine triphosphate (ATP)‐related compounds, total nitrogen and non‐protein nitrogen to explore the effect of steaming time on the taste substances and protein degradation of pickled black carp. The experimental result showed that the meat steamed within 8 min tasted better, showing high tastiness. The sensory assessment score increased significantly to the maximum value of 82.33 at 6 min. The content of umami and sweet amino acids increased significantly to the maximum value of 1.6801 g kg–1 at 6 min. In the meantime, the IMP (inosine monophosphate) content was 1.9128 g kg–1, with its taste activity value (TAV) reaching 7.65, which proved that IMP affected the taste most. Furthermore, the total nitrogen content was 30.77 g kg–1, which meant protein degraded a great deal. Based on equivalent umami concentration (EUC) and its TAV, the meat tasted best at 6–8 min. The longer the steaming time, the faster the protein degradation and the more the flavor precursors. CONCLUSION: The black carp pickled products (with a weight of 20 g, with the size of 3 cm × 3 cm × 2 cm) is suggested to be steamed for 6 to 8 min. This conclusion provides a theoretical basis for its better taste quality. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

In this study, black carp was chosen as the subject. Effects of moisture content, hardness, color, microstructure, amino nitrogen content, ATP‐related compounds, free amino acids, and equivalent umami concentration changes of black carp during hot air drying (HD) and vacuum drying (VD) process were studied. Results showed that the b* and hardness increased with the drying time extended and VD could effectively delay it. Whiteness, amino nitrogen content, ATP‐related compounds, free amino acids, and equivalent umami concentration increased at first and decreased when arriving at a certain time. In HD, substances like protein and fat change more dramatically. In conclusion, color and hardness of VD are better than that of HD and microstructure was less damaged, but HD can obtain more umami substances. Practical applications: As an effective method of food processing and preserving, drying not only improve the quality of the product, but also extend the shelf life. The reasonable drying will give food seductive color and unique flavor. The quality changes of black carp during drying for 12 hr were studied by measuring moisture, hardness, color, microstructure, nonvolatile taste compounds, and equivalent umami concentration. These results will provide benefit information for the quality control of black carp during the drying process. [ABSTRACT FROM AUTHOR]

Total volatile basic nitrogen (TVBN), biogenic amine, total viable count (TVC), volatile compounds, and sensory evaluation were conducted to assess the quality of Chinese Mitten Crabs (Eriocheir sinensis) at living, zero, 2, 5, 10, 15, and 24 hr postmortem. The sensory evaluation found a noticeable odor of spoilage becoming evident 10 hr postmortem. The TVBN value increased and then decreased as time increased, reaching 23.67 mg N/100 g at 24 hr postmortem. Although biogenic amines were detected at 5 hr postmortem, by 24 hr postmortem these had not reached dangerous levels of toxicity. The initial TVC (6.06 Log CFU/g) of the living crab samples was relatively high and climbed further postmortem, reaching 10.00 Log CFU/g 24 hr postmortem. Trimethylamine was detected in the living sample in belly meat and 2 hr postmortem in crab roe and reached 8.33 µg/g in the roe 24 hr postmortem. Indole was detected at 0 hr (belly meat) and 10 hr (crab roe) postmortem, but did not change significantly during the observation period. Sulfur‐containing compounds were detected 5 hr after death and gradually increased over the observation period. Most indicators showed major changes at 5 hr and 10 hr postmortem. By 10 hr postmortem, the crab had entered the putrefaction stage and was thus no longer safe for consumption. [ABSTRACT FROM AUTHOR]

