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Globally, fish processing industries are much concerned to produce fish proteins for the fulfilment of the nutritive requirements of human being. More than 60% fish by-products, including liver, head, skin, roes, viscera, and bones that the richest source of proteins, and these are processed to obtain valuable food products in different industries. Numerous studies have proved that fish proteins have a great potential to reduce the risks of cancer, aging, diabetics, and cardiovascular diseases. Their functional properties such as water and oil holding, film-forming, emulsification, solubility, and gelling capacities, which have increased their importance for the development of functional foods. So, this review is focused on different kinds of sources, extraction methods, and functional properties of fish proteins, also their utilization as functional bioactive compounds in the production of fish protein-enriched food products. [ABSTRACT FROM AUTHOR]

Chitosan is obtained from chitin and considered to be one of the most abundant natural polysaccharides. Due to its functional activity, chitosan has received intense and growing interest in terms of applications for food preservation over the last half-century. Compared with earlier studies, recent research has increasingly focused on the exploration of preservation mechanism as well as the targeted inhibition with higher efficiency, which is fueled by availability of more active composite ingredients and integration of more technologies, and gradually perceived as "chitosan-based biofilm preservation." In this Review, we comprehensively summarize the potential antimicrobial mechanisms or hypotheses of chitosan and its widely compounded ingredients, as well as their impacts on endogenous enzymes, oxidation and/or gas barriers. The strategies used for enhancing active function of the film-forming system and subsequent film fabrication processes including direct coating, bioactive packaging film and layer-by-layer assembly are introduced. Finally, future development of chitosan-based bioactive film is also proposed to broaden its application boundaries. Generally, our goal is that this Review is easily accessible and instructive for whose new to the field, as well as hope to advance to the filed forward. [ABSTRACT FROM AUTHOR]

This research evaluates the quality and acceptability of 25%, 50%, and 75% fish protein concentrate (FPC) egg substituted cakes. Proximate chemical composition, batter and cake physical quality, microbial activity, and sensory evaluation were carried out. An impressive increase in protein, fats and ash content was noticed in GPSC. By increasing the FPC concentration, the viscosity of batters and cake volume decreased, while the specific gravity increased. In texture, the hardness, chewiness, and gumminess were increased while elasticity and cohesiveness were decreased with increase in substitution. An increase in substitution increased baking loss (BL) but reduced the water activity (aw) and the number and size of air bubbles in cake batter. By evaluating microbial activity, the total plate count (TPC) value increased, and the total fungal count (TFC) decreased while the cake crumb showed inconsistent change. The cake with 75% egg substitution was highly nutritious but displayed lower sensory attributes due to slight fishy flavor and dark color, while 25% and 50% GPSCs showed almost similar sensory attributes but nutritional value of 50% GPSC was higher than 25% GPSC. So, the cake with 50% substitution is a better option to prepare a good quality protein-enriched cake with acceptable sensory attributes. [ABSTRACT FROM AUTHOR]

Fermentation is an important way to process and preserve fish. It not only gives the product a unique flavor and texture, but it also contributes to increased nutritional value and better functional properties. The production of fermented fish relies on naturally occurring enzymes (in the muscle or the intestinal tract) as well as microbial metabolic activity. This review focuses on the role of microorganisms on texture change, flavor formation, and biogenic amines accumulation in fermented fish. In addition, the production conditions and the major biochemical changes in fermented fish products are also introduced to help understand the factors influencing the quality of fermented fish. Moreover, prospects for further research of fermented fish are discussed. [ABSTRACT FROM AUTHOR]

Fishery products are delicious, nutritional and healthy foods, and their popularity in today's market is growing. With the changes in consumer consumption expectations as well as the development of reliable cold-chains, fresh preprocessed fishery products such as fillets are more popular with consumers and producers because of their convenience for processing and cooking. However, fishery products after being removed from water have a short shelf life due to their intrinsic characteristics. Therefore, developing effective preservation technology to extend postmortem shelf life of fishery products has been an on-going area of study. This review summarizes the patterns of quality deterioration and external factors that affect postmortem quality of fishery products, and then updates the recent advances with preservation methods for fishery products including superchilling, modified atmosphere packaging, active packaging, edible coatings, irradiation and high hydrostatic pressure. Moreover, the advantages and disadvantages of each technology are discussed, and future trends for improving the preservation of fishery products are also discussed. [ABSTRACT FROM AUTHOR]

