Antioxidative activity of protein hydrolysate produced by alcalase hydrolysis from shrimp waste (Penaeus monodon and Penaeus indicus)

Unlocking the potential of fishery waste: exploring diverse applications of fish protein hydrolysates in food and nonfood sectors

Fish and their byproducts play a pivotal role as protein sources. With the global population increasing, urbanization on the rise and increased affluence, efficient utilization of available protein resources is becoming increasingly critical. Additionally, the need for sustainable protein sources is gaining recognition. By 2050, the world's protein demand is expected to double, driven not only by population growth but also by heightened awareness of protein's role in maintaining health. The fishery industry has experienced continuous growth over the last decade. However, this growth comes with a significant challenge: inadequate waste management. The fisheries industry discards 35% to 70% of their production as waste, including fillet remains, skin, fins, bones, heads, viscera and scales. Despite the importance of these byproducts as protein sources, their effective utilization remains a hurdle. Various strategies have been proposed to address this issue. Among them, the production of protein hydrolysates stands out as an efficient method for value addition. Protein hydrolysis breaks down proteins into smaller peptides with diverse functional and bioactive properties. Therefore, fish protein hydrolysates have applications in both the food and nonfood sectors. Utilizing fishery byproducts and waste represents a sustainable approach toward waste valorization and resource optimization in the fishery industry. This approach offers promising opportunities for innovation and economic growth across multiple sectors. This comprehensive review explores fish protein hydrolysates derived from fishery byproducts and wastes, focusing on their applications in both the food and nonfood sectors.

Shrimp Waste Upcycling: Unveiling the Potential of Polysaccharides, Proteins, Carotenoids, and Fatty Acids with Emphasis on Extraction Techniques and Bioactive Properties

Shrimp processing generates substantial waste, which is rich in valuable components such as polysaccharides, proteins, carotenoids, and fatty acids. This review provides a comprehensive overview of the valorization of shrimp waste, mainly shrimp shells, focusing on extraction methods, bioactivities, and potential applications of these bioactive compounds. Various extraction techniques, including chemical extraction, microbial fermentation, enzyme-assisted extraction, microwave-assisted extraction, ultrasound-assisted extraction, and pressurized techniques are discussed, highlighting their efficacy in isolating polysaccharides, proteins, carotenoids, and fatty acids from shrimp waste. Additionally, the bioactivities associated with these compounds, such as antioxidant, antimicrobial, anti-inflammatory, and antitumor properties, among others, are elucidated, underscoring their potential in pharmaceutical, nutraceutical, and cosmeceutical applications. Furthermore, the review explores current and potential utilization avenues for these bioactive compounds, emphasizing the importance of sustainable resource management and circular economy principles in maximizing the value of shrimp waste. Overall, this review paper aims to provide insights into the multifaceted aspects of shrimp waste valorization, offering valuable information for researchers, industries, and policymakers interested in sustainable resource utilization and waste-management strategies.

Impact of Time and Enzyme Concentration on Sangyod Rice Bran Hydrolysate: Phytochemicals, Antioxidants, Amino Acids, and Cytotoxicity

This study investigated the production of Sangyod rice bran hydrolysate (SYRB) from Sangyod rice, focusing on incubation times (1, 3, and 5 h) and alcalase enzyme concentrations (0, 0.7, and 1% v/v). The results demonstrated a concentration-dependent relationship: higher alcalase concentrations increased hydrolysate yield. Prolonged incubation, especially with alcalase, enhanced substrate breakdown, further increasing hydrolysate production. The degree of hydrolysis, reflecting peptide bond cleavage, depended on both incubation time and enzyme concentration, emphasizing the role of enzyme activity in efficiency. Moreover, color analysis (L*, a*, b*) and color difference (∆E) revealed intricate changes from enzymatic hydrolysis. Proximate composition analysis showed higher protein and lipid content with increased enzyme concentration and longer incubation times, whereas ash content varied with both factors. Hydrolysate powders exhibited higher moisture content than raw rice bran, indicating the impact of the hydrolysis process. The study also explored SYRB's antioxidant properties and cytotoxicity, which were sensitive to incubation time and alcalase concentration. Longer incubation increased DPPH scavenging activity, with the highest efficacy at 3 h. Meanwhile, ABTS scavenging displayed a delicate balance with alcalase concentration. The cytotoxicity study of SYRB revealed that all concentrations of SYRB were non-toxic to C2C12 cells, with cell viability values exceeding 70%.

Valorisation of prawn/shrimp shell waste through the production of biologically active components for functional food purposes

BACKGROUND

The aim of the work was to develop a technology for using waste from prawn and shrimp processing as a source of active ingredients that could be used in the promotion of healthy foods. From fresh and freeze-dried prawn and shrimp shells, protein hydrolysates (carotenoproteins) were obtained using two different enzymes, Flavourzyme and Protamex.

