Fish protein isolate: Development of functional foods with nutraceutical ingredients

Tilapia-soybean protein co-precipitates: Focus on physicochemical properties, nutritional quality, and proteomics profile

The development of binary protein systems featuring superior nutritional properties and applied range is an interesting and challenging task in the food industry. In this study, the tilapia-soybean protein co-precipitates (TSPCs) with different mass ratios of tilapia meat and soybean meal were constructed. Results of physicochemical properties showed that the highest solubility and thermal stability values of TSPCs were 81.90 % and 90.30 °C, respectively. TSPCs have the full complement of amino acids and enhanced nutritional quality compared to tilapia protein isolate (TPI) and soybean protein isolate (SPI). TSPC2:1 and TSPC1:1 contained the highest levels of tryptophan, aspartic acid, glycine, histidine, and arginine relative to TPI and SPI. The in vitro protein digestibility and protein digestibility corrected amino acid scores of TSPCs were also higher than that of SPI. SDS-PAGE revealed that TSPCs contained protein subunits from TPI and SPI. Moreover, the lysine-to-arginine ratio and β subunit were greatly correlated with protein digestibility with correlation coefficients of -0.962 (P < 0.01) and -0.971 (P < 0.01), respectively. Compared to SPI, TSPCs displayed a lower lysine-to-arginine ratio and β-conglycinin content, which improved its digestibility. Proteomic analysis indicated that TSPC1:1 had 989 unique proteins, which gives TSPCs enhanced biological properties compared to TPI and SPI, allowing them to participate in a broad range of biochemical metabolic and signal transduction pathways. The study would advance the utilization of mixed proteins toward exceptional food industry applications.

Regenerative Food Innovation: The Role of Agro-Food Chain By-Products and Plant Origin Food to Obtain High-Value-Added Foods

Food losses in the agri-food sector have been estimated as representing between 30 and 80% of overall yield. The agro-food sector has a responsibility to work towards achieving FAO sustainable goals and global initiatives on responding to many issues, including climate pressures from changes we are experiencing globally. Regenerative agriculture has been discussed for many years in terms of improving our land and water. What we now need is a focus on the ability to transform innovation within the food production and process systems to address the needs of society in the fundamental arenas of food, health and wellbeing in a sustainable world. Thus, regenerative food innovation presents an opportunity to evaluate by-products from the agriculture and food industries to utilise these waste streams to minimise the global effects of food waste. The mini-review article aims to illustrate advancements in the valorisation of foods from some of the most recent publications published by peer-reviewed journals during the last 4-5 years. The focus will be applied to plant-based valorised food products and how these can be utilised to improve food nutritional components, texture, sensory and consumer perception to develop the foods for the future.

Factors governing consumers buying behavior concerning nutraceutical product

In recent years, consumers are increasingly attracted to nutraceuticals, an important part of food considered propitious for human health. Therefore, consumers are willingly switching to nutraceuticals and are ready to pay the premium price. This review aims to identify various factors that govern consumer purchasing of nutraceutical products. The outcomes presented in the review provide a closer understanding of consumer attitudes toward buying behavior and their impact on the growth of the global nutraceutical market. The nutraceutical market has been identified depending on the type of nutraceuticals, forms, and regions governing the nutraceutical market. Factors such as health consciousness, knowledge about a product, product availability, price, marketing strategies, and social factors influence consumers' actual buying behavior toward nutraceutical products. A mini survey in Mumbai city of India was conducted to add practical data to the review, and factors affecting consumers' willingness to buy nutraceutical products were identified. It was observed that the decision-making toward buying nutraceutical products was affected by gender, age, education level, and acculturation. It was also identified that the legislation governing nutraceuticals needs to be harmonized throughout many parts of the world, which restricts the growth of this sector to some extent. The findings elucidate that nutraceutical industries should overcome the regulatory barriers and focus on developing innovative products, which will keep current consumers intact and help increase the consumer base and thus expand the nutraceutical market globally.

