共查询到13条相似文献,搜索用时 15 毫秒
1.
Javier Vioque Raul Sánchez-Vioque Alfonso Clemente Justo Pedroche Juan Bautista Francisco Millan 《Journal of the American Oil Chemists' Society》1999,76(7):819-823
Rapeseed protein isolate has been used as starting material for the generation of an extensive protein hydrolysate. Protein
hydrolysis was produced by using sequentially an endopeptidase (Alcalase) and an exopeptidase (Flavourzyme). The final hydrolysate
has a 60% degree of hydrolysis and was completely soluble between pH values 2.5 and 7. Molecular weight profile of the protein
hydrolysate was characterized by gel filtration chromatography. A reduction in protein size was observed during the hydrolysis
process with accumulation of small peptides and free amino acids after Flavourzyme digestion. Amino acid composition of fractions
with different molecular weights of the final hydrolysate was analyzed. Some of these fractions, enriched or poor in certain
amino acids, could be used for supplementation or treatment of determined clinical syndromes. 相似文献
2.
M. P. Hojilla-Evangelista D. J. Myers L. A. Johnson 《Journal of the American Oil Chemists' Society》1992,69(3):199-204
An investigation was conducted to identify and characterize protein extracted by 45% ethanol:55% 0.1 M NaOH from flaked, defatted,
undegermed corn (Zea mays L.) during Sequential Extraction Processing (SEP). This new approach to corn milling, SEP, recycles the ethanol produced
from the fermentation of cornstarch to upstream steps of protein extraction and the simultaneous extraction of corn oil and
dehydration of the ethanol. About 10% of the protein was extracted by ethanol during counter-current-percolation oil extraction.
Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and amino acid analysis identified this protein as zein.
Nearly 65% of the total protein was recovered by the process in the protein extraction step from soft dent corn (Pioneer 3377),
medium-hard dent corn (Pioneer 3732) and high-lysine corn. The freeze-dried solids of the ethanol/alkali extracts from these
corn hybrids contained about 80% crude protein (db). The amino acids were present in quantities similar to those in whole
corn and markedly higher than those in corn gluten meal. These results indicate that SEP produces high-quality protein suitable
for food and industrial uses.
Paper presented at the Symposium on Oilseed Processing for Edible Food and Feed Products, 82nd Annual Meeting of the AOCS,
May 12–15, 1991.
Research Associate, Assistant Professor, and Professor, respectively. 相似文献
3.
Qing Li Yingjie Qin Yunfei Liu Jianjun Liu Qing Liu Pingli Li Liqiang Liu 《Frontiers of Chemical Science and Engineering》2019,13(1):140-151
Environmental and energy concerns have increased interest in renewable energy sources, particularly biofuels. Thus the fermentation of glucose from sulfuric acid-hydrolyzed corn stover for the production of bioethanol has been explored using a combined acid retardation and continuous-effect membrane distillation treatment process. This process resulted in the separation of the sugars and acids from the acid-catalyzed hydrolysate, the removal of most of the fermentation inhibitors from the hydrolysate and the concentration of the detoxified hydrolysate. The recovery rate of glucose from the sugar-acid mixture using acid retardation was greater than 99.12% and the sulfuric acid was completely recovered from the hydrolysate. When the treated com stover hydrolysate, containing 100 g/L glucose, was used as a carbon source, 43.06 g/L of ethanol was produced with a productivity of 1.79 g/(L· h) and a yield of 86.31 %, In the control experiment, where glucose was used as the carbon source these values were 1.97 g/(L·h) and 93.10% respectively. Thus the integration of acid retardation and a continuous-effect membrane distillation process are effective for the production of fuel ethanol from com stover. 相似文献
4.
Deland J. Myers Milagros P. Hojilla-Evangelista Lawrence A. Johnson 《Journal of the American Oil Chemists' Society》1994,71(11):1201-1204
Functional properties (solubility, foaming capacity and stability, emulsifying capacity, emulsion stability, heat coagulability,
heat gelation and film formation) of protein extracted by 45% ethanol/55% 0.1 M NaOH from flaked, defatted, undergermed corn
during the Sequential Extraction Process (SEP) were evaluated and compared with those of a laboratory-prepared soy protein
concentrate. SEP is a new approach to corn fractionation that recycles the ethanol produced from the fermentation of cornstarch
to unstream steps of protein extraction and the simultaneous extraction of corn oil and dehydration of the ethanol. Freeze-dried
corn protein extracts contained at least 80% crude protein (dry basis), which is indicative of protein concentrates. SEP protein
concentrates had solubilities in water of greater than 80% at pH values of 7 or above and were significantly more soluble
than the soy protein concentrate at pH above 3. SEP corn proteins also showed better heat stabilities and greater emulsifying
capacities and emulsion stabilities. Dilute dispersions (0.1%) of corn protein produced substantial but less stable foams.
Corn proteins produced films similar to zein and soy protein films but were unable to form heat-induced gels. These results
indicate that SEP produces a protein concentrate with functional properties suitable for food and industrial uses.