Fermentation is an important way to process and preserve fish. It not only gives the product a unique flavor and texture, but it also contributes to increased nutritional value and better functional properties. The production of fermented fish relies on naturally occurring enzymes (in the muscle or the intestinal tract) as well as microbial metabolic activity. This review focuses on the role of microorganisms on texture change, flavor formation, and biogenic amines accumulation in fermented fish. In addition, the production conditions and the major biochemical changes in fermented fish products are also introduced to help understand the factors influencing the quality of fermented fish. Moreover, prospects for further research of fermented fish are discussed. [ABSTRACT FROM AUTHOR]

Fermentation is a traditional food preservation method and is widely used for improving food safety, shelf life, and organoleptic and nutritional attributes. Fermented fish are produced and consumed in different parts of the world and are an integral part of many food cultures. Furthermore, fermented fish are a source of interesting microbes and are an important industry in many countries. This review tries to update the types and manufacturing processes for fermented fish around the world. The emphasis is on this work related to fermented fish and their health benefits, as well as the contribution of microorganisms to their fermentation. A variety of different approaches have been used to determine and understand microbial composition and functionality. Moreover, some challenges and future research directions regarding fermented fish are also discussed in this review. Further research into fermented fish products is of crucial importance not only for the food industry but also for human health. However, extensive in vivo and toxicological studies are essential before the application of bioactive-rich fermented fish products for human health benefits. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the quality of wheat flour noodles supplemented with 0%, 10%, 20% and 30% grass carp protein concentrate (GCPC). Proximate composition, color analyses, cooking properties (cooking time, cooking loss, swelling index and water absorption index), texture profile analyses (TPA), and sensory evaluations were performed. Significant (p ≤ 0.05) increases in the crude protein (18.94–35.19%), crude fat (0.88–1.06%), and ash (0.89–1.02%) were recorded for GCPC supplemented cooked noodles. Brightness (L*), redness (a*) and yellowness (b*) of GCPC 10–30% fortified cooked noodles was recorded as 77.00–69.97, 1.50–2.81 and 19.08–22.25, respectively. Cooking loss (CL) and optimal cooking time were significantly (p ≤ 0.05) increased with increased level of GCPC from 0%-30%, with readings of 6.13% −8.90% and 7.53–11.77 min, respectively. Swelling and water absorption indices showed a decreasing trend at 2.33–1.77 and 102.6–78.49%, respectively. A significant (p ≤ 0.05) decreasing trend in hardness (24.50–19.03N) was observed for cooked noodles with increased level of GCPC, while the remaining TPA parameters were significantly different at p>.05. Sensory analyses showed higher preference for control noodles and noodles fortified with 10% GCPC. [ABSTRACT FROM AUTHOR]

The popularity of preprocessed fresh fishery products such as fillets and peeled shrimps is growing in today s market due to their convenience for subsequent processing and cooking. However, fishery products are highly perishable because of the combined actions of biochemical reactions and microbial metabolism. Various methods have been proposed to address this problem. Among these methods, bio-based edible coating has been highlighted as a promising solution. This review updates and summarizes the recent literature on the application of coatings for the preservation of fishery products including the aspects of coating carriers, composite natural preservatives and coating methods, and a discussion of the protective effects based on microbial, physicochemical and sensorial evaluations. Moreover, some challenges and future research directions regarding optimization of formulas and exploration of mechanisms of coating are also discussed. Given consumer demand for fresh fishery products with long shelf life, edible coatings that are environmentally friendly and effective alternative will be used to extend the shelf life of fishery products. [ABSTRACT FROM AUTHOR]

Protein hydrolysates from Chinese sturgeon were prepared using Alcalase 2.4L enzyme. Under the optimum conditions (enzyme–substrate ratio of 3.5%, pH of 8.5, and temperature of 55°C), the degree of hydrolysis (DH) was 13.8%, 16.7%, and 19.1% after 1, 3, and 6 h, respectively. The contents of crude protein and amino acid increased at DH of 19.1% to 86.97% and 78.29%, respectively. There was an obvious increase in the low-molecular-weight peptides, which could enhance the hydrolysate's functional properties such as solubility, representing more than 90% at different pH levels. The obtained protein hydrolysates revealed good emulsification properties and high oil absorption. Furthermore, good antioxidant activities such as 1, 1-diphenyl-2-picrylhydrazyl (DPPH) inhibition, ferric reducing power, and ferrous ion (Fe2+) chelating ability were attained depending on the solution concentration. The findings indicate that the functional and antioxidant properties of protein hydrolysates could be useful in many applications of the food industry. [ABSTRACT FROM AUTHOR]