Background/Amis: Long non-coding RNAs (lncRNAs), a novel class of transcripts, have been shown to play critical roles in diverse cellular biological processes, including tumorigenesis. Small nucleolar RNA host gene 6 (SNHG6) regulates various biological processes in cancer cells. However, the biological role of SNHG6 in gastric cancer still remains to be explored. The aim of this study is to investigate the characteristic of the SNHG6 in gastric cancer. Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the expression of SNHG6 in gastric cancer tissues and cell lines. MTT assays, colony formation assays were used to determine the impact of SNHG6 on tumorigenesis . Flow cytometric analysis of cell cycle and apoptosis was performed to measure the effect of SNHG6 on cell cycle and apoptosis rate. Transwell assay was performed to measure the effect of SNHG6 on cell migration. Western blotting and immunofluorescence were utilized to examine the effect of SNHG6 on epithelial-mesenchymal transition (EMT) of GC cells. Chromatin immunoprecipitation (ChIP), RNA immunoprecipitation (RIP), RNA-pulldown and luciferase reporter assays were employed to dissect molecular mechanisms. Results: In this study, we revealed that SNHG6 was overexpressed in gastric cancer tissues and cell lines. High expression levels of SNHG6 wereassociated with invasion depth, lymph node metastasis, distant metastasis and tumor/node/metastasis (TNM) stage, and predicted poor prognosis. Loss-of-function assays revealed that silenced SNHG6 obviously inhibited gastric cancer cell growth, weakened cell migration capacity and suppressed the EMT processes of gastric cancer cells. Additionally, ChIP, RIP, RNA-pulldown and luciferase reporter assays evidenced that SNHG6 could epigenetically silenced p27 and could competitively sponging miR-101-3p thereby regulating zinc finger E-box-binding homeobox 1 (ZEB1). Conclusion: In summary, our findings demonstrated that SNHG6 acted as an oncogene in gastric cancer cells through regulating miR-101-3p/ZEB1 at a post-transcriptional level and silencing expression at a transcriptional level by recruiting enhancer of zeste homolog 2 (EZH2) to the promoter of p27. SNHG6 might serve as a candidate prognostic biomarker and a target for novel therapies of gastric cancer patients. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ultrasound combined with SPI enhanced the hardness and strength of low-salt surimi gel. • Ultrasonic and SPI enhanced the WHC of the gel, and quicker the T 2b , T 21 and T 22. • Ultrasound and SPI improved salt-soluble protein content and transform α-helix to β-sheet. • The gel had tighter and smaller pores of ultrasound combined with SPI. The effects of ultrasound combined (25 kHz, 400 ± 20 W/L, ultrasonic time of 5, 10 and 15 min) with soy protein isolate processing on gelling properties of low-salt silver carp surimi, aggregation and conformation of myofibrillar protein were investigated. The results revealed that, compared with only adding soy protein isolate components, ultrasound-assisted soy protein isolate had a more obvious effect on the protein structure in low-salt surimi, leading to the decrease in α-helix and total sulfhydryl contents, and the increase in β-sheet content and protein solubility. As a result, more proteins participated in the formation of the gel network, and significant improvements in hardness, gel strength and water-holding capacity of the low-salt surimi gel were observed, while the myosin heavy chain in SDS-PAGE was weakened. The low-field NMR results showed that the initial relaxation time of T 2 was apparently shorter, the free water content decreased and the bound water content increased under the action of ultrasound. Scanning electron microscope observation found that the surimi gel treated by ultrasound exhibited smaller holes, and had a more stable and denser network structure. In conclusion, the results of our work demonstrated that ultrasound combined with soy protein isolate can significantly improve the gel quality properties of low-salt silver carp. [ABSTRACT FROM AUTHOR]

BACKGROUND: Frozen tilapia fillet has become a leading aquatic product. High drip loss, dry and fibrous mouthfeel, and an unappealing appearance are its main problems. It was hypothesized that light salting could improve the quality, and that the preparation conditions would affect the storage stability of frozen tilapia fillets. RESULTS: The quality changes of lightly salted tilapia fillets were evaluated during frozen storage, and the underlying mechanisms were studied from the physicochemicaland microstructural perspectives. Though the salt content was 1.5% in all samples,the amount of ice crystals in frozen tissues decreased with the descending water content and freezing point (P < 0.05). No intracellular voids were observed in the samples prepared under proper salting conditions, and the myofibers were plump and smooth after freezing‐thawing, which contributed to the high water‐holding capacity of lightly salted fillets. After 28 days,the water‐binding capacity of the salted groups was 14.69%−18.62% higher than that of their unsalted counterparts (P < 0.05). The reduced protein solubility in the salted fillets was likely to have occurred because the solubilized and unfolded proteins interacted more easily during frozen storage. The oxidation degree of myofibrillar proteins was also affected by salting condition, and the fillets with less oxidized sulfhydryl groups maintained high springiness after 28 days of frozen storage. CONCLUSION: The salting condition of 9% NaCl solution for 1 h was recommended for the preparation of lightly salted fillets from freshwater fish, taking into account quality, processing efficiency, and storage stability. The enhanced water‐holding capacity and texture of lightly salted tilapia fillets were attributed to modified physicochemical and microstructural properties. These results could provide a scientific basis for the processing and storage of high‐quality, frozen, lightly salted fillets from freshwater fish. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In this study, the quality changes of grass carp during tea polyphenol-assisted curing were studied from physicochemical and flavor perspectives. The addition of tea polyphenols has a positive effect on maintaining the water content of fish as the curing time increases (p < 0.05). The tea polyphenol-assisted treatment maintains the brightness of grass carp meat. The addition of tea polyphenols also slowed down the rate of pH growth and enhances the texture of grass carp (p < 0.05). The addition of tea polyphenols reduced His content, which had a positive effect on the taste of the cured grass carp products. When the pickling time reached 60 min, the inosine monophosphate content of tea polyphenol-treated groups was higher than that of the group soaked in salt only. Combined with equivalent umami concentration and taste activity values, it was found that the addition of 0.1% TP could improve freshness of grass carp cured products. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of flavourzyme addition on protein degradation and flavor formation in grass carp during fermentation. The related results showed that the addition of flavourzyme reduced the moisture content and accelerated the hydrolysis of protein and generation of water‐soluble flavor substances (e.g., TCA‐soluble peptides, α‐amino nitrogen, and free amino acids), thereby contributing to fermented grass carp products with a better taste quality. Besides, radar map results of electronic tongue and electronic nose showed that flavourzyme addition gives fermented products a more intense umami taste and odor. Meanwhile, sensory evaluation results also further confirmed that the addition of flavourzyme significantly improved the sensory attributes of fermented grass carp products, especially the taste and odor attributes. Overall, flavourzyme addition may be an effective way to shorten fermentation time and improve the flavor quality of fermented grass carp products during fermentation. Practical Applications: In this study, to study the effects of flavourzyme addition on protein degradation and flavor formation in grass carp during fermentation, the related indicators include the moisture content, total nitrogen, non‐protein nitrogen, protein degradation index, TCA‐soluble peptides, α‐amino nitrogen, free amino acids, electronic tongue, electronic nose, and sensory attributes were analyzed. This study may provide some useful information for the improvement of fermentation methods and the production of high‐quality fermented grass carp products. [ABSTRACT FROM AUTHOR]