Functionality of Pea-Grass Carp Co-Precipitated Dual-Protein as Affected by Extraction pH

Isoelectric solubilisation/co-precipitation (ISP) has been proven to be a better method than blending for preparing plant-animal dual-proteins, which can achieve synergies in the functional properties of heterologous proteins. This paper aims to investigate the effect of extraction pH on the functional properties of co-precipitated dual-protein. The basic composition, subunit composition, solubility, surface hydrophobicity, emulsification and gel properties of co-precipitated dual-protein (Co) prepared from pea and grass carp with pH (2.0, 3.0, 9.0, 10.0 and 11.0) were analysed in this study using ISP. The results showed that the functional properties of Co (Co9, Co10, Co11) prepared by alkali extraction were generally better than those prepared by acid extraction (Co2, Co3). Among them, Co10 has the highest vicilin/legumin α + β value and solubility, while having the lowest surface hydrophobicity, making its emulsification and gel properties superior to other extraction pH values. This study provides an important method reference for preparing plant-animal Co with exceptional functional properties.

Functional proteins through green refining of seafood side streams

Scarcity of nutritive protein is a major global problem, the severity of which is bound to increase with the rising population. The situation demands finding additional sources of proteins that can be both safe as well as acceptable to the consumer. Food waste, particularly from seafood is a plausible feedstock of proteins in this respect. Fishing operations result in appreciable amounts of bycatch having poor food value. In addition, commercial processing results in 50 to 60% of seafood as discards, which consist of shell, head, fileting frames, bones, viscera, fin, skin, roe, and others. Furthermore, voluminous amounts of protein-rich effluents are released during commercial seafood processing. While meat from the bycatch can be raw material for proteinous edible products, proteins from the process discards and effluents can be recovered through biorefining employing upcoming, environmental-friendly, low-cost green processes. Microbial or enzyme treatments release proteins bound to the seafood matrices. Physico-chemical processes such as ultrasound, pulse electric field, high hydrostatic pressure, green solvent extractions and others are available to recover proteins from the by-products. Cultivation of photosynthetic microalgae in nutrient media consisting of seafood side streams generates algal cell mass, a rich source of functional proteins. A zero-waste marine bio-refinery approach can help almost total recovery of proteins and other ingredients from the seafood side streams. The recovered proteins can have high nutritive value and valuable applications as nutraceuticals and food additives.

Factors Influencing Italian Consumers’ Willingness to Pay for Eggs Enriched with Omega-3-Fatty Acids

This paper focused on eggs enriched with omega-3-fatty acids with the aim of understanding if functional eggs were of interest to Italian consumers, and analyzing which characteristics of table egg quality, consumers’ attitudes and socio-demographic characteristics affect the consumers’ willingness to pay (WTP) a premium price for eggs enriched with omega-3-fatty acids. We performed an online survey on 312 Italian consumers. The analysis was based on the Tobit regression model. The findings showed that unmarried females were more willing to pay a premium price for functional eggs than male consumers. Furthermore, the probability of showing a higher WTP for functional eggs increased among consumers reporting a higher income. Moreover, the WTP for functional eggs increased with the growing importance that people attributed to items such as the size of eggs, rearing type, feed given to chickens, and the provenience and brand of eggs. These results suggested that consumers need to have clear information about functional eggs. As expected, WTP for functional eggs decreased with increasing neophobia and food techno-neophobia factors. In conclusion, the findings showed an interesting potential for eggs enriched with omega-3-fatty acids, which seems to be a product with high possibility to be greatly appreciated on the market, especially if accompanied by a good, informative campaign for increasing people’s knowledge level.

A Comparative Functional Analysis of Pea Protein and Grass Carp Protein Mixture via Blending and Co-Precipitation

Currently, the application of protein mixture derived from plants and animals is of great interest to the food industry. However, the synergistic effects of isolated protein blends (BL) are not well established. Herein, the development of a more effective method (co-precipitation) for the production of protein mixtures from pea and grass carp is reported. Pea protein isolate (PPI), grass carp protein isolate (CPI), and pea–carp protein co-precipitates (Co) were prepared via isoelectric solubilization/precipitation using peas and grass carp as raw materials. Meanwhile, the BL was obtained by blending PPI with CPI. In addition, the subunit composition and functional properties of Co and BL were investigated. The results show that the ratios of vicilin to legumin α + β and the soluble aggregates of Co were 2.82- and 1.69-fold higher than that of BL. The surface hydrophobicity of Co was less than that of BL, PPI, and CPI (p < 0.05). The solubility of Co was greater than that of BL, PPI, and CPI (p < 0.05), and the foaming activity was higher than that of BL and CPI (p < 0.05) but slightly lower than that of PPI. In addition, based on the emulsifying activity index, particle size, microstructure, and viscosity, Co had better emulsifying properties than BL, PPI, and CPI. The study not only confirmed that co-precipitation was more effective than blending for the preparation of mixed protein using PPI and CPI but also provided a standard of reference for obtaining a mixture of plant and animal proteins.