This study aimed to microencapsulate silver carp oil by spray drying with different combinations of wall materials (gum Arabic, modified starch Hi-cap, maltodextrin, and inulin) and evaluate the effects of these combinations on the physiochemical and oxidative stability of the microcapsules. Feed emulsions were also investigated prior to spray drying. Modified starch-based microcapsules had higher encapsulation efficiency (91.22-92.78%) and yield (87.41-92.15%), excellent solubility (91.85-93.67%), good particle size (301.20-407.73 d.nm), color, and powder morphology. The presence of inulin reduced agglomeration in powders. All the powders exhibited good protection against lipid oxidation during 2 months of storage, whereas the modified starch and inulin combination provided the best stability. [ABSTRACT FROM AUTHOR]

This study assessed effects of high pressure processing on physicochemical quality and endogenous enzyme activities of grass carp fillets stored at 4 ºC for 21-day storage. Fresh fillets were vacuum-packed and subjected to high pressure processing (0.1, 200, 300, 400, 500, and 600 MPa at room temperature for 15 min). Results showed that high pressure processing significantly delayed microbial growth, and reduced total volatile basic nitrogen (TVB-N) and thiobarbituric acid reactive substances (TBARS) levels of grass carp fillets, especially for the 600 MPa group. On the 21st day, the corresponding increases of 6%, 35%, 45%, 43%, and 53% in hardness were observed for 200 MPa, 300 MPa, 400 MPa, 500 MPa, and 600 MPa samples compared with control samples, respectively. In addition, enzyme activities in different groups decreased during storage. Among them, calpain, and myofibril-bound serine proteinases (MBSP) activities were immediately reduced after high pressure treatments, while the activities of collagenase, cathepsin B, and cathepsin D were significantly (P < 0.05) inhibited when the pressure exceeded 400 MPa. However, the pressure treatments activated cathepsin L initially, and then the activity gradually decreased in treated samples. Generally, high pressure processing reduced activities of most of the endogenous enzymes and improved the quality and extended the shelf life by at least 4 ~ 6 days of refrigerated grass carp fillets. [ABSTRACT FROM AUTHOR]

Malnutrition in children is a current global burden. A common snack for children is biscuits prepared from cereals. However, these types of biscuits have low protein content. Therefore, producing healthier biscuits enriched with essential amino acids (EAAs) and other micronutrients is of great interest to researchers and manufacturers. In this study, biscuits produced from low gluten wheat flour fortified with sturgeon fillet powder (SFP) in various mixing ratios (100:0, 95:5, 93:7, and 90:10, respectively) were investigated. The results revealed that the nutritional and proximate composition of biscuits were significantly (P ≤ 0.05) improved: moisture (6.77 ± 0.06-7.65 ± 0.06), protein (13.23 ± 0.35-17.12 ± 0.02), fat (15.57 ± 0.18-15.85 ± 0.25), ash (0.84 ± 0.07-0.92 ± 0.06), spread ratio (14.0 ± 0.92-14.33 ± 0.21), and hardness (2,057.90 ± 28.33-3,089.02 ± 51.53). Total amino acids were 6.91, 9.34, 10.32, and 10.58; and EAAs were 2.43, 3.97, 4.48, and 4.22 g/100 g for 0%, 5%, 7%, and 10% SFP, respectively. Leucine was the major amino acid with 5% and 10% SFP, while methionine was the major amino acid with 7% SFP. Fungal counts were not observed, and quality indices were below the maximum acceptable limits in the products. Biscuits supplemented with 7% SFP showed the highest sensory evaluation score. Overall, the inclusion of 7% SFP could produce protein enriched cereal-based fortified biscuits with acceptable sensory and quality attributes and ultimately could insure effective fish utilization and solve malnutrition problems. [ABSTRACT FROM AUTHOR]