Paper presented at the session on New Processes: Extractions and Purifications II, 83rd Annual Meeting of the AOCS, Toronto,
May 10–14, 1992. 相似文献
5.
为了提高玉米秸秆酶解还原糖产率,利用蒸汽爆破法活化玉米秸秆原料,并利用离子液体[BMIM]Cl进行处理,考察了汽爆压力和维压时间对处理后物料酶解还原糖产率的影响。结果表明,汽爆压力2.6 MPa,维压时间90 s下汽爆活化秸秆原料,[BMIM]Cl处理后,酶解24 h后还原糖产率较汽爆活化后物料提高了84.03%,较原料提高了286.83%。秸秆化学组分分析表明,[BMIM]Cl处理后物料纤维素质量分数增加了64.86%,X射线衍射(XRD)与扫描电镜(SEM)分析表明,其晶形结构转变为无定形结构,更有利于纤维素酶与底物作用。说明汽爆活化[BMIM]Cl处理能显著提高玉米秸秆的酶解还原糖产率。 相似文献
6.
通过正交实验研究了硫酸水解预处理对玉米芯糖化效率及发酵产氢的影响,优化了相应的工艺参数,结果表明:玉米芯的最佳糖化效率和发酵产氢出现在水解温度115℃ ,硫酸浓度1.0%,水解时间1.5 h和固液比(M/V)l:10,在该条件下,玉米芯糖化效率为0.5433g·(g TVS)-1,酸解残渣的氢产氢达 85. ml H2·(g TVS)-1。此外,通过X射线粉末衍射分析和结晶度计算探讨了酸解预处理和氢发酵对玉米芯的作用机理。 相似文献
7.
Sodium dodecyl sulfate (SDS) is a frequently used anionic detergent, and proteins are among the widely used minor ingredients
in cosmetic products. Proteins may enhance the detergent functions and protect human skin from irritation caused by detergents.
Soy protein hydrolysates (SPH) were prepared by modifying soy protein (SP) with papain. Varying concentrations of SP or SPH
were mixed with various concentrations of SDS at different pH values to determine: (i) molecular characteristics, degree of
hydrolysis (DH), and surface hydrophobicity (S
0) of SP and SPH; (ii) the effect of SDS concentrations on the S
0 of SP; (iii) the storage stabilities of oil-in-water emulsions formed by SDS, SP, SPH, SP-SDS, and SPH-SDS; and (iv) the
effect of protein concentration (0.01 to 1.5%), DH (1.2 to 12.5%), and pH (3.0, 5.0, 7.0, and 9.0) on storage stabilities
of emulsions formed by SP-SDS or SPH-SDS. An increase in emulsion stability (ES) with increasing protein concentration was
observed. The ES values of emulsions formed by SPH-SDS complexes were significantly higher than those formed by SP-SDS at
pH 7.0 and 9.0. The ES of emulsions formed by the complexes were low at pH 5.0 and increased with increasing pH. At pH 3.0
the emulsions formed by SP-SDS at 1 to 1.5% protein concentration and by SPH-SDS at 1.5% protein concentration were very stable.
The results indicate that at least one-half of SDS content can be replaced by SP or SPH while maintaining emulsion stability. 相似文献
8.
P. Mercier L. Yerushalmi D. Rouleau D. Dochain 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1992,55(2):111-121
The biosynthesis of ammonium lactate, a product of lactic acid fermentation was studied from corn and glucose at five different pH values of 5.4 to 7.8. In the glucose fermentations, a 100% conversion of substrate was obtained resulting in a maximum lactic acid production yield of 93.2%. The optimum pH for the maximum volumetric rate of lactic acid biosynthesis (1.56 g dm?3 h?1) was between 6.0 and 6.5. The corn fermentations were slower than the glucose fermentations with a resulting lactic acid yield of 67.5%. Hydrolysis of corn by enzymatic or chemical methods as well as the use of ammonium hydroxide for pH control increased both the final concentration and the rates of lactic acid production. An enhanced yield of more than 90% was finally obtained in the corn fermentations. A logistic model adequately described the kinetics of biomass growth, lactic acid production and sugar utilization in the glucose fermentations at different pH values. The dynamics of lactic acid formation in the corn fermentations were also successfully described by the developed model. The dependence of the model parameters on pH was investigated. 相似文献
9.
以瞬间弹射蒸汽爆破(instant catapult steam explosion, ICSE)为基础,联用稀酸法、碱法、氨水法、有机溶剂法以及离子液体法进行预处理,对不同方法采用组分和酶解分析,以探索出一种绿色和高效的预处理方法.ICSE处理后的物料能够显著促进传统的化学预处理过程,其中ICSE与碱法联用预处理的糖收率最高,达到了77.54%,而ICSE与离子液体联用预处理后糖收率比单纯使用离子液体提高了7.78倍,达到了60.04%.选取ICSE与离子液体联用预处理过程作为最优预处理方法,并对其采用傅里叶-红外光谱、X射线晶体衍射和扫描电镜进行表征,经ICSE处理后玉米秸秆变得蓬松且不完整,半纤维素组分减少,促进离子液体对于纤维素的溶解;而与离子液体联用预处理后,物料纤维素和木质素相应官能团吸收峰增强,纤维素结晶构型由纤维素-Ⅰ型转变为纤维素-Ⅱ型,结晶指数降低. 相似文献
10.
