Optimization of enzymatic hydrolysis of Pleurotus ostreatus derived proteins through RSM and evaluation of nutritional and functional qualities of mushroom protein hydrolysates

Pleurotus ostreatus (Jacq.) P. Kumm., the second most widely cultivated oyster mushroom was grown on paddy straw, which is cheap and readily available waste material. After harvesting and drying, nutritional, and antinutritional composition of P. ostreatus were estimated using the standard assay methods. Tannin and phytic acid were present in very negligible amount (0.095 ± 0.027 mg/g and 0.150 ± 0.083 mg/g, respectively), whereas oxalate and cyanide were absent in whole mushroom. In fact, P. ostreatus was hydrolysed with commercially available proteinase K, pepsin and trypsin with different concentrations of the enzymes (0.05%, 0.10% and 0.15%), at different temperatures (30 °C, 40 °C and 50 °C) for different time periods (60, 90 and 120 min) to get the mushroom protein hydrolysates. Degree of hydrolysis and protein content varied from 4.29 ± 1.12% to 99.42 ± 0.02% and from 0.25 ± 0.07 mg/mL to 3.22 ± 0.12 mg/mL, respectively. Maximum degree of hydrolysis and the highest protein content of protein hydrolysate was obtained when using 0.15% proteinase K, at 50 °C for 120 minutes. Mushroom protein hydrolysates thus obtained exhibited improved functional characteristics such as foaming capacity, foaming stability and emulsifying property than the unhydrolysed mushroom. Based on the result of the present study, the mushroom protein hydrolysates could be served as useful ingredient for food and nutraceutical applications.

Hidrolisis Protein Teripang Hitam (Holothuria edulis) Menggunakan Bromelin Kasar dari Batang Nanas (Ananas comocus L)

Black sea cucumber is one type of sea cucumber whose protein content is quite high at 74-82%, not yet widely used by the community as a source of protein. One way to use it is to process the protein into a protein hydrolyzate using the bromelain enzyme which was isolated from pineapple stems. This study aims to determine the concentration of the bromelain enzyme extract and the optimum hydrolysis time to the value of the hydrolysis degree of the hydrolyzate of black sea cucumber protein. Protein hydrolysates are produced by variations of the crude bromelain concentration of 9%, 10%, 11%, and 12% (v/v) and hydrolysis time of 120, 180, 240, and 300 minutes. The results showed that the optimum degree of hydrolysis was obtained with the use of bromelain extract with a concentration of 12% with a value of 11.43% and a hydrolysis time of 240 minutes with a value of 19.17%.

Effects of High-Intensity Ultrasound Pretreatment on Structure, Properties, and Enzymolysis of Walnut Protein Isolate

The purpose of this paper was to investigate the effect of high-intensity ultrasonication (HIU) pretreatment before enzymolysis on structural conformations of walnut protein isolate (WPI) and antioxidant activity of its hydrolysates. Aqueous WPI suspensions were subjected to ultrasonic processing at different power levels (600–2000 W) and times (5–30 min), and then changes in the particle size, zeta (ζ) potential, and structure of WPI were investigated, and antioxidant activity of its hydrolysates was determined. The particle size of the particles of aqueous WPI suspensions was decreased after ultrasound, indicating that sonication destroyed protein aggregates. The ζ-potential values of a protein solution significantly changed after sonication, demonstrating that the original dense structure of the protein was destroyed. Fourier transform infrared spectroscopy indicated a change in the secondary structure of WPI after sonication, with a decrease in β-turn and an increase in α-helix, β-sheet, and random coil content. Two absorption peaks of WPI were generated, and the fluorescence emission intensity of the proteins decreased after ultrasonic treatment, indicating that the changes in protein tertiary structure occurred. Moreover, the degree of hydrolysis and the antioxidant activity of the WPI hydrolysates increased after sonication. These results suggest that HIU pretreatment is a potential tool for improving the functional properties of walnut proteins.