To improve the antioxidant activity of grass carp hydrolysate, washing and membrane removal pretreatments and ultrasonic treatment were applied in this study. Various pretreatment methods (washing methods and membrane removal methods) for removing the prooxidants and phospholipid in minced fish were evaluated. The effects of ultrasonic treatment prior to enzyme hydrolysis on the antioxidant activities of minced carp hydrolysate were investigated. The minced carp subjected to washing with 0.4% NaCl solution and subsequent membrane removal with CaCl2 and citric acid solution had the lowest content of prooxidants and phospholipid remaining in the minced fish. The hydrolysate produced from washing/membrane removal pretreated carp with ultrasonic treatment for 20 min had the highest ferric reducing antioxidant power and scavenging activities against 1,1-diphenyl-2-picrylhydrazyl and 2,2ʹ-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radicals. This suggested that the combination approach of washing/membrane removal pretreatment and ultrasonic treatment could improve the antioxidant activity of carp hydrolysate, and this hydrolysate could be a potential antioxidant ingredient for functional foods. [ABSTRACT FROM AUTHOR]

The effect of heating temperature and duration on the texture and protein composition of bighead carp (Aristichthys nobilis) muscle was investigated. Samples were heated at 90°C, 100°C, 110°C, and 120°C for different times. The results showed that cooking loss increased significantly with increasing temperature and heating time, and a fractional conversion model was used to describe the increase. Hardness, chewiness, and gumminess exhibited a similar four-phase change with two peaks at 90°C, 100°C, and 110°C, and the trend was not observed at 120°C. Analysis of sodium dodecyl sulfate polyacrylamide gel electropheresis (SDS-PAGE) revealed that contents of myosin heavy chain decreased entirely to disappear and contents of actin significantly decreased. Increasing the intensity of the heavy molecular weight bands indicated the aggregation of myosin. Content of water-soluble proteins presented an increasing trend, which reflected the protein degradation and the release of low-molecular-weight compounds. [ABSTRACT FROM AUTHOR]

This study investigated the effects of liquid nitrogen quick-freezing, −35°C air-blast freezing, and −18°C refrigerator direct-freezing on quality retention of frozen giant freshwater prawns using various indicators: microscopic structure, physicochemical, texture, and color properties. The results showed that the shelf lives of prawns treated with liquid nitrogen quick-freezing, −35°C air-blast freezing, and −18°C refrigerator direct-freezing were about 20, 12, and 8 weeks, respectively, in terms of total volatile basic nitrogen content and K-value. Meanwhile, liquid nitrogen quick-freezing could effectively improve texture property of frozen giant freshwater prawn. These findings confirm that liquid nitrogen quick-freezing is a promising method to extend the shelf life of frozen prawns. [ABSTRACT FROM AUTHOR]

Chitosan coating and plastic wrap coating were investigated for their effects on the quality of grass carp fillets stored at 4 ± 1ºC for a period of 20 days. The fillets were divided into groups of untreated (Control), wrapped with sterile preservative film (PE), and chitosan-treated (1, 2, and 2.5% w/v corresponding to CH1, CH2, and CH2.5, respectively). The final result demonstrated that chitosan coating has positive effects on the microbial inhibition of total volatile count (TVC), lactic acid bacteria (LAB),Enterobacteriaceae, Pseudomonas, H2S-producing bacteria (includingShewanella putrefaciens), andStaphylococcus. With regard to the results of biogenic amines (BAs), putrescine (PUT) and histamine (HIS) were the major amines, and their concentration was significantly (p< 0.05) higher in Control and PE than in chitosan-coated fillets at the end of storage. The final concentration in Control, PE, CH1, CH2, and CH2.5 was 143.7, 160.1, 83.0, 59.4, and 44.2 mg/kg for PUT and 228.0, 57.1, 4.1 3.2, and 2.9 for HIS, respectively. Chitosan coating was found to inhibit the increase of total volatile base nitrogen (TVB-N), microbial population, and total BAs and prolong the shelf life of grass carp fillets. However, sterile plastic wrap coating had little positive effect on maintaining the quality of grass carp fillets during refrigerated storage. [ABSTRACT FROM PUBLISHER]

