Highest Degree Of Hydrolysis Research Articles

Development of Kesari dal (Lathyrus sativus) protein hydrolysates, with reduced β-ODAP content exhibiting anti-oxidative and anti-diabetic properties

Kesari dal was pre-treated to ensure a low β-ODAP neurotoxin (≈ 0.08%) content, following which it was subjected to liquid enzymatic hydrolysis (LEH), solid state enzymatic hydrolysis (SSEH) using alcalase, modified SSEH (MSSEH) using cellulase, amylase and alcalase to produce Kesari dal liquid hydrolysate (KDLH), Kesari dal hydrolysed meal (KDHM) and modified Kesari dal hydrolysed meal (MKDHM) respectively. The hydrolysis was carried out at varying E:S ratios and time of reaction as well as moisture content in the case of SSEH and MSSEH, to yield a higher degree of hydrolysis (DH). The experimental variants of liquid hydrolysates and hydrolysed meals generated from pre-treated Kesari dal flour (KDF), were tested for various physicochemical properties and biological activities. KDLH, KDHM and MKDHM displayed improved protein solubility with a maximum solubility of 58%, 43.3% and 43.2% for the highest DH of 40.1%, 28.7%, 30.9% respectively, achieved in each process. The emulsifying properties and foaming properties of the protein hydrolysates showed a decline with increase in DH. FTIR spectra for KDHM and particularly MKDHM revealed an increase in breakage of peptide bonds, however no change in heat stability was observed under TGA analysis. KDLH, KDHM and MKDHM were subjected to in-vitro protein digestion (IVPD) and their antioxidant activity and antidiabetic activity were evaluated before and after IVPD. Hydrolysed products (KDLH, KDHM and MKDHM) displayed increased bioactivities as compared to unhydrolyzed KD (pre-treated KDF and KDLE) and further displayed either an unaltered or improved antioxidant activity as well as antidiabetic activity after IVPD.

Physicochemical and sensory properties of deep fried battered squid containing Brownstripe red snapper (Lutjanus vitta) protein hydrolysate

Deep-fried food is a fast and convenient way to prepare food that imparts desirable sensory characteristics of colour, flavour and in particular, a smooth texture, yet has been labelled as not healthy by consumers. Incorporation of other ingredients in the formulation of the batter could reduce the fat absorption in deep-fried foods. This research was aimed to determine the physicochemical and sensory properties of Brownstripe red snapper protein hydrolysate (BRSPH) and its utilisation in reducing the oil intake of deep-fried foods. The BRSPH were extracted using the enzymatic method utilizing Alcalase® as the working enzyme. Batter formulations were prepared by adding 0%, 2%, 4%, 6% and 8% of BRSPH into the sample mixtures. Addition of BRSPH into the batter was found to increase hardness and crispness of deep-fat fried battered squids. The fat content of the deep-fat fried battered squids with 8% BRSPH powder was found to be the lowest compared to those added with 2%, 4% and 6%, while sample without BRSPH powder was the highest (30.15%). Deep-fat fried squids with 4% of BRSPH powder showed the best acceptability scores in terms of crispness, taste and overall acceptability, but no significant differences were determined in the crispness between deep-fat fried squids with and without BRSPH. The findings indicate that enzymatic hydrolysis using Alcalase® has the potential to yield BRSPH with a high degree of hydrolysis (98.19%), low molecular weight (10-15 kDa), and low oil binding capacity (2.38 g oil/ g protein). Enzymatic hydrolysis proved to be a viable technique to produce protein hydrolysate which able to reduce the oil uptake and healthier with high acceptability of the end products. Research on how to optimize the use of BRSPH with a high economic, nutritional and industrial potential of understated resources would allow for the implementation of manufacturing practices to enhance the use of resources and increase the value of the by-product. This approach will offer the potential use of BRSPH for the production of batter formulation which is efficient in the reduction of oil uptake

Chicken Combs and Wattles as Sources of Bioactive Peptides: Optimization of Hydrolysis, Identification by LC-ESI-MS2 and Bioactivity Assessment.