BACKGROUND: Fish protein is a good source of amino acids and peptides with sensory properties. Theoretically, the type of protein affects the taste quality of the protein hydrolysates. To better use fish protein in the food ingredients industry, an in silico approach was adopted to evaluate the potential of fish protein to release taste‐active compounds. RESULTS: Six types of protein from seven commercial fishes were screened from the Uniprot knowledge base. The results showed that a remarkable number of umami fragments presented in myosin and parvalbumin (PB), such as glutamic acid (Glu), aspartic acid (Asp), and Asp‐ and Glu‐ containing peptides, whereas sweet amino acids and bitter peptides (e.g., Pro‐ and Gly‐ containing peptides) were mainly found in collagen (CGI) in all fish samples. After the in silico proteolysis by papain, a difference in the profile of taste‐active fragments was observed among the six types of proteins. Amino acids were the main hydrolysis products of these proteins, especially umami, sweet, and bitter amino acids, significantly contributing to the taste formation of protein hydrolysates. Besides, the myosin and CGI hydrolysates were abundant in taste active peptides both in types and quantities. CONCLUSION: Myosin is a promising protein source for producing umami fragments, and CGI seems to be a good precursor of sweet and bitter fragments. Different types of protein have an essential effect on the taste of protein hydrolysates. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

[Display omitted] • Myosin bound to heptanal or hexanal via non-covalent interactions. • The binding ability of hexanal to myosin was stronger than that of heptanal. • Ultrasonic treatment enhanced the binding ability of aldehydes to myosin and the stability of the complex. • The flavor regulation of pearl mussel myosin could be achieved by ultrasound. This study was aim to investigate the influencing mechanism of ultrasonic treatment on the interaction between volatile aldehydes and myosin. The results showed that when the mass concentration ratio of myosin to heptanal/hexanal was 1:0.3, ultrasonic treatment could enhance the binding capacity of myosin to heptanal/hexanal, especially the binding of myosin to hexanal. The entropy and enthalpy values of their interaction were negative, indicating that the interaction was mainly driven by hydrogen bond and van der Waals force. After ultrasonic treatment, the fluorescence wavelength of myosin-heptanal/hexanal complex was redshifted, the α-helix content was increased, while its roughness values, particle size and the polydispersity index were decreased. These demonstrated that ultrasonic treatment was conducive to myosin binding to heptanal/hexanal, thereby restraining the release of volatile flavor compounds from myosin, which could provide new insights for the regulation of volatile flavor compounds. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate volatile compounds of dried fish floss with different sugar using electronic nose (e‐nose) and headspace‐solid‐phase microextraction/gas chromatography‐mass spectrometry (HS‐SPME/GC‐MS). Maillard reaction (MR) was carried out by reducing sugar (glucose, xylose, fructose, and galactose) instead of sucrose to increase the flavor of fish floss. The results showed that 64 volatile compounds were detected in fish floss. Hexanal, heptanal, nonanal, decanal, undecanal, tridecanal, pentadecanal, 4‐ethyl‐benzaldehyde, dodecanal, benzene acetaltaldehyde, (E, E)‐2,6‐nonadienal, (E, E)‐2,4‐decadienal, 2‐undecanone, 1‐octen‐3‐ol, (E)‐2‐hepten‐1‐ol, 1‐heptanol, and 2‐pentyl‐furan were regarded as key volatile compounds. Furthermore, e‐nose and partial least squares‐discriminant analysis (PLS‐DA) showed that there were significant differences in flavor among fish floss samples. The correlation analysis of browning index, fatty acids, and key volatile compounds confirmed that MR and lipid oxidation made a great contribution to the flavor formation. These results might provide guidance for the production and flavor formation of fish floss. Practical applications: Dried fish floss deeply loved by the public is a traditional leisure food with unique odor and delicious taste. The attractive flavor of dried fish floss could be increased with the help of the Maillard reaction (MR). The type of sugar in MR has a great influence on the reaction process and the flavor of substances. The comprehensive information on the flavor among the dried fish floss with different sugar (sucrose, glucose, xylose, fructose, and galactose) was characterized by using HS‐SPME/GC‐MS, electronic nose (E‐nose), and fatty acid analysis, which may provide a reference for the quality improvement of dried fish floss. [ABSTRACT FROM AUTHOR]