A two-stage fermentation process of deproteinization and demineralization was used to purify chitin from Antarctic krill shell waste. Two bacterial cultures were isolated and tested for the degradation of krill shell waste. According to the morphological examination, physiological tests, and applied molecular techniques conducted, isolates were identified asBacillus subtilisandLactobacillus plantarum. At a temperature of 37°C, both strains were cultivated separately in flasks containing krill shell waste. At determined periods of time, deproteinization and demineralization of residuals were measured. For deproteinization tests, the liquid phase fermentation of krill shell waste showed protein removal of 88.9% after 60 h. For demineralization tests, the liquid phase fermentation of krill shell waste showed calcium carbonate removal of 84.6% after 72 h. Fourier transform infrared spectroscopy (FTIR) analysis of chitin prepared by the process was carried out and compared with spectra of samples treated by strong acids and bases. [ABSTRACT FROM PUBLISHER]

This study aimed to purify and identify a novel antidiabetic peptides from Chinese giant salamander (Andrias davidianus) protein hydrolysate and to evaluate its anti-diabetic properties against α-amylase and α-glucosidase. The isolation was done by gel filtration, reverse phase chromatography (RF-HLPC), and finally peptide and amino acid sequences were identified by LC/MS/MS system. Our results revealed five novel peptides that strongly inhibited α-amylase and α-glucosidase. The peptides’ amino acid sequences were Cys-Ser-Ser-Val (MW = 393.99 Da), Tyr-Ser-Phe-Arg (MW = 570.99 Da), Ser-Ala-Ala-Pro (MW = 343.89 Da), Pro-Gly-Gly-Pro (MW = 325.99 Da) and Leu-Gly-Gly-Gly-Asn (MW = 415.99 Da) possessing α-amylase inhibitory activity IC50 of 13.76 × 103, 10.82 × 103, 4.46 × 103, 4.23 × 103, and 2.86 × 103 µg/mL, respectively; and for α-glucosidase with IC50 of 206.00, 162.00, 66.90, 63.50, and 42.93 µg/mL, respectively. Intriguingly, the peptide LGGGN showed higher inhibition on both α-amylase and α-glucosidase and could be considered as a potential anti-diabetic inhibitor. [ABSTRACT FROM AUTHOR]

Previous studies have verified the protective role of n3 polyunsaturated fatty acids (PUFAs) in cancer. Fish brain lipids are rich in n3 PUFAs. However, the action and mechanism of their potent anticancer activities remain unclear. In this study, polar lipids (PLs) and neutral lipids (NLs) were isolated from the total lipids (TLs) of the silver carp brain, and the anticancer effects of the lipid fractions (LFs) were examined in a human breast cancer cell line (MCF-7). The LFs effectively inhibited the cell proliferation of MCF-7 cells in a time- and concentration-dependent manner by cell cycle arrest at the S stage and induction of apoptosis. Further analyses showed that the apoptotic effect of the LFs on MCF-7 cells was associated with the accumulation of elevated levels of reactive oxygen species and the loss of mitochondrial membrane potential. Among the TLs, PLs were more effective at causing breast cancer cell death than NLs. Our study showed that the LFs from silver carp brains may aid the prevention and treatment of human breast cancer. [ABSTRACT FROM AUTHOR]

The objective of this work was to investigate the effects of sodium replacement on the textural properties and water-holding capacity (WHC) of heat-set freshwater surimi gels. Potassium chloride and calcium chloride were chosen as salt substitutes. The surimi gels presented better water-holding capacity with potassium chloride than the treatments containing calcium chloride. Gel strength and rheological properties indicated that monovalent metal ions could improve surimi gel properties. The contents of chemical interactions, especially disulfide bonds, nondisulfide covalent bonds, and hydrophobic interactions of surimi gels, varied with the addition of salt type and concentration. Furthermore, microstructure observed from scanning electronic microscopy (SEM) demonstrated that surimi gels prepared with monovalent salt presented more compact and denser networks, while more aggregated particles existed in gels with calcium chloride. [ABSTRACT FROM AUTHOR]

This study investigated the effect of chitosan coating (1 and 2%) on the quality of grass carp fillets stored at 4°C for 20 days. During storage, the physicochemical properties (pH, thiobarbituric acid value, total volatile basic nitrogen value, trimethylamine nitrogen value,K-value, water loss, and instrumental texture), microbiology (total viable count and psychrotrophic count), and sensory properties were evaluated. The results showed that chitosan coating could effectively inhibit bacterial growth, improve physicochemical and sensory qualities, and it reduced the deterioration of the quality of grass carp fillets. Compared with fillets without chitosan coating, the shelf life of fillets with 1 and 2% chitosan coating was extended by ~3 and 6–7 days, respectively. [ABSTRACT FROM AUTHOR]