11.
Guan-Wen Chen Hong-Ting Victor Lin Li-Wen Huang Chia-Hua Lin Yu-Hsin Lin 《International journal of molecular sciences》2021,22(10)
This research focuses on the proteolytic capacity of sea bass byproduct (SB) and their hypocholesterolemic activity via the cholesterol micelle formation (CMF) inhibition. SB was fermented with seven mixed lactic acid bacteria for 5 h at 42 °C. The lactic fermented SB was hydrolyzed with Protease N for 6 h under HHP to obtain the SB hydrolysates (HHP-assisted Protease N hydrolysis after fermentation, F-HHP-PN6). The supernatant was separated from the SB hydrolysate and freeze-dried. As the hydrolysis time extended to 6 h, soluble protein content increased from 187.1 to 565.8 mg/g, and peptide content increased from 112.8 to 421.9 mg/g, while inhibition of CMF increased from 75.0% to 88.4%. Decreasing the CMF inhibitory activity from 88.4% to 42.1% by simulated gastrointestinal digestion (FHHP-PN6 was further hydrolyzed by gastrointestinal enzymes, F-HHP-PN6-PP) reduced the CMF inhibitory activity of F-HHP-PN6. Using gel filtration chromatography, the F-HHP-PN6-PP was fractioned into six fractions. The molecular weight of the fifth fraction from F-HHP-PN6-PP was between 340 and 290 Da, and the highest inhibitory efficiency ratio (IER) on CMF was 238.9%/mg/mL. Further purification and identification of new peptides with CMF inhibitory activity presented the peptide sequences in Ser-Ala-Gln, Pro-Trp, and Val-Gly-Gly-Thr; the IERs were 361.7, 3230.0, and 302.9%/mg/mL, respectively. 相似文献
12.
Melo-Silveira RF Fidelis GP Costa MS Telles CB Dantas-Santos N de Oliveira Elias S Ribeiro VB Barth AL Macedo AJ Leite EL Rocha HA 《International journal of molecular sciences》2012,13(1):409-426
Xylan is one of most abundant polymer after cellulose. However, its potential has yet to be completely recognized. Corn cobs contain a considerable reservoir of xylan. The aim of this work was to study some of the biological activities of xylan obtained from corn cobs after alkaline extraction enhanced by ultrasonication. Physical chemistry and infrared analyses showed 130 kDa heteroxylan containing mainly xylose:arabinose: galactose:glucose (5.0:1.5:2.0:1.2). Xylan obtained exhibited total antioxidant activity corresponding to 48.5 mg of ascorbic acid equivalent/g of xylan. Furthermore, xylan displayed high ferric chelating activity (70%) at 2 mg/mL. Xylan also showed anticoagulant activity in aPTT test. In antimicrobial assay, the polysaccharide significantly inhibited bacterial growth of Klebsiella pneumoniae. In a test with normal and tumor human cells, after 72 h, only HeLa tumor cell proliferation was inhibited (p < 0.05) in a dose-dependent manner by xylan, reaching saturation at around 2 mg/mL, whereas 3T3 normal cell proliferation was not affected. The results suggest that it has potential clinical applications as antioxidant, anticoagulant, antimicrobial and antiproliferative compounds. 相似文献
13.
Pattira Piumngam Christian Schachtrup Yuji Owada Hisatake Kondo Chamras Promptmas Friedrich Spener 《European Journal of Lipid Science and Technology》2005,107(3):145-152
Fatty acid‐binding proteins (FABP) in alveolar type II (TII) cells are required for surfactant synthesis and regulation. Beyond expression of heart‐type (H‐) and epidermal‐type (E‐) FABP in TII cells from mouse lung, we present the first evidence of the expression of liver‐type (L‐) FABP, by quantitative PCR and immunofluorescent confocal laser microscopy. Further, by making use of an acute mouse lung injury model, we examine whether these lipid‐binding proteins are released into the bronchoalveolar fluid (BALF) and into the circulation upon challenge of the lung with lipopolysaccharide. Applying FABP‐specific ELISAs, we found that neither H‐ nor E‐FABP can be detected in BALF and serum above background levels, up to 24 h after insult. In contrast, L‐FABP was detected in the BALF pellet, consisting of polymorphonuclear cells and alveolar macrophages, and in serum. A significant decrease in L‐FABP levels in the BALF pellet was associated with a significant increase in serum levels 6 h post insult. As contributions of L‐FABP from other organs were excluded, this protein could be used as a marker for acute lung injury. 相似文献