Fermentation of Soybean Meal Hydrolyzates with Saccharomyces cerevisiae and Zymomonas mobilis for Ethanol Production

Most of the ethanol currently produced by fermentation is derived from sugar cane, corn, or beets. However, it makes good ecological and economic sense to use the carbohydrates contained in by‐products and coproducts of the food processing industry for ethanol production. Soybean meal, a co‐product of the production of soybean oil, has a relatively high carbohydrate content that could be a reasonable substrate for ethanol production after fermentable sugars are released via hydrolysis. In this research, the capability of Saccharomyces cerevisiae NRRL Y‐2233 and Zymomonas mobilis subsp. mobilis NRRL B‐4286 to produce ethanol was evaluated using soybean meal hydrolyzates as substrates for the fermentation. These substrates were produced from the dilute‐acid hydrolysis of soybean meal at 135 °C for 45 min with 0, 0.5%, 1.25%, and 2% H₂SO₄ and at 120 °C for 30 min with 1.25% H₂SO₄. Kinetic parameters of the fermentation were estimated using the logistic model. Ethanol production using S. cerevisiae was highest with the substrates obtained at 135 °C, 45 min, and 0.5% H₂SO₄ and fermented for 8 h, 8 g/L (4 g ethanol/100 g fresh SBM), while Z. mobilis reached its maximum ethanol production, 9.2 g/L (4.6 g ethanol/100 g fresh SBM) in the first 20 h of fermentation with the same hydrolyzate.     

Extraction of soybean isoflavones from soybean meal with aqueous methanol modified supercritical carbon dioxide

The effects of modifier composition in terms of methanol content in water, modifier concentration, meal particle size and extraction conditions (temperature, pressure and CO₂ flow rate) on isoflavones recovery from soybean meal by supercritical carbon dioxide (SC–CO₂) extraction were investigated. The highest isoflavones recovery attained was 87.3%, at 40 °C and 50 MPa, using CO₂ flow rate of 9.80 kg/h containing a modifier 7.8 mass% of 80% (v/v) aqueous methanol. Using different modifier concentrations (60–100% methanol) at 50 MPa and 40 °C, it was shown that 80% methanol was optimum for isoflavones extraction. In addition, isoflavones recovery increased with the modifier content in SC–CO₂ up to 10.2%. The optimal particle size was 20–30 mesh with bigger and smaller particles resulting in lower isoflavones recovery. The results showed that increasing the temperature from 40 to 70 °C drastically reduced isoflavones recovery at 50 MPa. The higher the extraction pressure, the higher was the isoflavones recovery. The extraction rate increased with CO₂ flow rate but the percentage recovery was more or less the same.     

Effects of dietary rumen‐protected lysine on milk yield and composition in lactating cows fed diets containing double‐low rapeseed meal

This study investigated the effects of dietary rumen‐protected lysine (RPLys) on milk yield and composition in lactating cows fed diets containing double‐low rapeseed meal. Twenty‐four cows were divided into three groups and fed one of three dietary treatments: 10% soya bean meal (SBM) diet (control), 15% double‐low rapeseed meal (DLRSM) diet and 15% DLRSM + 32 g/d RPLys (DLRSML) diet. The results showed that no differences (P > 0.05) were observed in milk yield, 4% fat correction milk (FCM), energy correction milk (ECM), protein yield, milk fat yield, milk fat, lactose yield and lactose between control and DLRSM. Supplementation with DLRSML increased (P < 0.05) milk yield, 4% FCM, ECM, and protein yield compared with the SBM. The results indicated that DLRSM and DLRSML might be used to substitute for SBM as a protein source in lactating cows, and the latter might be more beneficial to improve the performance.     

Studies on the mashing conditions of teff (Eragrostis tef) malt as a raw material for lactic acid‐fermented gluten‐free beverage

Formation of extracts and fermentable sugars during mashing can be limited by incomplete starch gelatinisation. The aim of this research was to develop mashing programme for 100% teff malt as a potential raw material for gluten‐free lactic acid‐fermented beverage. Isothermal mashing at temperatures ranging between 60 and 84 °C was conducted, and the highest extract (85%) was observed for the wort samples produced at temperatures higher than 76 °C. Sixty‐minute rest at 71 °C resulted in higher fermentable sugars than other tested conversion rest temperatures. Inclusion of lower mashing‐in temperature in the mashing programme also substantially improved the concentrations of free amino nitrogen (128 mg L^?1) and fermentable sugar (58 g L^?1) in the final wort. Therefore, 30‐min rest at 40 °C followed by 60‐min rest at 71 °C and 10‐min rest at 78 °C was found to be a suitable mashing programme for teff malt.     