RESULTS

The obtained hydrolysates were characterised in terms of protein content, degree of hydrolysis, and antioxidant and antimicrobial activity. The hydrolysate with the best antioxidant properties (FRAP value of 2933.33 μmol L-1 TE; ORAC value of 115.58 μmol L-1 TE) was selected and tested for its possible use as a component of functional foods. Molecular weight distribution, amino acid profile and free amino acids, the solubility of the hydrolysate in different pH ranges as well as foaming ability were determined. It was found that this hydrolysate was characterised by an amino acid profile with high nutritional value, flavour enhancement properties and excellent solubility in a wide pH range (from 97.06% to 100%). Afterward, the possibility of using carotenoproteins from prawn waste as a component of an emulsion with furcellaran and a lipid preparation of astaxanthin, taken from post-hydrolysate production waste, was investigated. The obtained complexes were stable as proved by the measurement of zeta potential (ζ = -23.87 and -22.32 to -27.79 mV).

CONCLUSION

It is possible to produce stable complexes of the hydrolysate with furcellaran and to emulsify a lipid preparation of astaxanthin, obtained from waste following production of the hydrolysate, in them. © 2023 Society of Chemical Industry.

Bioactive characterization and optimization of Tamarindus indica seed protein hydrolysate: technology and application of natural enzymes

Tamarind seeds are one of the major sources of different nutrients and minerals and are used as antioxidant components in various food products. Bioactive peptides are released by enzymatic hydrolysis of major food proteins followed by different separation techniques to isolate them from the mixture of other components. Further incorporation of bioactive peptides in various food products may lead to more diversification, fulfilling different nutritional requirements, and promoting health benefits. The objective of this study was to optimize the parameters for the formation of tamarind protein hydrolysates with the use of pepsin and trypsin. It was observed that pepsin and trypsin derived hydrolysate showed the maximum degree of hydrolysis and other bioactive characteristics (DPPH activity, reducing power, ABTS activity, and antidiabetic activity) under optimized conditions. High-performance liquid chromatography was performed for amino acid profiling on trypsin derived protein hydrolysate. From this study, pepsin and trypsin derived hydrolysate can be considered as a rich source of natural antioxidants for developing food formulation.

Shrimp-waste based dispersant as oil spill treating agent: Biodegradation of dispersant and dispersed oil

The emerging demand for the enhancement of biodegradation of persistent organic pollutants from marine oil spills using oil-treating agents to minimize the environmental impacts promotes the development of green dispersants. Shrimp waste is a potential raw material to generate green dispersants. The biodegradability of dispersed oil and dispersants themselves are key factors for the national consideration of the approval, stockpile, and usage of dispersants. However, it is unknown whether shrimp-waste-based dispersant (SWD) has high bioavailability or facilitates the biodegradation of dispersed oil. In this study, we tackled the biodegradation of oil dispersed by a purified SWD. Furthermore, the SWD biodegradability was evaluated by exploring the degradation genes via metagenomic sequencing, analyzing the enzymatic activities for dispersant biodegradation by molecular docking, and discussing the SWD toxicity. We discovered that the SWD facilitated the biodegradation of two crude oils (Alaska North Slope and Marine Fuel-No.6). The metagenomic analysis with molecular docking showed that fresh seawater had feasible enzymes to degrade the SWD to safety components. Additionally, the SWD was low toxic and high bioactive. The findings helped confirm that the purified SWD is an effective and eco-sustainable marine oil spill treating agent and tracked the biodegradation of dispersed oil and the SWD.

Development of Fermented Shrimp Shell Product with Hypoglycemic and Hypolipidemic Effects on Diabetic Rats

In 2020, approximately 9.3 billion tons of crustaceans were consumed, and 45–48% of shrimp shell (SS) by-products were discarded as waste. In this study, the SS of Litopenaeus vannamei was fermented by Lactobacillus plantarum LV33204, Stenotrophomonas maltophilia LV2122 (strong proteolytic activity), and Aeromonas dhakensis LV1111 (chitin-degrading activity), and the optimal fermentation conditions of liquid-fermented SS was established. Contents of total peptide, astaxanthin, and total phenolic content of the fermented SS were significantly higher than that of unfermented SS. In the presence of fermented SS, glucose uptake and insulin resistance of TNF-α-stimulated FL83B hepatocytes were markedly improved. Furthermore, daily oral supplement of fermented SS to streptozotocin (STZ)/nicotinamide (NA)-induced diabetic rats for 7 weeks significantly reduced plasma glucose and insulin resistance. Meanwhile, ingestion of fermented SS might enhance hepatic catabolism of glucose by increasing hexokinase and glucose-6-phosphate dehydrogenase activity and decreasing glucose-6-phosphatase activity. In addition, the fermented SS downregulated plasma total cholesterol (TG), triglycerides (TCs), low-density lipoprotein cholesterol (LDL-C), liver TG, and TC and lipid peroxidation levels in diabetic rats. In conclusion, a biorefinery process for waste SS was established through mixed strain fermentation. The in vitro and in vivo data reveal that the fermented SS is a promising functional food for the management of diabetic hyperglycemia and hyperlipidemia.

