Flavored-functional protein hydrolysates from enzymatic hydrolysis of dried squid by-products: Effect of drying method

Enzymatic hydrolyzation of Cordyceps militaris mushroom extracts and its effect on spent hen chicken

OBJECTIVE

This study was aimed to investigate the effect of fresh and dried hydrolyzed Cordyceps militaris (CM) mushroom with proteolytic enzymes; bromelain (CMB), flavorzyme (CMF), and mixture of bromelain: flavorzyme (CMBF) on quality properties of spent hen chicken.

METHODS

Mushroom extract (CME) were combined with three proteolytic enzyme mixtures that had different peptidase activities; stem bromelain (CMB), flavorzyme (CMF), and mixture of stem bromelain:flavorzyme (CMBF) at (1:1). The effect of these hydrolysates was investigated on spent hen breast meat via dipping marination.

RESULTS

Hydrolyzation positively alters functional properties of CM protease. in which bromelain hydrolyzed group (CMB) displayed the highest proteolytic activity at 4.57 unit/mL. The antioxidant activity had a significant increment from 5.32% in CME to 61.79% in CMB. A significantly higher emulsion stability index and emulsification activity index compared to CME were another result from hydrolyzation (p<0.05). Texture properties along with the shear force value and myofibrillar fragmentation index were notably improved under CMB and CMBF in fresh condition. Marination with CM mushroom protease that was previously hydrolyzed with enzymes was proven to also increase the nucleotide compounds, indicated by higher adenosine 5'-monophosphate (AMP) and inosine 5'-monophosphate (IMP) in hydrolysate groups (p<0.05). The concentration of both total and insoluble collagen remained unchanged, meaning less effect from CM protease.

CONCLUSION

This study suggested the hydrolyzation of CM protease with bromelain or a mixture of bromelain:flavourzyme to significantly improve functional properties of protease and escalate the taste-related nucleotide compounds and texture profiles from spent hen breast meat.

Protein Hydrolysates from Fishery Processing By-Products: Production, Characteristics, Food Applications, and Challenges

Fish processing by-products such as frames, trimmings, and viscera of commercial fish species are rich in proteins. Thus, they could potentially be an economical source of proteins that may be used to obtain bioactive peptides and functional protein hydrolysates for the food and nutraceutical industries. The structure, composition, and biological activities of peptides and hydrolysates depend on the freshness and the actual composition of the material. Peptides isolated from fishery by-products showed antioxidant activity. Changes in hydrolysis parameters changed the sequence and properties of the peptides and determined their physiological functions. The optimization of the value of such peptides and the production costs must be considered for each particular source of marine by-products and for their specific food applications. This review will discuss the functional properties of fishery by-products prepared using hydrolysis and their potential food applications. It also reviews the structure-activity relationships of the antioxidant activity of peptides as well as challenges to the use of fishery by-products for protein hydrolysate production.

Antimicrobial and anticarcinogenic activity of bioactive peptides derived from abalone viscera (Haliotis fulgens and Haliotis corrugata)

Bioactive peptides have been studied in several sources due to their valuable potential in the pharmaceutical and food industries. Abalone viscera, which are normally discarded as byproducts, are a rich source of protein. Thus, the aim of this study was to explore the potential bioactivity of peptides derived from abalone viscera (Haliotis fulgens and Haliotis corrugata) after hydrolysis with a commercial mixture of enzymes. The hydrolysates obtained were fractionated using gel filtration chromatography. The resulting hydrolysate fractions were investigated for their antimicrobial and cytotoxic activities, including the expression of gelatinases mmp-2 and mmp-9 in human prostate cancer cell lines (PC3). Results showed antimicrobial activity for protein fractions of H. corrugata against Proteus mirabilis and Pseudomona aeuroginosa (66.2-116.25 kDa), Bacillus subtilis (6.5-21.5 kDa), and Aspergillus niger (97.4-116.25 kDa), while H. fulgens peptide fractions (200-31 kDa) displayed activity against six bacterial strains, and fractions from 116.25 to 21.5 kDa had effects on the fungus A. niger, Alternaria alternata, and Aspergillus flavus. Additionally, protein fractions displayed cytotoxic activity, inhibiting 30.4-53.8% of PC3 cellular growth. Selected fractions decreased the PMA-induced and not-induced expressions of mmp-2 and mmp-9 in PC3 cells. Abalone viscera, as byproducts, can be used as a potential source of antimicrobial and anticancer peptides.

