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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]

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]

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]

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]

• Germination increased the activities of α-amylase in GBR. • Germination altered structures and pasting properties of starch in brown rice. • The alternations in hierarchical structures were impacted by α -amylase activities in GBR. • Germination reduced the paste viscosity throughout the pasting course. • A structure-property relationship was established for the native and germinated starches. The study aimed to obtain the information on the effect of germination temperature on hierarchical structures (granular structure, crystal structure, short-range ordered structure and helical structures) of starch from brown rice and their relation to pasting properties. The results showed that brown rice had gradually elevated germination ability and α- amylase activity as the sprouting temperature rose. And the enhanced enzyme activities during germination promoted the erosion of starch granules, the decrease of relative crystallinity and short-range ordered degree, and the unwinding of double helix structure. In addition, the mathematical correlation and structure-pasting relationship were constructed in this work. These structural disorganizations of germinated rice starch resulted in reduced swelling degree and water-holding capacity, inducing the lower paste viscosity (e.g. , peak and final viscosity), breakdown and setback value. Thus, it is concluded that germination can efficiently regulate the pasting properties of starch, which provide a crucial basis for the development and utilization of germinated brown rice products. [ABSTRACT FROM AUTHOR]

Bamboo shoot dietary fiber was added into dough to study the processing characteristics and moisture distribution of the repeated freeze-thaw dough. The results showed that the hardness of the dough in the control group increased first and then decreased, the viscosity and the chewiness increased, the elasticity became smaller. However, the hardness, viscosity and elasticity of the dough added with BSDF had not been significantly affected during the process of repeated freezing and thawing. When the number of repeated freeze-thaw cycles exceeded one time, the modulus of elasticity and viscosity of the BSDF dough increased, and the loss angle tangent decreased. During the process of repeated freezing and thawing,the deep layer bound moisture content of the dough in the control group decreased, while the weakly bound water and free water content increased. However, the addition of BSDF made the deep layer bound moisture content increased, the weakly bound moisture content decreased, and the free moisture content did not change significantly. [ABSTRACT FROM AUTHOR]

Wheat starch was used as the research object, and ultrasonic treatment was carried out at different times (0 min,10 min,20 min,30 min) so as to investigate the effect of ultrasonic treatment on its aggregation structure, solubility, swelling degree, pasting properties and rheological properties. The results showed that ultrasonic treatment disrupted the granular structure, crystalline structure and short-range ordered structure of wheat starch, inducing the amorphization of starch aggregation structure were deeper. And these transformations were more obvious with the increase of ultrasound time. Moreover, due to the destruction of starch aggregation structure, the solubility, swelling degree, peak viscosity, final viscosity and setback value increased, but the disintegration value reduced and the rigidity of starch gel decreased. [ABSTRACT FROM AUTHOR]

Highlights • PGS addition led to enhanced viscosity and gel network for glutinous rice flour. • PGS addition induced structural disorganization for glutinous dumplings. • PGS addition improves storage and textural properties of glutinous dumplings. • PGS addition increases the SDS and bound water content of glutinous dumplings. • Statistical correlation found between flour properties and qualities of dumplings. Abstract In this study, the impacts of pregelatinized starch (PGS) with different conditions (2–8%, w/w) on the characteristics, microstructures and quality parameters of glutinous rice flour and dumplings were determined. The results indicated PGS favored the formation of elastic gel-like network structure on starch granules. PGS addition, especially at high PGS content, significantly influenced the granular, crystalline and molecular structure of glutinous dumplings, probably due to the structural amorphization of PGS. Accordingly, the dumplings complexation with suitable PGS exhibited a better storage, an increased content of slowly digestible starch (SDS), and integrated quality attributes including transmittance, cracking rate, and textural properties via weakening the water mobility. Pearson's correlation matrix exhibited that the quality of glutinous dumplings could be well predicted by physicochemical properties of rice flour. Thus, it is feasible to improve the textural and nutritional attribute of glutinous rice dumplings via simply complexation with PGS. [ABSTRACT FROM AUTHOR]

