Hydrolysate Powder Research Articles

Effect of Hydrodynamic Cavitation and Drying Technique on Moisture Sorption Isotherm and Structural Properties of Egg White Protein Hydrolysate Powder

Effect of Hydrodynamic Cavitation and Drying Technique on Moisture Sorption Isotherm and Structural Properties of Egg White Protein Hydrolysate Powder

Evaluation of Thai Silkworm (Bombyx mori L.) Hydrolysate Powder for Blood Pressure Reduction in Hypertensive Rats.

The angiotensin-I converting enzyme (ACE) plays a pivotal role in hypertension, and while ACE inhibitors are conventional in hypertension management, synthetic medications often carry undesirable side effects. This has spurred interest in alternative ACE inhibitors derived from natural sources, such as edible insects. The silkworm, recognized for its bioactive peptides with potent ACE-inhibitory properties, has emerged as a promising candidate. This study aims to evaluate the acute toxicity and assess the antihypertensive efficacy of crude mature silkworm hydrolysate powder (MSHP) obtained from mature Thai silkworms. Utilizing the commercial protease Alcalase®2.4L, MSHP was administered at various doses, including 50, 100, and 200 mg kg-1, to hypertensive rats. The investigation spans a 14-day period to observe any potential acute toxic effects. Results indicate that MSHP exhibits LD50 values equal to or exceeding 2000 mg kg-1, signifying a low level of acute toxicity. Furthermore, the effective dose for blood pressure reduction in hypertensive rats surpasses 100 mg kg-1 of rat body weight. These findings suggest that MSHP derived from Thai mature silkworms holds promise as a natural antihypertensive food source. The implications of this research extend to the development of functional foods, functional ingredients, and dietary supplements aimed at managing hypertension.

ACE‐inhibitory properties and antioxidative activities of hydrolysate powder obtained from Thai's mature silkworm (Bombyx mori)

SummaryThis study aimed to optimise the production of silkworm hydrolysate powder (SHP) from Thai's mature silkworm with potent ACE inhibition properties using commercial protease enzymes. Thai's mature silkworm (TMS) powder was hydrolysed with Alcalase® 2.4 L, Neutrase® 0.8 L and Flavourzyme® 500MG at varying enzyme concentrations and temperatures. The most effective method for ACE inhibition was found with Alcalase® 2.4 L at 5% concentration (w/w) of protein content in TMS powder, at 60 °C for 1 h. This condition also resulted in the highest SHP production and protein content, outperforming other enzyme treatments. Moreover, it exhibited significant total phenolic compounds and antioxidant activity including DPPH and ABTS radical scavenging. This finding establishes a foundation for scaling up the production of Thai's mature SHP to a commercial level. The resulting product can be utilised as a functional ingredient, functional food or therapeutic food for managing high blood pressure.

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%.

Effects of cluster dextrin encapsulation on the properties and antioxidant stability of fractionated Riceberry protein hydrolysate powder prepared by bromelain

In this work, the biological properties of fractionated Riceberry bran protein hydrolysate obtained by ultrafiltration (URBPH) were evaluated and the possibility of using cluster dextrin to produce hydrolysate powder by spray-drying was investigated. Fractionation into peptides < 3 kDa was observed to improve antioxidant activity. URBPH < 3 kDa was then freeze-dried (FD-URBPH) and spray-dried (SD-URBPH) at different inlet air temperatures of 100–160 °C. The water solubility and antioxidant activity of FD-URBPH were higher than those of SD-URBPH. Nevertheless, encapsulation of hydrolysate with 10% cluster dextrin and an inlet temperature of 120 °C was also successful in maintaining protein qualities, which showed high 2,2′-azino-bis 3-ethylbenzthiazoline-6-sulfonic (ABTS•+) scavenging activity (89.14%) and water solubility index (92.49%) and low water activity (aw = 0.53). Moreover, encapsulation preserved the antioxidant activity of peptides during gastrointestinal digestion better than the free form. URBPH and its spray-dried microcapsules could be used as bioactive ingredients in functional drinks or foods.