Assessment of quality attributes of porcine blood and liver hydrolysates incorporated pork loaves stored under aerobic and modified atmospheric packaging

Lipid oxidation and microbial proliferations were studied in pork loaves prepared with incorporation of blood and liver protein hydrolysates stored in aerobic and MAP packaging for 28 and 42 days at 4 ± 1 ºC. In in-vitro trials selected levels i.e. blood hydrolysate (T1 and T3-600 mg/g), and liver hydrolysate (T2 and T4-600 mg/g), control without hydrolysate (C1-00 and C2-00 mg/g) w/w of emulsion, were added into pork loaves and packaged under aerobic (C1, T1 and T2) and MAP (C2, T3 and T4) condition. Physico-chemicals as pH, water activity_, titratable acidity, lipid-oxidations, color profile, textural indices, microbial qualities and sensorial properties were analyzed. Significant (p < 0.05) lower lipid oxidation, microbial proliferations and decrease in sensory attributes were seen for tested groups and MAP than aerobic packaging. It can be concluded that pork loaves containing porcine blood and liver hydrolysates can be successfully stored upto 28th days in aerobically packed and 42 days in MAP condition at refrigerated storage with acceptable physico-chemical, oxidative stability, microbiological and sensory quality. Whereas, pork loves prepared with blood hydrolysate (T3-600 mg/g), packaged under MAP condition were superior for all studied attributes than other groups. Blood and liver hydrolysate might be used as an alternative to synthetic preservative for meat preservation.

Evaluating the effects of different processing methods on the nutritional composition of shrimp and the antioxidant activity of shrimp powder

Shrimp is a prevalent food in the Arabian Gulf that is known for its good sensory properties and high nutritional value. The aim of the present work was to assess the effects of diverse processing methods on the nutritional composition of shrimp and the antioxidant activity of shrimp powder. Shrimp (Penaeus semisulcatus) flesh was treated using four processes (salting, frying, grilling, and boiling), following which its macronutrient content, fatty acid profile, vitamins and mineral contents were measured. Also, the antioxidant activity of all shrimp powder extracts was assessed using the 2, 2 diphenyl 1 picrylhydrazyl (DPPH), linoleic acid oxidation inhibition, and reducing power methods. The results revealed that the fresh and processed shrimp flesh had significant nutritional value and the fresh and treated shrimp powders have high antioxidant activity, but the cooking processes have significant effects on the nutritional value and antioxidant activity of shrimp flesh. These effects were greater significantly in grilled shrimp followed by boiled shrimp and then fried shrimp. It is concluded that the high nutritional value and antioxidant activity of shrimp flesh make it an important food for nutritional health promotion for the community.

Structure and in vitro bioactive properties of O/W emulsions generated with fava bean protein hydrolysates

The use of plant-derived proteins in the generation of food products is gaining popularity as an alternative to proteins of animal origin. This study described the emulsifying and bioactive properties of fava bean protein hydrolysates (FBH) generated at low and high degree of hydrolysis (DH), i.e., FBH₈ (low DH: 8.4 ± 0.3) and FBH₂₁₀ (high DH: 15.6 ± 0.7) when adjusted to three different pHs (3.0, 5.0 and 8.0). Overall, FBH₈, had more favourable emulsifying properties compared to the FBH_210. The emulsion generated with FBH₈ at pH 8.0 also had the highest antioxidant activity when measured by the oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) assays with values of 1108.6 ± 3.8 and 1159.9 ± 20.5 μmol Trolox Eq·g^-1 emulsion, respectively. The antioxidant activity of the emulsions, in most cases, remained unchanged following in vitro simulated gastrointestinal digestion. Both the FBH₈ and FBH₂₁₀ emulsions following in vitro simulated gastrointestinal digestion were able to inhibit the activities of dipeptidyl peptidase-IV (DPP-IV) and angiotensin converting enzyme (ACE) with ∼45% and 65% inhibition, respectively. These results indicated that hydrolysates from fava bean may find use for the generation of bioactive emulsions.

