Increase In Degree Of Hydrolysis Research Articles

Effects of Hydrolysis Ratio on the Structure and Adsorption Properties of Porous Starch

This study was carried out to investigate the effects of hydrolysis ratio on the structure and adsorption properties of porous starch. The starches with different hydrolysis ratios were prepared by enzymolysis (combination of α-amylase and glucoamylase), and its adsorption capacity was evaluated by using methylene blue (MB) and soybean oil as adsorption objects. The results suggest that crystallinity, specific surface area and adsorption capacity of porous starch were gradually improved with the increase of hydrolysis degree. The crystallinity of native starch was increased by enzymolysis from 28.43±0.23% to 34.70±0.69%, and the specific surface area was increased from 0.58±0.002 m2/g to 1.82±0.014 m2/g. Moreover, the adsorption capacity toward (MB) was increased from 2.88 mg/g to 3.87 mg/g at 25°C, which was accurately described by the pseudo-first-order kinetic model, and the oil absorption ratio was also greatly improved from 23.2±0.16% to 76.1±0.11%. Thus, the properties of porous starch can be adjusted by controlling the hydrolysis ratio to meet different needs in the market.

Evaluation of Proprietary MDZenPro Formulation by Zenherb Labs in Mediating Protein Digestion under INFOGEST in-vitro Simulated Gastrointestinal Conditions

Protein breakdown by endogenous enzymes in the gastrointestinal (GI) tract results in generation of peptides and amino acids that act as building blocks in essential biological functions. Exogenous proteases possess immense potential as digestive enzyme supplements that can assist protein digestion in the GI system. Plant proteases, in addition to their promising activity, are considered to be safe in nature. The present study evaluated the potential application of a plant protease based proprietary formulation - MDZenPro in digesting raw whey protein, whey protein isolate and plant protein under INFOGEST simulated GI conditions. The gastric and GI digested protein products were analyzed for determining the degree of hydrolysis. The protein profiles were evaluated using SDS-PAGE. The results of the degree of hydrolysis study revealed that MDZenPro facilitated gastric and GI digestion of proteins. This increase in degree of hydrolysis was noted to be higher than that observed in proteins that were not treated with MDZenPro. The SDS-PAGE profile further supported these findings wherein, the MDZenPro treated protein samples displayed low molecular weight fragmented peptides in contrast to the profile of undigested proteins. The present study thus highlights the promising application of ‘MDZenPro’ as an effective supplement for protein digestion.

Buffalo cheese whey hydrolyzed with Alcalase as an antibrowning agent in minimally processed apple.

Buffalo whey was hydrolyzed with Alcalase for different times ti (i = 0, 0.5, 1, 2, 3, 4 or 6h) and the browning inhibition of minimally processed apples was investigated. The hydrolysis process was followed by determination of the degree of hydrolysis. In order to understand possible modes of action on the enzymatic browning, whey was submitted to the analysis of antioxidant activity (ABTS·+ radical sequestration, Fe2+ chelating activity and reducing power), reactivity with quinones and inhibitory activity on polyphenol oxidases (PPO) extracted from Red Delicious apples. Buffalo whey showed significant increase in degree of hydrolysis, antioxidant activity, reactivity with quinones and PPO-inhibitory activity as a function of the hydrolysis time. Maximum PPO-inhibitory activity was observed from 4h hydrolysis (t4h hydrolysate), reaching about 50% inhibition. Then, slices of minimally processed apples were immersed in a buffered solution of the t4h hydrolysate, packed and subjected to instrumental color evaluation during storage for up to 6days. As for the ability to inhibit the browning of the minimally processed apples, the hydrolyzate kept the parameter of the apples during 6days of storage, not statistically differing from the metabisulfite. In addition to the luminosity, the hydrolyzed whey was able to maintain the browning index of the apples at lower values during this storage time compared to the non-hydrolyzed whey. These results evidence possible applications of buffalo whey hydrolyzed with Alcalase as a natural substitute for additives conventionally used in the control of enzymatic browning in foods.