Rheological, textural properties and storage stability of mayonnaise formulated with protein hydrolysate derived from yellow mealworm (Tenebrio molitor)

Abstract Yellow mealworm (Tenebrio molitor), the larva stage of darkling beetle, confers high nutritional and functional protein and it can serve as a sustainable protein source. The present study therefore evaluated the effect of replacing the egg yolk as emulsifier with yellow mealworm protein hydrolysate powder (YMPH) (0-100%) at 20% increment levels on the rheological and textural properties, colour attributes, emulsion microstructure and storage stability of mayonnaise. The emulsion stability results demonstrated that mayonnaise with up to 60% substitution of YMPH displayed excellent storage stability for 3 weeks (&lt;2% phase separation). In terms of textural properties, all samples showed no significant difference () in firmness whereas consistency decreased steadily with increasing YMPH concentration levels. Microstructure observation of all mayonnaise formulations demonstrated a gradual increase in oil droplet size in parallel with the increase in YMPH concentration. For rheological properties, all mayonnaise exhibited similar gel-like behaviour with greater storage modulus (G’) than loss modulus (G”) and loss tangent (tan δ) less than 1.0. For the colour attributes, increasing YMPH level led to significant decrease () in the L* and b* factors from 73.0 to 27.2 and 23.9 to 8.1, respectively. However, the overall a* factor value increased significantly () from 1.11 to 5.10 as the YMPH concentration increased. This study revealed that insect-based protein hydrolysate has a good potential to serve as an emulsifier.

Water adsorption isotherms and phase transitions of spray-dried chickpea beverage

Chickpea hydrolysate powders were obtained by spray-drying (70 and 60 °C as outlet and 180 °C inlet air temperatures), using inulin and maltodextrin as adjuvants (12 or 25 g/100 g solids). No effects of the variables studied were observed on solubility (88–93 g/100 g solids) and final moisture (3.50–6.15 g/100 g db). Yields were 49.44–61.24 and 44.53–51.55% at 70° and 60 °C respectively. Moisture adsorption isotherms (25°, 35° and 45 °C) were obtained by dynamic dew point method and modeled with GAB and BET equations. BET monolayer moisture values (5.53–9.66 g/100 g db), were slightly different and higher than those obtained for the GAB model. Critical values of water activity (awc) and critical moisture (Mc), related with phase transitions, were determined using the second derived from moisture change with respect to water activity (Sovitsky-Golay 2nd derivate). At 25 °C the highest awc and Mc values, 0.515 and 0.535, and 8.5 and 9.35 g/100 g db occur for products dried at 60 °C and with the lowest level of both adjuvants, while the product without adjuvant has an awc and Mc f 0.466 and 7.46 g/100 g db. The increase in awc and Mc, due to the presence of the inulin and maltodextrin reflects their protective effect. According to these results spray-drying (Tout = 60 °C) could be used to generate a stable dehydrated hydrolysate chickpea beverage basis using 12.5 g/100 g db of the adjuvants evaluated.

Enzymatic dehairing of sheep skin: Recovery and characterization of commercially important wool hydrolysate and fats

