Towards generation of bioactive peptides from meat industry waste proteins: Generation of peptides using commercial microbial proteases

Hydrolyzing collagen by extracellular protease Hap of Aeromonas salmonicida: Turning chicken by-products into bioactive resources

Collagen-rich meat processing by-products have potential utilization value. Extracellular protease Hap from meat-borne Aeromonas salmonicida has been identified as an ideal protease for hydrolyzing collagen. Here, to explore the possible application of Hap for giving chicken by-products a high added value, the hydrolysis ability and mechanism were investigated. With a Vmax of 31.9 μg/mL/min and a Km of 1.18 mg/mL, Hap demonstrated obvious substrate specificity to pepsin-solubilized collagen (PSC) derived from chicken by-products, and significantly affected the tertiary structure and microstructure of PSC. Hap was found to preferentially cleave the peptide bond between Gly-X by peptide release kinetics, attacking from two ends to the middle region for α1 chain. Sixteen peptides are anticipated to be non-toxic with twenty potential biological activities at the end of hydrolysis. These observations will enrich the collagen hydrolysis mechanism of protease secreted by meat-borne bacteria and provide new insights into the utilization of meat by-products.

Antifungal peptides from living organisms

In the post-COVID-19 era, people are increasingly concerned about microbial infections, including fungal infections that have risen in recent years. However, the currently available antifungal agents are rather limited. Worse still, the widespread use of the antifungal agents has caused the emergence of antifungal resistance in Candida, Cryptococcus, and Aspergillus species. Therefore, the development of novel antifungals is urgently needed. Antimicrobial peptides (AMPs), as components of the first-line defense of the host, are found to exhibit broad antimicrobial activity against bacteria, fungi, parasites, viruses, and protozoa. AMPs with antifungal activity are specifically referred to as antifungal peptides (AFPs). AFPs are currently regarded as the most promising alternative to conventional antifungal agents due to the fact that they are highly selective and less prone to facilitate the selection of drug resistance. In this review, we present an overview of the origin and classification of natural AFPs as well as their modes of action. Additionally, the production of natural, semisynthetic, and synthetic AFPs with a view to greater levels of exploitation is discussed. Finally, we evaluate the current and potential applications of AFPs in clinics and in the food industry.

Angiotensin converting enzyme inhibitory hydrolysate and peptide fractions from chicken skin collagen, as modulators of lipid accumulation in adipocytes 3 T3-L1, after in vitro gastrointestinal digestion

Inhibitory activity against angiotensin-converting enzyme (IAACE) by chicken skin collagen hydrolysate (CSCH) and their peptide fractions before and after in-vitro gastrointestinal digestion, were evaluated; as well as their ability to modulate lipid accumulation in 3 T3-L1 adipocytes. Before digestion, peptide fraction <1 kDa (F4) showed the highest IAACE (p < 0.05) followed by CSCH. After these samples were digested, F4 presented an IAACE with IC50 similar to its digest (DF4) (188.84 and 220.03 μg/mL, respectively), which was 2-fold lower (p < 0.05) than IC50 of fraction <1 kDa from post-digested hydrolysate (FDH) (388.57 μg/mL). Nine peptides were identified as the potential ACE inhibitors in F4 and DF4. Addition of DF4 (800 μg/mL) reduced(p < 0.05) lipid accumulation by 83% within preadipocytes. A 45-60% reduction of lipid accumulation within differentiated adipocytes was obtained by adding FDH and DF4 (regardless the concentration). These results, digested CSCH and F4 with IAACE may be considered as potential adjuvants for obesity treatment.

Anti-fungal peptides: an emerging category with enthralling therapeutic prospects in the treatment of candidiasis

Candida infections, particularly invasive candidiasis, pose a serious global health threat. Candida albicans is the most prevalent species causing candidiasis, and resistance to key antifungal drugs, such as azoles, echinocandins, polyenes, and fluoropyrimidines, has emerged. This growing multidrug resistance (MDR) complicates treatment options, highlighting the need for novel therapeutic approaches. Antifungal peptides (AFPs) are gaining recognition for their potential as new antifungal agents due to their diverse structures and functions. These natural or recombinant peptides can effectively target fungal virulence and viability, making them promising candidates for future antifungal development. This review examines infections caused by Candida species, the limitations of current antifungal treatments, and the therapeutic potential of AFPs. It emphasizes the importance of identifying novel AFP targets and their production for advancing treatment strategies. By discussing the therapeutic development of AFPs, the review aims to draw researchers' attention to this promising field. The integration of knowledge about AFPs could pave the way for novel antifungal agents with broad-spectrum activity, reduced toxicity, targeted action, and mechanisms that limit resistance in pathogenic fungi, offering significant advancements in antifungal therapeutics.

