花椒提取物在化妆品中的抗菌活性研究

对花椒提取物在化妆品中的抗菌活性进行了研究,并将其应用于化妆品配方体系中,与目前市售防腐剂进行了抗菌对比试验。结果表明花椒提取物具有良好的抗菌活性,可作为化妆品防腐剂使用,为其以后在化妆品行业中的应用提供依据。     

大红袍花椒挥发性成分的HS-SPME/GC/MS分析

利用顶空固相微萃取-气相色谱/质谱联用技术研究大红袍花椒的挥发性成分,探讨了不同纤维头吸附对分析检测结果的影响。结果表明,DVB/CAR/PDMS纤维头能够有效地吸附花椒的挥发性成分;大红袍花椒主要挥发性成分为β-月桂烯（21.41%）、苎烯（17.06%）、β-水芹烯（10.60%）、γ-松油醇（萜品醇）（9.50%）、桧烯（8.32%）、β-罗勒烯（8.00%）、胺叶油素（7.09%）、罗勒烯（3.82%）、α-蒎烯（3.59%）、香橙烯（1.15%）、α-乙酸松油酯（1.08%）等萜烯类以及醇类或酯类化合物。     

Aqueous enzymatic extraction of peanut oil and protein hydrolysates

The aqueous enzymatic process of simultaneously preparing oil and protein hydrolysates from peanut was investigated. The optimum parameters for hydrolysis using Alcalase 2.4L were established by the single-factor and orthogonal test. The optimal processing conditions were as follows: hydrolysis temperature 60 °C, pH 9.5, ratio of material to water 1:5 (w/w), alkaline extraction time 90 min, enzyme amount 1.5% (w/w) and hydrolysis time 5 h. Under these conditions, the free oil and protein hydrolysates yields were 79.32% and 71.38% respectively. In order to improve these yields, As1398 was chosen to hydrolyze the residue and emulsion. The total free oil and protein hydrolysates yields were increased to 91.98% and 88.21% respectively.     

胃蛋白酶提取硫酸软骨素的研究

以鸡胸软骨为原料,采用稀碱-双酶(胰蛋白酶和胃蛋白酶)相结合的方法提取硫酸软骨素。研究了胃蛋白酶水解硫酸软骨素的影响因素,结果显示,胃蛋白酶水解部分pH值为5.9,酶解时间为100 m in,料液比为1 000∶1.1(g/mL),酶解温度为40℃,在此条件下,硫酸软骨素产率达到25.80%,纯度为85.65%,质量有较大提高。     

Production of Canolol from Canola Meal Phenolics via Hydrolysis and Microwave-Induced Decarboxylation

A potent antioxidant, anti-inflammatory and anti-mutagenic agent; 4-vinyl-2,6-dimethoxyphenol (canolol) was obtained from canola meal in a significant yield via alkaline (NaOH)/enzymatic (ferulic acid esterase) hydrolysis followed by microwave-assisted decarboxylation. The hydrolysis was carried out either through using canola meal directly as a substrate or by using the 70 % aqueous methanolic extract filtrates. The hydrolyzed extracts underwent RP-HPLC analysis which showed that 81.0 and 94.8 % of the total phenolics were hydrolyzed to sinapic acid after the alkaline hydrolysis of the meal and the methanolic extracts, respectively. The enzymatic hydrolysis showed lower conversion rates (49.5 and 58.3 %). The hydrolyzed extracts were consequently decarboxylated using 8-diazabicyclo[5.4.0]undec-7-ene under microwave irradiation at different conditions. The HPLC profiling of decarboxylated extracts showed that using microwave at 300 W of microwave power for 12 min brought the highest sinapic acid conversion to canolol (58.3 %) yielding 4.2 mg canolol from each gram of canola meal suggesting that the process could be commercially economical.     

亚临界水提取干花椒中精油的研究

采用亚临界水提取技术从干花椒中提取花椒精油.考察了原料颗粒度、提取时间、提取温度等因素对花椒精油提取得率的影响.确定亚临界水提取花椒精油的最佳工艺为:原料颗粒度0.5 mm、提取时间40 min、100～150℃的连续程序升温、压力5 Mpa,在此条件下花椒精油的提取得率为5.42%.同时,对亚临界水提取所得的花椒精油进行了抗氧化实验,并与常用抗氧化剂BHT和BHA进行了对比.结果表明,亚临界水提取所得的花椒精油具有较好的抗氧化性.用亚临界水提取技术提取花椒精油具有效率高、能耗低的优点.     

花椒有效成分的提取

花椒中含有挥发油、植物碱、酰胺类等物质,而且花椒作为中药也被广泛应用.本实验针对我国花椒资源丰富而加工利用技术缺乏的现状,开展花椒有效成分的高效及全面提取.本实验用不同溶剂在微波辐射催化下从花椒中萃取出不同的成份：水溶性、油溶性和酯溶性.     