Determination of biotin in low‐temperature fish‐meal processed from different species by means of a microbiological method using Lactobacillus plantarum as test organism

Determination of biotin content in 10 fish‐meals produced from different species was performed by a microbiological assay using Lactobacillus plantarum as test organism. The contents of biotin in the fish‐meal samples ranged between 0.36 and 0.80 mg kg⁻¹. Most of the fish‐meals contained approximately 0.4 mg biotin kg⁻¹. The highest value was found in meal processed from sand eel (Ammodytes marinus). The precision of the assay showed a 2.7% relative standard deviation. Recovery using addition of biotin to the fish‐meal ranged between 93 and 95%. Testing of extraction procedure suggested that hydrolysis in 1.5 M H₂SO₄ at 121 °C for 3 h is sufficient for biotin to be liberated from proteins and amino acids. © 1999 Society of Chemical Industry     

Improvement of soybean meal quality by one-step fermentation with mixed-culture based on protease activity

Microbial fermentation can improve the quality of soybean meal by reducing the level of anti-nutrition factors and increasing the content of protein and small peptides. In this study, Bacillus velezensis, Enterococcus faecium and Saccharomyces boulardii were used for one-step mixed fermentation of soybean meal. The fermentation of soybean meal was carried out in an anaerobic bag using fermentation liquid of strains with maximum protease activity as inoculum and water. The results of process optimization showed that the mixture ratio of B. velezensis: E. faecium: S. boulardii was 37.5%:25%:37.5%. The three microorganisms added together as a mixture. Under the conditions of 55% inoculation with microorganisms mixture, 0.8% acid protease addition, 46 ℃ and 6 days, the quality of fermented soybean meal was significantly improved. The small peptides increased from 4.48% to 47.4%, the TCA solution protein increased from 44.3 g/kg to 255.2 g/kg, the antigenic protein glycinin decreased by 94.37% from 320.12 μg/mL to 18.02 μg/mL, and β-conglycinin decreased by 85.83% from 232.11 μg/mL to 32.89 μg/mL. Other anti-nutritional factors urease, phytic acid and stachystryose all decreased. The result indicated that it was feasible to improve the feed quality of soybean meal by one-step mixed fermentation based on protease activity.Industrial relevanceFermentation is the main method to improve the feed quality of soybean meal. Our study revealed that one-step mixed-culture fermentation based on microbial protease activity showed a significant effect on increasing beneficial small peptides, reducing anti-nutrient factors and enhancing palatability of soybean meal. This process simplified the operation of mixed fermentation and could be implemented in solid fermentation system of feed and food industry to improve the beneficial properties of products.     

Lipase production by solid fermentation of soybean meal with different supplements

The aim of this work was to study the production of extracellular lipases by solid state fermentation in soybean meal with different supplements. Lipase production by two microorganisms, screened by their potential for lipase production, was followed in terms of hydrolytic activity at different pH values(4, 7 and 9). The supplementation of the medium with urea and soybean oil significantly increased the enzyme production for all studied pH and microorganisms. Microorganism Penicillium P58 and P74 showed the possibility of production of different lipases with alkaline and acidic characteristics. In soybean meal supplemented with urea and soybean oil, this microorganism yielded 139.2 and 140.7U lipase/g of dry substrate in 48 h of fermentation, in alkaline and acidic conditions, respectively. Different behavior was observed when the enzyme extract was evaluated in neutral conditions, which yielded 180.0U lipase/g in 72 h. A new promising lipase producer strain was testedon soybean meal with different supplements. The strain produced a lipase with high activities by solid state fermentation of soybean meal supplemented with urea and soybean oil.     

固态发酵豆粕的不同生产工艺及其营养品质比较

以米曲霉和植物乳杆菌WZ011为发酵菌种,研究了5种不同的固态发酵豆粕生产工艺及其营养品质。以灰分、粗蛋白量、可溶性蛋白量、游离总氨基酸量、氨基酸含量分布、酸溶性蛋白量、小肽含量、还原糖量、氮溶指数、蛋白分子量、脲酶含量、胰蛋白酶抑制因子含量以及体外消化率为指标,对发酵豆粕营养品质进行了比较和分析。结果表明,米曲霉单菌发酵后,高温水解处理对豆粕营养品质的提高有效,但在米曲霉和植物乳杆菌WZ011的双菌串联发酵过程中增加高温水解处理反而不利。在米曲霉有氧发酵后直接接种植物乳杆菌WZ011进行厌氧发酵条件下所得的豆粕营养品质最优,其中的胰蛋白酶抑制因子含量比原豆粕减少了91.8%,并含有小肽8.01%、乳酸4.95%、γ-氨基丁酸0.317 mg/g以及植物乳杆菌活菌数1.93×1010CFU/g。优化的豆粕发酵工艺操作简单且无污染,其产品富含营养。该工艺在饲料加工行业和养殖业具有应用意义。     