Formation of Oxidative Compounds during Enzymatic Hydrolysis of Byproducts of the Seafood Industry

There is a significant potential to increase the sustainability of the fishing and aquaculture industries through the maximization of the processing of byproducts. Enzymatic hydrolysis provides an opportunity to valorize downstream fish industry byproducts for the production of protein hydrolysates (FPH) as a source of bioactive peptides (BAP) with health benefits. Deteriorative oxidative reactions may occur during the enzymatic hydrolysis of byproducts, influencing the safety or bioactivities of the end product. Lipid oxidation, autolysis mediated by endogenous enzymes in viscera, protein degradation, and formation of low-molecular-weight metabolites are the main reactions that are expected to occur during hydrolysis and need to be controlled. These depend on the freshness, proper handling, and the type of byproducts used. Viscera, frames, trimmings, and heads are the byproducts most available for enzymatic hydrolysis. They differ in their composition, and, thus, require standardization of both the hydrolysis procedures and the testing methods for each source. Hydrolysis conditions (e.g., enzyme type and concentration, temperature, and time) also have a significant role in producing FPH with specific structures, stability, and bioactivity. Protein hydrolysates with good safety and quality should have many applications in foods, nutraceuticals, and pharmaceuticals. This review discusses the oxidative reactions during the enzymatic hydrolysis of byproducts from different fish industry sectors and possible ways to reduce oxidation.

Industrial Application of Protein Hydrolysates in Food

Protein hydrolysates, which may be produced by the protein in the middle of the process or added as an ingredient, are part of the food formula. In food, protein hydrolysates are found in many forms, which can regulate the texture and functionality of food, including emulsifying properties, foaming properties, and gelation. Therefore, the relationship between the physicochemical and structural characteristics of protein hydrolysates and their functional characteristics is of significant importance. In recent years, researchers have conducted many studies on the role of protein hydrolysates in food processing. This Review explains the relationship between the structure and function of protein hydrolysates, and their interaction with the main ingredients of food, to provide reference for their development and further research.

Physicochemical, structural, functional and flavor adsorption properties of white shrimp (Penaeus vannamei) proteins as affected by processing methods

Proteins contribute to the flavor release and texture of foods besides their nutritional attributes. However, processing affects the protein structural conformation and, thus, their functional properties. White shrimp proteins (WSP) are well known for their nutritional and functional properties and limited attention has been paid to the flavor adsorption properties of WSP. This study investigated the effects of processing methods such as microwave drying, hot air drying, roasting, and boiling on the structural (secondary and tertiary) changes and physicochemical, functional, and flavor adsorption properties of white shrimp proteins (WSP). Structural changes of WSPs were evaluated by Fourier Transform Infrared (FTIR) spectroscopy, fluorescence spectroscopy, and sulfhydryl bond content. Results revealed that the processing triggered structural changes that affected the functional properties of WSP. The highest surface hydrophobicity (H₀) of WSP in boiling (58.27 ± 1.68) and microwave drying (39.83 ± 0.83) caused increased emulsifying properties and decreased water solubility. The increased content of α-helix and random coils leads to cross-linking and protein aggregation in hot air drying (21.62 ± 0.37 %) and roasting (24.30 ± 0.24 %), which leads to low H₀ and high foaming properties. Processing has increased the flavor adsorption ability of WSP. Among all the processing methods, boiling has shown the highest flavor adsorption potential, followed by microwave drying. The findings broaden the scope of techno-functional properties of WSP in the food industry by thermal treatment modification.