FUNCTIONAL PROPERTIES OF CATFISH SKIN COLLAGEN HYDROLYSATES

Collagen hydrolysates were obtained from catfish skin collagen hydrolysis using catfish collagenase, pepsin and trypsin individually and mixed for 15-300min. The degree of hydrolysis , antioxidant activity based on, DPPH radical-scavenging activity (RSA), and reducing power (RP) for all obtained hydro lysates were studied , then the collagenase hydrolysate was (CH) was selected to be evaluated for antibacterial activity , functional properties including solubility, emulsification and foaming properties besides the toxicity . The highest values for RSA (72.5%) has been noticed when DH reached (24.30%) after 30 min. of hydrolysis by collagenase (CH). The water and oil holding capacities for this hydro lysate was compared to that for ASC (acid soluble collagen and PSC (pepsin soluble collagen), the results showed that the values recorded by CH were significantly higher than ASC & PSC. The molecular weight of CH peptides ranged from 180 to 11 Da. as analyzed by SDS- PAGE. The toxicity assay result revealed that CH is safe for human consumption. There was no antibacterial function for CH toward E.coli and S. aureus. At concentration of 2mg/ml. This study suggests that catfish collagen hydro lysate could be a good natural alternative for synthetic antioxidants in food industries.

Preparation of maltotetraose starch molasses using Maltotetraohydrolase Optimalt 4G

Одним из направлений решения актуальной задачи по расширению ассортимента сахаристых крахмалопродуктов является разработка способов получения мальтоолигосахаридов с различным углеводным составом, имеющих большой потенциал для использования в качестве пищевых добавок и ингредиентов продуктов здорового питания. Целью работы было изучение возможности получения нового вида крахмальной патоки с высоким содержанием мальтотетраозы с применением препарата мальтотетраогидролазы Optimalt 4G. Объектами являлись кукурузный крахмал, препараты альфа-амилазы Liquazyme Supra 2.8X и пуллуланазы Promozyme D6 (Novozymes), мальтотетраогидролазы Optimalt 4G (Du Pont), а также продукты гидролиза крахмала. Использованы методы определения массовой доли редуцирующих веществ (РВ), сухого вещества (СВ), углеводного состава, динамической вязкости гидролизатов и другие стандартные методы анализа. При осахаривании частично гидролизованной суспензии крахмала с концентрацией СВ 33 % и содержании РВ 7,9 % мальтотетраогидролаза наиболее активно действует в первые 3 ч осахаривания с резким снижением вязкости гидролизата с 197,6 до 20,0 мПа·с. При этом исчезали практически все олигосахариды с DР5-DР10, массовая доля ВМС снизилась на 60 %, увеличилось количество низкомолекулярных сахаров, а массовая доля мальтотетраозы составила 44,81 % против 2,38 % в исходном субстрате. Максимальное содержание мальтотетраозы 49,8 % в данных условиях наблюдалось в гидролизате после 8 ч инкубации, далее оно медленно снижалась. Установлена возможность получения крахмальной патоки с высоким содержанием мальтотетраозы до 45-48 % с использованием в качестве катализаторов гидролиза крахмала вышеуказанных ферментных препаратов. Использование композиции мальтотетраогидролазы с пуллуланазой увеличивает содержание мальтотетраозы на 1,5-2 %, снижает вязкость гидролизатов и позволяет сократить продолжительность гидролиза. Полученные данные являются актуальной основой для оптимизации технологических параметров процесса осахаривания с применением мальтотетраогидролазы с целью разработки технологии получения нового вида крахмальной патоки. One of the directions of solving the current problem of expanding the range of sugar starch products is the development of methods for producing maltooligosaccharides with a different carbohydrate composition, which have great potential for use as food additives and ingredients of healthy foods. The aim of the work was to study the possibility of obtaining a new type of starch syrup with a high content of maltotetraose using the preparation Maltotetraohydrolase Optimalt 4G. The objects were: corn starch, alpha-amylase preparations Liquazyme Supra 2.8X and pullulanase Promozyme D6 (Novozymes), maltotetraohydrolase Optimalt 4G (Du Pont), as well as starch hydrolysis products. Methods were used to determine the weight fraction of reducing substances (RS), dry solid (DS), carbohydrate composition, dynamic viscosity of hydrolysates and other standard methods of analysis. When a partially hydrolyzed suspension of starch with a concentration of DS 33 % and RS 7.9 % is saccharified, maltotetraohydrolase is most active in the first 3 hours of saccharification with a sharp decrease in the viscosity of the hydrolysate from 197.6 to 20.0 mPa·s. At the same time, almost all oligosaccharides with DP5-DP10 disappeared, the weight fraction of WMS decreased by 60 %, the number of low-molecular sugars of DP1-3 increased, and the weight fraction of maltotetraose was 44.81 % versus 2.38 % in the original substrate. The maximum maltotetraose content of 49.8 % under these conditions was observed in the hydrolysate after 8 hours of incubation, then it slowly decreased. It has been found that in order to obtain hydrolysates with a low DP1-3 content and increased (more than 45 %) maltotetraose, the degree of preliminary hydrolysis must be maintained within the range of RS 8-15 % by DS at an enzyme dosage of 0.06-0.08 units WMC/g DS starch and duration of saccharification up to 20 h. Use of maltotetraohydrolase composition with pullulanase during saccharification increases degree of hydrolysis and content of maltotetraose by 1.5-2 %, reduces viscosity of hydrolysates and reduces duration of hydrolysis. It is possible to produce starch syrup with high content of maltotetraose (up to 45-48 %) using the above enzyme preparations. The obtained data are the current basis for optimization of technological parameters of saccharification process with application of maltotetraohydrolase in order to develop technology of production of new kind of starch syrup.