SUMMARY: Effects of frozen storage temperature on the quality and oxidative stability of lightly salted tuna were investigated. The bright and vivid colour became totally brown after 4 weeks at −20 °C and 8 weeks at −30 °C, where the a*/b* value decreased from 1.35 to 0.38 and 0.58, respectively. Discoloration and lipid oxidation occurred concurrently in lightly salted tuna flesh, and it was speculated that the oxidation of oxymyoglobin to metmyoglobin exacerbated lipid oxidation and vice versa. Storage at −40 °C or lower temperatures effectively suppressed the discoloration and maintained the high water‐holding capacity and unique textural properties of lightly salted flesh. It was attributed to the reduction in the conformational changes and particularly hydrophobic interactions among proteins, protecting the myoglobin from oxidative damages during frozen storage. Considering the quality maintenance and energy savings, storage at −40 °C was appropriate for lightly salted tuna flesh. [ABSTRACT FROM AUTHOR]

• Ice crystal formation combined with protein denaturation to predict shelf life was first reported. • The prediction accuracy of the kinetic model was decreased at later stages of storage. • IFI λmax could be accurately described the quality changes of tilapia. • ANN could successfully predict the quality changes throughout the whole period. • It is the first time to use K value to predict the freshness range of other indexes. The objectives of this study were to study the quality changes (ice crystal morphology, Ca2+-ATPase activity, total sulfhydryl [SH] content, intrinsic fluorescence intensity [IFI], and K value [freshness determination]) of tilapia at different storage temperatures for 112 days, and kinetic models and artificial neuronal network (ANN) were developed to predict the changes. There was a dramatic increase in cross-section area and equivalent diameter and a sharp decrease in Ca2+-ATPase activity and SH content during the first 4 weeks (p < 0.05). IFI λmax decreased by 43.95%, 29.77%, 28.97% and 18.58% after 16 weeks at 265 K, 259 K, 253 K, and 233 K. The kinetic model established by IFI λmax could be accurately described the quality changes during storage at 233–265 K. However, the prediction accuracy established by other indices decreased at later stages (14–16 weeks). The ANN model was superior to Arrhenius models and performed better for all indicators. [ABSTRACT FROM AUTHOR]

Summary: This study was to investigate the effects of glycation on the quality of silver carp mince (SCM) proteins. The browning index (BI), sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS‐PAGE), Fourier transform infrared spectroscopy (FTIR), total amino acid composition, chemical score, protein digestibility and reductive power of digested products were determined. The correlation between the degree of glycation, protein structure and protein nutritional quality was analysed. The results showed that the BI value of SCM‐G increased with the increase in heating time. Myosin heavy chain (MHC), myosin light chain (MLC), tropomyosin and actin were the main protein reactants for glycation. Glycation led to the expansion of the secondary structure of SCM proteins. Glycation reduced lysine and cysteine content but did not change the first limiting amino acid (Val) in SCM. The essential amino acid content of glycated SCM remained consistent with the amino acid nutritional requirements for children and above recommended by FAO/WHO. In addition, glycation did not change protein digestibility but significantly increased the reducing power of digested products with increasing degree of glycation. These results provided a theoretical basis for the application of glycation in food processing industry and the development of aquatic products with high nutritional value. [ABSTRACT FROM AUTHOR]