Valuation of Goat and Sheep By-Products: Challenges and Opportunities for Their Use

Goat and sheep meat production is a challenge for the meat industry as well as for environmental management. Yet within cultures, certain by-products, such as liver, the lungs, heart, brain, spleen, blood, tail and ears, are traditionally used in the production of typical dishes for regional or local cuisine. These by-products are a rich source of lipids, proteins, essential amino acids, B-complex vitamins, and minerals. They can be effectively exploited for higher (value-added) applications, including functional foods or feed ingredients, food supplements, enzymes and other chemical products such as hydrolyzed proteins and flavorings. This review article gathers data on: (i) the production of by-products obtained from slaughter and available for processing, and (ii) potential strategies for using and applying these by-products in obtaining new value-added ingredients. Other than proteins, the review discusses other macromolecules and possible uses of these by-products in culinary dishes, as hydrolyzed enzymes, and as food additives. Even though these by-products undoubtedly present themselves as rich in nutrients, there remains an unfortunate lack of documented information on the potential use of these by-products for their bioactive components, peptides that have various biological and technological properties, and the use of hydrolyzed versions of these by-products as precursors for the production of flavorings.

Modification of Whey Proteins by Sonication and Hydrolysis for the Emulsification and Spray Drying Encapsulation of Grape Seed Oil

In this study, whey protein concentrate (WPC) was sonicated or partially hydrolyzed by Alcalase, then examined as an emulsifier and carrier for the emulsification and spray drying of grape seed oil (GSO)-in-water emulsions. The modification treatments increased the free amino acid content and antioxidant activity (against DPPH and ABTS free radicals), as well as, the solubility, emulsifying, and foaming activities of WPC. The modified WPC-stabilized emulsions had smaller, more homogeneous droplets and a higher zeta potential as compared to intact WPC. The corresponding spray-dried powders also showed improved encapsulation efficiency, oxidative stability, reconstitution ability, flowability, solubility, and hygroscopicity. The morphology of particles obtained from the primary WPC (matrix type, irregular with surface pores) and modified WPC (reservoir type, wrinkled with surface indentations), as well as the oxidative stability of the GSO were influenced by the functional characteristics and antioxidant activity of the carriers. Changes in the secondary structures and amide regions of WPC, as well as the embedding of GSO in its matrix, were deduced from FTIR spectra after modifications. Partial enzymolysis had better results than ultrasonication; hence, the WPC hydrolysates are recommended as emulsifiers, carriers, and antioxidants for the delivery and protection of bioactive compounds.

Threadfin bream surimi gel containing squid fin protein hydrolysate: Textural properties, acceptability, and volatile profile

Gel properties of threadfin bream surimi gels with squid fin protein hydrolysate (SFPH) at various concentrations (0, 1, 2, 3, and 4%; w/w) were determined. The gel without SFPH (CON) had the highest breaking force (BrF) and deformation (DeF) as compared to those with SFPH (p < 0.05). Among the gel with SFPH, gel containing 1 and 2% SFPH (SFPH-1 and SFPH-2, respectively) had the highest BrF, whereas the lowest value was obtained when 4% SFPH was used (SFPH-4) (p < 0.05). The whiteness of all samples was slightly decreased with an upsurging amount of SFPH. However, water holding capacity was increased with augmenting levels of SFPH (p < 0.05). Sensory analysis revealed that SFPH-2 had a higher squid odor and flavor likeness score than CON (p < 0.05). Textural properties, especially hardness, were decreased with increasing SFPH, except for SFPH-1 and SFPH-2 (p > 0.05). In addition, the rheological properties, microstructure, and volatile profile of the selected surimi gel were also studied. The storage modulus (G') of SFPH added samples was decreased as compared to the CON sample. The CON gel had a finer and more compact network as compared to SFPH-2 and SFPH-4 samples. Volatile profiles indicated that alcohols, carboxylic acids, ketones, and ether were the major volatile compounds present in both gel samples. Furthermore, thiophene, 3-methyl-, contributing to squid flavor, was found in the SFPH-2 sample. Overall, SFPH at 2% could act as a flavorant in the threadfin bream surimi gel without markedly negative impact on gelling and textural properties, while providing squid odor and flavor to the resulting gel. PRACTICAL APPLICATION: The various low-valued byproducts generated from the squid processing industry could result in various environmental problems. Those byproducts are rich in various biomolecules such as proteins, fats, enzymes, and so forth, which could be utilized to produce value-added products. Among them, protein hydrolysate (PH) rich in amino acids with excellent antioxidant properties could serve as an alternative flavorant. Therefore, PH from squid byproducts, especially fins, could be applied in foods such as fish balls, surimi gels, and so forth to enhance the nutritional and flavoring profile of a finished product. Moreover, bioactive peptides in PH with antioxidant potential could retard the oxidation of proteins and lipids.