Investigation of Antioxidant Activity of Protein Hydrolysates from New Zealand Commercial Low-Grade Fish Roes

The objective of this study was to investigate the nutrient composition of low-grade New Zealand commercial fish (Gemfish and Hoki) roe and to investigate the effects of delipidation and freeze-drying processes on roe hydrolysis and antioxidant activities of their protein hydrolysates. Enzymatic hydrolysis of the Hoki and Gemfish roe homogenates was carried out using three commercial proteases: Alcalase, bacterial protease HT, and fungal protease FP-II. The protein and lipid contents of Gemfish and Hoki roes were 23.8% and 7.6%; and 17.9% and 10.1%, respectively. The lipid fraction consisted mainly of monounsaturated fatty acid (MUFA) in both Gemfish roe (41.5%) and Hoki roe (40.2%), and docosahexaenoic (DHA) was the dominant polyunsaturated fatty acid (PUFA) in Gemfish roe (21.4%) and Hoki roe (18.6%). Phosphatidylcholine was the main phospholipid in Gemfish roe (34.6%) and Hoki roe (28.7%). Alcalase achieved the most extensive hydrolysis, and its hydrolysate displayed the highest 2,2-dipheny1-1-picrylhydrazyl (DPPH)˙ and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities and ferric reducing antioxidant power (FRAP). The combination of defatting and freeze-drying treatments reduced DPPH˙ scavenging activity (by 38%), ABTS˙ scavenging activity (by 40%) and ferric (Fe3+) reducing power by18% (p < 0.05). These findings indicate that pre-processing treatments of delipidation and freeze-drying could negatively impact the effectiveness of enzymatic hydrolysis in extracting valuable compounds from low grade roe.

Application of experimental design as a statistical approach to recover bioactive peptides from different food sources

Bioactive peptides (BAPs) derived from samples of animals and plants have been widely recommended and consumed for their beneficial properties to human health and to control several diseases. This work presents the applications of experimental designs (DoE) used to perform factor screening and/or optimization focused on finding the ideal hydrolysis condition to obtain BAPs with specific biological activities. The collection and discussion of articles revealed that Box Behnken Desing and Central Composite Design were the most used. The main parameters evaluated were pH, time, temperature and enzyme/substrate ratio. Among vegetable protein sources, soy was the most used in the generation of BAPs, and among animal proteins, milk and shrimp stood out as the most explored sources. The degree of hydrolysis and antioxidant activity were the most investigated responses in obtaining BAPs. This review brings new information that helps researchers apply these DoE to obtain high-quality BAPs with the desired biological activities.

Metabolizable Energy and Amino Acid Digestibility of Soybean Meal from Different Sources for Broiler Chickens Supplemented with Protease

This study investigated the effect of the serine protease on metabolizable energy and amino acids' digestibility of different soybean meal for broilers. A total of 684 broilers chickens form 14 to 23 d age were distributed with nineteen treatments, six replicates, and six birds per replicate. Nine samples of soybean meal from different regions in Brazil were used, with some samples supplemented with the protease enzyme and others without addition. Apparent and corrected-for-nitrogen-balance metabolizable energy were evaluated, as well as the coefficients of amino acid digestibility. All collected data were submitted to ANOVA at a significance level of 5% and Tukey's test was applied. The results showed that the addition of the protease enzyme significantly increased the values of AME and AMEn in all soybean meal samples. The soybean meal of different origins has significant variations in AME and AMEn. The addition of the protease improved the digestibility of essential amino acids compared to soybean meal without enzyme addition. These results indicate that supplementation with serine protease can improve the metabolizable energy and amino acid digestibility of soybean meal from different regions in the diet of broilers, potentially being an effective strategy to enhance nutrient utilization and animal performance.

Identification of the Bioavailable Peptidome of Chia Protein Hydrolysate and the In Silico Evaluation of Its Antioxidant and ACE Inhibitory Potential

The incorporation of novel, functional, and sustainable foods in human diets is increasing because of their beneficial effects and environmental-friendly nature. Chia (Salvia hispanica L.) has proved to be a suitable source of bioactive peptides via enzymatic hydrolysis. These peptides could be responsible for modulating several physiological processes if able to reach the target organ. The bioavailable peptides contained in a hydrolysate obtained with Alcalase, as functional foods, were identified using a transwell system with Caco-2 cell culture as the absorption model. Furthermore, 20 unique peptides with a molecular weight lower than 1000 Da and the higher statistical significance of the peptide-precursor spectrum match (-10 log P) were assessed by in silico tools to suggest which peptides could be those exerting the demonstrated bioactivity. From the characterized peptides, considering the molecular features and the results obtained, the peptides AGDAHWTY, VDAHPIKAM, PNYHPNPR, and ALPPGAVHW are anticipated to be contributing to the antioxidant and/or ACE inhibitor activity of the chia protein hydrolysates.

Identification, in silico selection, and mechanism study of novel antioxidant peptides derived from the rice bran protein hydrolysates

The work aimed to assess the antioxidant ability and obtain a new antioxidant peptide from rice bran protein. Rice bran protein was hydrolyzed by Alcalase, Neutral, Pepsin, Chymotrypsin, and Trypsin, separately. Trypsin hydrolysate (T-RBPH) showed high Fe²⁺ chelating activity (IC₅₀, 2.271 ± 0.007 mg/mL), DPPH and hydroxyl radical scavenging ability (IC₅₀, 0.191 ± 0.006 and 1.038 ± 0.034 mg/mL). Moreover, T-RBPH could alleviate the H₂O₂-induced oxidative damage in Caco-2. The T-RBPH was purified and identified by UF, GF, FPLC, and LC-MS/MS. Finally, 9-amino acid peptide-AFDEGPWPK with low molecular weight (1045.48 Da), high antioxidant activity, good safety, and solubility was screened by in silico method and chemical oxidation determination, and its interaction with Keap1 was also demonstrated. The ORAC and DPPH radical scavenging ability of AFDEGPWPK were 44.16 ± 0.79 and 28.38 ± 0.14 μmol TE/mM. Moreover, the Molecular docking and Western blot (WB) results showed that AFDEGPWPK could enter the binding pocket in the Kelch domain and activate Keap1/Nrf2/HO-1 pathway.