Proteolytic changes in Suanyu, a traditional fermented fish product of China, were determined during 6 weeks of fermentation. The gradual decrease of pH value andawwas detected, accompanied with an increasing trend detected in trichloroacetic acid–soluble C-1: peptides concentration. Protein composition changed throughout the fermentation. A decrease in sarcoplasmic and myofibrillar protein fractions was accompanied by an increase in the insoluble fraction. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed most bands of sarcoplasmic, myofibrillar, and insoluble proteins lightened or disappeared due to proteolysis or denaturation. New bands emerged especially in insoluble proteins. Fluctuation of molecular weight distribution of the water-soluble nitrogen in Suanyu was found during fermentation. The highest percentage in Suanyu end-products was observed in the fraction of <0.18 kDa, followed by 0.18–0.5 kDa, 66.02 ± 0.38% and 10.79 ± 0.27%, respectively. Free amino acids analysis showed that nearly all amino acids increased, especially for Asp, Glu, Met, Phe, Leu, Val, and Ile. Overall, intense proteolysis in Suanyu brought numerous of small peptides and free amino acids, which contribute to the taste and flavor of Suanyu. [ABSTRACT FROM AUTHOR]

Suan yu, a type of Chinese traditional fermented freshwater fish in solid form, is cheered among consumers due to its characteristic sensory flavour, primarily taste and smell. The purpose of this study was to investigate the presence of esterase activity ofLactobacillus plantarum120,Staphylococcus xylosus135, andSaccharomyces cerevisiae31, in selecting appropriate processing means to accelerate the formation of the desired flavour in Suan yu. The results showed that all strains exhibited esterase activities in both intracellular and extracellular fractions againstp-nitrophenyl (p-NP)-acetate,p-NP-butyrate, andp-NP-octanoate, and also that the maximum activity was observed in the intracellular fraction withp-NP-octanoate. Esterase activities of all strains were inhibited by low pH and low water activity (Aw), with the exception ofL. plantarum120 exhibiting an increase in intracellular activity with decreasing Aw. Moreover,L. plantarum120 andS. xylosus135 esterase were negatively affected by decreasing temperature, while a positive influence was observed on the intracellular esterase ofS. cerevisiae31. The results suggested that a low pH, a low Aw and a high temperature would be more appropriate for Suan yu processing to produce more flavour compounds which are acceptable by consumers. [ABSTRACT FROM AUTHOR]

Effect of pretreatment methods including ultrasonication (US), microwave (MW), and ultrafine milling (UM) on hydrolysis efficiency and antioxidative activity of peptides produced from bighead carp were investigated. The UM peptides showed higher hydrolysis efficiency (higher degree of hydrolysis, nitrogen recovery, and oligopeptide yield; narrower molecular-weight distribution), and higher 1,1-dipheny1-2-pycrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfomic acid) diammonium salt (ABTS) radical scavenging activities, and metal chelating activities than US and MW peptides. The hydrolysis efficiency and antioxidative activity of UM peptides could remain relatively high even when the substrate concentration increased up to 50%. In conclusion, ultrafine milling may be a suitable pretreatment method in the production of peptides. [ABSTRACT FROM PUBLISHER]

This study investigated the morphometrics, proximate chemical compositions, pH, total amino acid (TAA), fatty acid profile, and minerals of the processing by-products of Antarctic krill (Euphausia superba). The nutrient compositions and properties of the by-products were revealed by being compared to those of Antarctic krill muscle and the economically important species of freshwater prawns (Macrobrachium nipponense) and penaeid shrimps (Metapenaeus ensis). The by-products are worthy of utilization because of the high ratio to the total weight (65.7%). The crude protein contents in the muscle and by-products of krill are 17.4 and 11.7%, respectively. The krill proteins have higher contents of essential amino acids (EAAs). The EAAs constitute 42 and 37% of the TAAs in muscle and by-products, respectively. The krill processing by-products contain high levels of total lipid (3.3%), and polyunsaturated fatty acids constitute 34% of fatty acids with high levels of eicosapentaenoic acid (EPA; 19.08%) and docosahexaenoic acid (DHA; 10.02%). Krill meat provides considerable iron, zinc, calcium, selenium, and copper. It is imperative to lower the fluoride level (70.1 mg/kg, wet basis) in krill muscle. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) reveals that myosin heavy chain (MHC) and actin are the major proteins in muscle, and their contents vary between species. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the thermophysical properties of bighead carp (Aristichthys nobilis) fillets after curing and deep-fat frying. The kinetics of simultaneous curing and deep-fat frying and mass transfer models were utilized to study the predicted models programmed by Matlab and thermophysical models. The results show that the effective salt and water diffusion coefficient models for curing areand, respectively, which correspond to the multivariate nonlinear regression models. The specific rate and effective moisture diffusion coefficient models for frying based on the Arrhenius equation areand, respectively, which are fitted to accurately calculate the mass transfer processes. Moreover, the changes of thermophysical properties—including thermal conductivity, specific heat, and thermal diffusivity of the processed bighead carp muscle—were successfully predicted by incorporating the mass transfer models, the thermophysical properties models, and the components conversion equations into a Matlab program. [ABSTRACT FROM PUBLISHER]

