Assessment of dietary ratios of red clover and grass silages on milk production and milk quality in dairy cows

Twenty-four multiparous Holstein-Friesian dairy cows were used in a replicated 4 × 4 Latin square changeover design experiment to test the effects of changing from ryegrass (Lolium perenne) silage to red clover (Trifolium pratense) silage in graded proportions on feed intakes, milk production, milk organoleptic qualities, and whole-body nitrogen partitioning. Four dietary treatments, comprising ad libitum access to 1 of 4 forage mixtures plus a standard allowance of 4 kg/d dairy concentrates, were offered. The 4 forage mixtures were, on a dry matter (DM) basis: 1) 100% grass silage, 2) 66% grass silage: 34% red clover silage, 3) 34% grass silage: 66% red clover silage, and 4) 100% red clover silage. In each of 4 experimental periods, there were 21 d for adaptation to diets and 7 d for measurements. There was an increase in both DM intakes and milk yields as the proportion of red clover in the diet increased. However, the increase in milk yield was not as great as the increase in DM intake, so that the efficiency of milk production, in terms of yield (kg) of milk per kg of DM intake, decreased. The concentrations of protein, milk fat, and the shorter chain saturated fatty acids decreased, whereas C18 polyunsaturated fatty acids (PUFA) and long-chain PUFA (C20+) increased as the proportion of red clover in the diet increased. There was little effect of dietary treatment on the organoleptic qualities of milk as assessed by taste panel analysis. There were no effects on the aroma of milk, on aftertaste, or overall liking of the milk. Milk was thicker and creamier in color when cows were fed grass silage compared with red clover silage. The flavor of milk was largely unaffected by dietary treatment. In conclusion, increasing the proportion of red clover in the diet of dairy cows increased feed intakes and milk yields, decreased the concentration of fat and protein in milk, increased PUFA for healthiness, and had little effect on milk organoleptic characteristics.     

武陵山区葡萄酒品质及感官分析研究

根据国家标准分析了酵母辅助发酵（甲）与自然发酵（乙）两种工艺的葡萄酒的理化指标（糖度、酸度、酒精度和固形物含量）,并进行了微牛物指标的检测,并对其营养元素（钾、钠、镁、钙、锌、铁、铜等）、蛋白质、氨基酸和感官进行了分析。结果表明：两种葡萄酒的各项理化指标均在国家标准规定范围之内,其中甲的固形物含量高出乙5．36％;两种葡萄酒的微,丰物指标均能达到国家标准要求;甲的各种矿物质含量均比乙高,蛋白质含量也高出35．90％,氨基酸含量甲（35．4g／100mL）比乙（33．2g／100mL）高,且铁铜含量均在国家标准规定范围之内;通过观察和品尝,甲的色泽较乙好,且酒香较浓郁。通过对武陵山区葡萄酒的品质和感官的分析研究,为以后的理论研究提供实验数据,同时也为武陵山区葡萄酒大规模的牛产奠定理论基础。     

谈谈泥窖对浓香型大曲白酒生产的影响

论述了浓香型大曲白酒生产以依附的泥窖质量对酒质质量影响的重要性.以及怎样合理建窖,使用窖养护窖具体要求;泥的感观和理化要求.对提高酒质有实际的指导意义.     

食用酒精感官分析方法的初步设想

与国际标准相比我国食用酒精感官质量标准存在一些问题,为了与国际接轨,提出了食用酒精感官分析方法的设想,并参照了发达国家的酒精感官质量标准,提出了我国对食用酒精感官质量的要求,详细地介绍了食用酒精感官分析法对人员感官分析的物理条件、受检样品、参比样品的要求,对感官分析的基本方法进行了详述.     

2-取代-1,3-二硫杂环戊烷香料的合成和香气评价

以醛/酮与1,2-乙二硫醇或1,2-丙二硫醇在对甲苯磺酸催化下反应,合成了10种2-取代-1,3-二硫杂环戊烷,产率62.8%~87.8%;其中,2-正丙基-1,3-二硫杂环戊烷产率达87.8%,纯度99.5%。经元素分析、FTIR、GC-MS和1H NMR确定了10种产物的结构。香气评价结果表明:合成的2-正丙基-1,3-二硫杂环戊烷具有花香、肉汤香气,可用于食品香精和调味料中;其余9种2-取代-1,3-二硫杂环戊烷具有肉香、葱蒜香和萝卜香。     

甜叶菊饮料的研制

以甜叶菊水提液为主要原料,配以柠檬酸、蜂蜜、食盐,调制出香味浓郁,色泽明亮,酸甜可口的甜叶菊饮料.通过单因素试验和正交试验,确定出甜叶菊水提液的提取工艺为:料水比1:150、浸提时间3 h、浸提温度60℃.结合感官评定结果,确定得出甜叶菊饮料的最佳配比为:甜叶菊水提液14%、柠檬酸添加量0.002%、蜂蜜添加量0.4%、食盐添加量0.05%.     

温度波动对冷藏鸭肉品质的影响

将鸭肉分别放在(5±0.5)℃和(5±1～2)℃的冷藏环境中进行贮藏对比实验.在贮藏过程中定期对鸭肉进行感官评定和生化检测.贮期末,两个样品菌落总数为7.3×105cfu/100g和6.2×106cfu/100g;TVB-N值为22.26 mg/100g和27.68 mg/100g;pH为6.33和6.41.结果表明,温度波动下的鸭肉在第5天时已接近腐败,而恒温下贮藏的鸭肉在第7天时才接近腐败.     

苹果品质的模糊综合评价

将模糊综合评价法应用于苹果的感官质量评定中,介绍了具体的评价方法。结果表明,此法比常用的加权平均法更科学、合理、客观。     

白醋对发酵甘蓝微生物区系的影响

发酵蔬菜的加工中,经常加入一定量的食用醋,就食用白醋对发酵甘蓝微生物区系的影响进行研究.通过不同的浓度白醋(0%,0.3%,0.6%,0.9%,1.2%)于发酵甘蓝中乳酸菌、嗜温菌、肠道菌和真菌的计数,了解发酵甘蓝过程中微生物数量和种类的变化.测定结果表明:加醋发酵甘蓝中对人体有益的乳酸菌较自然发酵多,导致亚硝酸盐形成的肠菌数量降低的速度较自然发酵的快.而且加醋对发酵甘蓝有明显助益,能提高发酵甘蓝的感官品质.实验表明,加入食用白醋能加快完成发酵,加入食醋的浓度以0.6%为最好.     

蒙顶黄芽加工过程感官品质及化学成分变化的研究

以蒙顶黄芽加工过程中的茶样作为研究对象,系统地分析研究蒙顶黄芽在加工过程中感官品质和化学成分的变化。结果表明:在整个加工过程中氨基酸、可溶性蛋白质和可溶性糖含量呈先升高后降低的趋势;儿茶素、咖啡碱、茶多酚、叶绿素a和叶绿素b含量随加工进程逐渐减少,其中叶绿素a和叶绿素b含量降幅较大,分别为52.00%和44.44%;水浸出物和茶色素含量随加工进程逐渐增加,其中茶红素和茶黄素含量增幅较大,分别为56.52%、54.55%;由感官审评结果可知,经三炒工序后的茶样感官品质已接近蒙顶黄芽成品的品质特征,表明蒙顶黄芽独特的品质特征经过闷黄过程已初步形成。