Use of fungal and bacterial protease preparations to enhance extraction of lipid from fish roe: effect on lipidomic profile of extracted oil

•

Lipid extraction of fish roe was evaluated after hydrolysis with HT, FP-II and Alcalase proteases.

•

Alcalase hydrolysis of fish roe protein was more extensive than that of HT and FP-II.

•

The highest total lipid yield was obtained following hydrolysis of fish roe with Alcalase.

•

Alcalase hydrolysis achieved the greatest degree of hydrolysis and yielded less oxidised lipid.

•

The yield of omega-3 fatty acids and phospholipids was highest after HT hydrolysis.

The present study investigated the hydrolysis of protein in hoki roe homogenate using a HT (bacterial), a FP-II (fungal) protease preparations and Alcalase (bacterial) to enhance lipid yield extraction. The degree of hydrolysis was determined at various pH, temperature and time using casein and hoki roe. Total lipid extraction and lipidomic analysis was carried out following proteolysis of hoki roe homogenate. The degree of hydrolysis and SDS-PAGE revealed that the hydrolytic capability of Alcalase was better than HT and FPII. The total extracted lipid yield was better following hydrolysis with Alcalase (19.29 %), compared to HT (18.29 %) and FPII (18.33 %). However, the total phospholipid (PL) and n-3 fatty acid yields were better from HT hydrolysed hoki roe homogenate (PL = 30.7 μmol/g; n-3 = 10.5 %), compared to Alcalase (PL = 22 μmol/g; n-3 = 5.95 %). Overall, this study indicates that HT protease preparation hydrolysis of fish roe homogenate can both enhance lipid extraction and retain lipid quality.

In Silico Analysis of Bioactive Peptides Produced from Underutilized Sea Cucumber By-Products-A Bioinformatics Approach

Bioinformatic tools are widely used in predicting potent bioactive peptides from food derived materials. This study was focused on utilizing sea cucumber processing by-products for generating antioxidant and ACE inhibitory peptides by application of a range of in silico techniques. Identified peptides using LC-MS/MS were virtually screened by PepRank technique followed by in silico proteolysis simulation with representative digestive enzymes using BIOPEP-UWMTM data base tool. The resultant peptides after simulated digestion were evaluated for their toxicity using ToxinPred software. All digestive resistance peptides were found to be non-toxic and displayed favorable functional properties indicating their potential for use in a wide range of food applications, including hydrophobic and hydrophilic systems. Identified peptides were further assessed for their medicinal characteristics by employing SwissADME web-based application. Our findings provide an insight on potential use of undervalued sea cucumber processing discards for functional food product development and natural pharmaceutical ingredients attributed to the oral drug discovery process.

Peptidomics as a useful tool in the follow-up of food bioactive peptides

There is an intense research activity on bioactive peptides derived from food proteins in view of their health benefits for consumers. However, their identification is quite challenging as a consequence of their small size and low abundance in complex matrices such as foods or hydrolyzates. Recent advances in peptidomics and bioinformatics are getting improved sensitivity and accuracy and therefore such tools are contributing to the development of sophisticated methodologies for the identification and quantification of peptides. These developments are very useful for the follow-up of peptides released through proteolysis either in the food itself through the action of endogenous peptidases during processing stages like fermentation, drying or ripening, or from food proteins hydrolyzed by commercial peptidases or microorganisms with proteolytic activity. This chapter is presenting the latest advances in peptidomics and its use for the identification and quantification of peptides, and as a useful tool for controlling the proteolysis phenomena in foods and protein hydrolyzates.

Conventional and in silico approaches to select promising food-derived bioactive peptides: A review

•

Seaweed and edible insects are considered new sources of bioactive peptides.

•

Conventional approaches are necessary to validate the bioactivity of peptides.

•

Bioinformatics tools accelerate the obtaining of bioactive peptides.

•

The integrated approach is a promising strategy to obtain bioactive peptides.

The interest for food-derived bioactive peptides, either from common or unconventional sources, has increased due to their potential therapeutic effect against a wide range of diseases. The study of such bioactive peptides using conventional methods is a long journey, expensive and time-consuming. Hence, bioinformatic approaches, which can not only help to predict the formation of bioactive peptides from any known protein source, but also to analyze the protein structure/function relationship, have gained a new meaning in this scientific field. Therefore, this review aims to provides an overview of conventional characterization methods and the most recent advances in the field of in silico approaches for predicting and screening promising food-derived bioactive peptides.

Investigation of Microbial Hydrolysis of Hen Combs with Bacterial Concentrates

When slaughtering and processing poultry, large quantities of meat by-products are generated; therefore, the development of the newest methods for processing secondary raw materials is an urgent problem. Animal proteins have relevant technological applications and are also considered as a potential source of bioactive peptides. Current technologies suggested that protein substances can be isolated from meat co-products through microbial hydrolysis. The purpose of the study was to optimize the technological parameters of microbial hydrolysis of hen combs and to analyze the modification of the microstructure and properties of hydrolyzed by-products under the action of bacterial enzymes. Hen’s combs were hydrolyzed by bifidobacteria and concentrated Propionix liquid. A multifactorial experiment was used to determine the optimal conditions for the hydrolysis process. As a result of the study, multiple regression equations and response surfaces were obtained, which describe the process of hydrolysis of hen combs to identify the optimal hydrolysis parameters. Temperature, amount of bacterial concentrate and hydrolysis period are factors that have a significant impact on the degree of hydrolysis. The results of microscopic and dispersed analysis confirm the good hydrolyzability of combs due to changes in structural components and an increase in the amount of smaller protein particles.