The production of bioactive peptides from organic by-waste materials is in line with current trends devoted to guaranteeing environmental protection and a circular economy. The objectives of this study were i) to optimize the conditions for obtaining bioactive hydrolysates from chicken combs and wattles using Alcalase, ii) to identify the resulting peptides using LC-ESI-MS2 and iii) to evaluate their chelating and antioxidant activities. The hydrolysate obtained using a ratio of enzyme to substrate of 5% (w/w) and 240 min of hydrolysis showed excellent Fe2+ chelating and antioxidant capacities, reducing Fe3+ and inhibiting 2, 2′-Azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. The mapping of ion distribution showed that a high degree of hydrolysis led to the production of peptides with m/z ≤ 400, suggesting low mass peptides or peptides with multiple charge precursor ions. The peptides derived from the proteins of cartilage like Collagen alpha-2(I), Collagen alpha-1(I), Collagen alpha-1(III) and elastin contributed to generation of bioactive compounds. Hydrolysates from chicken waste materials could be regarded as candidates to be used as ingredients to design processed foods with functional properties.

Preparation of poly(tert‐butyl acrylate)‐poly(acrylic acid) amphiphilic copolymers via radiation‐induced reversible addition–fragmentation chain transfer mediated polymerization of tert‐butyl acrylate

AbstractPoly(tert‐butyl acrylate) (PtBA) is a versatile hydrophobic macromolecule usually preferred in the development of new materials for a host of applications. PtBA homopolymers with well‐defined structure and controlled molecular weight in a wide range were successfully synthesized via radiation‐induced reversible addition–fragmentation chain transfer (RAFT) polymerization in the presence of a trithiocarbonate type RAFT agent. The polymerization of tBA was performed under 60Co γ‐irradiation in the presence of 2‐(dodecylthiocarbonothioylthio)‐2‐methylpropionic acid (DDMAT) as the RAFT agent in toluene at room temperature with three [tBA]/[DDMAT] ratios (400, 600 and 1000) and different irradiation times. Radiation‐induced polymerization of tBA displayed controlled free radical polymerization characteristics: a narrow molecular weight distribution (Mw/Mn ~ 1.1), pseudo first order kinetics and controlled molecular weights. The system followed the RAFT polymerization mechanism even at very low amounts of RAFT agent ([tBA]/[DDMAT] = 1000), and molecular weights up to 113 900 with narrow dispersity (Ð =1.06) were obtained. PtBA was further hydrolysed into different amphiphilic PtBA‐co‐poly(acrylic acid) (PAA) copolymers by low (27.5%) and high (77.3%) degrees of hydrolysis. The pH sensitivity of the two copolymers was investigated by dynamic light scattering at pH 2 and pH 9 (above and below the pKa value of PAA) and their hydrodynamic diameters and zeta potential values were determined. © 2020 Society of Chemical Industry

Hydrolysis of plant proteins at the molecular and supra-molecular scales during in vitro digestion

The digestion of plant protein is highly dependent on multiple factors, with two of the most important being the protein source and the food matrix. The present study investigated the effects of these two factors on the digestion of seitan (a wheat-based food), tofu, soya juice, and a homemade emulsion of soy oil and water that was stabilised with pea protein. The four plant matrices and their respective protein isolates/concentrates (wheat gluten, soya protein, pea protein) were subjected to in vitro static digestion following the INFOGEST consensus protocol. We monitored the release of α-amino groups during digestion. We found that food matrix had a strong influence on protein digestion: soya juice was more hydrolysed than fresh tofu (51.1% versus 33.1%; P = 0.0087), but fresh tofu was more hydrolysed than soya protein isolate (33.1% versus 17.9%; P < 0.0001). Likewise, the pea-protein emulsion was better hydrolysed than the pea-protein isolate (P = 0.0033). Differences were also detected between the two solid foods investigated here: a higher degree of hydrolysis was found for tofu compared to seitan (33.1% versus 11.8%), which was perhaps a function of the presence of numerous dense protein aggregates in the latter but not the former. Furthermore, freeze-drying more than doubled the final degree of hydrolysis of seitan (P < 0.0001), but had no effect on tofu (P = 1.0000). Confocal microscopy revealed that protein networks in freeze-dried seitan were strongly altered with respect to the fresh product; instead, protein networks in freeze-dried and fresh tofu were largely similar. Finally, we found that the protease:protein ratio had a strong effect on the kinetics of proteolysis: a 3.7-fold increase in the concentration of the soya protein isolate with respect to that of the soya juice decreased the final degree of hydrolysis from 50.3 to 17.9% (P = 0.0988).