Innovative Non-Thermal Technologies for Recovery and Valorization of Value-Added Products from Crustacean Processing By-Products-An Opportunity for a Circular Economy Approach

The crustacean processing industry has experienced significant growth over recent decades resulting in the production of a great number of by-products. Crustacean by-products contain several valuable components such as proteins, lipids, and carotenoids, especially astaxanthin and chitin. When isolated, these valuable compounds are characterized by bioactivities such as anti-microbial, antioxidant, and anti-cancer ones, and that could be used as nutraceutical ingredients or additives in the food, pharmaceutical, and cosmetic industries. Different innovative non-thermal technologies have appeared as promising, safe, and efficient tools to recover these valuable compounds. This review aims at providing a summary of the main compounds that can be extracted from crustacean by-products, and of the results obtained by applying the main innovative non-thermal processes for recovering such high-value products. Moreover, from the perspective of the circular economy approach, specific case studies on some current applications of the recovered compounds in the seafood industry are presented. The extraction of valuable components from crustacean by-products, combined with the development of novel technological strategies aimed at their recovery and purification, will allow for important results related to the long-term sustainability of the seafood industry to be obtained. Furthermore, the reuse of extracted components in seafood products is an interesting strategy to increase the value of the seafood sector overall. However, to date, there are limited industrial applications for this promising approach.

Can be marine bioactive peptides (MBAs) lead the future of foodomics for human health?

Marine organisms are considered a cache of biologically active metabolites with pharmaceutical, functional, and nutraceutical properties. Among these, marine bioactive peptides (MBAs) present in diverse marine species (fish, sponges, cyanobacteria, fungi, ascidians, seaweeds, & mollusks) have acquired attention owing to their broad-spectrum health-promoting benefits. Nowadays, scientists are keener exploring marine bioactive peptides precisely due to their unique structural and biological properties. These MBAs have reported ameliorating potential against different diseases like hypertension, diabetes, obesity, HIV, cancer, oxidation, and inflammation. Furthermore, MBAs isolated from various marine organisms may also have a beneficial role in the cosmetic, nutraceutical, and food industries. Few marine peptides and their derivative are approved for commercial use, while many MBAs are in various pre-clinical and clinical trials. This review mainly focuses on the diversity of marine bioactive peptides in marine organisms and their production procedures, such as chemical and enzymatic hydrolysis. Moreover, MBAs' therapeutic and biological potential has also been critically discussed herein, along with their status in drug discovery, pre-clinical and clinical trials.

Use of Alcalase in the production of bioactive peptides: A review

This review aims to cover the uses of the commercially available protease Alcalase in the production of biologically active peptides since 2010. Immobilization of Alcalase has also been reviewed, as immobilization of the enzyme may improve the final reaction design enabling the use of more drastic conditions and the reuse of the biocatalyst. That way, this review presents the production, via Alcalase hydrolysis of different proteins, of peptides with antioxidant, angiotensin I-converting enzyme inhibitory, metal binding, antidiabetic, anti-inflammatory and antimicrobial activities (among other bioactivities) and peptides that improve the functional, sensory and nutritional properties of foods. Alcalase has proved to be among the most efficient proteases for this goal, using different protein sources, being especially interesting the use of the protein residues from food industry as feedstock, as this also solves nature pollution problems. Very interestingly, the bioactivities of the protein hydrolysates further improved when Alcalase is used in a combined way with other proteases both in a sequential way or in a simultaneous hydrolysis (something that could be related to the concept of combi-enzymes), as the combination of proteases with different selectivities and specificities enable the production of a larger amount of peptides and of a smaller size.

Influence of Hydrolysis on the Bioactive Properties and Stability of Chickpea-Protein-Based O/W Emulsions

This study evaluated the effect of enzymatic hydrolysis on the emulsion microstructure and bioactive properties of oil-in-water emulsions generated using chickpea protein concentrate (CP) and its 10 and 210 min Alcalase CP hydrolysates (CPH₁₀ and CPH₂₁₀, respectively) at three pH values (2.5, 5.0, and 7.5). Chromatographic profiles demonstrated CP protein breakdown following hydrolysis. Increasing the degree of hydrolysis resulted in increased emulsion droplet size and decreased viscoelastic moduli. The antioxidant capacities of the emulsions generated with CPH₁₀ and CPH₂₁₀ increased significantly compared to those generated with CP and were pH-dependent. Both angiotensin-converting enzyme and dipeptidyl peptidase-IV inhibitory activities were significantly increased in emulsions stabilized with CPH₂₁₀; however, these results were also pH-dependent. In vitro gastrointestinal digestion of the emulsions resulted in a significant increase in all bioactivities. These results demonstrate the potential for enzymatic hydrolysis to beneficially modulate the emulsifying and bioactive properties of CP proteins.