Enzymatic hydrolysis and microbial fermentation: The most favorable biotechnological methods for the release of bioactive peptides

•

Peptide release methods influence its bioactivity by generating different sequences.

•

The absorption, toxicity and taste of peptides is influenced by the production method.

•

The most used methods are enzymatic hydrolysis and microbial fermentation.

•

The most used methods are biotechnological and differ in their process.

Bioactive peptides are biomolecules derived from proteins. They contain anywhere from 2 to 20 amino acids and have different bioactivities. For example, they have antihypertensive activity, antioxidant activity, antimicrobial activity, etc. However, bioactive peptides are encrypted and inactive in the parental protein, so it is necessary to release them to show their bioactivity. For this, there are different methods, where biotechnological methods are highly favorable, highlighting enzymatic hydrolysis and microbial fermentation.

The choice of the method to be used depends on different factors, which is why it is essential to know about the process, its principle, and its advantages and disadvantages. The process of peptide release is critical to generate various peptide sequences, which will produce different biological effects in the hydrolysate. This review focuses on providing extensive information on the enzymatic method and microbial fermentation to facilitate selecting the method that provides the most benefits.

A Review on Extraction, Characterization, and Applications of Bioactive Peptides From Pressed Black Cumin Seed Cake

Plenty of black cumin cake was generated as a natural waste material after pressing the oil. Nigella sativa (black cumin) seeds and cakes are of precious nutritional value as they contain proteins, phenolics, essential amino acids, and bioactive compounds. Owing to their antioxidant properties, scientists and food manufacturers have extensively developed them. Notably, global awareness among consumers about the benefits of innovative food ingredients has been increased. Meanwhile, it has to be noted that vast amounts of cake by-products are not effectively utilized, which might cause economic loss and environmental consequences. This review aimed to highlight the antioxidant abilities, extraction, characterization, functional characteristics, and utilization of active peptides acquired from black seed oil cake. This overview would critically evaluate black seed cake proteins, plentiful in bioactive peptides that might be utilized as valuable additives in feed, food, pharmaceutical, and cosmetic industries. The addition of bioactive peptides to restrain the oxidation of fat-based products and preserve food safety is also addressed.

Functional Meat Products as Oxidative Stress Modulators: A Review

High meat consumption has been associated with increased oxidative stress mainly due to the generation of oxidized compounds in the body, such as malondialdehyde, 4-hydroxy-nonenal, oxysterols, or protein carbonyls, which can induce oxidative damage. Meat products are excellent matrices for introducing different bioactive compounds, to obtain functional meat products aimed at minimizing the pro-oxidant effects associated with high meat consumption. Therefore, this review aims to summarize the concept and preparation of healthy and functional meat, which could benefit antioxidant status. Likewise, the key strategies regarding meat production and storage as well as ingredients used (e.g., minerals, polyphenols, fatty acids, walnuts) for developing these functional meats are detailed. Although most effort has been made to reduce the oxidation status of meat, newly emerging approaches also aim to improve the oxidation status of consumers of meat products. Thus, we will delve into the relation between functional meats and their health effects on consumers. In this review, animal trials and intervention studies are discussed, ascertaining the extent of functional meat products' properties (e.g., neutralizing reactive oxygen species formation and increasing the antioxidant response). The effects of functional meat products in the frame of diet-gene interactions are analyzed to 1) discover target subjects that would benefit from their consumption, and 2) understand the molecular mechanisms that ensure precision in the prevention and treatment of diseases, where high oxidative stress takes place. Long-term intervention-controlled studies, testing different types and amounts of functional meat, are also necessary to ascertain their positive impact on degenerative diseases.

Management of meat by- and co-products for an improved meat processing sustainability

Large amounts of meat by- and co-products are generated during slaughtering and meat processing, and require rational management of these products for an ecological disposal. Efficient solutions are very important for sustainability and innovative developments create high added-value from meat by-products with the least environmental impact, handling and disposal costs, in its transition to bioeconomy. Some proteins have relevant technological uses for gelation, foaming and emulsification while protein hydrolyzates may contribute to a better digestibility and palatability. Protein hydrolysis generate added-value products such as bioactive peptides with relevant physiological effects of interest for applications in the food, pet food, pharmaceutical and cosmetics industry. Inedible fats are increasingly used as raw material for the generation of biodiesel. Other applications are focused on the development of new biodegradable plastics that can constitute an alternative to petroleum-based plastics. This manuscript presents the latest developments for adding value to meat by- and co-products and discusses opportunities for making meat production and processing more sustainable.