Development and stability of novel selenium colloidal particles complex with peanut meal peptides

A novel selenium nanoparticles (SeNPs) was prepared by using peanut meal peptides mixture (Ppm) as a stabilizer in ascorbic acid reduction sodium selenite system. It was found that Ppm prepared by alcalase and neutral protease had high degree of hydrolysis and antioxidant activity and the obtained Ppm-SeNPs solution were stabilized at 4 °C for 60 days with an average particle size of 140 nm. The interaction and morphological characterization revealed that Ppm-SeNPs were spherical and wrapped by Ppm successfully which may contributed to electrostatic and hydrophobic interaction. The results of infrared spectroscopy indicated that the N- and O- functional groups on the Ppm were combined with SeNPs. Moreover, ascorbic acid and cysteine were compared as the reducing agents for reducing sodium selenite, it turned out that the stability of Ppm-SeNPs obtained by ascorbic acid as reducing agent was better than that of cysteine.

Phytochemical Compounds and Antioxidant Activity Modified by Germination and Hydrolysis in Mexican Amaranth.

Amaranth (Amaranthus spp.) grains have become essential for human health and nutrition; due to the presence of bioactive compounds that have shown some biological activities. This study aimed to evaluate the effect of germination, enzymatic hydrolysis, and its combination on the phytochemical compounds and antioxidant activity in Mexican amaranth. Germinated amaranth flours (GAF) exhibited increases in the concentrations of soluble protein (SP), total phenolic content (TPC), total flavonoid content (TFC), total anthocyanin content (TAC) and antioxidant activity (AOX) by 35.7, 17.2, 163.0, 1472.2, and 54.3%, respectively, compared with ungerminated amaranth flours (UAF). In SDS-PAGE, both hydrolysates of UAF and GAF exhibited low molecular weight bands (< 10kDa). The hydrolysates of UAFH and GAFH had the highest degree of hydrolysis at 205min of sequential hydrolysis (pepsin with pancreatin) time with 73.4 and 60.3%, respectively. Both hydrolysates obtained from GAF and UAF released significantly SP, TPC, TFC after sequential enzymatic hydrolysis (up 205min), which led to a remarkable improvement of AOX when compared to nonhydrolyzed amaranth samples. The UAFH and GAFH had the best AOX at 270min of enzymatic hydrolysis with 983.1 and 1304.9μmol TE/mg SP, respectively. Hence, the combination of germination and enzymatic hydrolysis could be used to produce functional ingredients for food product development.

Antioxidant and chelating activities from Lion fish (Pterois volitans L.) muscle protein hydrolysates produced by in vitro digestion using pepsin and pancreatin.

The aim of the present research was to determine the antioxidant, and Cu2+ and Fe2+ chelating activities, amino acid content and estimated molecular weight of proteins and peptides from lion fish muscle-derived hydrolysates obtained by enzymatic hydrolysis with pepsin and pancreatin. The fillets were freeze-dried and hydrolysis was performed, taking aliquots at different times. The degree of hydrolysis, antioxidant activity against ABTS+ and DPPH, Cu2+ and Fe2+ chelating activity, as well as molecular weight estimated by SDS-PAGE and amino acid content by HPLC was determined. The highest degree of hydrolysis (DH) was at 180 min (37.75%). SDS-PAGE showed proteins with an estimated molecular weight of 45,259 and 42,487 Da, which could be associated with myofibrillar proteins. The progressive degradation of proteins by enzymes was also observed, detecting polypeptides with a EMW of 5,988 and 4,954 Da in the most representative hydrolysates. The H40 hydrolysate exhibited the highest ABTS and DPPH radical depuration activity, with values of 107.31 mM/mg protein and 54.27%, respectively. The iron and copper chelating activity was related to DH, since the highest values of iron and copper chelating activity were obtained in hydrolysates H120 and H140, with 90.83% chelation of Cu2+ and 56.33% chelation of Fe2+, respectively with no significant differences compared to subsequent times. In addition, the antioxidant and chelating activities were possibly related to Trp, Cys, Lys, Pro and Arg content. Lion fish muscle hydrolysates could be a potential source of functional ingredients due to their in vitro antioxidant and chelating activity.