[Display omitted] • A total of 45 volatile compounds were identified from naturally fermented grass carp. • 13 volatile compounds (OAV ≥ 1) were identified as the key volatile compounds. • Lactiplantibacillus contributed significantly to the volatile flavor formation during natural fermentation of grass carp. Complex microbial communities contribute significantly to the flavor formation of traditional fermented fish products. However, the relationship between microorganisms and flavor formation in traditional fermented grass carp products is still unclear. In this study, the diversity and succession of microbial communities and the variation of volatile compounds during natural fermentation of grass carp were analyzed using high-throughput sequencing of 16S rRNA and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), respectively. The core functional microorganism and key volatile compounds were identified, and their potential relationship was revealed using a correlation network model analysis. The microbial community analysis result showed that the microbial diversity during natural fermentation of grass carp decreased markedly with increasing fermentation time, and Lactiplantibacillus , Staphylococcus , and Enterobacter were the dominant genera in naturally fermented grass carp. HS-SPME-GC-MS analysis result showed that 45 volatile compounds were identified from fermented samples, among which 13 compounds (e.g., hexanal, heptanal, nonanal, decanal, 3-octanone, 3-methyl-1-butanol, 1-hexanol, 1-heptanol, 1-octen-3-ol, 1-octanol, ethyl acetate, 3-methyl-1-butanol acetate, and 2-methoxy-4-vinylphenol) were identified as the key volatile compounds. Additionally, the correlation network model analysis result revealed that Lactiplantibacillus showed significantly positive correlations with most of the key volatile compounds, making an important contribution to the formation of volatile flavor in naturally fermented grass carp. This study may lead to an understanding of the role of core functional microorganisms in the formation of volatile flavor during the natural fermentation of grass carp and provide some theoretical guidance for the industrial production of high-quality fermented grass carp products. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rinsing could significantly affect the aroma profiles of grass carp mince. • HS-SPME-GC-MS identified 57 volatile compounds in grass carp mince. • HS-GC-IMS identified 20 volatile compounds in grass carp mince. • The washing sample with a weak alkaline solution has better sensory acceptability. The aroma characteristics of grass carp mince washed in four processes were analyzed via electronic nose (E-nose), headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS), and sensory analysis techniques. Significant differences were revealed in the E-nose and sensory analysis results of the aroma characteristics of grass carp mince samples washed via different washing processes, while fifty-seven volatile compounds (thirteen aldehydes, eighteen alcohols, two ketones, eighteen hydrocarbons, two aromatic compounds, one furan, and two other compounds) and twenty volatile compounds (five aldehydes, four ketones, six alcohols, four esters, and one acid) were identified via HS-SPME-GC-MS and HS-GC-IMS of the Raw and washed grass carp mince samples, respectively. All these techniques revealed that the types and relative contents of volatile compounds in the grass carp mince decreased significantly and differently after each of the four washing processes. Moreover, compared with the water and saline solution washing processes, washing with weak alkaline solution processes exhibited the most significant removal effect on the volatile compounds of grass carp mince. Besides, the sensory analysis results also showed that weak alkaline solution washing processes (washing twice with pure water and once with 0.3% sodium bicarbonate solution) may be most effective in removing fishy off-odor compounds and contributing to a better overall aroma profile in grass carp mince. The findings of this study may provide some basic knowledge for the rational screening of washing methods in the production of high-quality grass carp surimi. [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]

This study aimed to investigate taste substances of shrimp heads stored at 20 °C, 4 °C, −3 °C, and − 18 °C, and the correlation between taste substances and 25 key volatile substances. Notably, samples stored at 20 °C showed significant changes in bitter amino acids and hypoxanthine, and quickly deteriorated. Samples stored at 4 °C for 14 d or − 3 °C for 30 d facilitated the development of umami amino acids, sweet amino acids, and IMP. Furthermore, samples stored at −18 °C for 30 d demonstrated no significant changes in taste profile. Changes in taste substances through quantitative analysis were consistent with changes in taste profile through e-tongue analysis. Based on the results of O2PLS (VIP > 1), Cys, Arg, Glu, Ser, Val, Ala, Ile, ADP, and IMP were correlated with 25 key volatile substances. This study provides fundamental data for the storage, transportation, and value-added utilization of shrimp heads. [Display omitted] • Comprehensive understanding of the changes in the taste substances of shrimp heads. • Storage at 4 °C and − 3 °C promoted the generation of taste substances in shrimp heads. • The correlation between flavor substances was identified by O2PLS-VIP value. [ABSTRACT FROM AUTHOR]