Bioactivities generated from meat proteins by enzymatic hydrolysis and the Maillard reaction

Bioactive peptides are released from meat proteins by enzymatic hydrolysis (i.e., gastrointestinal digestion, aging/storage, fermentation, and protease treatment). Such peptides attribute physiological functions to meat and meat products and are promising food ingredients for developing functional foods. Meat by-products (e.g., blood and collagen) are also good sources for generating bioactive peptides, since they are produced in large quantities and are rich in proteins. Although protein-derived bioactive peptides are attractive ingredients, their changes by the Maillard reaction during processing, cooking, and storage should be investigated. This article briefly reviews the production of bioactive peptides from meat and meat by-products. Such diverse peptides affects circulatory, nervous, alimentary, and immune systems. Then, the bioactivities of Maillard reaction products (MRPs) generated from protein hydrolysates are discussed. Special attention is paid to bioactivities of 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) inhalation. As such activities, we have evaluated the impact of DMHF on blood pressure, moods, brainwaves, and dietary intake. Our efforts for understanding various aspects and implication of peptides and MRPs from meat proteins would open new avenues in the meat and food industry.

Oral delivery of self-assembling bioactive peptides to target gastrointestinal tract disease

Peptides are known for their diverse bioactivities including antioxidant, antimicrobial, and anticancer activity, all three of which are potentially useful in treating colon-associated diseases. Beside their capability to stimulate positive health effects once released in the body, peptides are able to form useful nanostructures such as hydrogels. Combining peptide bioactivity and peptide gel-forming potentials can create interesting systems that can be used for oral delivery. This combination, acting as a two-in-one system, has the potential to avoid the need for delicate entrapment of a drug or natural bioactive compound. We here review the context and research progress, to date, in this area.

The role of protein hydrolysates for exercise-induced skeletal muscle recovery and adaptation: a current perspective

The protein supplement industry is expanding rapidly and estimated to have a multi-billion market worth. Recent research has centred on understanding how the manufacturing processes of protein supplements may impact muscle recovery and remodeling. The hydrolysed forms of protein undergo a further heating extraction process during production which may contribute to amino acids (AA) appearing in circulation at a slightly quicker rate, or greater amplitude, than the intact form. Whilst the relative significance of the rate of aminoacidemia to muscle protein synthesis is debated, it has been suggested that protein hydrolysates, potentially through the more rapid delivery and higher proportion of di-, tri- and smaller oligo-peptides into circulation, are superior to intact non-hydrolysed proteins and free AAs in promoting skeletal muscle protein remodeling and recovery. However, despite these claims, there is currently insufficient evidence to support superior muscle anabolic properties compared with intact non-hydrolysed proteins and/or free AA controls. Further research is warranted with appropriate protein controls, particularly in populations consuming insufficient amounts of protein, to support and/or refute an important muscle anabolic role of protein hydrolysates. The primary purpose of this review is to provide the reader with a current perspective on the potential anabolic effects of protein hydrolysates in individuals wishing to optimise recovery from, and maximise adaptation to, exercise training.

Valorized Food Processing By-Products in the EU: Finding the Balance between Safety, Nutrition, and Sustainability

Food businesses in the European Union are preparing for a carbon-neutral future by gradually transitioning to a circular way of operating. Building upon results from the EU REFRESH project, we consider the most valuable food processing by-streams in Europe and discuss potential food safety risks that must be considered while valorizing them for human consumption. These risks are weighed against the nutritional benefits offered by these products and their potential applications in food supply chains. Broadly, we examine whether it is possible for spent grains, cheese whey, fruit and vegetable scraps, meat processing waste, and oilseed cakes and meals to be safe, sustainable, and nutritionally valuable at the same time. The discussion highlights that valorizing by-products obtained from food processing operations is feasible on a large scale only if consumers deem it to be a safe and acceptable practice. Extracting valuable compounds from by-products and using them in the preparation of functional foods could be a way to gain consumer acceptance. Furthermore, we find that current EU food safety legislation does not sufficiently accommodate food processing by-products. A way to bridge this regulatory gap could be through the adoption of private food safety standards that have shown proclivity for sustainability-related issues in food supply chains. Finally, by proposing a decision tree, we show that it is indeed feasible for some food processing by-products to be valorized while ensuring sustainability, food safety, and nutritional relevance.

Enzymatic Digestion of Calf Fleshing Meat By-Products: Antioxidant and Anti-Tyrosinase Activity of Protein Hydrolysates, and Identification of Fatty Acids

The food waste reduction through an efficient recovery of its valuable building molecules has become an important topic with a positive effect on the economy and the environment. In this work, the revalorization of slaughterhouse calf fleshing meat through its enzymatic hydrolysis is proposed. The proteolytic activity of 11 enzymes was initially screened and the four most efficient enzymes (papain, trypsin, pancreatin, and bromelain) were selected. The molecular profiling of the different protein/peptide fractions by the Linear Trap Quadrupole-OrbiTrap technique showed compositional differences due to the specificity of the enzymes’ cleavage sites. In order to find a potential reuse of these hydrolysates, the analysis of antioxidant and, for the first time on fleshing meat hydrolysates, of anti-tyrosinase activities, was performed. Papain-digested samples were those showing the highest inhibition activity of tyrosinase enzyme (55.6%) as well as the highest antioxidant activity (3.52 g TEAC/L). In addition, the composition analysis of the lipid fraction was performed. The mono-unsaturated fatty acids resulted to be the most abundant lipid in all the samples with the exception of pancreatin-treated hydrolysates in which poly-unsaturated fatty acids were predominant. The present results seemed to support a possible valorization of isolated fractions from calf fleshing by-products, as food or feed ingredients, by the implementation of fraction isolation within the meat-processing pipeline.

