摘要：
Loss of energy potential during storage is a significant consideration when using crop residues for bioenergy production. However, previous studies about biomass storage only reported dry matter loss and composition change, but not the direct effects on bioenergy production. This study investigated the changes in chemical composition, enzymatic digestibility, and methane yield of corn stover after one-year outdoor dry bale storage under covered and uncovered conditions. The contents of easily degradable components, including extractives and hemicellulose, decreased by about 20%-50%, while the contents of cellulose and lignin did not change significantly. The methane yields of corn stover after one-year covered or uncovered storage declined by 13.2% and 22.7%, respectively, partially due to the decrease of cellulose degradability and the losses of hemicellulose and extractives. Increasing particle size from 1 mm to 12.7 mm reduced the methane yield of the stored corn stover by up to 26.4%. The modified Gompertz model suggested that both storage conditions and particle size affected methane yield, maximum methane production rate, and lag phase time of anaerobic digestion (AD) of corn stover. The information reported in this paper can provide important information for economic analysis and life cycle analysis of AD of corn stover. (C) 2018 Elsevier Ltd. All rights reserved.
摘要：
Using soybean beverage can improve the nutrition of cheeses and expand their varieties. However, addition of soybean beverage results in cheese-like products with undesirable soft texture and loose structure. Herein, soybean beverage was treated with flavourzyrne and then mixed with cow milk to prepare Cheddar cheese-like products, and the chemical composition was not standardized before the production. Compared with non hydrolysis soybean beverage, enzyme-modified soybean beverage significantly decreased the moisture content and yield of cheese-like products, increased the protein and fat content and pH, but had no effect on protein and fat recoveries. Changes were more dramatic in products with high degree of soybean beverage hydrolysis. Hardness and storage modulus were increased upon addition of enzyme-modified soybean beverage, and especially values of products supplemented with high hydrolysis soybean beverage were comparable with those of products made only with cow milk. The protein matrix became compact upon adding enzyme-modified soybean beverage, with numerous small whey pockets, similar to the microstructure of products made only with cow milk. Thus, without decreasing the yield, low hydrolysis soybean beverage can effectively improve the texture and structure of Cheddar cheese-like products.
通讯机构：
Hunan Engineering Laboratory for Alcohol Fuels from Biomass, College of Food Science and Technology, Hunan Agricultural University, Changsha, China
摘要：
The thermal stability of donkey milk, which largely depends on the stability of casein and whey proteins, plays a critical role in the manufacture of donkey dairy products. However, the thermal stability of donkey casein micelles is poorly understood. Our study first found that donkey milk exhibited poor thermal stability, with sedimentation observed after heating at 75 degrees C for 10min. Moreover, electrophoresis results indicated that donkey casein micelles were more sensitive to heat treatment than whey protein. The characteristics of donkey casein micelles were then studied to determine the thermal instability mechanism. Donkey casein micelles had a larger diameter (295+/-11nm) and lower absolute zeta potential (-15.4+/-0.5mV) than bovine casein micelles, mainly due to their very low kappa-casein levels. The higher proportion (51%) of beta-casein in donkey casein micelles made them less hydrated. Furthermore, <40% of calcium in donkey milk was associated with donkey casein micelles. To eliminate the influence of whey protein, micellar casein was isolated from skim donkey milk by ultracentrifugation and then redispersed in its ultrafiltrate. Transmission electron microscopy and particle size analysis showed the extensive aggregation of isolated casein micelles after thermal treatment, which confirmed the thermal instability of casein micelles observed in donkey milk. Overall, poor colloidal stability and a highcalcium environment largely contributed to the thermal instability of donkey casein micelles.