Assessing the Enzymatic Hydrolysis of Salmon Frame Proteins through Different By-Product/Water Ratios and pH Regimes

The enzymatic hydrolysis of fish by-product proteins is traditionally carried out by mixing ground by-products with water. In addition, pH control is used to avoid pH drops. Higher costs are involved due to the use of pH control systems and the consequent energy cost in the drying stage. This work aimed to evaluate the effect of these conditions on the hydrolysis of salmon frame (SF) proteins, including the SF hydrolysis without added water. SF hydrolysis by subtilisin at 50, 75, and 100% SF under different pH regimes were evaluated by released α-amino (α-NH) groups, total nitrogen, degree of hydrolysis, and estimated peptide chain length (PCL) at 55 °C. The concentration of released α-NH groups was higher in the conditions with less added water. However, the nitrogen recovery decreased from 50 to 24% at 50 and 100% SF, respectively. Changing the SF/water ratio had a more significant effect than changing the pH regime. Estimated PCL changed from 5–7 to 7–9 at 50 and 100% SF, respectively. The operating conditions affected the hydrolysis performance and the molecular characteristics of the hydrolysate.

Optimization of Enzymatic Hydrolysis by Alcalase and Flavourzyme To Enhance the Antioxidant Properties of Jasmine Rice Bran Protein Hydrolysate

This study aimed to optimize the hydrolysis conditions for producing jasmine rice bran protein hydrolysate (JBH) using response surface methodology (RSM). The independent variables were the ratio of flavourzyme to alcalase (Fl: Al; 0: 100 to 15: 85; 2.84% enzyme concentration) and hydrolysis time (60–540 min). The optimum hydrolysate was obtained at an Fl: Al ratio of 9.81: 90.19 for 60 min, since it enabled high amounts of protein, high antioxidant activity and more low molecular weight proteins. The experimental values obtained were a degree of hydrolysis (DH) of 7.18%, a protein content of 41.73%, an IC50 for DPPH of 6.59 mg/mL, an IC50 for ABTS of 0.99 mg/mL, FRAP of 724.81 mmol FeSO4/100 g, and 322.35 and 479.05 mAU*s for peptides with a molecular weight of <3 and 3–5 kDa, respectively. Using a mixture of enzymes revealed the potential of mixed enzymes to produce JBH containing more small peptides and high antioxidant activity.