FermFooDb: A database of bioactive peptides derived from fermented foods

Globally fermented foods are in demands due to their functional and nutritional benefits. These foods are sources of probiotic organisms and bioactive peptides, various amino acids, enzymes etc. that provides numerous health benefits. FermFooDb (https://webs.iiitd.edu.in/raghava/fermfoodb/) is a manually curated database of bioactive peptides derived from wide range of foods that maintain comprehensive information about peptides and process of fermentation. This database comprises of 2205 entries with following major fields, peptide sequence, Mass and IC50, food source, functional activity, fermentation conditions, starter culture, testing conditions of sequences in vitro or in vivo, type of model and method of analysis. The bioactive peptides in our database have wide range of therapeutic potentials that includes antihypertensive, ACE-inhibitory, antioxidant, antimicrobial, immunomodulatory and cholesterol lowering peptides. These bioactive peptides were derived from different types of fermented foods that include milk, cheese, yogurt, wheat and rice. Numerous, web-based tools have been integrated to retrieve data, peptide mapping of proteins, similarity search and multiple-sequence alignment. This database will be useful for the food industry and researchers to explore full therapeutic potential of fermented foods from specific cultures.

Enzymatic hydrolysis of black cricket (Gryllus assimilis) proteins positively affects their antioxidant properties

The development of innovative ingredients through biotechnological routes has established insect proteins as an emerging source of bioactive peptides. The current study aimed to evaluate the antioxidant properties of black cricket (Gryllus assimilis) protein hydrolysates produced using the proteases Flavourzyme^TM 500L, Alcalase^TM 2.4L, and Neutrase^TM 0.8L, either individually or in binary/ternary combinations. The enzymatic hydrolysis promoted an increase of approximately 160% in total antioxidant capacity and 93% in the ferric reducing antioxidant power. The isolated use of the enzyme Flavourzyme^TM 500L showed the most prominent positive effect on the antioxidant properties, presenting an IC₅₀ value of 455 and 71 µg/mL for DPPH and ABTS radicals scavenging activities, respectively. This sample was composed mainly of small peptides (MW < 3 kDa), in which the antioxidant properties increased after fractionation by ultrafiltration. Gel electrophoresis analysis showed protein hydrolysates composed mainly of polypeptide chains with a mass of less than 14 kDa. Finally, the enzymatic treatment proved to be an efficient process to improve the antioxidant properties of black cricket proteins, increasing the possibility of applying these hydrolysates as bioactive ingredients in food or nutraceutical products. PRACTICAL APPLICATION: Insects represent an alternative source of proteins. Their modification through hydrolysis allows for the acquisition of compounds with great potential in industrial applications, such as functional ingredients or for nutraceutical purposes. The use of our experimental design proved to be an adequate tool for defining the best process conditions required for increasing the attainment of biologically active compounds.

Effects of periodical application of bioactive peptides derived from cottonseed on performance, immunity, total antioxidant activity of serum and intestinal development of broilers

This experiment aimed to examine the effect of periodical application of bioactive peptides derived from cottonseed (BPC) in comparison with using sub-therapeutic doses of lincomycin and the excessive inclusion of vitamin E on performance, immunity, total antioxidant capacity of serum and intestinal morphology of broiler chickens. A total of 240 one-d-old male broiler chicks with similar initial weight (Ross strain) were randomly assigned to 6 groups (8 chicks/pen): non-treated group (basal diet), basal diet supplemented with 2 mg/kg lincomycin, basal diet supplemented with 50 IU vitamin E, basal diet supplemented with 6 g BPC/kg in starter period, basal diet supplemented with 6 g BPC/kg in starter and grower periods and basal diet supplemented with 6 g BPC/kg throughout the whole experiment. The highest final body weight was obtained in the group supplemented with BPC in starter and grower periods. In the finisher phase, broilers fed the diet containing BPC in the starter period and in the whole trial had significantly (P < 0.05) better feed conversion ratios (FCR). Jejunal villus height was significantly elevated in broilers supplemented with antibiotic (P < 0.001), furthermore it tended to be greater in broilers fed BPC in the starter period. The jejunal villus height-to-crypt depth ratio was significantly (P < 0.01) higher in broilers fed the diet containing antibiotic in comparison to other groups. Humoral immune response against Newcastle disease vaccine tended to be elevated in broilers fed the diet containing BPC in the whole trial (P > 0.05). Broilers supplemented with BPC in starter and grower, and in the whole trial had significantly (P < 0.05) higher antibody titers against sheep red blood cells (SRBC). The highest total antioxidant capacity was obtained in broilers supplemented with the excessive level of vitamin E, furthermore it tended to improve in broilers fed the diet containing BPC in the whole trial. In summary, the results of the study indicated that addition of BPC in broiler diets in the whole trial could improve FCR, immune responses and total antioxidant activity of serum, and BPC could be used in broiler diets as an alternative to in-feed antibiotics.

Insetos comestíveis como potenciais fontes de proteínas para obtenção de peptídeos bioativos

Resumo O consumo de insetos como uma fonte alternativa de proteínas é considerado uma tendência futura e uma estratégia viável, com potencial notório para garantia do fornecimento de alimentos em nível global. Os insetos são uma fonte não convencional de proteínas, seja para consumo humano direto ou indiretamente, como ingredientes em alimentos formulados. Além disso, estudos científicos têm demonstrado que a hidrólise enzimática destas proteínas resulta na produção de peptídeos com atividades biológicas de grande interesse, como atividade antioxidante, antidiabética, anti-hipertensiva e antimicrobiana. O uso desses peptídeos com fim nutracêutico pode substituir ou reduzir o uso de drogas sintéticas, as quais estão associadas a efeitos colaterais indesejáveis. O presente trabalho teve como objetivo abordar o uso de insetos na alimentação humana, destacando sua aplicação como substrato proteico na hidrólise enzimática para produção de peptídeos bioativos. As principais propriedades bioativas dos peptídeos foram relatadas.