作者机构：
[郭红英; 姚荷; 刘楚岑; 王锋; 周红丽; 谭兴和; 刘宗敏] College of Food Science and Technology, Hunan Agricultural University, Changsha, 410128, China;[严钦武; 徐永兵] Hunan Chaqi Vegetables Industry Co. Ltd., Yueyang, 414000, China;[王栏树] Hunan Jiayan Food Co. Ltd., Changsha, 410000, China
关键词：
植物乳杆菌;发酵;萝卜干;亚硝酸盐;品质
摘要：
为加快发酵速率,降低产品亚硝酸盐含量,并提高产品品质,本研究以萝卜干为原料,分别接种植物乳杆菌L4(Lactobacillus plantarum L4)和植物乳杆菌B5(L. plantarum B5),并以自然发酵为对照,萝卜干发酵时间为56 d,研究L4和B5对萝卜干品质的影响。结果表明:L4、B5和自然发酵pH值降低的速率依次为: L4>B5>自然发酵。亚硝酸盐含量随着发酵时间的延长先增加后减小,其中L4发酵在22 d左右出现亚硝酸盐峰,峰值为(3.23±0.17)mg/kg,B5和自然发酵在33 d左右出现亚硝酸盐峰,峰值分别为(2.04±0.12)mg/kg和(3.79±0.25)mg/kg(P<0.05)。挥发酯含量、游离氨基酸含量都随着发酵时间的延长呈上升趋势。L*、b*随着发酵时间的延长呈下降趋势,而a*随着发酵时间的延长呈上升趋势。发酵结束时,L4、B5和自然发酵感官评分别为88.7±2.56、81.8±1.49和74.1±3.88。由此表明,植物乳杆菌L4和B5可以缩短萝卜干的发酵周期,提高萝卜干安全性和品质,其中L4表现比B5好。
通讯机构：
Hunan Provincial Key Laboratory of Food Science and Biotechnology, College of Food Science and Technology, Hunan Agricultural University, Changsha, China
摘要：
A sustainable process of value-added utilization of wastes including waste cooking oil (WCO) and post-consumer PET bottles for the production of biodiesel and polyurethane (PU) foams was developed. WCO collected from campus cafeteria was firstly converted into biodiesel, which can be used as vehicle fuel. Then crude glycerol (CG), a byproduct of the above biodiesel process, was incorporated into the glycolysis process of post-consumer PET bottles collected from campus to produce polyols. Thirdly, PU foams were synthesized through the reaction of the above produced polyols with isocyanate in the presence of catalysts and other additives. The characterization of the produced biodiesel demonstrated that its properties meet the specification of biodiesel standard. The effect of crude glycerol loading on the properties of polyols and PU foams were investigated. All the polyols showed satisfactory properties for the production of rigid PU foams which had performance comparable to those of some petroleum-based analogs. A mass balance and a cost analysis for the conversion of WCO and waste PET into biodiesel and PU foams were also discussed. This study demonstrated the potential of WCO and PET waste for the production of value-added products.
作者机构：
[郭红英; 刘梦浩; 蔡文; 张喻; 金慧鸣; 王锋; 邓洁红; 谭兴和] Key Laboratory for Food Science and Bio-Technology of Hunan Province, College of Food Science and Technology, Hunan Agricultural University, Changsha, 410128, China
摘要：
The aim of this study was to investigate the effect of capsaicin on hypoxia-reoxygenation (H/R)-induced apoptosis in primary rat hippocampal neurons. Three hours of hypoxia (1% O2) and subsequent reoxygenation for 24 h significantly increased the apoptotic death of hippocampal neurons, as evidenced by increases in both TUNEL-positive cell number and caspase-3 activity. Pretreatment with capsaicin (3-30 micromol/L) or the caspase-3-specific inhibitor acetyl-DEVD-CHO (100 micromol/L) markedly attenuated H/R-induced apoptosis in hippocampal neurons. Capsaicin also markedly induced the phosphorylation of Akt. The phosphoinositide 3-kinase (PI3K) inhibitor LY294002 (10 micromol/L) prevented any capsaicin-induced survival effect in hippocampal neurons. Intracellular levels of reactive oxygen species (ROS), which were greatly increased after H/R, were significantly inhibited by capsaicin, pyrrolidine dithiocarbamate (PDTC) (50 micromol/L), and LY294002. Taken together, these data suggest that capsaicin protects against H/R-induced apoptosis of hippocampal neurons via the PI3K/Akt-mediated signaling pathway, which is related to the inhibition of oxidative stress and caspase-3 activation.