Influence of Commercial Protease and Drying Process on Antioxidant and Physicochemical Properties of Chicken Breast Protein Hydrolysates

Different proteases can be applied to produce certain bioactive peptides. This study focused on the effects of some commercial proteases and drying processes on the physical, chemical, and biological properties of chicken breast hydrolysates (CBH). Chicken breast hydrolyzed with Alcalase® presented a higher degree of hydrolysis (DH) than papain. Moreover, the treatment with Alcalase®, followed by papain (A-P), was more proficient in producing antioxidant activities than a single enzyme treatment. Conditions comprising 0.63% Alcalase® (w/w) at pH 8.0 and 52.5 °C for 3 h, followed by 0.13% papain (w/w) at pH 6.0 and 37 °C for 3 h, resulted in the highest yields of DH and peptide contents. The spray-dried microencapsulated powder improved the physicochemical properties including moisture content, color measurement, solubility, and particle morphology. In summary, the dual enzyme application involving the hydrolysis of Alcalase® and papain, coupled with the spray-drying process, could be used to produced antioxidant CBH.

Upgrading the fermentability and prebiotic potential of palm decanter cake through fibre-degrading enzymatic treatments

Palm oil milling has produced tonnes of solid waste including palm decanter cake (PDC). The recalcitrant nature of PDC limits its full inclusion in animal feed. This study aims to investigate the effect of fibre-degrading enzyme such as cellulase and xylanase on the prebiotic activity and solid state fermentability of PDC. We used the following commercial enzyme loading: 5U cellulase (5UC), 5U xylanase (5UX) and combined enzymatic treatment 2.5U:2.5U (C25U) per gram of substrate to hydrolyse the defatted PDC. The sugar profile in the effluent was analysed by using high-performance liquid chromatography, and the degree of hydrolysis (DH) was estimated based on the total carbohydrates amount in the effluent. The DH of enzymatic-hydrolysed PDC followed the order of 5UC< C25U <5UX, which was 7.8 %, 44.2 2% and 46.27 %, respectively. The prebiotic activity score of ethanolic extract obtained from the PDC followed the order of untreated < C25U < 5UX < 5UC, which were -1.04, -0.74, -0.10 and 0.58, respectively. To further investigate the role of lignin (which can be eliminated through alkaline hydrogen peroxide treatment (AHPT) on the extent of hydrolysis and the fermentability of enzymatic-hydrolysed PDC, we tested the invasion capacity of fungus Aspergillus oryzae on untreated, and AHPT followed by enzymatic-treated PDC. Pre-treatment of PDC with AHP improved accessibility for enzymatic hydrolysis in which the highest fungus growth rate was observed on the AHP-C25U PDC. Enzymatic treatment succeeding AHPT is a feasible way to improve the fermentability of palm decanter cake.

Effect of gastrointestinal alterations mimicking elderly conditions on in vitro digestion of meat and soy proteins

We evaluated the digestion of meat (chicken, beef, and pork) and soy proteins under in vitro conditions mimicking gastrointestinal (GI) conditions of adults (control, C) and elderly with achlorhydria (EA). The changes in degree of hydrolysis (DH), SDS-PAGE profiles, peptide concentration, and proteomics profiles during the digestion process were investigated. Digestion under the EA condition markedly decreased the DH of all protein sources, especially for soy protein. SDS-PAGE profiling and proteomics showed that myofibrillar/sarcoplasmic protein from meat and glycinin/beta-conglycinin from soy were the proteins most affected by the different digestive conditions. Our results indicated that the difference in the digestibility of meat protein between EA and control conditions gradually narrowed from the gastric to the intestinal phase, while a pronounced difference between control and EA conditions was maintained also in the intestinal phase. This work provides new insights of value for future dietary recommendations for elderly individuals.