Recent Progress in Enzymatic Release of Peptides in Foods of Animal Origin and Assessment of Bioactivity

There is a wide variety of peptides released from food proteins that are able to exert a relevant benefit for human health, such as angiotensin-converting enzyme inhibition, antioxidant, anti-inflammatory, hypoglucemic, or antithrombotic activity, among others. This manuscript is reviewing the recent advances on enzymatic mechanisms for the hydrolysis of proteins from foods of animal origin, including the types of enzymes and mechanisms of action involved, the strategies followed for the isolation and identification of bioactive peptides through advanced proteomic tools, and the assessment of bioactivity and its beneficial effects. Specific applications in fermented and/or ripened foods where a significant number of bioactive peptides have been reported with relevant in vivo physiological effects on laboratory rats and humans as well as the hydrolysis of animal food proteins for the production of bioactive peptides are also reviewed.

Fatty Acid Profile and Antioxidative Properties of Peptides Isolated from Fermented Lamb Loin Treated with Fermented Milk

This study evaluated the impact of fermented milk maceration on fermented lamb loin without nitrate to obtain peptides with high activity against oxidative changes (ABTS, DPPH, reducing power) as well as a favorable fatty acid profile, including CLA content. Additionally, an attempt was made to evaluate the influence of the lamb breed on the assessed properties. Raw loins (m. Longissimus dorsi) obtained from sheep of three polish breeds—Wrzosówka, Uhruska, and Świniarka—and fermented products were tested. The fermented loins obtained after 14 days of processing were characterized by pH and water activity values in the ranges, respectively, 4.76–5.12 and 0.902–0.915. The maceration of meat in a fermented milk has caused greater acidification of the meat during fermentation. Statistical analysis indicated that treatment was the factor with significant effect on peptide content; no effect of animal breed was found. The peptide content isolated from raw meat ranged from 2.90 to 4.31 mg g⁻¹ of sample, while in fermented meat products it was significant higher (11.59–16.37 mg g⁻¹ of product). The antioxidant properties of peptides were positively correlated with peptides content. The maceration in fermented milk resulted in a statistically significant increase of ABTS value in case of fermented lamb loin of Świniarka breed. The raw meat and fermented meat products form the Świniarka lamb breed were characterized by the highest content of the total CLA isomers. The main CLA isomer found was cis9-trans11 (rumenic acid), followed by cis9-cis11, trans9-trans11, and trans10-cis12. The rumenic acid content was higher than, respectively, 87% and 80–88% of total CLA isomers in case of raw meat and fermented lamb loins of three breeds.

Effect of animal-sourced bioactive peptides on the in vitro development of mouse preantral follicles

The aim of this study was to investigate the effect of bioactive peptides (BAPT) from animal sources on the development of mouse preantral follicles in vitro. Preantral follicles were isolated and randomly divided into the following groups: an untreated group (control) and three groups supplemented with 20, 40 and 60 μg/mL BAPT, respectively. After establishing the in vitro follicle culture, the gene expression levels and hormone levels were quantified. After in vitro maturation, the developmental rates, reactive oxygen species (ROS) production levels and mitochondrial distributions of MII oocytes were investigated, followed by the analyses of embryonic developmental rates after in vitro fertilization.The results showed that BAPT promoted the growth of mouse preantral follicles. Notably, after 14 d of in vitro culture, the levels of 17 β-estradiol and progesterone were up-regulated with BAPT treatments. Moreover, the expression levels of Oct4, Bmp15, GDF9, FOXO3, Zp3, FOXL2, Inhibin alpha, SOD2, Catalase, GPx and Bcl-2 in the developing follicles were significantly up-regulated after BAPT treatments (P < 0.05), while BAPT significantly inhibited the expression levels of BAX (P < 0.05). Following BAPT treatments, the ROS production levels of MII oocytes were decreased while the mitochondrial distributions were significantly enhanced. Furthermore, increased maturation rates, fertilization and embryonic developmental rates were found in these BAPT-treated groups (P < 0.05).These results demonstrated that BAPT significantly improved the development of preantral follicles in vitro by reducing ROS-dependent cellular damages and by enhancing mitochondrial distributions, thereby promoting the further applications of animal-derived BAPT in biomedical research.

