高通量筛选葡萄糖酸钙高产菌株

以黑曲霉为研究对象,建立了高通量筛选葡萄糖酸钙高产菌株流程。结果表明:紫外线-LiCl复合诱变处理的黑曲霉孢子悬浮液,高通量筛选得到4株高产菌株,传代后发酵性能稳定。菌株P-9,其发酵液葡萄糖酸钙含量达到23.04 g/100 mL,比原始菌种高5.86 g/100 mL。相较于传统摇瓶发酵筛选工作量大,周期长,该方法显著提高了筛选效率。     

Predicting bull fertility using genomic data and biological information

The genomic prediction of unobserved genetic values or future phenotypes for complex traits has revolutionized agriculture and human medicine. Fertility traits are undoubtedly complex traits of great economic importance to the dairy industry. Although genomic prediction for improved cow fertility has received much attention, bull fertility largely has been ignored. The first aim of this study was to investigate the feasibility of genomic prediction of sire conception rate (SCR) in US Holstein dairy cattle. Standard genomic prediction often ignores any available information about functional features of the genome, although it is believed that such information can yield more accurate and more persistent predictions. Hence, the second objective was to incorporate prior biological information into predictive models and evaluate their performance. The analyses included the use of kernel-based models fitting either all single nucleotide polymorphisms (SNP; 55K) or only markers with presumed functional roles, such as SNP linked to Gene Ontology or Medical Subject Heading terms related to male fertility, or SNP significantly associated with SCR. Both single- and multikernel models were evaluated using linear and Gaussian kernels. Predictive ability was evaluated in 5-fold cross-validation. The entire set of SNP exhibited predictive correlations around 0.35. Neither Gene Ontology nor Medical Subject Heading gene sets achieved predictive abilities higher than their counterparts using random sets of SNP. Notably, kernel models fitting significant SNP achieved the best performance with increases in accuracy up to 5% compared with the standard whole-genome approach. Models fitting Gaussian kernels outperformed their counterparts fitting linear kernels irrespective of the set of SNP. Overall, our findings suggest that genomic prediction of bull fertility is feasible in dairy cattle. This provides potential for accurate genome-guided decisions, such as early culling of bull calves with low SCR predictions. In addition, exploiting nonlinear effects through the use of Gaussian kernels together with the incorporation of relevant markers seems to be a promising alternative to the standard approach. The inclusion of gene set results into prediction models deserves further research.     

混合试验仪确定冷冻面团馒头复配添加剂最佳配方

利用混合试验仪研究硬酯酰乳酸钠（SSL）、黄原胶、抗坏血酸（VC）对冷冻面团特性的影响。通过单因素试验、正交试验确定了冷冻面团复配添加剂的最佳配方为SSL0.1%、VC0.010%和黄原胶0.3%。用不同复配添加剂配方制作冷冻面团馒头,利用感官品质评分、质构品质测定进行综合评价,最佳结果与Mixolab试验结果一致。     

春砂仁凝胶软糖的研制

采用广东阳春春砂仁的提取浓缩物为原料,选择并比较了几种亲水胶体的凝胶性能及形成凝胶软糖的工艺条件。通过胶体的复配,研制出一种外观晶莹透明、质地软糯而富有弹性、口感具有春砂仁特征滋味的凝胶软糖。其中亲水胶体含量为1%、总糖含量为66%、水分含量为17.6%。     

Effects of chloride,thiocyanate and sulphate salts on β‐lactoglobulin–pectin associative complexes

Protein–polysaccharide complexes are used to improve protein stability and encapsulate high‐value ingredients, yet the influence of different salts on their formation has not been investigated. Using light scattering and turbidimetry, effects of chloride, sulphate and thiocyanate salts on β‐lactoglobulin and pectin complexes (protein/pectin ratio = 2:1 and 4:1) were determined in relation to effects of pH and ionic strength. Effects of anions on complex formation were significant at 25 mmol kg^?1 added ionic strength. Cation effects were not significant. At 100 mmol kg^?1 ionic strength, pH of complex formation increased with sulphate salts (pH 5.1) relative to chloride and thiocyanate salts (pH 4.9), while pH of coacervation increased with sulphate salts (pH 4.7) and decreased with thiocyanate salts (pH 4.4) relative to chloride salts (pH 4.6). Pure β‐lactoglobulin stability was otherwise reduced with thiocyanate salts below pH 5, implying a significant effect of pectin interactions.     

刺梨酥李复合果酒发酵研究

以刺梨、酥李为原料,用酿酒活性干酵母作为发酵剂,对刺梨酥李复合果酒发酵工艺进行研究,试验结果表明,刺梨酥李复合果酒的最佳工艺为:刺梨汁与酥李汁配比为3∶1(体积比),前发酵温度为24℃,后发酵温度为18℃,酵母接种量0.4%,糖度25%。按此工艺加工的刺梨酥李复合果酒具有独特的诱人风味,是一种值得开发的复合型果酒。     

离子缔合体系测定痕量硒(Ⅳ)的研究与应用

在吐温-60存在下,研究了硒(Ⅳ)与硫氰酸钾和乙基罗丹明B形成的三元离子缔合物的吸收光谱特性,最大吸收峰为605nm,表观摩尔吸光系数ε605=1.50×106L/mol·cm,硒(Ⅳ)浓度在0.0~2.0μg/25mL范围内符合比耳定律。用巯基棉富集分离干扰离子,测定了水样和食品中痕量硒,结果满意。     

山茱萸复合晶固体饮料的研制

以山茱萸为原料,蔗糖为甜味剂,苹果浓缩汁、猕猴桃浓缩汁为调味剂,采用正交试验设计出最佳风味配方的山茱萸复合晶固体饮料.该饮料的最佳配方为:山茱萸浓缩汁中添加(质量分数)蔗糖60%,柠檬酸0.7%,β-环糊精0.4%.最佳工艺为:复水,100℃,6 min;浸汁,80℃,20倍稀释,2 h 2次浸汁;澄清,1%果胶酶,6 h;浓缩,0.1 MPa,50℃;干燥:前期,65℃,71.82 kPa~74.48 kPa;中期,80℃,77.14 kPa;后期,70℃,79.8 kPa.     

喷雾干燥条件对速溶胡萝卜、大豆蛋白复合饮料品质影响研究

本研究以胡萝卜、大豆为主要功能原料,采用喷雾干燥法生产冲溶性良好的固体饮料。对胡萝卜和大豆制汁（浆）的喷雾干燥最佳工艺条件以及加工过程中营养成分损失和产品保存等一系列问题进行了研究。最优工艺参数为：进风温度250℃、进料总固形物含量9％,进料速度25ml／min,喷头压力0．35Mpa。胡萝卜素保存率和产品的水分含量与进风温度,进料速度,喷头压力显著相关。     

大曲生衣复合菌在大曲生产中的应用

造成大曲不生衣的原因很多，主要是受气候、环境和工艺条件的制约，不能给有益微生物菌系提供一个最佳的生长条件。目前，全国大曲生衣率仅在20％～50％之间，使用大曲生衣复合菌及新工艺操作，可提高大曲生衣率及大曲质量。试验表明，用0．1％。的大曲生衣复合菌，可使大曲生衣率提高到90％以上。