The Quality and Functional Improvement of Retorted Korean Ginseng Chicken Soup (Samgyetang) by Enzymolysis Pre-Treatment with Cordyceps militaris Mushroom Extract

This study aimed to investigate the functional and quality improvement of retorted Korean ginseng chicken soup that was hydrolyzed using a single extract from Cordyceps militaris (CM) mushroom, or in combination with bromelain, flavorzyme, or a mix of both. A total of 36 fat-trimmed breast meat from commercial broilers were hydrolyzed with one of six treatments, (1) flavorzyme as a positive control (PC), (2) no addition as negative control (NC), (3) crude CM extract (CME), CM extract prepared with either (4) bromelain (CMB), (5) flavorzyme (CMF), or (6) bromelain:flavorzyme mixture (CMBF) in a water bath at 55 °C for 2.5 h, and subsequently retorted at 121.1 °C, 147.1 kPa for 1 h. The highest antioxidant activity was observed in the CMB treatment (40.32%), followed by CMBF (34.20%), and CME (32.97%). The suppression of malondialdehyde ranged between 28 and 83%. The water-holding-capacity of the treated samples increased, ranging between 59.69 and 62.98%, and significantly tenderized the meat. The shear force decreased from 23.05 N in negative control to 11.67 N in the CMB samples. The predominant nucleotides across the samples were 5′-IMP and hypoxanthine, and the lowest was adenosine. The intensification of the taste properties was due to the increase of umami substances, both by 5′-nucleotides (5′-IMP, 5′-GMP) and free amino acids (FAAs), whereas the highest improvement was observed in the CMB group. Therefore, the hydrolyzation of Korean ginseng chicken soup using CM extract, prepared using bromelain, improves functional and quality profiles.

Technological properties of protein hydrolysate from the cutting byproduct of serra spanish mackerel (Scomberomorus brasiliensis)

High fish production is essential to meet the demand, but inappropriate destination of large volumes of byproduct cause environmental pollution. The cutting step for frozen eviscerated fish using band saw machines produces a type of "fish powder" byproduct with high protein content. The objective of this study was to optimize the process of obtaining protein hydrolysates from the cutting byproducts of Serra Spanish Mackerel (SSM) and to evaluate the final product regarding its technological properties. The optimal conditions for obtaining the protein hydrolysate from the cutting byproducts of SSM using a band saw machine were an enzyme:substrate ratio (w/w) of 5.0% and 240 min of enzymatic hydrolysis. Both treatments (+ DH and - DH) yielded volatile compounds with a characteristic fish aroma, and both can be used for flavoring. The - DH hydrolysate showed better technological performance by stabilizing emulsions and retaining oil, and they could be added to emulsified products, improving their technological and sensory aspects. For the antioxidant capacity, the + DH hydrolysate showed higher efficiency, and it was indicated for use in food products, with the aim of extending the shelf life by stabilizing food lipids and proteins, ensuring the quality of the product during storage.

Reclamation of Fishery Processing Waste: A Mini-Review

: Seafood such as fish, shellfish, and squid are a unique source of nutrients. However, many marine processing byproducts, such as viscera, shells, heads, and bones, are discarded, even though they are rich sources of structurally diverse bioactive nitrogenous components. Based on emerging evidence of their potential health benefits, these components show significant promise as functional food ingredients. Fish waste components contain significant levels of high-quality protein, which represents a source for biofunctional peptide mining. The chitin contained in shrimp shells, crab shells, and squid pens may also be of value. The components produced by bioconversion are reported to have antioxidative, antimicrobial, anticancer, antihypertensive, antidiabetic, and anticoagulant activities. This review provides an overview of the extraordinary potential of processing fish and chitin-containing seafood byproducts via chemical procedures, enzymatic and fermentation technologies, and chemical modifications, as well as their applications.