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In this study,Lactobacillus plantarum 120, Lactobacillus plantarum 145,andPediococcus pentosaceus 220, which exhibit optimal properties among those isolated from the traditional fermented fish products, were selected as the starter cultures for the preparation of fermented whole carp. During the fermentation, samples inoculated with different single starter cultures showed rapid growth of lactic acid bacteria (LAB), decline in pH, suppression in the growth of main microflora, as well as increase of thiobarbituric acid reactive substances (TBARS) values and total volatile base nitrogen (TVB-N). Quantities of nonprotein nitrogen (NPN) and free amino acids (FAA) were higher in whole carp with starter cultures compared to those in the control. Severe hydrolysis of protein was observed utilizing sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis during fermentation. Moreover, sensory evaluation indicated the higher acceptability of fermented products. The results show that inoculation with the autochthonous starter cultures reduced fermentation time and improved the quality of samples. Therefore, isolates of the strains could be used as potential starters for the fermentation of whole carp. [ABSTRACT FROM AUTHOR]

In this study, a traditional Chinese dish, a ready-to-eat sweet and sour carp was developed. The effects of sterilization temperature (110, 115, 121, and 130°C) on the selected properties, including heat penetration characteristics, as well as rheological, instrumental color, texture, and sensory attributes, were investigated at the same lethality value (F0) of 4.5 min. The results showed that the heat penetration parameters of cooking value (C-value) and the ratio of C-value to F0value (C-value/F0) exhibited an inverse relationship with processing temperature. The color and rheological properties of the sauce and the texture of the fish sterilized at 130°C were better preserved compared to those sterilized at other temperatures. The sensory attributes of the product sterilized at 130°C scored highest among the final products sterilized at the four temperatures. This study suggested that short-time sterilization at a high temperature can minimize the negative thermal impact on sweet and sour carp product, which would be feasible in the practical production. [ABSTRACT FROM PUBLISHER]

In this study, freshwater mussel adhesive proteins (FMAPs) were extracted by different solvents and preliminarily purified using differential precipitation with ammonium sulphate and acetone. FMAPs extracted by the fourth method (M4) were further purified by twice column chromatography and characterized in terms of isoelectric point, gel electrophoresis, and amino acid composition. Results showed that 50 mM Tris-HCl (pH 7.5) solution containing 1 M NaCl exhibited better extraction efficiency for FMAPs. The purity of FMAPs got further enrichment after column chromatography, and two purified FMAPs fraction I and fraction II with hydroxyl amino acid of higher content (>43.3%) were obtained. Amino acid analysis demonstrated that DOPA contents in fraction I and fraction II were 13.04% and 12.02%, respectively. The isoelectric point of FMAPs was close to pH 9.5. [ABSTRACT FROM PUBLISHER]

In this study, chitosan flake was micronized in a ball mill to make fine powder. The effects of the milling on properties of chitosan, such as particle size, molecular parameters, bulk density, crystalline structure, color, chemical structure, and solubility, were investigated. Results showed that the volume weight mean diameter (D[4,3]) of chitosan was reduced to 37.53 μm after 8 h of milling and extended milling did not cause a further decrease in particle size. After milling, the viscosity average molecular weight (Mv) of chitosan was decreased, but the degree of acetylation (DD) remained nearly unchanged. The bulk density of chitosan increased with increasing milling time. The crystalline structure of chitosan was destroyed by the milling. The ball-milling treatment deepened the color of chitosan. UV-vis spectra showed that new C=O groups might be formed during the milling process. Further, the micronized powders showed high dissolution rates in simulated gastric juice. [ABSTRACT FROM AUTHOR]