利用高温豆粕生产醇洗大豆浓缩蛋白的研究

分别以高温豆粕和低温豆粕为原料采用醇洗工艺制取大豆浓缩蛋白。测定高温豆粕和低温豆粕醇洗浓缩蛋白的蛋白质含量、NSI以及乙醇萃取液糖蜜中皂甙、异黄酮、总糖、蛋白质含量。结果显示:高温豆粕(蛋白质含量47.16%)醇洗浓缩蛋白的蛋白质含量(59.64%)虽然低于低温豆粕(蛋白质含量51.83%)醇洗浓缩蛋白的蛋白质含量(67.71%),但已接近60%,且高温豆粕乙醇萃取液糖蜜中皂甙、异黄酮含量(分别为8.04%、2.67%)与低温豆粕乙醇萃取液糖蜜中的含量接近(8.53%、2.13%)。表明利用高温豆粕生产饲用大豆浓缩蛋白应该是可行的,且副产物糖蜜是提取大豆皂甙、异黄酮、低聚糖的优质原料。     

微生物发酵对豆粕抗原性的影响

探讨了微生物发酵对豆粕抗原性的影响。选用植物乳杆菌、干酪乳杆菌、枯草芽孢杆菌、地衣芽孢杆菌和米曲霉这5种菌株,在液态和固态条件下分别发酵豆粕12 h,对发酵产物进行抗原性测定。结果表明:豆粕经这5种菌株发酵后,粗蛋白含量均有所提高,其中枯草芽孢杆菌在固态发酵时降解豆粕抗原蛋白和降低豆粕抗原性的效果优于其它菌株,此时,豆粕蛋白水解度为4.89%,必需氨基酸含量为193.51mg/g。SDS-PAGE显示发酵豆粕中β-伴大豆球蛋白的α’和α亚基消失,β亚基条带和大豆球蛋白的酸性亚基条带密度减弱,同时大豆球蛋白与β-伴大豆球蛋白的抗原性降低率分别为20.62%和50.12%。     

大豆粕蛋白酶酶解条件和产物分析研究

以水解度为衡量指标,通过正交试验设计,对木瓜蛋白酶、胰蛋白酶和As1.398蛋白酶酶解大豆粕的最佳水解条件进行了筛选.试验结果表明:木瓜蛋白酶水解大豆粕的最佳条件为pH7.0、温度60℃、时间5 h、酶浓度5%.胰蛋白酶水解大豆粕的最佳条件为pH7.0、温度50℃、时间7 h、酶浓度5%;As1.398蛋白酶水解大豆粕的最佳条件为pH6.5、温度50℃、时间7 h、酶浓度5%.对酶解产物进行超滤和SDS-PAGE电泳分析表明,因酶解条件不同,大豆粕酶解产物中蛋白质和肽的组成及其数量也不同;酶的种类不同,大豆粕酶解产物组成也不同;大豆粕水解度越高,其酶解产物中小分子肽数量越多.     

通过粗壮脉纹孢菌发酵改善豆粕营养结构的研究

以粗壮脉纹孢菌发酵豆粕为研究对象,探讨豆粕在发酵过程中主要营养成分及其抗营养因子的变化情况。研究结果表明,随着发酵时间的延长,粗纤维降解率和粗蛋白含量总体呈上升趋势,粗脂肪含量呈下降趋势,可溶性总糖含量则先呈下降趋势,下降至谷底后又逐渐增加,这些变化规律是由粗壮脉纹孢菌产的纤维素酶引起的;类胡萝卜素含量随着发酵时间的延长而上升,植酸含量下降至12 h后趋于稳定,胰蛋白酶抑制剂活性降低至在48 h后检测不出。发酵豆粕营养成分和抗营养因子的变化规律为豆粕的进一步加工提供了理论依据。      

酶解及二次发酵豆粕生产富肽蛋白的研究

利用黑曲霉和米曲霉混菌一次固态发酵所得豆粕,通过酶解及二次发酵生产富肽产品,研究酶解及二次发酵条件对生产富肽蛋白的影响。结果表明,一次发酵豆粕补3倍水磨浆、接种1%乳酸菌、活性干酵母1∶1混合菌种,木瓜蛋白酶0.3%,37℃发酵12h,再55℃酶解36h所得富肽蛋白小肽质量分数达到75.40%。     