Conventional dehairing methods in the traditional leather-making processes, consume large amounts of toxic chemicals and produce a toxic sludge/effluent, posing disposal challenges and consequently environmental pollution. The by-products of leather processing such as hair and fat, contain toxic chemicals. In this study, crude alkaline protease from &lt;i&gt;bacillus cereus strain 1-p, &lt;/i&gt;was used to dehair sheepskin with up to 99.00% recovery of valuable wool and fat. The optimum temperature and pH for wool removal were found to be 30 &lt;sup&gt;°&lt;/sup&gt;C and 11, respectively. The recovered wool was enzymatically hydrolyzed to obtain wool hydrolysate powder (48.1% yield). FTIR spectra of the wool hydrolysate showed the presence of amide A, I, and II absorption bands. Further, the amino acid analysis, revealed the presence of 15 amino acids, with glutamic acid (19.65 mole %), glycine (12.72 mole %), and leucine (9.42 mole %) being the most abundant. Fat was trans-esterified using methanol, in the presence of tert-butanol, and the resultant fatty acid methyl esters characterization was done using gas chromatography/mass spectrometry (GC/MS) analysis. GC/MS analysis showed the presence of 60 methyl esters corresponding to 60 fatty acids. The most abundant fatty acid was 9-octadecenoic (oleic) acid (41.64%), followed by hexa-decanoic (palmitic) acid (22.50%), and tetra-decanoic (myristic) acid (4.21%). Thermo-gravimetric analysis of the wool hydrolysate showed that it had good thermal stability. It is shown that crude alkaline protease extracted from &lt;i&gt;bacillus cereus strain 1-p&lt;/i&gt; can completely eliminate the use of toxic sodium sulfide and lime in dehairing of skins/hide in tanneries, eliminating environmental pollution. Furthermore, the recovery of fat and wool using an eco-friendly enzymatic dehairing process can significantly reduce the pollution load in the effluent. The recovered wool and fats can be applied in the production of wool hydrolysate, which is high in protein content, amino acids and biodiesel.

Development of a Ready-to-Eat Fish Product Enriched with Fish Oil Entrapped in a κ-Carrageenan Egg White Fish Protein Hydrolysate Dry Powder.

This work describes the development of a ready-to-eat (RTE) product based on an equal mixture of fish mince from three undervalued fish species with different fat contents and protein gelling capacity, which was enriched with fish oil entrapped in a κ-carrageenan egg white fish protein hydrolysate powder, obtained by either spray drying (SD) or heat drying (HD) at 80 °C (HD80). Previously, the spray-dried (SD) powder and heat-dried powders obtained at 45 °C, 60 °C and 80 °C (HD45, HD60 and HD80) were characterised in terms of water solubility, lipid oxidation (TBARS), hygroscopicity and ζ potential. All HD powders showed higher hygroscopicity and lower TBARS than the SD powder. The dry powder was incorporated into a blend composed of salt-ground batter and raw mince to improve binding and textural properties. Changes in water-holding capacity, colour, shear strength and microorganisms were monitored during the processing steps. The RTE product presented a high protein content and a noticeable amount of long-chain ω-3 fatty acids. The use of undervalued fish species together with fish oil and a protein hydrolysate from fish waste contribute to improving the sustainability of fishery resources, being conducive to obtaining a potentially functional RTE product.

Production of functional spent hen protein hydrolysate powder and its fortification in food supplements: A waste to health strategy

Spent hens are discarded from the poultry industry as they lose their ability to lay eggs and are rendered unsuitable for consumption due to poor meat quality. This work provides a strategy to utilize spent hen meat by developing protein hydrolysates with enhanced antioxidative properties for developing functional protein supplement which was previously unexplored. Spent hen meat was hydrolysed using two proteases (alcalase and flavourzyme) followed by drying (spray and freeze drying). Hydrolysate powders thus generated were further characterized for their physico-chemical and functional attributes. Particle size and morphology were more prominently affected by drying method while the functional properties were influenced by the enzyme type. The solubility, antioxidant activity and bioaccessibility of spray dried spent hen hydrolysate powder developed using flavourzyme (SD-SPHF) was found superior to those developed using alcalase. Hydrophobic amino acids with rich antioxidant activity were also found to be higher in SD-SPHF. Considering higher functionality of SD-SPHF, it was incorporated @10% in whey protein supplement and was found to be acceptable from a sensory viewpoint. The study highlights that spent hen protein hydrolysate powders can be effectively utilized for the development of economic functional food supplements after suitable biotechnological interventions.