Potato protein microgel ( PPM2, PPM4, PPM6, PPM8 ) were prepared at different mass fractions (2%, 4%, 6%, 8%). The particle size, Zeta-potential, fluorescence characteristic, emulsifying activity, emulsion stability and microstructure of of microgel were investigated. The effect of potato protein microgel on the emulsification characteristics of Pickering emulsion was studied. The results showed that the particle size of the microgel particles increased significantly (116. 31 ~181.99 nm) with the increase of protein fraction during microgel preparation. The Zeta-potentials of PPM2, PPM4 and PPM6 were about 30 mV and higher than that of the control group. The fluorescence intensity of PPM2, PPM4 and PPM6 was higher than that of the control group, while the fluorescence intensity of PPM8 was lower than that of the control group. Compared with the control group, the microgel significantly improved the emulsion activity and emulsion stability of the Pickering emulsion. The microstructure results showed that the surface of the control group and all potato protein microgel were smooth, the control group was spherical, the potato protein microgel was aggregated in a sheet form, and the aggregation unit was larger with the increase of the potato protein mass fraction. [ABSTRACT FROM AUTHOR]

• The addition of glucose promoted the glycation reaction rate of silver carp mince (SCM). • Lysine and cysteine were the main amino acids involved in the glycation of SCM. • Glycation accelerated lipid oxidation and the production of Strecker aldehydes of SCM. • Glycation was positively correlated with volatile compounds. • Glycation can be used as a flavor enhancement technology for low-value fish. The purpose of this study was to explore the effect of glycation on physicochemical properties and volatile flavor characteristics of silver carp mince (SCM). The changes in the degree of grafting, chemical composition, pH, color, total amino acid composition, and volatile flavor compounds of SCM with or without glucose were studied at different heating times. The results showed that the addition of glucose could promote the glycation reaction rate of SCM. Lysine and cysteine were the main amino acids involved in glycation. Glycation enhanced the overall aroma of SCM by accelerating lipid oxidation and Strecker degradation. In conclusion, these results suggest that glycation can enhance the volatile flavor of SCM during thermal processing and can be used as a volatile flavor enhancement technology for the development of protein nutrition food with good flavor from low-value fish. [ABSTRACT FROM AUTHOR]

• Effect of heat-moisture treatment (HMT) on starch in adlay seeds were revealed. • HMT could alter the hierarchical structures of starch in adlay seeds. • HMT reduced the digested ratio and rate of starch in adlay seeds. • The new ordered structure formed during HMT weakened starch digestibility. • HMT effects on starch in adlay seeds are intensified by treatment moisture content. In the present study, starches isolated from heat-moisture treated (HMT) adlay seeds were characterized with hierarchical structures and digestibility to understand the relationships in structural and digestible behaviors of starches in a HMT starch-based food system. The results indicated that HMT not only caused the disorganizations of hierarchical structures, but also promoted the molecular rearrangements and reassembly of starch chains to form a new ordered molecular aggregation architecture (i.e. , highly ordered molecular structure, amylose-lipids complexes and thicker crystalline lamella). And the reinforced molecular interactions between starch molecules during HMT occurred to form more densely ordered structure, thus reducing the digestibility and digestion rate coefficients (k) of adlay starch. Particularly, HMT applied directly in adlay seeds with 30% moisture content displayed the highest resistant starch level (20.6%) and lowest k (2.74 × 10−3 min−1). Thus, the results are useful to realize the desired regulation of starch digestibility in adlay products following HMT. [ABSTRACT FROM AUTHOR]