醇酶法提取苦杏仁油工艺优化及微胶囊的制备

在单因素试验基础上,根据Box-Behnken中心组合设计原理,以苦杏仁油得率为评价指标进行工艺优化。苦杏仁油提取的最佳工艺条件为乙醇体积分数20.5%、酶添加量3.5%、酶解时间147 min,料液比1︰8(g/mL),验证试验表明苦杏仁油平均得率为39.11%±0.21%,符合预测值。为提高苦杏仁油抗氧化性,以β-环状糊精和大豆分离蛋白为壁材,采用真空冷冻干燥法制得微胶囊,并利用电子显微镜及荧光显微镜进行扫描观察。电子显微镜扫描结果显示,苦杏仁油微胶囊呈现出颗粒均匀且表面完整的立体结构;荧光显微镜显示微胶囊呈现荧光反应,表明微胶囊制备成功,油脂被包埋进微胶囊内,能够有效解决油脂易氧化、货架期短等问题,为苦杏仁油资源的开发与利用奠定基础。

Alcohol dehydrogenase: A potential new marker for diagnosis of intestinal ischemia using rat as a model

AIM: Intestinal ischemia (Ii) is an abdominal emergency due to blockade of the superior mesenteric artery resulting in 60-100% mortality if diagnosed late. Changes in several biochemical parameters such as D (-)-lactate, Creatinine kinase isoenzymes and lactate dehydrogenase suggested for early diagnosis, lack specificity and sensitivity. Therefore a biochemical parameter with greater sensitivity needs to be identified. METHODS: Wistar male rats were randomly assigned into two groups; control sham operated (n = 24) and ischemic test (n = 24) group. Superior mesenteric arterial occlusion was performed in the ischemic test group for 1 h. Alcohol dehydrogenase (ADH) was estimated in blood from portal vein, right ventricle of heart, dorsal aorta (DA) and inferior vena cava (IVC). The Serum glutamic acid pyruvate transaminase (SGPT) was also estimated in blood from portal vein and right ventricle of heart. RESULTS: A significant increase (P<0.001) in the levels of ADH in both portal blood as well as heart blood of the test group (232.72±99.45 EU and 250.85±95.14 EU, respectively) as compared to the control group (46.39±21.69 EU and 65.389±30.55 EU, respectively) were observed. Similarly, increased levels of ADH were observed in blood samples withdrawn from DA and IVC in test animals (319.52±80.14 EU and 363.90±120.68 EU, respectively) as compared to the control group (67.68±63.22 EU and 72.50±58.45 EU, respectively). However, in test animals there was significant increase in SGPT in portal blood (P= 0.054) without much increase in heart blood. CONCLUSION: Significant increase in the levels of ADH in portal and heart blood within 1 h of SMA occlusion without increase in SGPT in heart blood, suggests that the origin of ADH is from ischemic intestine and not from liver. Similarly, raised ADH levels were found in DA and IVC as well. IVC blood does represent peripheral blood sample. A raised level of ADH in test animals confirms it to be a potential marker in the early diagnosis of li.

Brewing of low-alcoholic drink from corncobs via yeast-cellulase synchronous fermentation process

The present work focuses on the influence of various parameters, i.e., the dosage of cellulase, the inoculum concentration of yeast, the fermentation temperature and the fermentation time, on the alcohol content and sensory evaluation of the low-alcoholic health drink produced from corncob in a yeast-cellulase synchronous fermentation process. The fermentation was performed by inoculating the seed solution (containing corncob powder and yeast) and cellulase into the synchronous saccharification fermentation medium. Single-factor experiments and orthogonal experiments were performed, and the optimal processing conditions were obtained based on the characterizations of alcohol content and sensory evaluation. The results show that the alcohol content and sensory evaluation of the drink can reach 6.1 vol.% and 92, respectively, when the dosage of cellulase, inoculum concentration of yeast, the fermentation temperature and the fermentation time are 15 U/g, 7%, 32℃ and 84 h, respectively.