Antioxidant Activity of Cocoa Flavored Sterilized Milk Fortified with Whey Protein Hydrolysate Derived from Gastrointestinal Proteinases Digestion

The objectives of this work were to study the change in α-amino content and antioxidant activity of whey protein hydrolysate (WPH) using gastrointestinal proteinases (pepsin and pancreatin). In addition, whey protein hydrolysate powder (WPHP) with high antioxidant activity were produced by simulated GI digestion using an in vitro pepsin - pancreatin hydrolysis for supplementation in flavored milk. Whey protein was hydrolyzed with pepsin for 2 h followed by pancreatin for 3 h. WPH was collected to determine the α-amino content and antioxidant activity. The results showed that digested WPH contained higher α-amino content and antioxidant activity than undigested whey. To study optimum temperature, WPH was dried using Spray Dryer at 130, 140, and 150 °C. Results showed that WPHP at 150 °C exhibited the highest antioxidant activity with a major area peak of molecular weight around &gt;12,000 - 990 Da (43.4 %) and 990 - 336 Da (23.7 %). WPHP at 150 °C was selected to supplement in Cocoa flavored sterilized milk (CFSM_WPHP). α-Amino content, antioxidant activity, and microbiological of CFSM_WPHP were investigated. CFSM_WPHP contained higher α-amino content and antioxidant activity than Control (without addition of WPHP). Total plate count, fecal coliform, and E. coli of CFSM_WPHP were under Notification of the Ministry of Public Health of Flavored milk. These results suggested that WPHP has the potential as nutritive and antioxidative supplementation for Cocoa flavored sterilized milk.&#x0D; HIGHLIGHTS&#x0D; &#x0D; Whey protein hydrolysate prepared by pepsin-pancreatin had antioxidant activity&#x0D; At 150 ºC was the optimum drying temperature to produce WPH powder&#x0D; WPH exhibited the molecular weight around &gt;12,000-990 Da and 990 - 336 Da&#x0D; Addition of WPH improved antioxidant activity of Cocoa flavored sterilized milk&#x0D; WPH powder exhibited the potential of being used as a functional peptide&#x0D; &#x0D; GRAPHICAL ABSTRACT

Preparation of a protein drink from fish protein hydrolysate obtained from tilapia skin waste

This study investigated the extraction of protein hydrolysate from tilapia skin waste and its utilisation for the preparation of a protein drink. Tilapia skin was first prepared by removing lipids using 95% ethanol. Protein hydrolysate was then extracted using 0.375% papain at 40°C for 120 mins. The physicochemical properties of the protein hydrolysate were analysed and were then used to prepare a protein drink. The analysis of shelf-life and the prediction of shelf-life of products using the accelerated shelf-life testing method (Q10) were carried out. The content of protein hydrolysate powder in tilapia skin was 29.68±1.32 (g/100 g). Sensory analysis results showed that the protein beverage received an overall liking score of 7.13±1.27 from the sensory panel. Based on the Q10 calculations, the product shelf-life at the recommended temperature of 4°C with a safety factor of 10% was 12 days. According to the Thai FDA for pasteurised beverage regulation no. 195, the product complied with the Thai FDA standard guidelines. These results suggested that the fish protein hydrolysate obtained from tilapia skin waste is a rich resource of protein and is suitable for producing value-added fish skin protein drinks.

Wound Healing Modulation through the Local Application of Powder Collagen-Derived Treatments in an Excisional Cutaneous Murine Model.

Wound healing includes dynamic processes grouped into three overlapping phases: inflammatory, proliferative, and maturation/remodeling. Collagen is a critical component of a healing wound and, due to its properties, is of great interest in regenerative medicine. This preclinical study was designed to compare the effects of a new collagen-based hydrolysate powder on wound repair to a commercial non-hydrolysate product, in a murine model of cutaneous healing. Circular excisional defects were created on the dorsal skin of Wistar rats (n = 36). Three study groups were established according to the treatment administered. Animals were euthanized after 7 and 18 days. Morphometric and morphological studies were performed to evaluate the healing process. The new collagen treatment led to the smallest open wound area throughout most of the study. After seven days, wound morphometry, contraction, and epithelialization were similar in all groups. Treated animals showed reduced granulation tissue formation and fewer inflammatory cells, and induction of vasculature with respect to untreated animals. After 18 days, animals treated with the new collagen treatment showed accelerated wound closure, significantly increased epithelialization, and more organized repair tissue. Our findings suggest that the new collagen treatment, compared to the untreated control group, produces significantly faster wound closure and, at the same time, promotes a slight progression of the reparative process compared with the rest of the groups.