Advances on Food-Derived Peptidic Antioxidants-A Review

The oxidation process is considered to be the main reason behind human aging, human degenerative diseases and food quality degradation. Food-derived peptidic antioxidants (PAs) have wide sources and great activity, and have broad application prospects in removing excess reactive oxygen species in the body, anti-aging and preventing and treating diseases related to oxidative stress. On the other hand, PAs are expected to inhibit the lipid peroxidation of foods and increase the stability of the food system in the food industry. However, the production pathways and action mechanism of food-derived PAs are diverse, which makes it is difficult to evaluate the performance of PAs which is why the commercial application of PAs is still in its infancy. This article focuses on reviewing the preparation, purification, and characterization methods of food-derived PAs, and expounds the latest progress in performance evaluation and potential applications, in order to provide an effective reference for subsequent related research of PAs.

Antioxidant and Antimicrobial Activity of Porcine Liver Hydrolysate in Meat Emulsion and Their Influence on Physico-Chemical and Color Deterioration During Refrigeration Storage

Present study explored the quality changes in meat emulsion during storage at refrigerated temperature prepared with inclusion of three different levels of liver protein hydrolysate (LPH) in meat emulsion (LPH-1: 0.03, LPH-2: 0.06, and LPH-3: 0.09%) and compared with control (LPH: 0.00%) and positive control (butylated hydroxytoluene: 0.02% w/w meat emulsion). Physico-chemicals, antioxidant activities, lipid oxidation, color profile, microbial quality, and microbial challenge test (MCT) were assessed for all groups. Results indicated that all evaluated attributes were considerably improved with increase in LPH concentration. Among treated groups, LPH-3 was maintained comparatively better for every attribute assessed during storage studying. Regarding microbial quality, LPH-3 showed (P ≤ 0.05) lower aerobic plate count, coliforms, and yeast mold counts than others. Likewise for MCT, significantly (P ≤ 0.05) lower microbial counts were recorded in LPH-3 during storage. Results concluded that LPH can be a good alternative substance for the preservation of meat for lower oxidation activity and bacterial growth. PRACTICAL APPLICATION: Meat emulsion is more prone to lipid oxidation and microbial contamination than fresh meat. However, for the preparation of convenient, value added meat products, better utilization of freezed meat and reduced cooking time have enhanced the demand of emulsion-based meat products. Liver protein hydrolysate can be a good alternative substance for the preservation of emulsion-based meat products. Treated groups better retained their physico-chemical properties, color indices, and showed lower oxidation and microbial counts than control. It can be exploited commercially for the preparation of functional foods, nutraceuticals, and cosmeceuticals.

Evaluation of the potential use of a carp (Cyprinus carpio) skin gelatine hydrolysate as an antioxidant component

Gelatine hydrolysates are of increasing interest as potential ingredients used in various health-promoting functional foods. Cyprinus carpio skin gelatine hydrolysates can be a potential source of bioactive peptides with antioxidant properties. Therefore, the aim of this research was to evaluate the potential use of a carp skin gelatine hydrolysate with proven antioxidant properties as a bioactive compound in functional foods as well as its stability under various processing conditions. The analysis of the hydrolysate included its characterisation (ζ-potential, particle size distribution), solubility, antioxidant ability and stability (DPPH, FRAP, chelating properties) under various conditions (heating, pH and NaCl). Additionally, an analysis of residual environmental pollutants (heavy metals, dioxins and pesticides) was also conducted. The hydrolysate had high solubility over a range of pH values from 2 to 12 (84%-98%), and its antioxidant properties remained stable in low concentration NaCl solutions as well as after being heated at temperatures between 40 and 100 °C. The hydrolysate was not contaminated with heavy metals, dioxins or pesticides. According to our study, carp skin hydrolysates can be incorporated into food processing systems without significant loss of their antioxidant activities.

Quality and storage stability of goat meat emulsion during refrigerated storage upon incorporation of α-chymotrypsin hydrolysed camel milk casein

Three different levels, viz. T1 (0.03%), T2 (0.06%) and T3 (0.09%) (w/w) of α-chymotrypsin hydrolysed camel milk casein was incorporated into goat meat emulsion, and compared with control (C: 0% hydrolysate) and positive control (PC: 0.02% butylated hydroxytoluene (BHT), w/w) for changes in quality at 4±1°C. During storage, the water activity, extract release volume and emulsion stability decreased significantly, while pH increased. Except in T3, improvement in antioxidant potential of treated emulsions was recorded. Lower fatty acid oxidation was recorded in treated emulsions during storage. The treated emulsions had better instrumental colour profile, however, lightness (L*), redness (a* value) and yellowness (b*) values decreased with the advancement of storage period. The microbiological counts in treated emulsions were initially reduced, and at the end of storage, significantly lower counts were recorded. In microbial challenging test (MCT), the colony forming units in treated emulsions decreased upto 4th day for all the tested pathogens, thereafter increased significantly on 6th day except in T3, whereas, in C and PC groups, the counts increased significantly throughout the storage period. The findings suggested that camel milk casein hydrolysate with α-chymotrypsin could be used as a potential food ingredient to improve its quality.