BACKGROUND Although exogenous and endogenous formaldehyde in squid has led to severe health threat, an in‐depth study on natural edible scavengers for formaldehyde in squid is still lacking. RESULTS: Response surface methodology (RSM) combined with experimental verification approaches was applied to obtain an optimal 'recipe' to achieve formaldehyde removal rate of >85%: 6 mg mL−1 tea polyphenols, 20 mg mL−1 chitosan, 3:2 (v/v) tea polyphenols and chitosan, a pH value of 3 and 60 min treatment time. Apart from the capability of removing formaldehyde, the scavenger derived from natural food exhibited a significant preservation effect (extension of preservation time up to 40%) on squid during chilled storage, and was safe and environmentally friendly. Meanwhile, a synergetic effect of the two components on scavenging formaldehyde was unraveled by multimolecular infrared spectroscopy. CONCLUSION: An edible and bifunctional reagent composed of tea polyphenols and chitosan was developed for simultaneously removing artificially added or endogenous formaldehyde and for preservation of squid. The bifunctional coating shows promise as a formaldehyde scavenger and green preservative for aquatic products. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This study focused on the effect of different levels of l‐arabinose addition on the sensory quality and digestibility of silver carp sausage by testing color, texture, smell, taste, sensory score, and digestibility. The results showed that the L* value of fish sausage decreased with the increase of l‐arabinose, while a* value, b* value, and BI increased. In addition, the hardness, springiness, and chewiness of fish sausage reached the maximum when adding 2% l‐arabinose. Principal component analysis results of E‐nose and E‐tongue data showed that l‐arabinose enhanced the aroma and taste profiles. Sensory evaluation found that fish sausage with 2% l‐arabinose had the highest overall acceptability. Moreover, the addition of 2% arabinose could better maintain the protein digestibility of fish sausage intact. This study has suggested a promising potential for applying glycation in aquatic product processing and the development of nutritious ready‐to‐eat fish products using l‐arabinose. Novelty impact statement: This work investigates the impact of different levels of l‐arabinose addition on the color, texture, smell, taste, and digestibility of silver carp sausage. It explains how the change of glycation degree affects the sensory quality and digestibility of silver carp sausage. Fish sausage with good overall acceptability and digestibility was obtained by adding 2% l‐arabinose. This work contributes a theoretical basis for applying glycation in aquatic product processing and developing nutritious ready‐to‐eat fish products using l‐arabinose. [ABSTRACT FROM AUTHOR]

In this study, the correlation between protein phosphorylation and deterioration in the quality of tilapia during storage in ice was examined by assessing changes in texture, water-holding capacity (WHC), and biochemical characteristics of myofibrillar protein throughout 7 days of storage. The hardness significantly decreased from 471.50 to 252.17 g, whereas cooking and drip losses significantly increased from 26.5% to 32.6% and 2.9% to 9.1%, respectively (P < 0.05). Myofibril fragmentation increased, while myofibrillar protein sulfhydryl content and Ca2+-ATPase activity decreased from 119.33 to 89.29 μmol/g prot and 0.85 to 0.46 μmolPi/mg prot/h, respectively (P < 0.05). Correlation analysis revealed that the myofibrillar protein phosphorylation level was positively correlated with hardness and Ca2+-ATPase activity but negatively correlated with WHC. Myofibrillar protein phosphorylation affects muscle contraction by influencing the dissociation of actomyosin, thereby regulating hardness and WHC. This study provides novel insights for the establishment of quality control strategies for tilapia storage based on protein phosphorylation. • Myofibrillar protein phosphorylation was negatively correlated with cohesion and WHC. • Phosphorylation was positively correlated with hardness and Ca2+-ATPase activity. • Phosphorylation affects tilapia quality by influencing dissociation of actomyosin. [ABSTRACT FROM AUTHOR]

The effects of microwave drying (MD), hot air drying (HAD), vacuum hot air drying (VD), and vacuum freeze drying (VFD) on the volatile profiles of Penaeus vannamei were investigated. A total of 89 and 94 volatile compounds were identified by headspace solid-phase microextraction-gas chromatography–mass spectrometry (HS-SPME-GC–MS) and monolithic material sorptive extraction gas chromatography–mass spectrometry (MMSE-GC–MS), respectively. Orthogonal partial least squares-discriminant analysis (OPLS-DA) and variable influence on projection (VIP) models were utilized to select characteristic volatiles and key marker compounds (e.g., octanal, 1-octen-3-ol, 2-methyl-butanal, 2-ethyl-furan, and trimethyl-pyrazine) to discriminate among four drying methods. Based on synthesis of odor descriptions and sensory evaluation, it was found that P. vannamei via MD, HAD, and VD greatly reduced the fishy and generated roasted, fatty, and smoked odors. This study systematically analyzed the aroma characteristics of four traditional dried P. vannamei products, which may provide theoretical guidance for industrial production. [Display omitted] • Drying reduced fishy odor and provided roasted and smoked smells. • Marker chemicals were found to distinguish among drying methods. • Combining OAV and VIP to analyze the distinctive aroma formation. • Combining MMSE and SPME extractions for precise detection. [ABSTRACT FROM AUTHOR]

