scholarly journals Optimization of Enzymatic Hydrolysis of Waste Bread before Fermentation

Author(s):  
Helena Hudečková ◽  
Petra Šupinová ◽  
Libor Babák

Finding of optimal hydrolysis conditions is important for increasing the yield of saccharides. The higher yield of saccharides is usable for increase of the following fermentation effectivity. In this study optimal conditions (pH and temperature) for amylolytic enzymes were searched. As raw material was used waste bread. Two analytical methods for analysis were used. Efficiency and process of hydrolysis was analysed spectrophotometrically by Somogyi-Nelson method. Final yields of glucose were analysed by HPLC. As raw material was used waste bread from local cafe. Waste bread was pretreated by grinding into small particles. Hydrolysis was performed in 100 mL of 15 % (w/v) waste bread particles in the form of water suspension. Waste bread was hydrolysed by two commercial enzymes. For the liquefaction was used α‑amylase (BAN 240 L). The saccharification was performed by glucoamylase (AMG 300 L). Optimal conditions for α‑amylase (pH 6; 80 °C) were found. The yield of total sugars was 67.08 g∙L-1 (calculated to maltose). As optimal conditions for glucoamylase (pH 4.2; 60 °C) were found. Amount of glucose was 70.28 g∙L1. The time of waste bread liquefaction was 180 minutes. The time of saccharification was 90 minutes. The results were presented at the conference CECE Junior 2014.

2013 ◽  
Vol 411-414 ◽  
pp. 3205-3209
Author(s):  
Fang Qian ◽  
Lei Zhao ◽  
Shu Juan Jiang ◽  
Guang Qing Mu

Based on single factor analysis for the enzymatic hydrolysis of whey protein, papain was selected as the optimal enzyme and its enzymatic hydrolysis conditions were optimized by the quadratic regression orthogonal rotary test. The orthogonal regression model for degree of hydrolysis (DH) to three factors including temperature (X1), time (X2), enzyme dosage (X3) was established as follow: DH=10.40+0.22X1+0.30X2+1.31X3+0.019X1X2+0.011X1X3-0.039X2X3-0.39X12-0.16X22-0.40X32, Verification test showed a DH of 11.7% was obtained at the optimal hydrolysis condition of 56.6°C, 113.8 min and enzyme 8213.7 U /g protein, which basically consisted with the model theoretical value.


2018 ◽  
Vol 33 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Dan Huo ◽  
Qiulin Yang ◽  
Guigan Fang ◽  
Qiujuan Liu ◽  
Chuanling Si ◽  
...  

Abstract Eucalyptus residues from pulp mill were pretreated with aqueous ammonia soaking (AAS) method to improve the efficiency of enzymatic hydrolysis. The optimized condition of AAS was obtained by response surface methodology. Meanwhile, hydrogen peroxide was introduced into the AAS system to modify the AAS pretreatment (AASP). The results showed that a fermentable sugar yield of 64.96 % was obtained when the eucalypt fibers were pretreated at the optimal conditions, with 80 % of ammonia (w/w) for 11 h and keeping the temperature at 90 °C. In further research it was found that the addition of H2O2 to the AAS could improve the pretreatment efficiency. The delignification rate and enzymatic digestibility were increased to 64.49 % and 73.85 %, respectively, with 5 % of hydrogen peroxide being used. FTIR analysis indicated that most syringyl and guaiacyl lignin and a trace amount of xylan were degraded and dissolved during the AAS and AASP pretreatments. The CrI of the raw material was increased after AAS and AASP pretreatments, which was attributed to the removal of amorphous portion. SEM images showed that microfibers were separated and explored from the initial fiber structure after AAS pretreatment, and the AASP method could improve the destructiveness of the fiber surface.


