Effects of polysaccharides and polyphenolics fractions of Zijuan tea (Camellia sinensis var. kitamura) on α‐glucosidase activity and blood glucose level and glucose tolerance of hyperglycaemic mice

The effects of polysaccharides, theaflavins, thearubigins and theabrownin fractions of Zijuan tea on α‐glucosidase and blood glucose level and intolerance of hyperglycaemic mice were evaluated. The polysaccharides or theaflavins fraction exhibited greater inhibition rate of α‐glucosidase than acarbose positive control, thearubigins fraction or theabrownin fraction. The four fractions were delivered to the treatment mice through oval gavage each day for 15 days. The mice in polysaccharides and theaflavins high‐ and low‐dose and theabrownin high‐dose treatments significantly lowered their blood glucose levels while all the treatment mice gained body weight. The mice in polysaccharides, theaflavins and theabrownin high‐ and low‐dose treatments had greater glucose tolerance as well. Thus, the theaflavins and polysaccharides fractions of Zijuan tea effectively moderated the complications of hyperglycaemic mice. The lower effectiveness of thearubigins and theabrownin fractions may be caused by the highly polymerised polyphenolics which decreased their accessibility to α‐glucosidase and digestibility in mice.     

Effects of green tea powder on the quality attributes of hard red winter wheat flour and Chinese steamed bread

The effects of green tea powder (GTP) on the properties of hard red winter (HRW) flour and Chinese steamed bread were investigated. GTP was blended with HRW flour at levels of 0.00, 1.00, 2.00, 3.00 and 4.00 g GTP/100 g wheat flour. With the addition of GTP, the maximum torque of flour became stronger. The resilience and degree of green colour of steamed bread increased, while hardness and chewiness decreased, with the addition of GTP. The addition of 1.00% GTP did not significantly affect the specific volume, but remarkably influenced the hardness and resilience of steamed bread. In steamed bread formulated with GTP, the antioxidant activity was 0.84 mm TE per g at 1.00% of GTP and increased with GTP levels. The steamed bread had a pleasant flavour, and the degree of overall liking of steamed bread increased with GTP levels to the maximum used in this work.     

Quality identification and evaluation of Pu‐erh teas of different grade levels and various ages through sensory evaluation and instrumental analysis

To develop an objective, effective, flexible and cost‐saving method to assess Pu‐erh tea quality, Pu‐erh tea samples of different grade levels and various ages were analysed using sensory evaluation and various instrumental techniques, including chemical analysis and electronic tongue (ET). Results showed that taste profile analysis as a sensory evaluation method can meticulously describe and distinguish different Pu‐erh tea samples. Chemical analysis combined with hierarchical cluster analysis can cluster Pu‐erh ripened and raw tea both in compressed and scattered forms. However, no obvious variation tendency was observed in the chemical composition parameters of Pu‐erh tea of different grade levels or various ages. ET combined with principal components analysis (PCA) is effective in classifying Pu‐erh tea samples of different grade levels and various ages. ET followed by linear discriminant analysis (LDA) performs well in identifying Pu‐erh tea samples of various ages by establishing a discriminant model.     

Production of yellow wine from Camellia Oleifera meal pretreated by mixed cultured solid‐state fermentation

Camellia oleifera meal was evaluated to be a potential feedstock for the production of yellow wine (YW), and process conditions were investigated. In this study, C. oleifera meal was firstly pretreated using mixed cultured Bacillus subtilis and Aspergillus niger under solid‐substrate fermentation to degrade the tea saponin (TS) for the following YW fermentation. Response surface methodology helped evaluate the effects of the selected operating parameters, and the optimal condition at a fixed time of 4 days, which gave a 67.84 ± 0.23% degradation rate of TS, was reached as inoculum concentration of 16%, initial moisture content of 55% and temperature of 30 °C. Finally, 7‐day fermentation was harvested to be the most suitable pretreatment for producing YW from C. oleifera meal, and the twice‐feeding fermentation for YW was obtained as wheat koji 12% and active yeast 1.2%. In addition, ample amino acids, phenolic components and the trace TS endowed the C. oleifera wine, the more nutritional characteristics.     

高职高专计算机应用基础以证代考模式研究

随着我国社会主义现代化建设的发展,信息化、办公管理现代化的要求愈来愈迫切,作为现代化管理的重要手段—计算机应用已深入各领域、各行业、各部门。计算机知识的掌握和应用是高职高专学生服务社会的必备条件。由于信息技术的快速发展及高职高专的特点,本文针对我院多年来实践"以证代考"模式的实施方案、取得效果、存在问题几个方面进行阐述。     

4-Methylimidazole in soluble coffee and coffee substitutes

Soluble coffee and coffee substitutes' consumption has grown considerably in recent years. These products, prepared from roasted coffee and/or cereal extracts, are more consumer-friendly than plain coffee, being usually cheaper. During roasting, several toxic compounds can be produced from carbohydrate degradation in presence of aminoacids, including 4-methylimidazole (4-MeI). This work aimed to screen the presence of 4-MeI in soluble coffee and its surrogates commercialized in Portugal using a previously validated gas chromatography-mass spectrometry (GC–MS) method. In a total of 45 soluble samples analyzed, including 10 plain coffees, 8 decaffeinated coffees, 12 cereal mixtures with coffee and 15 cereal mixtures without coffee, all the samples were positive for 4-MeI, with levels that ranged from 136 to 1411 μg/kg. All cereal-containing samples had significantly higher amounts (p < 0.01) than coffee samples, whilst no statistical differences were observed between decaffeinated and plain coffees. The high variability observed between samples is not influenced by the “brand” effect as well as by raw-material.     

水温及浸泡时间对日照绿茶氨基酸含量影响的研究

实验主要研究了水温及浸泡时间对日照绿茶中氨基酸含量的影响。研究表明:水温90℃,浸泡时间30min时,日照绿茶中氨基酸含量较高。