Further Stabilization of Alcalase Immobilized on Glyoxyl Supports: Amination Plus Modification with Glutaraldehyde

Alcalase was immobilized on glyoxyl 4% CL agarose beads. This permitted to have Alcalase preparations with 50% activity retention versus Boc-l-alanine 4-nitrophenyl ester. However, the recovered activity versus casein was under 20% at 50 °C, as it may be expected from the most likely area of the protein involved in the immobilization. The situation was different at 60 °C, where the activities of immobilized and free enzyme became similar. The chemical amination of the immobilized enzyme or the treatment of the enzyme with glutaraldehyde did not produce any significant stabilization (a factor of 2) with high costs in terms of activity. However, the modification with glutaraldehyde of the previously aminated enzyme permitted to give a jump in Alcalase stability (e.g., with most than 80% of enzyme activity retention for the modified enzyme and less than 30% for the just immobilized enzyme in stress inactivation at pH 7 or 9). This preparation could be used in the hydrolysis of casein at pH 9 even at 67 °C, retaining around 50% of the activity after 5 hydrolytic cycles when the just immobilized preparation was almost inactive after 3 cycles. The modified enzyme can be reused in hydrolysis of casein at 45 °C and pH 9 for 6 cycles (6 h) without any decrease in enzyme activity.

Effects of inclusion of porcine blood hydrolysate on physico-chemical quality, oxidative and microbial stability of pork batter stored at (4 ± 1 °C)

Present study was conducted to evaluate the anti-oxidant and anti-microbial efficiency of porcine blood hydrolysate (PBH) in refrigerated pork batter. PBH produced by alcalase was included into pork batter at different levels viz. PBH1-0.03, PBH2-0.06 and PBH3-0.09% (w/w) and compared with control (C-0%) and positive control (PC-0.02% BHT w/w). The pH increased, whereas water activity, extract release volume and emulsion stability decreased during storage; however, all these parameters were better maintained in the treated groups. Anti-oxidant efficacy of treatments improved in a concentration dependent manner. Peroxide, thiobarbituric acid reacting substances and free fatty acid values were significantly lower than control throughout storage. The colour and microbial quality was better maintained in treatments than C and PC. In microbial challenge test, counts of tested microbes in treatment batter reduced up to 4th day but increased thereafter. Results suggest that PBH can be utilized as a potential component to improve physico-chemical quality, colour, oxidative and microbial stability of meat batter during refrigerated storage.

Generation of shrimp waste-based dispersant for oil spill response

In this study, shrimp waste was enzymatically hydrolyzed to generate a green dispersant and the product was tested for crude oil dispersion in seawater. The hydrolysis process was first optimized based on the dispersant effectiveness (DE) of the product. The functional properties of the product were identified including stability, critical micelle concentration, and emulsification activity. Water was confirmed as a good solvent for dispersant generation when compared with three chemical solvents. The effects of salinity, mixing energy, and temperature on the dispersion of the Alaska North Slope (ANS) crude oil were examined. Microtox acute toxicity test was also conducted to evaluate the toxicity of the produced dispersant. In addition, DE of the product on three different types of crude oil, including ANS crude oil, Prudhoe Bay crude oil (PBC), and Arabian Light crude oil (ALC) was compared with that of the Corexit 9500, respectively. The research output could lead to a promising green solution to the oil spill problem and might result in many other environmental applications.

Efficacy of antioxidant and antimicrobial activity of whole porcine blood hydrolysates and its fractions under in-vitro conditions

Protein hydrolysates were recovered from porcine blood hydrolysate (PBH) using enzymatic hydrolysis viz. alcalase, trypsin and papain. The PBH were ultra-filtered by using molecular weight cut off, these PBH and different fractions were evaluated for antioxidant and antimicrobial activity. The PBH and fractions were assessed for antioxidant efficacy viz. 2, 2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid), 2, 2-diphenyl-1-picrylhydrazyl and Ferric reducing antioxidant power assay and antimicrobial activity by zone of inhibition assay. All antioxidant parameters assessed for inhibition activity were observed significantly (P < 0.05) higher for whole PBH whereas among fractions (5–10 kDa), (1–5 kDa) for all hydrolysates had comparatively higher antioxidant efficacy. The results showed that PBH obtained from trypsin and its fractions have highest antioxidant activities. The antimicrobial efficacy was also higher for whole PBH than their respective fractions; however, the zone of inhibition varied significantly (P < 0.05) among different fractions. Results revealed that among enzymes trypsin and alcalase could produce peptides with comparatively higher antimicrobial activity for all tested microbes than papain. The results concluded that porcine blood hydrolysates can be fractioned to get lower molecular weight peptides of interest; however, for addition of whole PBH in meat products or other use could be more useful with regards to its antioxidant, antimicrobial activity and economic production.