Holzforschung ◽  
2011 ◽  
Vol 65 (4) ◽  
Author(s):  
Fokko Schütt ◽  
Jürgen Puls ◽  
Bodo Saake

Abstract Steam refining was investigated as a pretreatment for enzymatic hydrolysis of poplar wood from a short rotation plantation. The experiments were carried out without debarking to use an economically realistic raw material. Steam refining conditions were varied in the range of 3–30 min and 170–220°C, according to a factorial design created with the software JMP from SAS Institute Inc., Cary, NC, USA. Predicted steaming conditions for highest glucose and xylose yields after enzymatic hydrolysis were at 210°C and 15 min. Control tests under the optimized conditions verified the predicted results. Further pretreatments without bark showed that the enzymes were not significantly inhibited by the bark. The yield of glucose and xylose was 61.9% of theoretical for the experiments with the whole raw material, whereas the yield for the experiments without bark was 63.6%. Alkaline extraction of lignin from the fibers before enzymatic hydrolysis resulted in an increase of glucose yields from mild pretreated fibers and a decrease for severe pretreated fibers. The extracted lignin had a high content of xylose of up to 14% after very mild pretreatments. On the other hand, molecular weights of the extracted lignin increased substantially after pretreatments with a severity factor above 4. Hence, alkaline extraction of the lignin seems only attractive in a narrow range of steaming conditions.


2016 ◽  
Vol 46 (6) ◽  
pp. 778-790 ◽  
Author(s):  
Ghassan Abo Chameh ◽  
Fadi Kheder ◽  
Francois Karabet

Purpose The purpose of this paper was to find out the appropriate enzymatic hydrolysis conditions of alkali pretreated olive pomace (OP) which enable maximum yield of reducing sugar. Design/methodology/approach The commercial enzymatic preparation (Viscozyme® L) was used for the hydrolysis of OP. The effects of pretreatment, time, temperature, pH, enzyme quantity and substrate loading on the hydrolysis yield were investigated. Findings This study showed that enzymatic hydrolysis of OP using Viscozyme® L can be successfully performed at 50°C. Alkaline pretreatment step of OP prior the enzymatic hydrolysis was indispensable. The hydrolysis yield of alkaline pretreated OP was 2.6 times higher than the hydrolysis yield of untreated OP. Highest hydrolysis yield (33.5 ± 1.5 per cent) was achieved after 24 h using 1 per cent (w/v) OP load in the presence of 100 μl Viscozyme® L at 50°C and pH 5.5 with mixing rate of 100 rpm (p = 0.05). Originality/value Reaction time, temperature, pH value and enzyme quantity were found to have a significant effect on enzymatic hydrolysis yield of alkali pretreated of OP. Although high-solid loadings of OP lowered the hydrolysis yield, it produced higher concentration of reducing sugars, which may render the OP conversion process more economically feasible.


2016 ◽  
Vol 33 (No. 5) ◽  
pp. 449-457 ◽  
Author(s):  
H.J. Im ◽  
K.Y. Yoon

We examined the potential use of buckwheat hulls as a raw material for producing soluble dietary fibre. The insoluble fibre fraction obtained from buckwheat hulls was hydrolysed by two commercial enzymes (Celluclast 1.5L for the cellulose fraction and Viscozyme L for the hemicellulose fraction) to obtain soluble fibre hydrolysates. Alcohol-insoluble dietary fibre (AIF) was separated from the freeze-dried soluble hydrolysate by treatment with 85% ethanol. The water-holding, oil-binding, and swelling capacities of AIF were increased by enzymatic hydrolysis. AIF had significantly (P < 0.05) higher functional properties than the control. AIF from the hemicellulose fraction effectively hindered the diffusion of glucose and bile acid from dialysis membranes, and had a significantly (P < 0.05) greater bile acid inhibitory effect than carboxymethylcellulose or pectin. It can be concluded that AIF from buckwheat hulls by enzymatic hydrolysis can used as dietary supplement and additive in the food industry.