Effect of Different Pretreatment Methods on Enzymatic Saccharification and Ethanol Production from Sugarcane Shoots and Leaves

Sugarcane shoots and leaves consist of 35.2% cellulose, 23.43% hemicellulose, 12.6% lignin and 6.59% ash on dry solid （DS） basis and have the potential to serve as low cost feedstocks for ethanol production. To improve the enzymatic digestibility of these biomass and bioethanol production, three pretreatment methods had been investigated and compared, including： （1） 2% w/v NaOH solution autoclaving pretreatment; （2） 2% w/v H2SO4 solution autoclaving pretreatment and （3） two steps of 2% w/v NaOH solution autoclaving followed by 2% w/v H2SO4 solution autoclaving pretreatment. Among them, the best result for ethanol production was obtained when 15 g DS of sugarcane shoots and leaves was pretreated by using two step of 2% w/v NaOH solution autoclaving followed by 2% w/v H2SO4 solution autoclaving. The highest ethanol concentration 30.40 g/L （92.65% in fermentation efficiency） was obtained from reducing sugar 89.25 g/L at 48 h. Moreover, the washing step of solid residue after pretreatment could reduce furfural and hydroxymethylfurfural （HMF） in all pretreatment methods when compared to unwashing solid residue after pretreatment.

Enzymatic detection of ethanol based on H_2O_2-sensitive quantum dots

A rapid and sensitive fluorometric method for the enzymatic detection of ethanol using CdSe/ZnS quantum dots （QDs） is proposed. The photoluminescence of QDs is sensitive to H202. This finding leads to a novel approach for the determination of ethanol using alcohol oxidase （AOx） which, on oxidation of ethanol, produces H202. The method has higher sensitivity, wider analytical range （0.1-8 mmol/L）, and a lower detection limit （0.05 mmol/L）. The relationship between quenching of the photoluminescence of the QDs and the concentration of ethanol is linear.

The Use of Bone Morphogenetic Protein-7 and Resveratrol in Collagen Type II of Articular Cartilage

This study aimed to investigate the effects of resveratrol and bone morphogenetic protein 7 on type II collagen from superficial and middle zone of porcine articular chondrocytes. Articular cartilage was isolated from dissected porcine knee joint n = 12. Isolated cells were plated as monolayers at a density of 1 × 105 cells/well in 12-well culture plates and incubated at 37℃ in a humid atmosphere of 5% carbon dioxide and 95% air. Cell cultures were treated for four days with various concentrations of bone morphogenetic protein-7 and resveratroL Cells were then collected and analysed for collagen type II expression by real time polymerase chain reaction and protein level quantification by enzyme-linked immunosorbent assay. Cartilage tissue sections were localised for collagen type II by immunohistochemistry. Moreover, resveratrol and bone morphogenetic protein-7 effects on cartilage matrix contents were analysed by histology. Resveratrol and bone morphogenetic protein-7 stimulates expression of collagen type II mRNA and protein level accumulation in the surface zone and middle zone at 50μM ＋ 300 ng/ml （RSV ＋ BMP-7）. Immunohistochemistry results confirmed the presence of collagen type II on articular cartilage. Histological tissue sections confirmed that chondrocytes were obtained from different zones of articular cartilage. The study suggests that a combination of bone morphogenetic protein-7 and resveratrol up-regulate the expression and synthesis of collagen type II.

Mycotoxins Incidence in Romanian Malting Barley （Harvest 2009）

The presence of deoxynivalenol （DON）, total aflatoxins, ochratoxin （OTA） and zearalenone （ZEA） was investigated in malting barley samples harvested in Romania using an ELISA method （VERATOX, Neogen）. In 7 out of 14 barley samples the aflatoxins were not found at detectable levels （50%）. In 9 out of 14 barley samples the OTA was not found at detectable levels （64.29%）. In 1 out of 14 barley samples the DON was not found at detectable levels （7.14%）. In 13 out of 14 barley samples （92.86%） the ZEA was above the acceptable limit （100μg/kg）. For all barley samples the aflatoxins, DON and OTA were in line with European Union regulations in force （4.0 μg/kg for aflatoxins, 1,250.0μg/kg for DON, 5.0 μg/kg for OTA, respectively）.