Optimization of Enzymatic Hydrolysis of Sacha Inchi Oil using Conventional and Supercritical Carbon Dioxide Processes

Sacha inchi (Plukenetia volubilis) oil has high polyunsaturated fatty acids content. The hydrolysis of this oil is an efficient way to obtain desirable free fatty acids (FFA). The optimization of parameters was carried out according to the maximum production of FFA using two enzymatic hydrolysis processes. The effect of enzyme concentration (5–40 % based on weight of oil), temperature (40–60 °C), and oil:water molar ratio (1:5–1:70) were studied for the conventional enzymatic hydrolysis process, while pressure (10–30 MPa) and oil:water molar ratio (1:5–1:30) were studied for the enzymatic hydrolysis in supercritical carbon dioxide (SC-CO₂) media. The hydrolysis in SC-CO₂ media resulted in higher production of FFA (77.98 % w/w) at 30 MPa and an oil:water molar ratio equal to 1:5 compared to the conventional process (68.40 ± 0.98 % w/w) at 60 °C, oil:water molar ratio equal to 1:70, and 26.17 % w/w, enzyme/oil. The only significant parameter on the production of FFA for conventional enzymatic hydrolysis was enzyme concentration, while for the hydrolysis in SC-CO₂ media both pressure and the molar ratio of oil:water were significant. Lipid class analyses showed that with both methods, FFA, monoglycerides, and diglycerides content in the final product increased compared to pure oil, while triglycerides content decreased. Fatty acid composition analysis showed that the content of fatty acids in the FFA form were similar to their triglyceride form.     

Enrichment of salmon oil with n‐3 PUFA by lipolysis,filtration and enzymatic re‐esterification

Selective enzymatic hydrolysis of salmon oil extracted without solvent from by‐products was carried out under mild conditions, using a stereospecific sn‐1, sn‐3 lipase Novozyme^®. A modification of the lipid class composition was obtained by controlling the degree of hydrolysis (40%, 24 h). The mixture of acylglycerols and free fatty acids was submitted to a filtration step to retain in the retentate most of the saturated fatty acids, with melting peaks ranging from ‐31.9 °C to +14.7 °C obtained by differential scanning calorimetry. This step allowed a significant increase of polyunsaturated fatty acids (PUFA) from 39.2 mol‐% in the crude oil to 43.3% in the permeate. The remaining free fatty acids in the permeate (20.2 wt‐%) was re‐esterified with an immobilized 1, 3‐specific lipase IM60. Acylglycerols synthesis reached 90% in optimized conditions. After 48 h of reaction, the distribution of monoacylglycerols, diacylglycerols and triacylglycerols was 22.1, 28.7, 43.4 (w/w), respectively. The re‐esterification step did not modify the PUFA content obtained after membrane filtration.     

Enhanced Xylooligosaccharides Yields and Enzymatic Hydrolyzability of Cellulose using Acetic Acid Catalysis of Poplar Sawdust

To increase the value and promote the utilization of woody processing residues, poplar sawdust was used to produce xylooligosaccharides (XOS) with polymerization degrees of 2–6 by acetic acid catalysis. This process is considered to be an environmental friendly process, and the remaining solid fraction was decomposed to fermentable sugars by enzymatic hydrolysis. Response surface methodology (RSM) was applied to determine the main factors affecting the yield of XOS. XOS production was optimal at 170?±?3?°C with a 6.5?±?1% acetic acid concentration and 27?±?2?min reaction time. These conditions produced a 36.0?±?0.8% XOS yield from xylan, similar to the predicted value from the model. Careful analysis of the kinetic profile of XOS revealed that xylobiose to xylohexaose were the main products. Detectable degraded chemicals accounted for 71.0% xylan during acidic hydrolysis. When using enzymatic hydrolysis at a cellulase loading of 20 FPU/g cellulose, a 51.0% yield was achieved, which represented an 80% increase relative to pretreated autohydrolysis (28.3%), and reached production yields similar to that of diluted sulfuric acid pretreatment.     

An approach to optimization of enzymatic hydrolysis from sugarcane bagasse based on organosolv pretreatment