2014 ◽  
Vol 40 (2) ◽  
pp. 103-113
Author(s):  
Marcin Wołczyński ◽  
Marta Janosz-Rajczyk

Abstract The presented results of research on the effectiveness of enzymatic hydrolysis of lignocellulosic waste, depending on their initial depolymerisation in alkaline medium were considered in the context of the possibility of their further use in the fermentation media focused on the recovery of energy in the form of molecular hydrogen. The aim of this study was to determine the appropriate dose and concentration of a chemical reagent, whose efficiency would be high enough to cause decomposition of the complex, but without an excessive production of by-products which could adversely affect the progress and effectiveness of the enzymatic hydrolysis and fermentation. The effect of treatment on physical-chemical changes of homogenates’ properties such as pH, COD, the concentration of monosaccharide and total sugars and the concentration of total suspended solids and volatile suspended solids was determined. The enzymatic decomposition of lignocellulosic complex was repeatedly more efficient if the sample homogenates were subjected to an initial exposure to NaOH. The degree of conversion of complex sugars into simple sugars during enzymatic hydrolysis of homogenates pre-alkalized to pH 11.5 and 12.0 was 83.3 and 84.2% respectively, which should be sufficient for efficient hydrogen fermentation process.


1996 ◽  
Vol 48 (3) ◽  
pp. 101-104 ◽  
Author(s):  
E. de A. Mélo ◽  
R. Vieira ◽  
N. Krieger ◽  
N. B. Guerra ◽  
M. P. C. Silva ◽  
...  

2005 ◽  
Vol 277-279 ◽  
pp. 450-454 ◽  
Author(s):  
Young Hee Lee ◽  
Jung Soo Kim ◽  
Han Do Kim

Biodegradable superabsorbents, hydrolyzed AN(acrylonitrile)-grafted-SA(sodium alginate) copolymers were prepared in this study by graft copolymerization of acrylonitrile on sodium alginate and the subsequent hydrolysis of the resulting grafted copolymer. The absorbency was found to significantly depend on the % add-on, graft copolymerization conditions and hydrolysis conditions. The optimum condition for graft copolymerization to obtain the maximum % add-on (64.5%) was 4g SA, 12g AN, and 8.42g H2O2 in 100ml water at 70 oC for 10hr., respectively. The optimum hydrolysis conditions for the graft copolymer (64.5 % add-on) to reach the maximum water absorbency (2518g/g), saline absorbency (1558g/g), and WRV (288g/g) is 1g graft copolymer in 10 ml aqueous NaOH (1.0N) at 110 oC for 1 hr. Furthermore, this hydrolyzed AN-graft-SA showed a good biodegradability in enzymatic hydrolysis tests when compared with commercial superabsorbent materials.


2016 ◽  
Vol 15 (2) ◽  
pp. 133-141 ◽  
Author(s):  
Eva Ürgeová ◽  
Katarína Vulganová

Abstract AHyaluronic acid (HA) is part of the extracellular matrix of connective, epithelial and neural tissues, as well as the synovial fluid, skin, and cartilage. It is composed of repeating disaccharide units of D-glucuronic acid and N-acetyl glucosamine. Hyaluronic acid is used in abdominal surgery, ophthalmology, dermatology, rhinology; it is usable for the osteoarthritis treatment. The membranes of eggshell are a natural source of hyaluronic acid, collagen, glycosaminoglycan and collagenous proteins. In paper, we tested the possibility of extraction hyaluronic acid from the eggshell membranes by enzymatic hydrolysis. We identified optimal conditions of hydrolysis with trypsin at reaction temperature of 37 °C and pH 8; with pepsin at 40 °C and pH 3, as well as with papain at 60 °C and pH 7.5. The content of hyaluronic acid in samples was determined spectrophotometrically using the carbazole method. The experimental results showed a yield of ~ 4 -4.5 % hyaluronic acid per 1 g of dry eggshell membranes.


Sign in / Sign up

Export Citation Format

Share Document