Seafood Flavor Perception, Liking, Emotion, and Purchase Intent of Coated Peanuts as Affected by Coating Color and Hydrolyzed Squid Peptide Powder

This study evaluated effects of green compared with brown coating colors and varying levels of hydrolyzed squid peptide powder (HSP) on seafood flavor perception, sensory liking, emotions, and purchase intent (PI) of coated peanuts. Dried squid head was enzymatically hydrolyzed to produce HSP, which was then incorporated into peanut coating material at 0%, 0.89%, 1.78%, and 2.66% levels. Green-coated peanuts (GCP) and brown-coated peanuts (BCP) were produced and tested with U.S. consumers. A 2-AC test (N = 100 consumers) was used to determine effects of coating colors on expected/perceived seafood flavor intensity of GCP compared with BCP at an equal HSP level based separately on looking, smelling, and tasting. Only tasting produced perceptual differences, at 1.78% and 2.66% HSP, with stronger seafood flavor intensity observed for GCP. Consumer testing (N = 160) yielded low mean seafood aroma liking scores for BCP (4.04) and GCP (4.13) at 2.66% HSP. The emotion "disgusted" was most affected by HSP addition for GCP. Presenting consumers with health benefit information (HBI) increased positive PI from 62.5% to 81.25% for BCP at 1.78% HSP, which had higher mean overall liking scores (6.05 before HBI, 6.24 after HBI) than 2.66% HSP samples. Overall liking was a significant predictor for positive PI with odds ratios of 1.52 to 2.20. Overall, green color and HSP addition levels of the coating inserted negative effects on liking, emotion, and PI of coated peanuts. This study demonstrated that HSP made from byproduct of squid processing could be successfully incorporated into coated peanuts, supporting the concept of sustainability of food supply. PRACTICAL APPLICATION: In this study, the functional peptide ingredient made from squid head, a byproduct from seafood industry, was incorporated into coated peanuts. Effects of different coating colors (green compared with brown) and varying levels of hydrolyzed squid peptide powder on consumers' seafood flavor perception, liking, emotions, and purchase intent of seasoned coated peanuts were clearly observed. The color of the coating material played an important visual cue that influenced product liking. Presenting consumers with health benefit information increased overall liking and positive purchase intent of the samples. Multisensory interactions of color and seafood aroma/flavor in these products should be further optimized.

Comparative Assessment of Enzymatic Hydrolysis for Valorization of Different Protein-Rich Industrial Byproducts

Hydrolyzed protein-rich byproducts from food production may find a variety of applications, for example, as rich ingredients of fermentation media. We have conducted a study of the enzymatic hydrolysis of three byproducts from Norwegian food industries: chicken byproducts, mixed pork and beef byproducts, and salmon viscera. The efficiency and optimization of the enzymatic hydrolysis were evaluated using endogenous enzymes alone and in combination with commercial proteases. Hydrolysis reactions were conducted with freshly thawed raw materials using short incubation times and including an initial temperature gradient from 4 to 60 °C to both harness the power of endogenous enzymes and minimize microbial contamination. Subsequently, hydrolysates were characterized by analyzing the total recovery of protein, the peptide molecular-weight distribution, and the composition of total and free amino acids. The action of endogenous enzymes played an important role in raw-material hydrolysis, particularly when hydrolyzing salmon viscera but less so when hydrolyzing chicken byproducts. For pork-beef and chicken byproducts, the addition of Alcalase or Papain improved protein recovery, reaching levels up to 90%. Next to showing efficient hydrolysis protocols, the present data also provide a comparison of the amino acid compositions of hydrolysates derived from these three different protein-rich byproducts. Growth studies showed that the obtained protein-rich hydrolysates from meat and fish industries are a promising alternative for expensive nitrogen sources that are commonly used for fermenting yeasts.