BACKGROUND: The organosolv pretreatment followed by enzymatic hydrolysis of the pretreated material and subsequent fermentation of the hydrolysate produced, was the strategy used for ethanol production from sugarcane bagasse. The effect of different operational variables affecting the pretreatment (the catalyst type and its concentration, and the pretreatment time) and enzymatic hydrolysis stage (substrate concentration, cellulase loading, addition of xylanase and Tween 20, and the cellulase/β‐glucosidase ratio), were investigated. RESULTS: The best values of glucose concentration (28.8 g L^?1) and yield (25.1 g per 100 g dry matter) were obtained when the material was pretreated with 1.25% (w/w) H₂SO₄ for 60 min, and subsequently hydrolyzed using 10% (w/v) substrate concentration in a reaction medium supplemented with xylanase (300 UI g^?1) and Tween 20 (2.5% w/w). Fermentation of the broth obtained under these optimum conditions by Saccharomyces cerevisiae resulted in an ethanol yield of 92.8% based on the theoretical yield, after 24 h. CONCLUSION: Organosolv pretreatment of sugarcane bagasse under soft conditions, and subsequent enzymatic hydrolysis of the pretreated material with a cellulolytic system supplemented with xylanase and Tween 20, is a suitable procedure to obtain a glucose rich hydrolysate efficiently fermentable to ethanol by Sacharomyces cerevisiae yeasts. Copyright © 2010 Society of Chemical Industry     

Effect of ultrasound- and pulsed electric field-assisted enzymatic treatment on the recovery and quality of sunflower oil

The aim of this study was to evaluate the effect of cavitation and electroporation on enzymolysis extraction of sunflower oil. The optimum extraction conditions during 2 h under enzyme-assisted extraction (EAE) with a maximum oil yield of ≈23.70 ± 0.11% were as follows: cellulase/pectinase ratio 2:1, enzyme concentration 2%, pH 4.5, liquid/solid ratio 6:1 ml/g, and extraction temperature 40°C. Under the optimized enzymatic conditions, the application of ultrasound- (250 W) and pulsed electric field- (1.2 kV/cm; 52.4 kJ/kg) assisted enzymatic extraction for 30 min significantly increased the oil extraction yield by 91.1% and 18.6%, respectively, as compared with EAE.     

Ethanol-Assisted Aqueous Enzymatic Extraction of Peony Seed Oil

An ethanol-assisted aqueous enzymatic extraction was performed for peony seed oil (content of 30%). This method included cooking pretreatment, pectinase hydrolysis, and aqueous ethanol extraction, and the corresponding variables in each step were investigated. The changes in viscosity and dextrose equivalent values of the reaction medium as a function of changing enzymatic hydrolysis time were compared to the oil yield. The microstructures of peony seeds were analyzed using confocal laser scanning microscopy to understand the process of oil release as a result of cooking and grinding. The highest oil yield of 92.06% was obtained when peony seeds were cooked in deionized water with a solid–liquid ratio of 1:5 (w/v) at 110°C for 1 hour, ground to 31.29 μm particle size, treated with 0.15% (w/w) pectinase (temperature 50°C, pH 4.5, time 1 hour), and then extracted with 30% (v/v) aqueous ethanol (temperature 60°C, pH 9.0, time 1 hour). After processing with pectinase followed by ethanol extraction, the residual oil content in water and sediment phase decreased to 5% and 3%, respectively. The quality of the oil obtained by ethanol-assisted aqueous enzymatic extraction was good, complying with the Chinese standard.     

Novel Green Liquor Pretreatment of Loblolly Pine Chips to Facilitate Enzymatic Hydrolysis into Fermentable Sugars for Ethanol Production

Abstract

Softwood species generally have been found very recalcitrant to enzymatic hydrolysis of the carbohydrate fractions to monomeric sugars. To solve this problem, loblolly pine chips were pretreated with green liquor at 12–20% Total Titratable Alkali (TTA) (as Na₂O on wood) at 170°C for 800 H-factor. The yield of resulting pulp was 76.5–78.6% and the lignin content decreased from 29.2 to 20.2–22.4% and the total polysaccharide decreased from 62.6 to 53.8–55.0%, all based on the weight of original wood. When the pulp was subjected to enzymatic hydrolysis using 40 Filter Paper Unit (FPU)/g pulp, only 41% of the polysaccharides in wood were converted to monomeric sugars. This conversion figure is much lower than that of mixed southern hardwoods (80%) treated under similar conditions. If the green liquor treated pulp was further subjected to either oxygen delignification or mechanical refining prior to the enzymatic hydrolysis, the conversion rate increased to around 55% and 60%, respectively. Furthermore, combination of oxygen delignification and refining further increased the total sugar conversion to 78% of the total sugar in wood, approximately equal to that of the mixed southern hardwoods.     

Enzymolysis kinetics of garlic powder with single frequency countercurrent ultrasound pretreatment

This research was to describe the enzymolysis process of garlic powder which was pretreated by single frequency countercurrent ultrasound. The kinetic constants for ultrasonic pretreated and traditional enzymolysis have been determined. Results showed the value of K_M in ultrasonic pretreated enzymolysis decreased by 12.7% over the traditional enzymolysis, which indicates a fast reaction speed induced by ultrasound pretreatment. Degrees of hydrolysis (DH) in the enzymolysis of garlic powder were determined and kinetics of the reaction was considered in detail in relation to substrate concentration, enzyme concentration, reaction time and DH. Our results suggested a general kinetic equation for the enzymolysis model of ultrasonic pretreated garlic powder. For the model system, the calculated values agree well with the experimental data with average relative error of 4.42%. The proposed kinetic equation can be used to model the bio-reaction process of protein enzymatic hydrolysis and optimize the operation parameters for bioreactor design.     