Recent developments in maintaining gel properties of surimi products under reduced salt conditions and use of additives

Salt is a necessary condition to produce a surimi product that is based on the gelation of salt-soluble myofibrillar proteins. Recently, there has been a growing concern among consumers to consume healthy foods due to the threat of several chronic diseases caused by an unhealthy diet. Methods of reducing salt content out of concern for health issues caused by excessive sodium intake may affect the gel properties of surimi, as can many health-oriented food additives. Several studies have investigated different strategies to improve the health characteristics of surimi products without decreasing gel properties. This review reports recent developments in this area and how the gel properties were successfully maintained under reduced-salt conditions and the use of additives. This review of recent studies presents a great deal of progress made in the health benefits of surimi and can be used as a reference for further development in the surimi product processing industry.

Functional Food-Consumer Motivations and Expectations

This review provides insight into consumer attitudes toward functional food (FF), with the purpose of better understanding the needs and behavior regarding this kind of product. A total of 47 articles were selected for this paper. The available studies from last 20 years differ according to the focus (awareness, attitudes, motivations, willingness, acceptance by consumers) and methodologies used. Several factors, including socio-demographic, cognitive and attitudinal ones, seem to be serve as the basis for the acceptance of functional products. The research papers showed that nutritional knowledge is the most important of these. Older people are more interested in functional products than younger consumers, because of their stronger belief in the health benefits of FF. Moreover, women are more open to compromise between taste and health properties. Claims concerning the disease preventative properties of FF are the most attractive for consumers. This review focuses also on future perspectives for the functional food market. Adequate knowledge and evidence-based communication seem to be the most promising ways to increase consumers’ interest in these kinds of products.

Hydrolysis of raw fish proteins extracts by Carnobacterium maltaromaticum strains isolated from Argentinean freshwater fish

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Carnobacterium and Vagococcus genera were identified from Paraná River freshwater fishes.

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Low acidifying and antilisterial Carnobacterium strains were selected.

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Proteolysis of raw fish extract by C. maltaromaticum strains was confirmed.

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C. maltaromaticum strains may be used as functional cultures to develop novel LPFP.

Lactic acid bacteria (LAB) isolated from freshwater fish (hatcheries and captures) from Paraná river (Argentina) were analyzed by using culture-dependent approaches. The species belonging to Carnobacterium (C.) divergens, C. inhibens, C. maltaromaticum, C. viridans and Vagococcus (V.) salmoninarum were identify as predominant by RAPD-PCR and 16 s rRNA gene sequencing. C. maltaromaticum (H-17, S-30, B-42 and S-44) grew in raw fish extract and slightly reduced the medium pH (5.81–5.91). These strains exhibited moderate fish sarcoplasmic protein degradation (≤ 73 %) releasing small peptides and free amino acids, being alanine, glycine, asparagine and arginine concentrations increased in a higher extent (17.84, 1.47, 1.26 and 0.47 mg/100 mL, respectively) by S-44 strain at 96 h incubation. Interestingly C. maltaromaticum H-17 was able to inhibit Listeria monocytogenes. Results suggest that these strains would contribute to the development of new safe and healthy fishery products with improved nutritional and sensory characteristics.

Functional Foods: Product Development, Technological Trends, Efficacy Testing, and Safety

Functional foods is a very popular term in the social and scientific media; consequently, food producers have invested resources in the development of processed foods that may provide added functional benefits to consumers' well-being. Because of intrinsic regulation and end-of-use purposes in different countries, worldwide meanings and definitions of this term are still unclear. Hence, here we standardize this definition and propose a guideline to attest that some ingredients or foods truly deserve this special designation. Furthermore, focus is directed at the most recent studies and practical guidelines that can be used to develop and test the efficacy of potentially functional foods and ingredients. The most widespread functional ingredients, such as polyunsaturated fatty acids (PUFAs), probiotics/prebiotics/synbiotics, and antioxidants, and their technological means of delivery in food products are described. The review discusses the steps that food companies should take to ensure that their developed food product is truly functional.

