新疆冰川冰缘冻土低温淀粉酶部菌株分子生物学鉴定及酶学特性研究

[目的]对新疆冰川冰缘地区冻土中筛选出的具有良好产低温淀粉酶能力的菌株进行分子生物学鉴定,分析其酶学特性.[方法]用种子培养液活化菌株提取基因组DNA进行PCR扩增,将扩增成功菌株的PCR产物测序结果通过NCBI数据库比对,对冻土中产低温淀粉酶菌株的16S rDNA序列用MegAlign Fasta软件进行系统发育分析.利用Yoo改良法测低温淀粉酶酶活力.[结果]菌株A-2,A-3,A-4经16S rDNA序列分析获得的序列与数据库中解淀粉芽孢杆菌(Bacillus amyloliquefaciens strain NBRC 15535 16S ribosomal RNA,partial sequence(NR_04145))比对相似率达到99;.该菌株产生的低温淀粉酶的最适作用温度为30℃,最适pH为6.[结论]菌株A-2,A-3,A-4均属解淀粉芽孢杆菌.     

Quality Evaluation of Grass Carp (Ctenopharyngodon idella) Protein Concentrate Supplemented Noodles

ABSTRACT

The aim of the present study was to evaluate the quality of wheat flour noodles supplemented with 0%, 10%, 20% and 30% grass carp protein concentrate (GCPC). Proximate composition, color analyses, cooking properties (cooking time, cooking loss, swelling index and water absorption index), texture profile analyses (TPA), and sensory evaluations were performed. Significant (p ≤ 0.05) increases in the crude protein (18.94–35.19%), crude fat (0.88–1.06%), and ash (0.89–1.02%) were recorded for GCPC supplemented cooked noodles. Brightness (L*), redness (a*) and yellowness (b*) of GCPC 10–30% fortified cooked noodles was recorded as 77.00–69.97, 1.50–2.81 and 19.08–22.25, respectively. Cooking loss (CL) and optimal cooking time were significantly (p ≤ 0.05) increased with increased level of GCPC from 0%-30%, with readings of 6.13% ?8.90% and 7.53–11.77 min, respectively. Swelling and water absorption indices showed a decreasing trend at 2.33–1.77 and 102.6–78.49%, respectively. A significant (p ≤ 0.05) decreasing trend in hardness (24.50–19.03N) was observed for cooked noodles with increased level of GCPC, while the remaining TPA parameters were significantly different at p> .05. Sensory analyses showed higher preference for control noodles and noodles fortified with 10% GCPC.     

南美白对虾冷冻保鲜研究进展

从冻结速率、冻藏温度和时间、解冻速率、冻融循环次数和水分保持剂等方面综述了南美白对虾冷冻保鲜工艺。     

二次发酵冷冻面团成品品质影响因素研究

为了改善不同发酵工艺下冷冻面团成品的品质,采用测量物性指标结合感官评价以及正交试验等方法,研究了发酵时间和添加剂对冷冻面团比容、色度及感官品质的影响。结果表明,最佳的二次醒发时间为20 min,添加剂组合为:单甘脂0.40%,维生素C 0.32%,CMC-Na(羧甲基纤维素钠)0.125%,在此条件下制作的冷冻面团品质优良。     

桂林冰冻分布及气候特征分析

对桂林1957～2008年13个气象观测站的地面气象观测资料进行了分类研究,概括了冰冻出现的频率及其在时间和地理上的分布规律,分析总结了冰冻天气的地形、年代分布特征。结果表明：20世纪70年代后,冰冻日的发生呈下降趋势,随年分布也随之减少;桂林冰冻日的时间和空间分布具有明显的地域性。     

Principal Component Analysis of Cooked Rice Texture Qualities

Texture qualities of cooked rice are comprised of many indexes with the complex relationship, so it is difficult to analyze and evaluate cooked rice. In this paper, the related indexes of texture properties were conversed into the independent indexes of principal component based on the principal component analysis method. The results showed that the rice kernel types influenced the meanings of principal components indexes. For long and short rice, the first principal component was comprehensive index. But the second principal component was springiness for the short rice, while it was adhesiveness for long rice. Therefore, the first principal component can be used to express the quality of cooked rice with a few of indexes, and the rice type can be recognized according to the second principal component.     

熟食品消费的网络评论对线上销量的影响研究——以水禽熟食产品为例

为探究最受消费者关注的产品属性以及在线评论的偏好差异性对熟食品销量的影响,选取水禽熟食为研究对象,通过收集14种水禽熟食品牌在一个月内的消费者评论,并对评论的属性进行分类,在量化属性评分的基础上对水禽熟食产品在线销量的影响机制进行了实证检验。研究结果表明:1)消费者最关注熟食产品的质量属性和安全属性,而水禽熟食评论中的偏好差异性对销量有着负向作用;2)在线评论的口碑量和口碑极性会在一定程度上削弱偏好差异性的影响,进而增加产品的销量。在此基础上,建议水禽熟食生产商多方兼顾,从产品质量、产品安全等方面全面提升产品的总体质量,并且尽可能采取一些激励措施来提高产品的口碑量和口碑极性,进而提升产品销量。     

火龙果皮柚子皮复合保健生鲜面的研制

在传统面条的基础上加入具有保健功能的火龙果皮和柚子皮,研制一种新型营养保健生鲜面,在单因素试验的基础上,通过正交试验确定生鲜面的最佳制作工艺。结果表明,以干面粉的质量为基数,柚子皮与水在制浆时的质量比为1∶2,柚子皮浆与火龙果皮浆质量比为1∶1,混合浆添加量30%,压延次数10次,食盐添加量1.0%。制得的产品组织细腻,色泽呈悦目的淡紫红色,口感光滑有弹性,无特殊异味且具有柚子的清香。     

食品添加剂对速冻水饺品质特性的影响

[目的]为水饺生产提供技术指导。[方法]以金苑饺子粉为原料、白菜和猪肉为饺子馅主料制作速冻水饺,研究三聚磷酸钠、黄原胶、硬脂酰乳酸钠、淀粉磷酸酯钠4种食品添加剂对水饺品质的影响。[结果]硬脂酰乳酸钠抗水饺冻裂的效果最明显,淀粉磷酸酯钠对水饺色泽、口感具有明显的改善效果,但单独使用1种食品添加剂不能全面改善速冻水饺各方面的性能;通过正交试验确定复合添加剂的最优组合为：黄原胶0.1%,硬脂酰乳酸钠0.4%、三聚磷酸钠0.25%、淀粉磷酸酯钠0.5%。[结论]该研究确定了速冻水饺的最佳添加剂类型及用量。     

凉州区黄牛冻配改良工作现状与存在的问题及对策

凉州区一直以来就是全省黄牛改良和肉牛养殖的大区,本文就凉州区黄牛改良工作的现状和存在的问题作以阐述交流,以促进该区黄牛改良工作的健康发展,为全省黄牛改良工作提供交流和借鉴。