Effects of ruminal exposure on the amino acid profile of heated and formaldehyde-treated soybean meal

Rumen cannulated Holstein steers, fed corn silage and a corn-soybean grain mixture twice a day, were used to compare the effectiveness of heat and formaldehyde treatments in preserving the amino acid profile of soybean meal exposed to ruminal fermentation for 12 h. Formaldehyde treatments were 0, .3, .6, and .9 g/100 g soybean meal. Defatted soybean flakes treated at 250, 250, 215, and 180 degrees C for 30, 20, 20, and 25 min, respectively, and unheated soybean meal comprised the heat treatments. The in situ polyester bag technique was used to obtain estimates of ruminal degradation of the treated and untreated soybean meals and to obtain undegraded residues from the soybean meals following 12 h of rumen exposure. Diaminopimelic acid was used to assess the extent of bacterial contamination. Significant amounts of apparent diaminopimelic acid were detected in unexposed samples (2.0 to 7.6% of soybean nitrogen) and in residues (4.8 to 12.7% of residue nitrogen). Significant differences in amino acid contents were detected between untreated and heat-treated soybean meals and their respective residues. Formaldehyde treatment was effective in preserving the original amino acid profile of soybean meal.     

戊糖片球菌NCU301对豆粕强化发酵工艺优化及营养成分的测定

研究戊糖片球菌NCU301对豆粕(未灭菌)强化发酵的最佳工艺条件,测定豆粕发酵前后营养成分和抗营养因子的变化。以乳酸菌活菌量为指标,通过单因素实验和Box-Behnken响应面分析法优化豆粕强化发酵工艺,确定最佳工艺条件为:发酵时间50.0 h、发酵温度30.0 ℃、料水比1：0.82、接种量8%,优化后活菌量达到1.15×10¹⁰ CFU/g。此外,测定豆粕发酵前后营养成分和抗营养因子变化。结果表明:与未发酵豆粕相比,强化发酵豆粕中粗蛋白、酸溶性蛋白、小肽、游离氨基酸的含量分别提高4.78%、36.04%、52.21%、19.10%,胰蛋白酶抑制剂活性和脲酶活性分别下降89.56%、91.72%;与自然发酵豆粕相比,粗蛋白、游离氨基酸总量分别提高0.6%、35.89%,酸溶性蛋白含量、小肽含量,胰蛋白酶抑制剂活性和脲酶活性分别下降4.64%、3.35%、72.79%、60%。使用戊糖片球菌作为豆粕发酵的菌种不仅可以作为抗生素替代品,还可以提高豆粕的营养价值。     

发酵豆粕蛋白提取工艺及其品质的研究

采用单因素实验,考察不同碱溶p H、碱溶时间、碱溶温度和料液比对发酵豆粕乳中蛋白提取率的影响;通过响应面优化实验,建立了发酵豆粕乳中蛋白的最佳提取工艺;并测定了提取蛋白的主要品质指标。结果表明,不同因素对蛋白提取率的影响强弱顺序为:碱溶时间>碱溶p H>碱溶温度>料液比。优化后的最佳工艺为碱溶p H 9.4、碱溶时间56 min、碱溶温度41℃、料液比1∶12,在此条件下,蛋白的提取率达60.36%。经实验表明,植物乳杆菌发酵豆粕中提取的大豆分离蛋白(SPI)溶解性、体外消化率、酸溶蛋白含量较未发酵豆粕均有显著提高(p<0.05)。应用本文所得工艺参数提取发酵豆粕蛋白,方法经济易行,SPI品质良好,可为豆粕蛋白的开发利用提供参考。      

Lactational performance,enteric gas emissions,and plasma amino acid profile of dairy cows fed diets with soybean or canola meals included on an equal protein basis

