Evaluation Of Enzymatic Hydrolysis Research Articles

Application of sunflower meal in diets of on-growing grass carp (Ctenopharyngodon idellus) and evaluation of enzymatic hydrolysis

An 8-week trial was performed to investigate the effects of replacing soybean meal (SBM) by sunflower meal (SM) or enzymolysis sunflower meal (ESM) on the growth, lipid metabolism, and intestinal health of Ctenopharyngodon idellus. Compared with SM, the small peptides and amino acids contents in ESM increased, while the crude fiber decreased. Seven isonitrogenous and isolipid diets (SM0, SM25, SM50, SM75, SM100, ESM75, and ESM100) were prepared for SM to replace 0, 25, 50, 75, 100% SBM and ESM to replace 75 and 100% SBM, respectively. The results showed that with an increasing proportion of SM instead of SBM, weight gain rate (WGR) of grass carp showed a decreasing trend, while feed conversion ratio (FCR) showed a rising trend, and significantly changed in the SM75 and SM100 groups. WGR in the ESM75 group was significantly increased compared with the SM75 group, and there was no statistical difference with the SM0 group. Replacing 75% and 100% SBM with ESM was beneficial to lipid metabolism, which was mainly manifested in decreased serum low-density lipoprotein, triglyceride, and total cholesterol contents, and significantly down-regulated acetyl-CoA carboxylase (acc), fatty acid synthase (fas) and sterol regulatory element binding protein 1 (srebp1) gene expression in liver. Replacing 75% and 100% SBM with SM resulted in intestinal oxidative damage (reactive oxygen species and malondialdehyde contents increased; superoxide dismutase, glutathione reductase, and glutathione peroxidase activities decreased) and disrupted intestinal physical and immune barrier functions (claudin15, myosin light chain kinase (mlck), interleukin-1β, 6, 12β (il-1β, il-6, il-12β), tumor necrosis factor-α (tnf-α), and nuclear factor-κB (nf-κb) gene expression up-regulated; zonula occluden 1, 2 (zo1, zo2), transforming growth factor β1 (tgf-β1), and il-10 gene expression down-regulated), while substitution of 75% and 100% SBM by ESM alleviated oxidative damage and improved intestinal immune and physical barrier functions. In addition, the α-diversity index and the abundances of Erysipelatoclostridium and Bacteroides in the ESM75 group were significantly increased compared with the SM0 and SM75 groups. In conclusion, the replacement proportion of SBM with SM should not exceed 50%, otherwise it will lead to reduced growth, lipid deposition, intestinal health damage and intestinal microbiota disorder. However, the replacement of 75% SBM with ESM has no negative effect on grass carp, and it improved lipid metabolism and intestinal health compared with substitution of SBM with SM.

Evaluation of enzymatic hydrolysis via alcoholic fermentation of corn flour

Abstract The research was concerned with the enzymatic hydrolysis followed by alcoholic fermentation of corn flour. Commercial corn flour purchased from local market contained starch of 87.25%, moisture 11.86% and ash 0.70%. The kinetics of corn flour hydrolysis was performed at 50°C, 65°C and 80°C using commercial thermos table-∞-amylase and ∞-amyloglucosidase. During hydrolysis the residual starch content was decreased with increasing hydrolysis time. The line weaver- Burk plot for enzyme hydrolysis of corn starch for 2.5%, 5% and 10% flour solution showed a Km value of 2.46, 2.27 and 1.73 mg/ml and Vmax values 1.23, 1.21 and 0.96 U/ml for 50°C, 65°C and 80°C respectively. Thin layer chromatography (TLC) was used to detect the presence of dextrose in the hydrolyzates. The Rf (Retention factors) values showed that the starch was mainly composed of dextrose and depended on carrier solvent use for dextrose assessment. When 100% ethyl alcohol used as carrier solvent the Rf value was 0.72 and ethyl alcohol: ethyl acetate= 1:1 the Rf value was 0.65. Both corn flour solution and its enzymatic hydrolysates were fermented with commercial baker’s yeast. Both the cases starch content was decreased and alcohol content was increased during hydrolysis and alcohol production was 3 times more from hydrolysates. The results obtained here will be useful for further research in the production of other value added products like white vinegar from the produced alcohol from con flour.