Effect of milk-derived bioactive peptides on the lipid stability and functional properties of beef nuggets

The present study was conducted to ascertain the beneficial effects of bioactive peptides on the oxidative stability and functional properties of beef nuggets. In this study, milk casein protein hydrolysates were extracted and incorporated into beef nuggets which were then subjected to different assessment parameters including oxidative stability, functional capability as well as microbial and physico-chemical quality tests were performed for determining the meat quality at different storage periods. The casein protein hydrolysate powder (CPH) was added at different concentrations in nuggets CPH 2%, 4%, 6% and 8%, with reference to storage period of 0, 5, 10 and 15 days at 4 °C. The results regarding total phenolic contents (TPC) and DPPH free radical scavenging assay showed a significant increased with respect to CPH powder and significantly decreased with respect to storage interval. The TVBN, TBARS and POV of the CPH powder incorporated raw beef nuggets also differed significantly within groups with storage time. Higher POV and TBARS were noticed in the CPH 8% incorporated beef nuggets. However, the raw beef nuggets that were made by the incorporation 8% CPH powder, maintained significantly lower level of TBARS at the end of the storage period in contrast with the levels of the control (CPH 0%). The results of the pH and Hunter color test also showed a significant difference with respect to different groups. The microbiological analysis of beef nuggets showed a significant decrease in the level of both the total aerobic and coliform counts and also indicated a decreasing trend in the level of contamination by these bacteria within the groups. This depicted that the casein protein hydrolysate powder (CPH) or simply, the peptide powder has the strong ability to decrease lipid oxidation and related shelf-life retarding natural processes occurring in the meat. It can also greatly enhance the functional properties of the raw meat (beef) and meat products. Thus, it is seen that the bioactive peptides (BAP’s) are a key factor in improving the oxidative stability and functional properties of beef nuggets.

Functional and morphological characterization of undersized crawfish minced meat hydrolysate powders produced with alkaline protease and bacterial protease

Undersized crawfish meat protein may be enzymatically hydrolyzed to produce protein hydrolysate powders with functional properties. The objective of the study was to evaluate the functional and morphological characterization of undersized crawfish minced meat hydrolysate powders produced with alkaline protease and bacterial protease. The degree of hydrolysis vs. time was determined and hydrolyzation times chosen. Alkaline and bacterial protease enzymes were added to the crawfish minced meat at 3% w/w and hydrolyzed for 0.5, 3, and 7 h. After hydrolysis, the enzymes were inactivated, and the hydrolysates were spray dried at 150 °C. Molecular weight, morphology, minerals, amino acid profile, color and functional properties including antioxidant activity, emulsification stability, water absorption, and fat absorption capacity were evaluated for the spray dried hydrolysate powders. Triplicate experiments were conducted, and the data was statistically analyzed (P < 0.05). All the powders had 5 and 2 kDa molecular weight bands. Functional properties of hydrolysate powders were affected by enzyme type and reaction time, which indicated that the enzymes promote the production of different peptides that could be responsible for differences in the functional properties of the hydrolysate powders. The morphology of CPH powders showed round and smooth and irregularly spherical shape particles with dents.

Development of a spray-dried conjugated whey protein hydrolysate powder with entrapped probiotics