This study aimed to develop an active biodegradable bilayer film and to investigate the release behaviors of active compounds into different food matrices. Cinnamaldehyde (CI) or thymol (Ty) was encapsulated in β-cyclodextrin (β-CD) to prepare the active β-CD inclusion complex (β-CD-CI/β-CD-Ty). The tilapia fish gelatin-sodium alginate composite (FGSA) containing β-CD-CI or β-CD-Ty was coated on the surface of PLA film to obtain the active bilayer film. Different food simulants including liquid food simulants (water, 3% acetic acid, 10% ethanol, and 95% ethanol), solid dry food simulant (modified polyphenylene oxide (Tenax TA)), and the real food (Japanese sea bass) were selected to investigate the release behaviors of bilayer films into different food matrixes. The results showed that the prepared β-CD inclusion complexes distributed evenly in the cross-linking structure of FGSA and improved the thickness and water contact angle of the bilayer films. Active compounds possessed the lowest release rates in Tenax TA, compared to the release to liquid simulants and sea bass. CI and Ty sustained the release to the sea bass matrix with a similar behavior to the release to 95% ethanol. The bilayer film containing β-CD-Ty exhibited stronger active antibacterial and antioxidant activities, probably due to the higher release efficiency of Ty in test mediums. [ABSTRACT FROM AUTHOR]

Summary: The aim of this study was to investigate the changes in physicochemical properties and myofibrillar protein properties of grass carp meat during brining and brine injection at 4 °C. The time reached equilibrium was 7 h in brining group and 5 h by injection, where the salt content was about 1.76%. The water content, water holding capacity and yield in injection group (86.59%, 9.18% and 110%, respectively) were higher than brining group (84.76%, 11.47%, and 108%, respectively) at equilibrium point significantly (P < 0.05). This was attributed to the more swollen filament lattices and disordered protein structure in injection group (P < 0.05). The myofibrillar protein structure was compared, including sulphydryl content, surface hydrophobicity, solubility, sodium dodecyl sulphate polyacrylamide gel electrophoresis pattern and secondary structure. The injection group presented the better quality of salted fish meat in shorter time. [ABSTRACT FROM AUTHOR]

The study aims to obtain the information on taste and odor among different edible parts (white dorsal meat, white abdomen meat, white tail meat, and dark meat) of bighead carp. The results showed that the white dorsal meat and white abdomen meat had the higher content of total amino acids among all edible parts of bighead carp samples. The highest inosine monophosphate and adenosine monophosphate content presented in white abdomen meat, and the highest equivalent umami concentration value presented in dark meat. The principal component analysis result of electronic tongue and electronic nose showed significant differences in the overall taste and odor characteristics among four group samples. Additionally, 41, 30, 42, and 29 volatile compounds were identified by headspace solid‐phase microextraction/gas chromatography‐mass spectrometry among white dorsal meat, white abdomen meat, white tail meat, and dark meat of bighead carp, respectively. Based on the data of relative olfactory activity value (ROAV ≥ 1), 12 relative olfactory activity compounds may mainly contribute to the overall odor of bighead carp, including 2‐methylbutanal, hexanal, heptanal, (E)‐2‐octenal, nonanal, dodecanal, undecanal, decanal, 3‐methyl‐1‐pentanol, 1‐octen‐3‐ol, (Z)‐2‐octen‐1‐ol, and eucalyptol. Furthermore, according to the Partial Least Squares Discriminant Analysis profile derived from the ROAV of 12 characteristic volatile compounds, significant variations in the odor of different edible parts of bighead carp. Overall, there was a significant difference in taste and odor among different edible parts of bighead carp, and this study may provide useful information for unraveling the flavor characteristics of each edible part of raw bighead carp. Practical applications: The comprehensive information on taste and odor among different edible parts (white dorsal meat, white abdomen meat, white tail meat, and dark meat) of bighead carp were obtained using liquid chromatography‐mass spectrometry, automatic amino acid analyzer, electronic tongue (E‐tongue), headspace solid‐phase microextraction/gas chromatography‐mass spectrometry (HS‐SPME/GC‐MS), and electronic nose (E‐tongue), respectively. This study may provide useful information for unraveling the flavor characteristics of each edible part of raw bighead carp and improving the flavor of bighead carp products. [ABSTRACT FROM AUTHOR]

This study investigated the effect of rutin-grass carp myofibrillar protein (R-GMP) co-stable fish oil high internal phase emulsion on the quality of surimi gel compared with the direct addition of soybean oil. Combined with the stability, microstructure and rheological properties, R-GMP (GMP: 3.0%, rutin: 12%,/GMP, w/w) could form a stable O/W type high internal phase Pickering emulsion with an oil-water ratio of 0.75. The L*, a *, and b * values and whiteness of silver carp surimi gel were increased significantly (P < 0.05) after fish oil-based high internal phase emulsion was added as oil. Meanwhile, compared with the direct addition of soybean oil, the hardness, chewiness, gel strength and water-holding capacity of surimi gel were significantly enhanced (P < 0.05) after the addition of R-GMP high internal phase emulsion, and more free water was bound to the gel network. The microstructure showed that the R-GMP high internal phase emulsion could be evenly distributed in the dense and ordered protein network gel in the form of small oil droplets, while the direct addition of soybean oil would produce an aggregation of oil droplets and destroy the network structure of the gel. In conclusion, R-GMP stabilized fish oil high internal phase emulsion optimizes the gel quality of oil-enhanced surimi gel, providing new ideas for healthy fat replacement and the development of functional emulsified surimi products. [Display omitted] • A stable HIPE gel with R-GMP synergistic stabilization was constructed. • Compared with soybean oil, HIPE improved the gel strength and TPA of the surimi gel. • The free water content of surimi gel with HIPE was reduced, the WHC was enhanced. • The oil of small droplets in HIPE was evenly distributed in the surimi gel network. [ABSTRACT FROM AUTHOR]