Study on the culture of Escherichia coli with different hydrolysis depth of globin

Objective: To explore the effect of culture medium made of peptide fragments of different sizes of globin hydrolyzed by protease on the culture of Escherichia coli. Method: with fresh pig blood as raw material, hydrolyze pig blood protein under fixed conditions, and screen out the enzyme with the highest degree of hydrolysis. Then conduct orthogonal test on the enzyme to determine the best hydrolysis conditions; the beads were obtained under the best hydrolysis conditions. The Escherichia coli was cultured on different peptone culture bases that were prepared by hydrolysate going through different pore size ultrafiltration membrane samples. The culture of Escherichia coli at different hydrolysis depths is determined by detecting the total amount with Escherichia coli detection method. Results: Trypsin has the best hydrolysis effect. The best hydrolysis conditions are as follows: enzyme dosage of 0.2%, hydrolysis time of 12h, temperature of 50°C, initial pH of 7.5 and mass fraction of substrate protein of 8%. Through growth curves of Escherichia coli, it is known that the smaller the pore size of the ultrafiltration membrane, the smaller the molecular weight of the peptide fragment, and the greater the density of the Escherichia coli bacterial solution. Conclusion: Through analyzing the production curves of Escherichia coli in different culture medium, it is concluded that the smaller the molecular weight of the protein peptides, the higher the density of Escherichia coli solution in the LB liquid medium prepared by it, and the better the Escherichia coli culture effect.

Influence of enzymatic hydrolysis conditions on biochemical and antioxidant properties of pacific thread herring (Ophistonema libertate) hydrolysates

ABSTRACT Pacific thread herring (Ophistonema libertate) muscle was hydrolyzed with Alcalase for the preparation of protein hydrolysates. The effect of enzyme concentration (EC; 1% and 3%), pH (8 and 9) and temperature (40°C and 50°C) on some biochemical properties and antioxidant activity (AOXA) was determined. The degree of hydrolysis (DH) ranged between 9.6% and 33.1%. The highest DH was obtained with the following conditons: EC of 3%, pH 9 and temperature of 50°C; however, the highest AOXA measured by DPPH (183.7 µmol TE/mg), FRAP (0.98 µmol TE/mg), and ABTS (144.9 µmol TE/mg) was obtained at EC of 3%, pH 8 and temperature of 50°C. These also exhibited a higher percentage of peptides of MW lower than 1.35 kDa and high concentrations of anionic and cationic amino acids. These results suggest that protein hydrolysates from Pacific thread herring muscle have a potential for application in the formulation of functional food.

The Potential of Fractionated Rice Bran Protein Hydrolysates as Antioxidative and Anti-Inflammatory Agents.

Rice bran is generally used as animal feed despite containing numerous nutritional compounds. Small peptides possessing high antioxidant activity can be obtained from rice bran protein via enzymatic hydrolysis. Immune-modulating and antioxidative activity of rice bran protein hydrolysates from crude rice bran protein and its fractions were studied. Albumin, globulin, glutelin, and prolamin proteins were fractionated based on solubility differences and hydrolyzed with two types of enzyme, namely pepsin and protease M. Albumin fraction showed a high degree of hydrolysis in both enzymes. Protease M differently digested rice bran protein fractions, in which it showed low digestion in glutelin and prolamin fractions. After 30 min of hydrolysis time, the reaction slowed down, and antioxidant activity remained constant in pepsin hydrolysis. Due to the high presence of lipopolysaccharide (LPS) in protease M digested fractions (caused by the enzyme), it could not be used to determine immune-modulating activity. THP-1 macrophages were simultaneously stimulated with 100 ng/mL LPS and rice bran protein hydrolysates from 4 h of pepsin digestion. Reduction of pro-inflammatory cytokine IL-1β and increase of anti-inflammatory cytokine IL-10 were observed from crude rice bran protein and albumin. In conclusion, pepsin-digested rice bran protein could be potentially used as antioxidative and anti-inflammatory agent.