Bifidobacterium animalis ssp. lactis ATCC27536 and Lactobacillus acidophilus ATCC4356 were encapsulated in a conjugated whey protein hydrolysate (WPH10) through spray drying. Probiotic cultures were added at the ratio of 1:1 into the conjugated WPH10 solution at a spiking level of about 10 log10 cfu/mL. The mixture was spray dried in a Niro drier with inlet and outlet temperatures of 200°C and 90°C, respectively. The final dried product was determined for cell viability and further stored for 16 wk at 25°, 4°, and -18°C to monitor viability and functionality. Micro images showed the presence of link bridges in non-conjugated WPH10, whereas, in the case of conjugated WPH10, round particles with pores were observed. The mean probiotic counts before and after spray drying were 10.59 log10 cfu/mL and 8.98 log10 cfu/g, respectively, indicating good retention of viability after spray drying. The solubility and wetting time of the WPH10-maltodextrin (MD) encapsulated probiotic powder were 91.03% and 47 min, whereas for WPH10, the solubility and wetting time were 82.03% and 53 min, respectively. At the end of storage period, the counts were 7.18 log10 cfu/g at 4°C and 7.87 log10 cfu/g at -18°C, whereas at 25°C the counts were significantly reduced, to 3.97 log10 cfu/g. The solubility of WPH-MD powder was 82.36%, 83.1%, and 81.19% at -18°C, 4°C, and 25°C, respectively, and wetting times were 61 min, 60 min, and 63 min at -18°C, 4°C, and 25°C, respectively. By contrast, for WPH10 powder, the solubility significantly reduced to 69.41%, 69.97%, and 68.99% at -18°C, 4°C, and 25°C, and wetting times increased to 71 min, 70 min, and 72 min at -18°C, 4°C, and 25°C, respectively. The conjugated WPH10 is thus demonstrated as a promising carrier for probiotics and can be further used as an ingredient for developing functional foods, to harness their enhanced functionality and health benefits derived from both WPH and probiotics.

Protease Catalyzed Production of Spent Hen Meat Hydrolysate Powder for Health Food Applications

Whole spent hen meat of Indian commercial layer bird (BV-300 breed) was enzymatically hydrolyzed using Flavourzyme® derived from Aspergillus oryzae. Different time, temperature, and pH combinations generated through response surface methodology (RSM) were tested to find the optimal hydrolysis condition at which maximum antioxidant potential and degree of hydrolysis can be achieved. Hydrolysis for 30 min at a temperature of 53.9°C and pH of 6.56 was found suitable for achieving high degree of hydrolysis and antioxidant activity. Antioxidant potential at optimized conditions was estimated at 93.26% by DPPH radical scavenging assay and 2.32 mM TEAC by FRAP assay. Amino acid profiling of the hydrolysate correlated very well with SDS-PAGE profiling. SDS-PAGE results confirmed that 30 min hydrolysis time was enough to produce low molecular weight peptides (2–5 kDa) with high antioxidant potential. Antioxidant rich Indian spent hen meat hydrolysate powder was economically produced using spray drying. Sensory analysis revealed that 10% hydrolysate powder had satisfactory overall acceptability and has potential to be used in health/functional foods at this concentration. This is the first study wherein optimum hydrolysis conditions for Indian spent hen meat have been reported.

Physicochemical and Functional Properties of Snack Bars Enriched with Tilapia (Oreochromis niloticus) By-Product Powders.

This research aimed to evaluate tilapia by-product powders as a novel food ingredient and the suitable cooking method for snack bar (SBs) production. Tilapia by-product powders were made by two processing methods; one powder was oven-dried as tilapia dry powder (TDP) and another was bromelain-hydrolyzed and then freeze-dried as tilapia hydrolysate powder (THP). SBs were prepared by incorporating tilapia dry powders (TDP or THP; 10%). SBs were further separated in two different cooking methods, namely unbaked and baked ones. The baked SBs had yellow and darker coloration (L* value ranged from 66.38 to 76.12) and more reddish color (a* value range from −1.26 to 1.06). Addition of tilapia by-product powders significantly (p < 0.05) increased the protein content of the original SB from 21.58 to 32.08% (SB + THP). Regarding DPPH scavenging activity, the control group showed the lowest activity, followed by SB + TDP and SB + THP with the highest activity (p < 0.05), with DPPH scavenging activity ranged from 12.40 to 26.04%. The baking process significantly (p < 0.05) increased the angiotensin converting enzyme (ACE) inhibitory activity of the SBs. In particular, the SB + THP group showed the highest activity (17.78%). All samples exhibited antibacterial activity against Staphylococcus aureus, and the SB + THP group showed the highest activity (15.08 ± 1.95 mm growth inhibition). Based on principal component analysis, four principal components (nutraceutical pigmentation, physical characteristics, nutrition value, and greater dehydration) were contributed towards the physicochemical and functional properties of the SBs. The overall results suggested that tilapia by-product powders can be potential ingredients for adding functional values to food products.