Correlation Between the Water Solubility and Secondary Structure of Tilapia-Soybean Protein Co-Precipitates

The secondary structure of a protein has been identified to be a crucial indicator that governs its water solubility. Tilapia protein isolate (TPI), soybean protein isolate (SPI), and tilapia-soybean protein co-precipitates (TSPC_3:1, TSPC_2:1, TSPC_1:1, TSPC_1:2, and TSPC_1:3) were prepared by mixing tilapia meat and soybean meal at different mass ratios. The results demonstrated that the water solubility of TSPCs was significantly greater than that of TPI (p <0.05). The changes in ultraviolet–visible and near-ultraviolet circular dichroism spectra indicated that the local structure of TSPCs was different from that of TPI and SPI. Fourier transform infrared Spectroscopy revealed the co-existence of TPI and SPI structures in TSPCs. The secondary structures of TSPCs were predominantly α-helix and β-sheet. TSPC_1:1 was unique compared to the other TSPCs. In addition, there was a good correlation between the water solubility and secondary structure of TSPCs, in which the correlation coefficients of α-helix and β-sheet were −0.964 (p <0.01) and 0.743, respectively. TSPCs displayed lower α-helix contents and higher β-sheet contents compared to TPI, which resulted in a significant increase in their water solubility. Our findings could provide insight into the structure–function relationship of food proteins, thus creating more opportunities to develop innovative applications for mixed proteins.

Physiochemical Properties and Functional Characteristics of Protein Isolates from the Scallop (Patinopecten yessoensis) Gonad

Protein isolates were recovered from scallop (Patinopecten yessoensis) gonads to develop a novel functional matrix by investigating their physiochemical and functional properties. Scallop gonad protein isolates (SGPIs) were prepared from degreased scallop gonads (DSGs) by an alkali extraction and isoelectric solubilization/precipitation (ISP) process. The protein compositions of the SGPIs were mainly vitellogenin and beta-actin with molecular weights of 266 and 42 kDa, respectively, as determined using Nano-liquid chromatography-mass/mass (Nano-LC-MS/MS). After the ISP process, the protein solubility of the SGPIs was significantly improved, and the surface hydrophobicity of SGPIs intensely increased by 1.1-fold, which were attributed to the exposure of aromatic residues such as phenylalanine, tyrosine, and tryptophan. However, the content of total/reactive sulfhydryl in SGPIs was decreased compared with that of DSGs. Meanwhile, the ISP process caused partial protein unfolding, as indicated by circular dichroism analysis, which exhibited a remarkable rise in the β-sheet content with a parallel decline in the α-helix and random coil contents (P < 0.05). SGPIs exhibited a better oil absorption capacity and foaming property than both DSGs and soybean protein isolates (SPIs). Moreover, the emulsifying capacity of SGPIs was greatly enhanced by the ISP process, which was superior to the effect of commercial SPIs and was ascribed to its favorable solubility as well as surface characteristics. PRACTICAL APPLICATION: During the processing of scallop (Patinopecten yessoensis) adductors, scallop gonad, a high-protein part, is usually discarded as processing by-products despite its edibility. In recent years, scallop gonads are regarded as good sources to develop protein matrices due to their high protein content and numerous nutrients. In this study, scallop gonad protein isolates (SGPIs) were isolated by isoelectric solubilization/precipitation (ISP) process. The preferable solubility, foaming property coupled with high emulsifying property of SGPIs indicated that the SGPIs could be potentially utilized as a good protein emulsifier and additives in production of kamaboko gels, hamburger patties, sausages, and pet foods.

Acid and alkaline solubilization (pH shift) process: a better approach for the utilization of fish processing waste and by-products

Several technologies and methods have been developed over the years to address the environmental pollution and nutritional losses associated with the dumping of fish processing waste and low-cost fish and by-products. Despite the continuous efforts put in this field, none of the developed technologies was successful in addressing the issues due to various technical problems. To solve the problems associated with the fish processing waste and low-value fish and by-products, a process called pH shift/acid and alkaline solubilization process was developed. In this process, proteins are first solubilized using acid and alkali followed by precipitating them at their isoelectric pH to recover functional and stable protein isolates from underutilized fish species and by-products. Many studies were conducted using pH shift process to recover proteins from fish and fish by-products and found to be most successful in recovering proteins with increased yields than conventional surimi (three cycle washing) process and with good functional properties. In this paper, problems associated with conventional processing, advantages and principle of pH shift processing, effect of pH shift process on the quality and storage stability of recovered isolates, applications protein isolates, etc. are discussed in detail for better understanding.