Novel double-layered planar scaffold combining electrospun PCL fibers and PVA hydrogels with high shape integrity and water stability

Novel double-layered materials with different properties of each side were prepared via needleless electrospinning and compared in terms of morphology, wettability, adhesion and proliferation of mouse fibroblasts. The materials consist of hydrophilic poly(vinyl alcohol) fibers with low (PVA_L) or high (PVA_H) degree of hydrolysis, and hydrophobic poly(ε-caprolactone) (PCL) fibrous layer. Although the PVA_L fibers were fully dissolved following a water exposure, the shape of the scaffold was maintained due to water stable PCL layer. Exposing PVA_H based fibrous layer to water created a hydrogel-like structure with shape defined by the PCL layer. According to the MTT assay, the mouse fibroblasts seeded on the scaffold exhibited the greatest proliferative activity on the PCL fibers. These double-layered scaffolds with different features on each side are very promising for many novel medical applications such as wound dressing or abdominal adhesion prevention.

BIOCONVERSION OF SECONDARY PRODUCTS OF PROCESSING OF GRAIN CEREALS CROPS

A method has been developed for the production of organic ingredients from secondary products resulting from the high-quality grinding of triticale and wheat into flour, which involves the enzymatic action of amylolytic enzymes to release starch polysaccharides while preserving the native properties of dietary fibers and biologically active substances associated with them. To a large extent, the features of the properties of the obtained ingredients are due to the number and composition of the components of dietary fiber of grain, as well as the morphological features of their structure. It is shown that the viscosity of aqueous colloidal systems at a concentration of soluble dietary fiber of the ingredient 0.5 % increases 11 times; at a concentration of 1.0 % — 30 times, forming a viscous gel-like structure. This allows them to be used for gelling, thickening and stabilization of aquatic food systems. The use of ingredients with a high content of NLP in baking is possible only taking into account their water absorption capacity. A method for the enzymatic modification of secondary products of processing of grain triticale was developed. On the basis of the study of the kinetics and efficiency of the effect of proteolytic and cellulolytic enzyme preparations (EP) and their compositions, optimal conditions for enzymatic modification (the EP dosage is 0.5…0.75 units of PA/g of bran, 0.3…0.4 units of CA/g of bran, the optimum temperature is 40–50 °С, pH is 5.0 and 3.5, the duration of reactions is 1.5 hours) have been determined. The use of cellulolytic EP allowed to increase the amount of reducing substances and soluble protein by 1.5–2.5 times in comparison with the control sample. The biomodified bran obtained using the MEC «Shearzyme 500 L» + «Neutrase 1.5 MG» and «Viscoferm L» + «Distizym Protacid Extra» has a high degree of hydrolysis of non-starch polysaccharides and proteins, is characterized by a certain ratio of high-, medium-, low-molecular peptides and amino acids, has different functional and technological properties. They can be used in the production of a wide range of general-purpose, functional and treatmentand-prophylactic food products.

Valorization of Aquaculture By-Products of Salmonids to Produce Enzymatic Hydrolysates: Process Optimization, Chemical Characterization and Evaluation of Bioactives.

In the present manuscript, various by-products (heads, trimmings, and frames) generated from salmonids (rainbow trout and salmon) processing were evaluated as substrates for the production of fish protein hydrolysates (FPHs), potentially adequate as protein ingredients of aquaculture feeds. Initially, enzymatic conditions of hydrolysis were optimized using second order rotatable designs and multivariable statistical analysis. The optimal conditions for the Alcalase hydrolysis of heads were 0.1% (v/w) of enzyme concentration, pH 8.27, 56.2°C, ratio (Solid:Liquid = 1:1), 3 h of hydrolysis, and agitation of 200 rpm for rainbow trout and 0.2% (v/w) of enzyme, pH 8.98, 64.2 °C, 200 rpm, 3 h of hydrolysis, and S:L = 1:1 for salmon. These conditions obtained at 100 mL-reactor scale were then validated at 5L-reactor scale. The hydrolytic capacity of Alcalase and the protein quality of FPHs were excellent in terms of digestion of wastes (Vdig > 84%), high degrees of hydrolysis (Hm > 30%), high concentration of soluble protein (Prs > 48 g/L), good balance of amino acids, and almost full in vitro digestibility (Dig > 93%). Fish oils were recovered from wastes jointly with FPHs and bioactive properties of hydrolysates (antioxidant and antihypertensive) were also determined. The salmon FPHs from trimmings + frames (TF) showed the higher protein content in comparison to the rest of FPHs from salmonids. Average molecular weights of salmonid-FPHs ranged from 1.4 to 2.0 kDa and the peptide sizes distribution indicated that hydrolysates of rainbow trout heads and salmon TF led to the highest percentages of small peptides (0–500 Da).