鸡肉及其酶解液挥发性风味成分的对比分析

为了研究酶解对鸡肉挥发性风味成分的影响,采用SPME法提取鸡肉及其酶解液中的挥发性风味成分,用气相色谱-质谱联用技术进行分离鉴定。结果显示:鸡肉酶解液共鉴定出63种挥发性风味成分,包括醛类19种、醇类7种、酸类2种、酮类6种、酯类2种、醚类2种、酚类3种、烃类8种、杂环化合物14种。水煮鸡肉的挥发性风味成分共19种,包括醛类11种、醇类3种、酮类1种、酯类1种、烃类2种、杂环化合物1种。两者共同鉴定出的物质有:己醛、辛醛、壬醛、(E)-2-辛烯醛、苯甲醛、苯乙醛、(E,E)-2,4-癸二烯醛、对甲氧基苯甲醛、1-辛烯-3-醇、右旋萜二烯。     

Enhanced enzymatic hydrolysis of rice straw pretreated by alkali assisted with photocatalysis technology

BACKGROUND: The fermentable sugars in lignocellulose are derived from cellulose and hemicellulose, which are not readily accessible to enzymatic hydrolysis because of their biological resistance, so that pretreatment of lignocellulose is needed for this process. In this work, a novel lignocellulose pretreatment method using alkali solution assisted by photocatalysis was investigated. RESULTS: The reaction conditions of nano‐TiO₂ dosage and photocatalysis time were optimized at 2 g L^?1 and 1 h, respectively. After pretreatment under these conditions, cellulose in rice straw was increased from 37.5% to 71.5%, and lignin decreased from 18.5% to 9.0%. The results of X‐ray diffraction (XRD), Fourier transform infrared (FT‐IR) and scanning electron microscopy (SEM) analysis showed that the physical properties and microstructure of the straw were changed by this pretreatment, which favored the following enzymatic hydrolysis. The enzymatic hydrolysis rate of the straw pretreated using this technology was verified to be 73.96%, which was 2.56 times higher than that obtained with the alkali procedure. CONCLUSION: The proposed photocatalysis pretreatment technology was more efficient at degrading the lignin and hemicellulose in rice straw than alkali pretreatment, making it more readily available for the following enzymatic hydrolysis process. Copyright © 2009 Society of Chemical Industry     

Preparation and mechanism analysis of morphology-controlled cellulose nanocrystals via compound enzymatic hydrolysis of eucalyptus pulp

First, making from eucalyptus cellulose fiber, the influences of different compound enzymolysis conditions on the morphology of cellulose nanocrystals (CNCs) were studied. Under the actions of the compound enzyme composed of cellulase and xylanase with the concentration ratio of 9:1, total enzyme concentrations of 10 and 500 U mL⁻¹ and the hydrolysis time of 12 and 5 h, the rod-like CNCs (length 600 nm, width 30 nm) and the spherical CNCs (40 nm) were obtained, respectively. Subsequently, the crystallinities, chemical structures, and thermal stabilities of the rod-like and spherical CNCs revealed that, the CNCs structures were still similar to those of the eucalyptus cellulose fiber, the thermal decomposition temperatures of the rod-like and spherical CNCs (345, 343 °C) were a little lower than that of the eucalyptus cellulose fiber (364 °C). Lastly, the control mechanism of CNC morphology by the compound enzymatic hydrolysis was also discussed. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48407.     

Ultrasonic-Assisted Enzymolysis to Improve the Antioxidant Activities of Peanut (Arachin conarachin L.) Antioxidant Hydrolysate

The objective of this work is to provide a theoretical basis for preparing peanut antioxidant hydrolysate in order to improve its antioxidant activities. Therefore, response surface methodology (RSM) based on the Box-Behnken design was used to optimize ultrasonic-assisted enzymolysis for the purpose of preparing peanut antioxidant hydrolysate. Results indicated that the DPPH free radical scavenging activity of peanut hydrolysate could reach 90.06% under the following optimum conditions: ultrasonic power of 150.0 w, reaction temperature of 62.0 °C, incubation time of 25.0 min, and initial pH value of 8.5. The DPPH free radical scavenging rate of peanut hydrolysate from ultrasonic-assisted enzymolysis improved comparing with that of peanut hydrolysate from protease hydrolysis alone. The peanut antioxidant hydrolysate was found to display eight improved kinds of antioxidant activities. In conclusion, the optimal ultrasonic-assisted enzymolysis technology conditions described in this paper, appear to be beneficial for preparing peanut antioxidant hydrolysate.