Enzyme-Assisted Discovery of Antioxidant Peptides from Edible Marine Invertebrates: A Review

Marine invertebrates, such as oysters, mussels, clams, scallop, jellyfishes, squids, prawns, sea cucumbers and sea squirts, are consumed as foods. These edible marine invertebrates are sources of potent bioactive peptides. The last two decades have seen a surge of interest in the discovery of antioxidant peptides from edible marine invertebrates. Enzymatic hydrolysis is an efficient strategy commonly used for releasing antioxidant peptides from food proteins. A growing number of antioxidant peptide sequences have been identified from the enzymatic hydrolysates of edible marine invertebrates. Antioxidant peptides have potential applications in food, pharmaceuticals and cosmetics. In this review, we first give a brief overview of the current state of progress of antioxidant peptide research, with special attention to marine antioxidant peptides. We then focus on 22 investigations which identified 32 antioxidant peptides from enzymatic hydrolysates of edible marine invertebrates. Strategies adopted by various research groups in the purification and identification of the antioxidant peptides will be summarized. Structural characteristic of the peptide sequences in relation to their antioxidant activities will be reviewed. Potential applications of the peptide sequences and future research prospects will also be discussed.

Antioxidant and functional properties of protein hydrolysates obtained from squid pen chitosan extraction effluent

Squid pens were subjected to alkali hydrolysis to extract chitin and chitosan. Proteins present in the alkaline extraction wastewater were recovered at pH 3, 4, 5 and 6, and were subjected to hydrolysis by trypsin, pepsin and a bacterial protease called HT for 1, 2, 4 and 24h. Hydrolysis of the extracted proteins with either trypsin or HT generated more antioxidant activity than hydrolysis with pepsin. Higher ACE-inhibitory activity was generated in the trypsin and pepsin hydrolysates than in the HT hydrolysate. Squid pen protein recovered from chitosan processing waste alkaline solution can be a potential source of bioactive peptides for addition to foods. The antioxidant and ACE-inhibitory activities of the extracted proteins were initially low and increased upon incubation with the proteases. Pepsin generated significantly lower (P<0.05) antioxidant activities compared to trypsin and HT, while trypsin and pepsin hydrolysates exhibited higher ACE-inhibitory activity than HT (P<0.05).

Enzymes in Fish and Seafood Processing

Enzymes have been used for the production and processing of fish and seafood for several centuries in an empirical manner. In recent decades, a growing trend toward a rational and controlled application of enzymes for such goals has emerged. Underlying such pattern are, among others, the increasingly wider array of enzyme activities and enzyme sources, improved enzyme formulations, and enhanced requirements for cost-effective and environmentally friendly processes. The better use of enzyme action in fish- and seafood-related application has had a significant impact on fish-related industry. Thus, new products have surfaced, product quality has improved, more sustainable processes have been developed, and innovative and reliable analytical techniques have been implemented. Recent development in these fields are presented and discussed, and prospective developments are suggested.

Valorization of tomato waste proteins through production of antioxidant and antibacterial hydrolysates by proteolytic Bacillus subtilis: optimization of fermentation conditions

In this study, protein-rich waste of tomato processing industries was fermented by Bacillus subtilis A14h to produce hydrolysates with antioxidant and antibacterial activities. The effects of different levels of initial pH, incubation temperature, fermentation time, protein concentration and inoculum size on proteolytic activity, release of amino acids and peptides, antioxidant and antibacterial activities of hydrolysates were evaluated and optimized by using response surface methodology (RSM). Results showed that all the evaluated variables significantly influenced the hydrolysis and bioactivities of hydrolysates in polynomial models. Hydrolysates showed remarkable 2, 2'-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity (up to 70 %), ferric ion reducing power, and inhibitory activity against B. cereus (up to 69.8 %) and E. coli (up to 29.8 %). Overall, good correlation between the concentration of amino acids and peptides, and antioxidant as well as antibacterial activities (in particular for B. cereus inhibition activity) was observed. Finally, optimum conditions for fermentative conversion of tomato waste proteins to antioxidant and antibacterial hydrolysates were established. Results of this study showed that tomato waste protein can be valorized to produce antioxidant and antibacterial hydrolysates in a fermentative system using B. subtilis A14h.