Separation and Purification of Antioxidant Peptides from Enzymatically Prepared Scorpion (Buthus martensii Karsch) Protein Hydrolysates

The purpose of this study was to separate and purify antioxidant peptides from the scorpion (Buthus martensii Karsch) protein hydrolysates (SPHs). Scorpion protein (SP) was first hydrolyzed by trypsin, papain, and alcalase, respectively. Results from hydrolysis tests revealed that peptides hydrolyzed with papain showed the highest degree of hydrolysis (DH), yield and antioxidant activity. The effect of papain hydrolysis on scorpion protein was optimized using the response surface methodology. The highest DH (31.31%) and yield (52.02%) of SPHs were obtained under the following conditions: hydrolysis time, 4.0 h; hydrolysis temperature, 50 °C; and enzyme/substrate ratio, 2.43%. Ultrafiltration, gel filtration and reversed-phase high-performance liquid chromatography was used and two novel antioxidant peptides were obtained. The sequences of the peptides determined by MALDI–TOF–MS/MS were LPTETLH (MW: 810.43 Da, P4-1) and IEEDLER (MW: 903.44 Da, P4-2), respectively. The results revealed SPHs as a potential valuable bioresource for production of antioxidant peptides in the food system.

Optimization of process conditions for the development of rice milk by using response surface methodology

Rice milk is a dairy product alternative for who are allergenic milk protein, lactose and concern about cholesterol. Unlike cow’s milk, rice milk contains little protein but has a higher carbohydrate content. The purpose of this research was to study the optimal condition to develop rice milk nutritionally equivalent to cow milk with consumer acceptability. In this study, we used rice protein concentrate, rice flour, rice bran oil, sugar and calcium lactate as ingredients. Firstly, the selection of enzymes for rice protein hydrolysis was carried out and neutrase had high degree of hydrolysis with the highest consumer acceptability (p<0.05). Response surface methodology (RSM) base on central composite design was then employed to investigate the optimum condition with three independent variables: enzyme: protein ratios, speeds and times of homogenization. Our results reveal that the experimental variables significantly affected the color and sensory attributes. The optimum condition for rice milk production was found to be 16000 rpm,20 minutes of homogenization and 1:40 (w/w). The milk produced from this condition had protein 3.14 %, fat 3.28%, fiber 0.45%, ash 0.44% moisture 86.85% and carbohydrate 5.84%, which was similar to the nutritional value of cow’s milk. The developed product showed good nutritional and sensory characteristics and this could be used for the development of commercial rice milk beverage after conducting appropriate scale up and pilot plant study.

Revealing Antioxidant and Antidiabetic Potency of Melinjo (Gnetum Gnemon) Seed Protein Hydrolysate at Different Stages of Seed Maturation

roteins hydrolyzed from melinjo seeds (Gnetum gnemon) at green (GM), yellow (YM) and red (RM) stages of maturity were studied for their effectiveness in antioxidant and antidiabetic activities. The seed protein extract was hydrolyzed using alcalase 2.4L, and the resulting hydrolysates with the highest degree of hydrolysis, protein profile, and the most potent contributors to antioxidant and invitro antidiabetic activities were identified. The degree of hydrolysis value of hydrolysates ranged from 52-84%, and the SDS-PAGE protein profile showed two distinct bands in which the band with molecular weight of 30 kDa degraded more intensively. Antioxidant capacity was measured using different standard methods, including radical cation 2,2-azinobis-(3-ethylbenzothizoline-6-sulphonate) (ABTS•+) assay, hydroxyl radical (OH•), and superoxide anion (O2•-) scavenging. The green hydrolysate (GMH) had significantly higher (p&lt;0.05) free radical scavenging (ABTS•+, OH•, and O2•-) activities than that of the yellow hydrolysate (YMH) and red hydrolysate (RMH). However, invitro antidiabetic testing was performed based on the inhibitory activity of α-amylase and α-glucosidase. GMH was found to be more effective than YMH and RMH. These results showed that the antioxidant and antidiabetic activity in hydrolyzed GM protein has high potential to be utilized as natural nutraceuticals.