Effects of high solid concentrations on the efficacy of enzymatic hydrolysis of yeast cells and the taste characteristics of the resulting hydrolysates

SummaryEffects of solid concentrations on enzymatic hydrolysis of yeast cells and the taste characteristics of the resulting hydrolysates were examined. Results showed that increased solid concentrations ranging from 10% to 30% resulted in a mild increase in degree of hydrolysis (DH) of hydrolysates during the whole hydrolysis process, whereas an obvious inhibition effect on DH was found at hydrolysates with 40% of solid concentration. The levels of amino nitrogen and total nitrogen of supernatant with 40% of solid concentration were six‐fold higher than those of hydrolysates with 10% of solid concentration at all hydrolysis time. After 21 h of hydrolysis, there was no significant difference in molecular weight distributions of hydrolysates with different solid concentrations, while a significant increase in amino acid contents of hydrolysates with high solid concentrations was found. Results from sensory evaluation showed that the intensities of umami, mouthfulness and continuity in umami solution could be significantly improved by supplementing with the resulting hydrolysates with high solid concentrations.

Test and Analysis of Heat-Resistant Polymer Solution’s Hydrolysis

This paper research the hydrolysis law of BH heat-resistant polymer in distilled water, oil field clear water and oil field waste water, and inspect its long-term thermal stability in the waste water. The results showed that there is few difference about hydrolysis degree between the ZIIordinary polymer and BH heat-resistant polymer in distilled water. BH heat-resistant polymer will hydrolyze faster in the waste water than in the clear water. The hydrolysis degree of different concentrations of BH of polymer solution under the same temperature increases with the increase of aging time, the higher the polymer concentration, the higher the viscosity of the solution, the smaller the hydrolysis degree. BH heat-resistant polymer hydrolysis under high temperature will increase, caused the increase of hydrolysis degree from 95°C to 120°C. AMPS group of BH heat-resistant polymer will not hydrolyze under 95°C.

Kinetic study on the changes in the susceptibility of egg white proteins to enzymatic hydrolysis induced by heat and high hydrostatic pressure pretreatment.

A kinetic study was conducted on the effect of heat pretreatment in the temperature range of 50-85 degrees C at atmospheric pressure and of high hydrostatic pressure pretreatment (100-700 MPa) at four temperatures (10, 25, 40, and 60 degrees C) on the susceptibility of egg white solutions (10% v/v, pH 7.6) to subsequent enzymatic hydrolysis by a mixture of trypsin and alpha-chymotrypsin at 37 degrees C and pH 8.0. Both heat pretreatment at atmospheric pressure and high-pressure pretreatment resulted in an increase in degree of hydrolysis (DH) after 10 min of enzymatic reaction (DH10) of egg white solutions, as measured using the pH-stat method, which could be described by a fractional conversion model (based on an apparent first-order reaction kinetic model). The temperature dependence of the corresponding rate constants could be described by the Arrhenius equation. At elevated pressure, a negative apparent activation energy was obtained, implying an antagonistic effect of pressure and temperature. The pressure dependence of the rate constants could be described by the Eyring equation, and negative activation volumes were observed, which demonstrates the positive effect of pressure on the susceptibility of egg white solutions to subsequent enzymatic hydrolysis.

Heat-induced changes in the susceptibility of egg white proteins to enzymatic hydrolysis: a kinetic study.

A kinetic study was conducted on the effect of heating in the temperature range of 50-92 degrees C, on the susceptibility of ovalbumin and albumen solutions to enzymatic hydrolysis by a mixture of trypsin and alpha-chymotrypsin at 37 degrees C and pH 8.0. Heat treatment resulted in an increase in degree of hydrolysis after 10 min of enzymatic reaction of both ovalbumin and albumen, as measured using the pH-stat method. The time-dependent change in the susceptibility to enzymatic hydrolysis after heat treatment was described by a fractional conversion model (based on an apparent first-order reaction kinetic model). Different end levels of degree of hydrolysis were obtained after heating for a long time at different temperatures, which suggests that the final degree of unfolding of the protein is temperature dependent.