This study investigated the effects of feeding solvent-extracted canola meal (CM), extruded soybean meal (ESBM), or solvent-extracted soybean meal (SSBM) on an equivalent crude protein basis on performance, plasma AA profiles, enteric gas emissions, milk fatty acids, and nutrient digestibility in lactating dairy cows. Fifteen Holstein cows (95 ± 20 d in milk) were used in a replicated 3 × 3 Latin square design experiment with 3 periods of 28 d each. Treatments were 3 diets containing 17.1% CM, 14.2% ESBM, or 13.6% SSBM (dry matter basis). Vegetable oil was added (canola oil for CM or soybean oil for SSBM) to equalize the ether extract concentration of the diets. Rumen-protected Met was supplemented targeting digestible Met supply of 2.2% of metabolizable protein in all diets. Canola meal increased dry matter intake (DMI) by 5.9 and 8.9% in comparison with ESBM and SSBM, respectively. Milk urea nitrogen was lowest in CM, followed by SSBM, and was highest for ESBM. No differences were observed in feed efficiency, energy-corrected milk yield, and milk composition or component yields among treatments. Cows fed CM emitted less enteric CH₄ per kg of DMI compared with both ESBM and SSBM, but CH₄ emission intensity (CH₄ per kg of energy-corrected milk) was similar among treatments. In summary, replacement of ESBM or SSBM with CM, on an equal crude protein basis, in the diet of lactating dairy cows enhanced DMI, but yields of energy-corrected milk and milk components and feed efficiency were similar among treatments.     

罗非鱼-豆粕共沉淀蛋白的提取工艺及蛋白组成分析

以罗非鱼肉和脱脂豆粕为原料,采用p H调节法制备罗非鱼-大豆共沉淀蛋白（Co-p）,探讨溶解p H、不同质量比混合的原料、溶解时间对可溶性蛋白得率的影响及沉淀p H对蛋白沉淀得率的影响。结果表明,p H调节法回收罗非鱼-豆粕共沉淀蛋白的最佳酸溶p H2.0、3.0,碱溶p H11.0、12.0,原料比1∶1,溶解时间30 min;SDS-PAGE分析显示,可溶性共沉淀蛋白条带深/浅（极端p H2.0蛋白降解）,表明可溶性蛋白含量高/低,从分子量分布范围可知,共沉淀蛋白主要由肌球蛋白重链、7 S抗原蛋白的三个亚基、肌动蛋白、肌球蛋白轻链、11 S抗原蛋白的两个亚基和小分子水溶性蛋白组成,表示可溶性共沉淀蛋白组成齐全;酸/碱可溶性共沉淀蛋白最佳沉淀p H为4.5,在此条件下,溶解、沉淀过程的蛋白得率分别为88.05%⁹4.70%。经冷冻干燥得到共沉淀蛋白粉即Co-p（1∶1）,其蛋白含量高于85%,脂肪含量在0.84%左右,灰分含量低于4.17%;可用p H调节法回收罗非鱼-豆粕共沉淀蛋白。      

霉变大豆对豆粕质量的影响

大豆霉变后，营养物质含量减少，籽粒变色变味，某些微生物分泌的毒素富集在大豆上可能使籽粒感染上毒素。通过对霉变大豆含量不同的大豆样品和豆粕样品进行油脂含量、粗蛋白含量、氢氧化钾蛋白质溶解度、尿素酶活性、色泽和气味等质量指标的测定，分析和研究霉变大豆对豆粕质量的影响。结果显示，随着霉变大豆含量的增加，豆粕粗蛋白含量有所升高，豆粕氢氧化钾蛋白质溶解度降低，豆粕尿素酶活性降低，豆粕颜色灰暗无光泽，霉变味加重。由此得出。用豆粕蛋白质含量作为评价霉变大豆加工所得豆粕质量的指标是不合适的，而采用豆粕氢氧化钾蛋白质溶解度作为评价指标更为合理。这一结果应在大豆油脂生产和豆粕贸易中受到重视。     

Acid hydrolysis of kappa‐carrageenan as a way of gaining new substances for freezing process modification and protection from excessive recrystallisation of ice

The effects of κ‐carrageenan and its hydrolysates on modification of the freezing process and also on inhibition of excessive recrystallisation of ice in sucrose solutions during storage were compared. Acid hydrolysis of κ‐carrageenan was carried out using sulphuric (H₂SO₄) and hydrochloric acid (HCl). Most effective in the hydrolysis process turned out to be H₂SO₄, which degraded κ‐carrageenan to a molecular mass of around 3 × 10⁶ Da, after 1.5 h of hydrolysis. Addition of 0.005% of the new poligeenan (degraded carrageenan), to a sucrose solution (30%), frozen at ?20 °C, caused a nearly 50% reduction in the phase‐change stages, and consequently, the total time of freezing was shorter. Significant retardation of recrystallisation was observed for both types of poligeenan, but a stronger effect was observed for the oligosaccharides obtained after HCl hydrolysis, and after 96 h of storage at ?8 °C, the equivalent diameter of ice crystals was not greater than 11 μm.