Effects of enzyme-modified soybean beverage on the composition, yield, functionality and microstructure of Cheddar cheese-like products

Using soybean beverage can improve the nutrition of cheeses and expand their varieties. However, addition of soybean beverage results in cheese-like products with undesirable soft texture and loose structure. Herein, soybean beverage was treated with flavourzyme and then mixed with cow milk to prepare Cheddar cheese-like products, and the chemical composition was not standardized before the production. Compared with non hydrolysis soybean beverage, enzyme-modified soybean beverage significantly decreased the moisture content and yield of cheese-like products, increased the protein and fat content and pH, but had no effect on protein and fat recoveries. Changes were more dramatic in products with high degree of soybean beverage hydrolysis. Hardness and storage modulus were increased upon addition of enzyme-modified soybean beverage, and especially values of products supplemented with high hydrolysis soybean beverage were comparable with those of products made only with cow milk. The protein matrix became compact upon adding enzyme-modified soybean beverage, with numerous small whey pockets, similar to the microstructure of products made only with cow milk. Thus, without decreasing the yield, low hydrolysis soybean beverage can effectively improve the texture and structure of Cheddar cheese-like products.

Enzymatic hydrolysis of okara protein concentrate by mixture of endo and exopeptidase

The objective of this study was to obtain a model and optimize the enzymatic hydrolysis of okara protein concentrate using a combined mixture of alcalase and flavourzyme. The highest degree of hydrolysis (DH) was 22% obtained at 40°C, enzyme/substrate ratio of 5 g/100 g protein, pH of 7.1, and alcalase/flavourzyme ratio of 90%/10%. Additionally, under optimal condition, protein hydrolysates with DH 0, 6, 12, 18, and 22% were obtained and analyzed. Protein hydrolysis was confirmed by the electrophoretic profile, which showed diffuse bands with smaller molecular weight. The total amino acid profile showed that the protein hydrolysate with DH 22% had a balanced composition of all essential amino acids. All protein hydrolysates contained threefold higher aglycone isoflavone content than the okara protein concentrate. Enzymatic hydrolysis enhanced the antioxidant capacity of the protein hydrolysates, which was approximately 2.3- and 2.7-fold higher according to ABTS and FRAP analyses, respectively, compared to the intact protein. Thus, the protein hydrolysate can be incorporated into real food systems as a natural antioxidant alternative to the synthetic compounds. Practical applications Bioactive compounds have increasingly been studied due to their beneficial effects, such as antioxidant capacity. Therefore, it is necessary to research how to obtain these bioactive compounds and what are the most important parameters to obtain an efficient process. Most papers evaluated the hydrolysis process using only one enzyme. In this work, a central composite rotatable design was carried out to optimize the use of two enzymes with different specificities to obtain bioactive compounds with high antioxidant capacity.

Comparative studies on the antioxidant potential of hydrolysates of &lt;i&gt;Mormyrus rume&lt;/i&gt; muscle protein

This study determined the degree of hydrolysis of Mormyrus rume muscle proteins by digestive proteases and the antioxidant potential of the hydrolysates produced was evaluated. The proteins were extracted with distilled water adjusted to neutral pH. The proteases used include trypsin, chymotrypsin and pepsin and the degree of hydrolysis was determined using trichloroacetic acid precipitation method. The antioxidative activities of the hydrolysates were evaluated using different in-vitro antioxidant assay methods such as 1,1-diphenyl-2- picrylhydrazyl (DPPH) radical scavenging, hydrogen peroxide scavenging, metal chelating capacity and reductive potentials. Degree of hydrolysis was generally low and ranges between 17.68% and 32.20% with pepsin given the highest degree of hydrolysis. The protein hydrolysates obtained with trypsin exhibited the highest antioxidant activities when assessed with metal chelating activity assay with half maximal inhibitory concentration (IC ) of 0.32 ± 0.01 mg/ml; hydrogen peroxide scavenging assay with IC of 0.18 ± 0.01 mg/ml 50 50 and reductive potential of 0.41 ± 0.002 units at the highest concentration tested (1.0 mg/ml). Pepsin-produced hydrolysates showed the highest DPPH radical scavenging potential at all concentrations with IC of 0.35 ± 50 0.003mg/ml. The study concluded that the hydrolysates produced contain bioactive peptides which possessed significant amount of antioxidant activities, which may be a promising health promoting agent if isolated. Keywords : Hydrolysates, Pepsin, Trypsin, Chymotrypsin, Antioxidant, Enzyme, Mormyrus rume .