Optimization of enzymatic protein hydrolysis conditions of Asiatic hard clam (Meretrix meretrix)

This study was aimed to optimise the Alcalase® enzymatic hydrolysis extraction of Asiatic hard clam (AHC) (Meretrix meretrix) protein hydrolysate in terms of hydrolysis time, hydrolysis temperature, hydrolysis pH, and concentration of enzyme. Protein hydrolysate produced from AHC (M. meretrix) meat was used to determine the optimum hydrolysis conditions. Hydrolysis of AHC meat was optimised using the Central Composite Design Response Surface Methodology (RSM) (CCD). The relationship between four parameters such as temperature (45 – 65°C), enzyme to substrate concentration (1 – 2%), hydrolysis time (60 – 180 mins), and pH (7.5 – 9.5) to the degree of hydrolysis was investigated. The optimum conditions for enzymatic hydrolysis of AHC meat to achieve the maximum degree of hydrolysis (DH) were observed at 65°C, enzyme to substrate concentration of 1%, hydrolysis time of 60 mins, and pH 7.5. The enzymatic protein hydrolysis of AHC meat was predicted using a two factors interaction (2FI) model. Under these optimum conditions, DH's predicted value was 97.41%, which was close to the experimental value (97.89%). The freeze-dried protein hydrolysate powder was characterized concerning the proximate composition. Proximate analysis revealed that the AHC meat contains 7.92±1.76% of moisture, 2.23±0.89% of crude fat, 1.98±0.82 of ash, and 10.53±0.04% of crude protein. While the Asiatic hard clam protein hydrolysate (AHCPH) composed 9.12±0.02% of moisture, 0.80±0.29% of crude fat, and 27.76±0.10% of ash. The protein hydrolysate produced also contained high protein content (50.09±0.88%) and may serve as a good protein source.

Hydrolysis products from sockeye (Oncorhynchus nerka L.) heads from the Kamchatka Peninsula produced by different methods: biological value

Introduction. Sockeye salmon (Oncorhynchus nerka L.) is a valuable Pacific salmon. Sockeye heads are a significant share in processing sockeye salmon. Traditionally, fish by-products are used to make fishmeal. However, due to the high content of collagen proteins and fat in sockeye salmon heads, it is difficult to produce fishmeal from this raw material. Controlled enzymatic or combined hydrolysis allows protein, fat, and minerals to be extracted to supply the market with higher value products with desirable features. This research was aimed to analyse the chemical composition and biological value of hydrolysis products obtained from sockeye heads.&#x0D; Study objects and methods. We investigated hydrolysis products of sockeye salmon heads, namely protein hydrolysates, fat and sludge. Thermal hydrolysis and enzymatic-thermal hydrolysis were used for the tests. Thermal hydrolysis was realized in reactor. For enzymatic-thermal hydrolysis, the raw material was pre-treated by proteolytic enzyme Alcalase. The hydrolysates obtained were investigated. Chemical composition was determined in accordance with State Standard 7636-85. HPLC was used for molecular weight and amino acid analysis. Gas chromatography was used for fatty acid analysis. Biological value of proteins was determined by the balance of the amino acid composition comparing it with the “ideal protein model”.&#x0D; Results and discussion. Thermal hydrolysis resulted in the production of protein hydrolysate powder with protein content of 92.0% dry matter and a protein recovery rate of 39.6%. Combined hydrolysis resulted in the production of protein hydrolysate powder with protein content of 92.6% and a protein recovery rate of 83%. All protein hydrolysates contained all essential amino acids. The biological value of protein hydrolysate obtained by thermal and combined hydrolysis was 80.1 and 82.8%, respectively.&#x0D; Conclusion. Hydrolysed products obtained by thermal and enzymatic-thermal hydrolysis had a valuable chemical composition and could be recommended for food and feed use.