A diffusion model has been developed for predicting the change of moisture content in lightly salted grass carp fillets under the consideration of shrinkage and variable volumetric effective diffusivity. The established relationship between moisture content, temperature, and effective diffusivity validated the effectiveness of considering the variable volumetric effective diffusivity. The appearance of shrinkage during drying and the shrinkage coefficient have been determined for better predicting the variation of moisture content during drying to provide a thorough theoretical basis for industrial processes. [ABSTRACT FROM PUBLISHER]

Microwave-assisted extraction (MAE) was applied in the extraction of phenolics from Canarium album L. Effects of various conditions including the solvent, solvent to material ratio, microwave power and irradiation time on extraction yield of phenolics were investigated. In terms of the optimal conditions of MAE, it was concluded that 70% (v/v) of ethanol was the proper extraction solvent, the solvent to material ratio was 10 : 1 (mL : g), and the microwave power and irradiation time were 600 W and 15 s, respectively. Compared with normal stirring extraction and ultrasound-assisted extraction, the MAE of phenolics from C. album L. was more time efficient and gave a high extraction rate. More than 1.2% extraction yield was achieved with MAE, and the purity of the phenolics in the extract product was up to 25%. In addition, by ultraviolet-visible (UV) spectrometry and electrospray ionised mass spectrometry (ESI/MS), the main phenolic compound in the extract product was identified as gallic acid. [ABSTRACT FROM AUTHOR]

Effects of chitosan pentamer ((GLcN)5) and chitosan hexamer ((GLcN)6) in vivo and in vitro on gene transcription and protein translation of interleukin-1 (IL-1), tumour necrosis, factor alpha (TNF-α), interleukin-2 and interferon-γ (IFN-γ) were investigated by relatively quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. The results showed that the expression of IL-1 mRNA, TNF-α mRNA, IFN-γ mRNA as well as the secretion of IL-1, TNF-α and IFN-γ can both be promoted by (GLcN)6 and (GLcN)5. The promotion effects caused by (GLcN)6 were greater than that of (GLcN)5. Gene transcription and protein secretion of cytokines were promoted by (GLcN)5 and (GLcN)6 in vivo and in vitro and thus the immuno-modulating ability was promoted. This may be one of the molecular mechanisms for elucidation of immunity of chitooligosaccharides. [ABSTRACT FROM AUTHOR]

Phenolic compounds like simple phenols, flavonoids, and phenolic acids are commonly in foods of plant origin. Several studies, including animal and epidemiological investigations, have demonstrated that phenolic compounds in foods possess positive attributes such as anticarcinogenesis, antioxidant potential, antiviral activity, antimicrobial activity, and antimutagenic activity. However, other studies have shown that the same phenolics have negative attributes such as carcinogenic activity and antinutritional activity, as well as imparting negative attributes to foods. This review summarizes the information about food phenolics and presents the most current knowledge with respect to its role in human health, food attributes, and toxicity among others. [ABSTRACT FROM AUTHOR]

Milk contains components that provide critical nutritive elements, immunological protection, and biologically active substances to both neonates and adults. Milk proteins are currently the main source of a range of biologically active peptides. Concentrates of these peptides are potential health-enhancing nutraceuticals for food and pharmaceutical applications. Several bioactive peptides may be used as nutraceuticals, for example, in the treatment of diarrhea, hypertension, thrombosis, dental diseases, as well as mineral malabsorption, and immunodeficiency. Minor whey proteins, such as lactoferrin, lactoperoxidase, lysozyme, and immunoglobulins, are considered antimicrobial proteins. Milk also contains some natural bioactive substances. These include oligosaccharides, fucosylated oligosaccharides, hormones, growth factors, mucin, gangliosides, and endogenous peptides, which are present in milk at secretion. Most of the claimed physiological properties of milk bioactive components have been carried out in vitro or in animal model systems, and these hypothesized properties remain to be proven in humans. Whether these milk bioactive components will replace drugs entirely in the immediate future is still unclear, but the increasing appreciation of “drug foods” or nutraceuticals plays a complementary rather than a substitutional role to the synthetic pharmacological drugs. [ABSTRACT FROM AUTHOR]