Effect of bioactive peptide on ram semen cryopreservation

This present study investigated the effect of bioactive peptide (BAPT) (BAPT) on the quality of ram semen during cryopreservation. Ram ejaculates were extended with Tris buffer supplemented with no antioxidants (as control group), 20 μg/mL BAPT (as BAPT20 group), 40 μg/mL BAPT (as BAPT40 group) and 60 μg/mL BAPT (as BAPT60 group). After cryopreservation, sperm quality including motility, vitality, the percentage of hypoosmotic swelling test (HOST)-positive spermatozoa and the percentage of intact acrosomes was assessed. Furthermore, the malondialdehyde (MDA) in seminal plasma and spermatozoa were analyzed, followed by the measurement of superoxide dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GSH-Px) levels in seminal plasma. After in vitro fertilization, the embryonic cleavage rates and development rates of different groups were analyzed to compare the developmental abilities of spermatozoa. The results showed that the post-thaw sperm motility was significantly higher in the BAPT60 group compared to those in the BAPT20, BAPT40 and control groups (P < 0.05). The percentage of live sperms significantly increased from 48.12 ± 2.35% for the BAPT20 group, 55.43 ± 2.16% for the BAPT40 group to 57.53 ± 3.15% for the BAPT60 group. The percentage of HOST-positive spermatozoa was significantly higher in the BAPT60 group than those in BAPT20, BAPT40 and control groups (P < 0.05). The MDA levels in seminal plasma and spermatozoa were significantly reduced with BAPT supplement (P < 0.05). Additionally, the SOD, CAT and GSH-Px levels in the BAPT experimental groups were significantly higher than those of the control group, which further indicated that BAPT significantly inhibit the reactive oxygen species (ROS) production during the cryopreservation of ram semen. Furthermore, the embryonic cleavage rates and development rates of the BAPT40 and BAPT60 groups were significantly increased in comparison with the BAPT20 and control groups (P < 0.05). In conclusion, BAPT improved the ram sperm quality via inhibiting the ROS production during cryopreservation, and could be applied as a promising supplement for ram semen cryopreservation.

Antifungal Peptides as Therapeutic Agents

Fungi have been used since ancient times in food and beverage-making processes and, more recently, have been harnessed for the production of antibiotics and in processes of relevance to the bioeconomy. Moreover, they are starting to gain attention as a key component of the human microbiome. However, fungi are also responsible for human infections. The incidence of community-acquired and nosocomial fungal infections has increased considerably in recent decades. Antibiotic resistance development, the increasing number of immunodeficiency- and/or immunosuppression-related diseases and limited therapeutic options available are triggering the search for novel alternatives. These new antifungals should be less toxic for the host, with targeted or broader antimicrobial spectra (for diseases of known and unknown etiology, respectively) and modes of actions that limit the potential for the emergence of resistance among pathogenic fungi. Given these criteria, antimicrobial peptides with antifungal properties, i.e., antifungal peptides (AFPs), have emerged as powerful candidates due to their efficacy and high selectivity. In this review, we provide an overview of the bioactivity and classification of AFPs (natural and synthetic) as well as their mode of action and advantages over current antifungal drugs. Additionally, natural, heterologous and synthetic production of AFPs with a view to greater levels of exploitation is discussed. Finally, we evaluate the current and potential applications of these peptides, along with the future challenges relating to antifungal treatments.

The dual functions of flavor and antioxidant potential of porcine bone marrow extract (PBME)

To improve and confirm the dual functions of flavor and antioxidant potential of porcine bone marrow extract (PBME). Response surface methodology and Box-Behnken design was employed to optimize the conditions for enzymatic hydrolysis of PBME. The optimal hydrolysis conditions were: hydrolysis time, 3h; temperature, 55 °C; substrate concentration, 375g/L; and amount of enzyme, 0.4%. L₁₆(3⁵) orthogonal experimental was utilized to obtain the optimal Maillard reaction conditions for PBME and enzymatic hydrolysate of PBME (EH-PBME). The optimal conditions for PBME were: components, 4% glucose, 2% xylose, 1.5% Tyr, 1.5% Ala, and 4% VB₁; reaction time, 40 min; and reaction temperature, 115 °C. The optimal conditions for EH-PBME were: components, 2% glucose, 2% xylose, 3% Ala, and 5% VB₁; reaction time, 40 min; temperature, 110 °C. The antioxidant activities for PBME, EH-PBME, Maillard reaction products of PBME (MPRs A) and Maillard reaction products of EH-PBME (MPRs B) were 50%, 86%, 84% and 41% respectively. The content of taste-active substances and volatile compounds were also determined. Finally, PLSR was employed to evaluate the correlation between flavor compounds and sensory data.

FeptideDB: A web application for new bioactive peptides from food protein

BACKGROUND

Bioactive peptides derived from food are important sources for alternative medicine and possess therapeutic activity. Several biochemical methods have been achieved to isolate bioactive peptides from food, which are tedious and time consuming. In silico methods are an alternative process to reduce cost and time with respect to bioactive peptide production. In this paper, FeptideDB was used to collect bioactive peptide (BP) data from both published research articles and available bioactive peptide databases. FeptideDB was developed to assist in forecasting bioactive peptides from food by combining peptide cleavage tools and database matching. Furthermore, this application was able to predict the potential of cleaved peptides from 'enzyme digestion module' to identify new ACE (angiotensin converting enzyme) inhibitors using an automatic molecular docking approach.

RESULTS

The FeptideDB web application contains tools for generating all possible peptides cleaved from input protein by various available enzymes. This database was also used for analysis and visualization to assist in bioactive peptide discovery. One module of FeptideDB has the ability to create 3-dimensional peptide structures to further predict inhibitors for the target protein, ACE (angiotensin converting enzyme).

CONCLUSIONS

FeptideDB is freely available to researchers who are interested in exploring bioactive peptides. The FeptideDB interface is easy to use, allowing users to rapidly retrieve data based on desired search criteria. FeptideDB is freely available at http://www4g.biotec.or.th/FeptideDB/. Ultimately, FeptideDB is a computational aid for assessing peptide bioactivities.