Antioxidant activities and functional properties of enzymatic protein hydrolysates from defatted Camellia oleifera seed cake

Seed cake protein (SCP) from Camellia oleifera was hydrolyzed by five commercial proteases (Flavorzyme, Trypsin, Neutrase, Papain, Alcalase). Amino acid composition, molecular weight distribution, antioxidant activity and functional property of the seed cake protein hydrolysates (SCPH) were investigated. Enzymatic hydrolysis improved protein solubility significantly but impaired the foaming and emulsifying property. Hydrolysate generated by alcalase had the highest hydrolysis degree (DH) and antioxidant activity, and displayed excellent protein solubility over wide range of pH, while hydrolysate prepared by flavorzyme showed better copper chelating capacity and emulsifying stability with low molecular weight distribution. Trypsin-treated SCPH showed better foaming property than original protein. The results indicated that enzyme type greatly influenced the molecular weight, functional property and antioxidant activity of SCPH. It was also found that electing appropriate protease and controlling the DH could be enhanced or reduced functional property according to actual applications.

Marine protein hydrolysates: their present and future perspectives in food chemistry – a review

Marine protein hydrolysates are usually prepared by the enzymatic digestion with different proteases at controlled pH and temperature.

Pilot-scale production of soybean oligopeptides and antioxidant and antihypertensive effects in vitro and in vivo

Soybean oligopeptides (SOP) with low molecular weights were prepared by two-step enzymatic hydrolysis on a pilot-scale. Peptide and free amino acid contents of SOP were 82.5 ± 1.13 % and 3.7 ± 0.28 % respectively. The molecular weight distribution of SOP was mainly bellow 1,000 Da (85.4 %), 56.7 % of which were 140-500 Da. SOP showed strong stability to proteolytic digestion by pepsin and trypsin. The antioxidant activities and in vitro and in vivo antihypertensive effects of SOP were evaluated. Results showed that SOP exhibited 1,1-diphenyl-2-picrylhydrazyl radical scavenging effect (IC50 = 4.5 ± 0.13 mg/mL), and significantly inhibited lipid peroxidation in linoleic acid oxidation system (IC50 = 1.2 ± 0.09 mg/mL). SOP had potent angiotensin I-converting enzyme inhibitory activity (IC50 = 1.1 ± 0.06 mg/mL), and antihypertensive effect in spontaneously hypertensive rats at a dose of 200 mg/kg. This study indicated that SOP could be a natural antioxidative or antihypertensive compound in the medicine and food industries.

Effects of production factors and egg-bearing period on the antioxidant activity of enzymatic hydrolysates from shrimp (Pandalopsis dispar) processing byproducts

The effects of production factors (protease used, percent enzyme, hydrolysis time, and water-to-substrate ratio) on the antioxidant activity of hydrolysates produced from shrimp processing byproducts (SPB) were assessed using Taguchi's L16 (4(5)) fractional factorial design. SPB hydrolysates showed excellent ABTS radical scavenging activity, metal ion chelating capacity, and inhibition of lipid peroxidation, but weak DPPH radical scavenging activity and ferric ion reducing antioxidant power. The protease used significantly influenced antioxidant activities while hydrolysis time and percent enzyme affected radical scavenging activities and inhibition of lipid peroxidation, respectively. Differences in the lipid and amino acid contents observed between SPB collected early and late in the egg-bearing period may have contributed to the slight variance in antioxidant activities displayed by their hydrolysates. Nevertheless, SPB hydrolysates produced using Alcalase or Protamex had high antioxidant activity regardless of production factors and egg-bearing period.

Bioactive peptides and depsipeptides with anticancer potential: sources from marine animals

Biologically active compounds with different modes of action, such as, antiproliferative, antioxidant, antimicrotubule, have been isolated from marine sources, specifically algae and cyanobacteria. Recently research has been focused on peptides from marine animal sources, since they have been found as secondary metabolites from sponges, ascidians, tunicates, and mollusks. The structural characteristics of these peptides include various unusual amino acid residues which may be responsible for their bioactivity. Moreover, protein hydrolysates formed by the enzymatic digestion of aquatic and marine by-products are an important source of bioactive peptides. Purified peptides from these sources have been shown to have antioxidant activity and cytotoxic effect on several human cancer cell lines such as HeLa, AGS, and DLD-1. These characteristics imply that the use of peptides from marine sources has potential for the prevention and treatment of cancer, and that they might also be useful as molecular models in anticancer drug research. This review focuses on the latest studies and critical research in this field, and evidences the immense potential of marine animals as bioactive peptide sources.