【作者】 陈杭君；

【导师】 徐幸莲；

【作者基本信息】 南京农业大学 ， 食品科学， 2008， 硕士

【摘要】 本文根据我国南美白对虾的养殖和加工现状,结合国内实际情况,有针对性的研究了南美白对虾捕捞前后各因子对虾黑变与保鲜期的影响。全文主要分三个部分：(1)捕前禁食对南美白对虾品质与黑变的影响；(2)不同温度对南美白对虾贮藏过程鲜度的影响；(3)不同处理方式对南美白对虾鲜度和黑变的影响。1、采用捕捞前禁食1d、禁食2d和不禁食的处理方式,研究其对捕捞后南美白对虾品质与黑变的影响,结果表明：南美白对虾捕捞前禁食处理使脂肪和蛋白质含量都出现不同程度的下降,但禁食前期虾维持生命代谢主要以消耗脂肪为主；禁食1 d左右有利于提高虾在无氧环境中的生存能力,显著降低捕捞后虾体的初始细菌总数,并减轻虾的黑变以及腐烂程度；禁食2d以上容易降低虾捕捞后的营养品质。2、把南美白对虾放在0℃、5℃、10℃不同温度下贮藏,通过分析理化、微生物指标和感官评价的变化,研究了不同温度处理对南美白对虾贮藏过程鲜度的影响,结果表明：贮藏环境温度越高,细菌的繁殖速度越快,TVBN含量和K值增加也越快,低温能在一定程度有效保持虾的品质和新鲜度,延长贮藏期。虾在0℃、5℃、10℃条件下贮藏,较适宜的贮藏时间分别为6d、4d和2d。但仅采用低温的方法不能阻止虾黑变的产生,要解决虾加工中的黑变问题,必须辅以其它的研究方法和手段。3、试验分四组(A：亚硫酸氢钠溶液浸泡；B：二氧化氯溶液浸泡；C：二氧化氯缓释贮藏；D：蒸馏水浸泡),研究不同处理方式对南美白对虾鲜度和黑变的影响,结果表明：采用亚硫酸氢钠溶液浸泡处理能有效防止虾的腐败及黑变,但亚硫酸盐会对对人体产生危害；采用二氧化氯溶液浸泡在贮藏前期能有效的杀灭微生物,但2d后失去了抗菌作用；二氧化氯缓释贮藏能延缓虾黑变的发生,虾保鲜8d仍能保持较好的品质和鲜度,保鲜时间比对照延长2～3d。更多还原

【Abstract】 On the Basis of present situation of aquaculture and processing of prawn (penaeus vannamei) in our country, effects of major factors before and after capture on browning and preservation were studied in this paper. Three main parts were included here:Firstly, Effect of withholding food methods before capture on quality and browning of prawn; Secondly, Effect of different temperatures on freshness of prawn during storage; Thirdly, Effect of different treatments on freshness and browning of prawn.Results were listed below:1. Effects of food withheld with 0,1,2 days on quality and browning of prawn after capture were measured. The results indicated that withholding food treatments decreased the contents of fat and protein and the metabolism of prawn was mainly digested by fat during early non-feeding stage. Food withheld with 1 day contributed to enhancing survival of prawn under aerobic conditions, effectively reduced the initial number of bacteria, alleviate browning and rotting development of prawn after capture, however food withheld with 2 day easily decreased the quality of prawn.2. To investigate the effects of different temperatures on freshness of prawn, changes of physical, chemical, microbial and sensory evaluation indexes of prawn were measured at different storage temperature (0℃,5℃and 10℃). Data showed that higher storage temperature, the faster propagation of bacteria and the quicker increase in TVBN content and K value. Low temperature storage maintained quality and freshness of prawn, and extended storage life. The optimal storage life of prawn was 6,4 and 2 days respectively, when stored at 0,5 and 10℃. However, the browning of prawn could not be prevented by low temperatures, and other methods must be used.3. Effects of different treatments on freshness and browning of prawn were investigated under conditions of sodium bisulfite soaking and chlorine dioxide soaking as well as chlorine dioxide releasing way, and distilled water soaking was the control. The results indicated that the browning of prawn was effectively inhibited by sodium bisulfite solutions soaking, however because of the concerns for food safety, sulfite was restricted to humans. Chlorine dioxide soaking way could effectively kill microbe, but quickly lost the effort after 2 days. Chlorine dioxide releasing storage delayed markedly the browning, maintained the quality and freshness of prawn after 8 days, and extended the storage life over 2 to 3 days compared to the control.更多还原