Enzymatic Hydrolysis of Catfish (Pangasius hypophthalmus) By-Product: Kinetic Analysis of Key Process Parameters and Characteristics of the Hydrolysates Obtained

ABSTRACTIn this study, kinetic evaluation of enzymatic hydrolysis of catfish (Pangasius hypophthalmus) by-product meat was conducted. The effects of key factors such as type of proteases (neutrase, papain, and bromelain), enzyme to substrate ratio (E/S), substrate concentration, and extent of hydrolysis on process efficiency, properties and functionalities of hydrolysates were evaluated. The results demonstrated that, for catfish shredded meat, bromelain and papain had higher affinity than neutrase. Kinetics parameters Vm and Km of neutrase, papain, and bromelain were 4.486, 9.060, and 18.249 μM/min and 35.433, 6.582, and 7.034 g/l, respectively. Optimal E/S ratios of neutrase, papain, and bromelain were estimated to be 0.92, 2.76, and 3.31 mg/g. At optimal E/S, the highest possible substrate concentrations were found to be 108.4 g/l for neutrase, 36.2 g/l for papain, and 135.8 g/l for bromelain. Both kinetics study and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that bromelain and papain had higher proteolytic activity toward catfish protein than neutrase. A significant increase in antioxidant activity of hydrolysates was observed with neutrase and papain hydrolysate, but not with bromelain. The results could be helpful for industrial processors to develop an efficient process for catfish by-product valorization.

Hydrothermal treatment and enzymatic hydrolysis of Tamarix ramosissima: Evaluation of the process as a conversion method in a biorefinery concept

The present work investigated the effects of hydrothermal treatment (HTT) of Tamarix ramosissima by determination of sugar and inhibitor formation in the liquid fraction, and chemical and morphological changes of the pretreated solid material coupled with an evaluation of enzymatic hydrolysis. HTT was carried out in a batch reactor system at a maximal temperature (TMAX 180–240°C) and evaluated for severities logRo ranging from 2.40 to 4.17. The liquid fractions were analyzed by HPLC, GPC, and GC–MS. The morphology and composition of the solid residues were characterized using an array of techniques, such as SEM, XRD, BET surface area, and CP/MAS 13C NMR. Using a variety of tools, we have developed a better understanding of how HTT process affects biomass structure and cellulose properties that impact on its digestibility. These results provided new insights into the factors limiting enzymatic digestibility and mechanism of biomass deconstruction during hydrothermal process.

Process Evaluation of Enzymatic Hydrolysis with Filtrate Recycle for the Production of High Concentration Sugars

Process simulation and lab trials were carried out to demonstrate and confirm the efficiency of the concept that recycling hydrolysate at low total solid enzymatic hydrolysis is one of the options to increase the sugar concentration without mixing problems. Higher sugar concentration can reduce the capital cost for fermentation and distillation because of smaller retention volume. Meanwhile, operation cost will also decrease for less operating volume and less energy required for distillation. With the computer simulation, time and efforts can be saved to achieve the steady state of recycling process, which is the scenario for industrial production. This paper, to the best of our knowledge, is the first paper discussing steady-state saccharification with recycling of the filtrate form enzymatic hydrolysis to increase sugar concentration. Recycled enzymes in the filtrate (15-30% of the original enzyme loading) resulted in 5-10% higher carbohydrate conversion compared to the case in which recycled enzymes were denatured. The recycled hydrolysate yielded 10% higher carbohydrate conversion compared to pure sugar simulated hydrolysate at the same enzyme loading, which indicated hydrolysis by-products could boost enzymatic hydrolysis. The high sugar concentration (pure sugar simulated) showed inhibition effect, since about 15% decrease in carbohydrate conversion was observed compared with the case with no sugar added. The overall effect of hydrolysate recycling at WinGEMS simulated steady-state conditions with 5% total solids was increasing the sugar concentration from 35 to 141g/l, while the carbohydrate conversion was 2% higher for recycling at steady state (87%) compared with no recycling strategy (85%). Ten percent and 15% total solid processes were also evaluated in this study.

Susceptibility of a Polycaprolactone-based Root Canal–filling Material to Degradation. III. Turbidimetric Evaluation of Enzymatic Hydrolysis

The susceptibility of Resilon (Pentron Clinical Technologies, Wallingford, CT) to biotic biodegradation by two hydrolases, lipase PS and cholesterol esterase, was investigated with a turbidimetric approach by measuring the optical density reductions in aqueous emulsions containing dissolved, filtered, surfactant-stabilized polymeric components of Resilon. Polycaprolactone, the major polymeric component of Resilon, was also examined in a similar manner using equivalent or a four-fold increase in enzyme concentration. Optical density time plots were characterized by an initially linear steep reduction in optical density, from which the reaction rates were derived. For both enzymes, the rates of hydrolysis for Resilon were much faster than those of polycaprolactone at 1x or even 4x enzyme concentration. Field-emission scanning electron microscopy of air-dried Resilon and polycaprolactone emulsions revealed the presence of spherical polymer droplets that appeared deformed, pitted, or much reduced in dimensions after enzymatic hydrolysis.