Removal of boron from aqueous solutions by continuous polymer-enhanced ultrafiltration with polyvinyl alcohol

Boron is a highly contaminating metal due to its toxic effects for plants even at very low concentrations. Continuous polymer-enhanced ultrafiltration (PEUF) was applied for removal of boron from aqueous solutions. The effects of operating parameters on the performance of PEUF were investigated. A commercial polymer, polyvinyl alcohol (PVA) was used as the boron-complexing agent. The methodology consists of two steps: complexing boron with PVA following separation of boron and polymer complexes by ultrafiltration process. The pilot scale system utilized for the PEUF process accommodates a spiral-wound cellulose cartridge with 10,000 Da MWCO. The experimental parameters studied are metal/polymer ratio (loading) (0.01–0.5), pH (7–10), and the polymer characteristics such as molecular weight (M n) of the polymer and degree of hydrolysis (DoH). The results showed that PEUF could be a successful alternative method for removal of boron. The permeate flux remained constant at around 19 L/m2 hr throughout the runs and the fluxes were not affected by the operating parameters studied and by the polymer characteristics. When the loading values were decreased, the retention of boron was increased. Also, pH had an important influence as increase in pH resulted in increase in retention of boron. The polymeric M n of the polymer did not have any influence on the retention of boron while an increase in DoH caused a decrease in retention of boron.

Sorption isotherms and glass transition temperatures of fish protein hydrolysates with different degrees of hydrolysis

The objective of this research was the determination of the sorption isotherms and glass transition temperatures of five protein hydrolysates with different degrees of hydrolysis (DH). The hydrolysates were obtained by proteolysis of concentrated myofibrillar proteins obtained from Nile tilapia (Oreochromus niloticus) using the enzyme Flavourzyme™. There was no significant difference between the different isotherms. Agglomeration and/or compactation was observed in all samples stored in atmospheres with relative humidities (RH) of. 57%. The glass transition temperature (Tg) of the hydrolysates, determined by differential scanning calorimetry (DSC), diminished with increasing moisture content, showing values between 1° and 55°C for moisture values between 17 and 6 g water/100g solids. Contrary to what has been reported in the literature, the increase in degree of hydrolysis of the hydrolysates was not reflected in a decrease in Tg. It was observed that Tg increased with increasing DH, when the hydrolysates were stored at low RH (22% to 32%). When stored at 57% RH, the Tg decreased with increase in DH.

REACTIONS BETWEEN ALUMINUM AND SULFATE IN DILUTE NUTRIENT SOLUTIONS WITH VARYING DEGREES OF HYDROLYSIS

Effects of hydrolysis of AI (300 μM) at OH/AI molar ratios of 0, 1, or 2 on forms of AI were studied in de-ionized water and in a dilute nutrient solution matrix during 20 d of aging. In the dilute nutrient solution series, varying sulfate (SO4) additions were made to attain a SO4/AI molar ratio of 5 or 20. Aluminum was supplied as AIK(SO4)2δ12H2O or AI(NO3)δ9H2O, and additional SO4 was supplied as CaSO4δ2H2O. The solution pH varied from 4.2 to 4.7 with increase in degree of hydrolysis. The trends in pH with time were generally similar in the absence or presence of basal nutrients. In the absence of basal nutrients, increase in OH/AI molar ratio decreased the concentration of total AI in solution with AIK(SO4)2 but not with AI(NO3)3. However, in the presence of basal nutrients, concentrations of total and monomeric AI decreased with an increase in OH/AI molar ratio in solutions with either AIK(SO4)2 or AI(NO3)3. Increase in the SO4/AI ratio resulted in a slight but consistent decrease in concentrations of monomeric and total AI only in hydrolyzed AI solutions. Precipitates found in hydrolyzed AI solutions were amorphous and contained AI and S, with the S/AI ratio ranging from 0.15 to 0.27, depending on the source of AI, the degree of hydrolysis, the presence of basal nutrients, and the SO4/AI molar ratio. Speciation calculations using the MINTEQ program showed super-saturation with respect to AIOHSO4, AI4(OH)10SO4, and alunite in solutions containing a SO4/AI molar ratio of 5 or 20 using either AIK(SO4)2 or AI(NO3)3 and in solutions containing AIK(SO4)2 with no addition of SO4.