In this work, physicochemical, rheological, and antibacterial properties of chitosan (CS) extracted from white shrimp (WS), giant river prawn (GP), and Antarctic krill (AK) were investigated. The results demonstrated that molecular weight (MW) of commercial chitosan (CCS), WSCS, GPCS, and AKCS were 1175.8, 2130.4, 1293.3, and 1109.3 kDa with the degree of deacetylation (DDA) of 73.5, 74.1, 82.1, and 75.9%, respectively. Fourier transform infrared (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscope (SEM) were employed to study the structural differences of CS. Moreover, storage modulus (G′) and loss modulus (G″) of AKCS were lower than that of WSCS and GPCS, respectively, but higher than that of CCS. Minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) of CS against Escherichia coli and Staphylococcus aureus were investigated at concentration between 0.0125 and 1 mg/mL. These results highlighted that AKCS with low viscoelastic properties had a potential application in food and pharmaceutical application. [ABSTRACT FROM AUTHOR]

A 45‐day fattening trial was conducted using iso‐nitrogenous and iso‐fatty fattening diets, among which 0%, 25%, 50%, 75%, and 100% of fish oil were, respectively, replaced by blending vegetable oils (canola oil: soybean oil = 1:1), recorded as Diet 1 ~ Diet 5, respectively. The results showed that the meat of crabs (150 ± 25 g) cultured by five fattening feed were distinguished effectively with the electronic tongue. The total free amino acids and taste nucleotides in the meat of crab cultured by Diet 1 were higher than others. The contents of betaine (taste activity value <1) and umami amino acids in the meat of Diet 3 were highest. The contents of sweet amino acids in the meat of crab cultured by Diet 5 was the highest among the different diet. The equivalent umami concentration of Diet 1 was the highest, suggesting that the umami taste is better. In conclusion, 50% of fish oil could be replaced by vegetable oil in fattening feeds. Practical applications: This paper provided technical support for blending vegetable oils instead of fish oil in fattening feed for swimming crab by using electronic tongue, automatic amino acid analysis, and high performance liquid chromatography to research the changes in the contents of free amino acids, nucleotides, and betaine in female meat of swimming crab, and the taste impacts were evaluated by taste activity values and equivalent umami concentration methods. [ABSTRACT FROM AUTHOR]

In this study, the quality changes of grass carp fillets dried by microwave‐hot‐air combined drying under different microwave time were investigated. The salted fillets were dried at 385 W microwave with different time (0, 2, 4, 6, 8, and 10 min), followed by 65℃ hot air to the end. The quality of fillets was evaluated by drying time, color, hardness, rehydration ratio, and taste characteristics (ATP‐related compounds, free amino acids, E‐tongue taste profile, EUC, and TAV). Results showed that grass carp fillets dried by microwave‐hot‐air combined drying had better qualities compared with single hot‐air drying. Besides, microwave time had obvious effects on the quality changes of grass carp fillets, and 6 min was considered as the optimal drying time. [ABSTRACT FROM AUTHOR]

The effect of heating medium (with water and steam) and initial temperature of heating medium (cold and boiling) on the taste quality and sensory properties of Portunus trituberculatus was investigated. Nonvolatile taste active components in the meat and gonad of crabs cooked under four different methods were detected and compared. Sensory evaluation and electronic tongue assessment were also conducted. Sensory evaluation and electronic tongue indicated that taste quality was different under four cooking methods. The results showed that steaming cooking preserved more water‐soluble substances as compared with boiling cooking, especially cooking began with boiling water. It is noteworthy that the umami intensity in gonad cooked from boiling water was stronger, either steaming or boiling. Therefore, this study can provide a theoretical basis and suggest the dynamic chemical changes of different organs during heating process need to be further studied. [ABSTRACT FROM AUTHOR]

