有机酯在低酒精度水溶液中的贮存变化分析

低度白酒中有机酯在酒体中的变化一直是白酒行业中非常热门的话题 ,通过对有机酯在单纯低度酒精 -水溶液的贮存变化和添加对应有机酸后的变化从而验证有机酯在低度酒精 -水溶液中的变化规律属于有机酯的酸水解过程 。

中低度瓶装白酒贮存期的变化

通过大量的研究发现,中低度的瓶装白酒贮存中酸升酯降,是必然规律。低度白酒经较长时间贮存后其理化指标检测难以符合国标,虽然近年生产企业采取很多措施,但仍难彻底解决,应引起标准制定部门的重视。

低度董酒贮存后的变化

对贮存1年和贮存多年的酒度为28%vol和38%vol低度董酒进行比较研究,结果表明,28%vol董酒在贮存13年之后、38%vol董酒贮存18年之后其质量仍然符合要求。因为董酒是以醇类、酸类、部分酯类及微量药香呈香呈味,在醇类、酸类及微量药香种类变化不大的情况下,董酒的风格特点保持得较好。

低度白酒发展的思考

回顾我国低度白酒近30年的发展历程,低度白酒和降度白酒已为广大消费者接受,并成为白酒产销的主流。通过系统分析研究,找出低度白酒贮存中质量风格变化的原因。阐述了提高低度白酒质量的技术关键。

Effect of Storage Temperature on the Quality of Glass Bottled Pasteurized Whole Milk

Shelf life of pasteurized milk is relatively short, mainly due to cold chain conditions. This study investigated the effects of different storage temperatures （8, 10 and 12 ℃） on acidity, microorganism index, physical and chemical indicators and sensory quality of pasteurized milk packaged in glass bottle to determine the main factor affecting the quality of pasteurized milk during shelf life under different tem- peratures. The results showed that within the first five days, the protein, fat, lactose and non-fat milk solids contents in the milk samples did not change under different storage temperatures; the acidity was almost unchanged at 8 and 10 ℃, and in- creased slightly at 12 ℃; the sensory quality of milk samples did not change at 8 and 10 ℃, and began to decline from the 4th d at 12 ℃; the aerobic plate count in the milk samples accorded with the requirement of national standard at 8 and 10℃, and exceeded the national standard on the 5th day at 12℃. No coliform bac- teria were detected in the milk samples within the storage time at 8 ℃. When the milk samples were stored at 10 ℃, the coliform group count exceeded the national standard on the 5th day. When the milk samples were stored at 12 ℃, coliform bacteria began to be found in the milk samples from the 2rd day, and the coliform group count exceeded the national standard from the 3rd day. It indicated that stor- age time had a great impact on the quality of glass bottled pasteurized milk. Low storage temperature and relatively short storage time were conducive to the reten- tion of high quality of pasteurized milk. Coliform group count was one of the impor- tant factors affecting the quality of glass bottled pasteurized milk during shelf life.

基于生物稳定性的贮存水水质变化规律及消毒策略

通过对贮存水中可同化有机碳(AOC)、微生物再生长潜能(BRP)及细菌总数(HPC)等微生物指标变化规律的了解,探究饮用水贮存过程中细菌二次生长、生物稳定性下降等问题。结果表明:在贮存过程中,HPC呈现先上升后下降的趋势;而AOC及BRP则在贮存初期(2 d内)出现上升,后基本保持稳定。通过向贮存水中投加不同浓度的氯或氯胺,研究了不同种类、不同浓度的消毒剂对贮存水HPC的影响及其衰减速率的变化规律。结果表明:随着氯或氯胺初始投加量的增加,HPC开始增加及达到峰值所需时间延长,且HPC峰值下降;当氯或氯胺初始投加量达到1.0 mg·L^(-1)以上,贮存水中氯残留量>0.05 mg·L^(-1)或氯胺残留量>0.5 mg·L^(-1)时,即可保证贮存过程HPC<100 CFU·mL^(-1)。与氯消毒相比,氯胺消毒剂的衰减速率更为缓慢,可长期维持贮存水中较高的消毒剂残留,进而控制贮存水中HPC处于相对较低的范围,更有利于保证贮存水生物的稳定性。