Collagen plays a pivotal role in human physiological functions and extracted collagen has multiple potential applications. Tilapia skin can be applied to extract collagen for maximizing the profit of tilapia processing. Electrospinning/electrospraying is novel micro- and nano-techniques to fabricate microfibers and microspheres in a simple and easy way. In this work, we extract collagens from tilapia skin by three types of extraction methods: acetic acid method, hot water method, and sodium hydroxide method. Then, these extracted collagens are characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Fourier transform infrared spectrometry. These extracted collagens have different molecular weights and different protein secondary structures. Finally, these extracted collagens are applied to fabricate electrosprayed microspheres, electrospun microfibers, and mixed microspheres/microfibers with multiple potential applications by adjusting the collagen concentrations. Higher polymer molecular weight only needs lower concentration to produce microfibers. The microfiber diameter increases with the increase of collagen concentration. This work proves that extraction methods have obvious effect on the preparation of electrospun/electrosprayed microstructures of tilapia skin collagen and provide a way to maximize resource utilization of tilapia processing waste. Image 1 [ABSTRACT FROM AUTHOR]

[Display omitted] • The molecular properties of Eriocheir sinensis HC were revealed for the first time. • Heat treatment induced an increase in β-sheet of HC and reduced its allergenicity. • Anti-digestibility of HC was different from allergen tropomyosin of crustaceans. • Five allergenic epitopes of HC were validated by murine sensitization model. Hemocyanin in crustaceans is an allergen for humans. However, little information was available on its molecular, structural and allergenic properties. In this study, the purified natural protein was identified as Eriocheir sinensis HC by LC-MS/MS, which was allergenic because its reaction with the serum IgE of crustacean patients. Results of the molecular properties showed that, HC was resistant to trypsin digestion, but not a heat-stable protein. Boiling (55.05 ± 3.50 %) and steaming (66.84 ± 1.65 %) induced an increase in β-sheet and decreased allergenicity of HC. By comparing the amino acid sequences of eight crustaceans, HC was found to be highly conserved. Five epitopes of HC were identified and validated by murine sensitization model, and two of them (P3 and P10) were exactly as the predicted by six types of bioinformatics. Multiple bioinformatics analysis combining with murine sensitization model seemed to be effective way for identification of allergenic epitopes. [ABSTRACT FROM AUTHOR]

Polysaccharide-based nanoparticles formed by the polyelectrolyte complexation between chitosan (CS) and flaxseed gum (FG) was developed in this work, and it was further used as a carrier for bighead carp peptide (BCP) delivery. The CS molecular weight (M W) of 50 kDa and CS/FG mass ratio of 1:2 at pH 3.5 were optimal conditions for the NP preparation, with the minimum particle size (∼155.1 nm) and the maximum BCP encapsulation efficiency (60.3 %). The BCP-loaded CS/FG NPs exhibited the smallest particle size (175.8 nm). Both CS/FG NPs and CS/FG-BCP NPs exhibited roughly uniform spherical shape. FT-IR spectra confirmed the existence of hydrogen bonds and electrostatic interactions in the nanoparticles. The BCP-loaded NPs displayed a higher thermal stability than BCP. Moreover, the release of BCP was controllable and dose-dependent, following a first-order kinetics model. These findings suggested that our CS/FG NPs are a promising carrier for bioactive peptide delivery. Schematic diagram of preparation and structure of CS/FG-BCP NPs. [Display omitted] • Polysaccharide-based nanoparticles (NPs) were developed by chitosan (CS)-flaxseed gum (FG) complexation. • Bighead carp peptide (BCP)-loaded CS/FG NPs showed good thermal stability. • CS/FG NPs showed good protective effect on BCP functionalities. • CS/FG NPs are successfully applied for controlled release of BCP. [ABSTRACT FROM AUTHOR]

Frozen tilapia muscle-based Shanghai smoked fish without fish bones was developed using a three-stage method (salt pickling, frying, and sugar smoking), and the effect of varying salt amounts (0.5%, 1.0%, and 1.5% of muscles) was studied. The muscle with 1.0% salt had the best sensory evaluation score. Salt pickling significantly increased and then frying significantly decreased the numbers and concentrations of the volatile organic compounds (VOCs) in the muscles. Compared with the others, 1.0% salt resulted in the lowest numbers and concentrations of the VOCs in the frying stage and the highest VOC concentrations in the sugar smoking stage. Statistical analyses of VOC concentrations suggested that two VOC classes (esters and aldehydes) and 42 VOC individuals could be used to differentiate the treated tilapia muscles with different salt amounts. This work provided a basic knowledge of the effects of food processing stages and salt amounts on fish quality. • Frozen tilapia muscle-based Shanghai smoked fish without bones was developed. • The muscle with 1.0% salt had the best consumer acceptance. • VOC numbers and concentrations changed after different preparation stages. • Compared with others, 1.0% salt induced the highest VOC concentration after smoking. • Two VOC classes (esters and aldehydes) and 42 individuals had VIP scores of >1. [ABSTRACT FROM AUTHOR]