【作者】 付军杰；

【导师】 贺稚非；

【作者基本信息】 西南大学 ， 食品科学， 2012， 硕士

【摘要】 为研究灌肠类低温肉制品货架期期间的品质变化规律,从而为制定相应生产操作规范提供基础数据；本文通过模拟超市温度环境,实验在0-4℃和6-10℃条件下对市场上不同厂家的方腿类和脆皮肠类两种类型的低温肉制品在贮藏过程中的理化和微生物指标进行了检测,主要指标有：细菌总数、大肠菌群、致病菌、pH值、保水性、水分含量、色泽、硬度、弹性、粘结性、咀嚼性、恢复性等。并依据实验结果,参考相应的国标、法规制定了一份灌肠类产品的储运操作规范。具体实验结果如下：(1)菌落总数的变化：检测的六种产品在各自货架期内的菌落总数均未超过国家标准规定的1.0×104；在前期,菌落总数增长较为缓慢,之后增长速度逐渐加快,部分产品到后期会有增长放缓的现象出现,这可能与产品中营养物质被消耗过多有关；其中,在0-4℃条件下贮藏产品的菌落总数增加速度和最终数量都低于6-10℃的贮藏环境,说明低的贮藏温度对抑制微生物的生长有明显效果。(2)pH值的变化：在贮藏期间六种产品的pH值总体都呈下降趋势,且在6-10℃环境下的产品的pH值波动较大,0-4℃的贮藏环境下,产品的pH值相对稳定；其中三种脆皮肠类产品的pH值前期变化不显著,在贮藏后期开始出现明显的下降趋势,这可能与后期产品中微生物数量增多,微生物利用肉制品中大量营养物质而发酵产酸有关。(3)保水性的变化：在贮藏期间,六种产品的保水性均没有出现显著的变化；在方腿类产品中,双汇方腿和雨润方腿的保水性在两种温度条件下均呈下降趋势,且在6-10。C温度条件下产品的保水性波动范围较大；美好方腿的保水性在储藏期间上下波动较大,变化规律不明显；三种脆皮肠类产品在不同温度下的保水性均呈现上升趋势,不同贮藏温度间没有显著差异。(4)水分含量的变化：六种产品的水分含量在贮藏期间都是呈下降趋势,且在6-10℃的贮藏环境下下降的更明显,但总体差异不显著；方腿类产品中雨润方腿的水分含量下降最为明显,但所有产品在贮藏期间均没有出现明显的变干现象,产品没有出现显著的质量变化。(5)感官评分的变化：感官变化中,方腿类的三种产品在储藏期间的感官评分都呈现下降趋势,且前期不同温度条件下的感官评分差别很小,温度对于产品感官上的影响有待进一步研究；脆皮肠类的三种产品在储藏的前期产品的感官评分都有一个上升趋势,这可能是产品固有的香味的一个逐渐释放过程,在中后期,随着时间的推移,产品的感官评分开始逐渐下降,且6-10℃的口感开始变差,从而导致评分下降。(6)大肠菌群的变化：所检测的产品在整个贮藏期间均没有检测出大肠菌群,说明产品卫生质量保持较好,原料肉没有受到明显的污染。在所有产品中未有致病菌检出。(7)色泽的变化：在贮藏期间六种产品的L*总体都呈下降趋势,6-10℃条件下的波动大于0-4℃,说明低温有利于保护肉制品的亮度,L*的变化总体不显著；在贮藏期间,产品的a*没有出现明显的趋向性变化,且不同贮藏环境下的a*差别也不明显,时间以及温度对于a*的影响有待进一步研究；b*代表黄度值,产品的b*贮藏期间保持稳定,均没有出现明显的变化,但是6-10℃贮藏条件下的b*波动高于0-4℃的贮藏环境。(8)质构的变化：产品在不同贮藏温度下的硬度均呈现下降趋势,前期下降速度较慢或基本没有变化,后期下降速度明显加快,在6-10℃的贮藏温度下硬度的变化快于0-4℃,硬度的下降主要与产品的含水率有关,水分含量的下降导致了硬度的下降；弹性的变化方面,方腿类的三种产品在整个贮藏期间其弹性都呈下降趋势,但下降均不显著,三种脆皮肠类产品的弹性没有变化,不同温度间差别不显著；粘结性的变化规律方面,在整个贮藏期间六种产品的粘结性均呈显著的上升趋势,其中在6-10℃的贮藏条件下粘结性上升的趋势明显快于0-4℃的贮藏条件,由此可以看出温度对于抑制产品粘度的上升有着明显的效果；在整个贮藏过程中,产品的恢复性保持相对稳定没有出现明显的变化,不同的贮藏温度间也没有出现明显的差异,温度对于产品恢复性的影响有待进一步研究；在整个贮藏期间六种产品的咀嚼性均呈现上升的趋势,且在6-10℃的贮藏条件下咀嚼性的上升速度明显快于0-4℃的贮藏环境,这可能是与在较高的温度条件下,产品失水较多有关。更多还原

【Abstract】 In order to study the quality variation of low temperature-heated meat products during the shelf life, provided basic data for the development of manufacturing practices.This experiment chose different companies luncheon ham and dish sausage. Experiment on the sensory, chemical, microbiological and other indicators to study the quality changes under different storage temperature (0-4℃or 6-10℃) regularly. It included the total number of bacteria, coliform bacteria, pH value, water holding capacity, moisture content, sensory evaluation, color, hardness, springiness, adhesiveness, chewiness, resilience in the shelf life. And based on experimental results, refer to the corresponding national standard and regulations drawn up a sausage products storage and transportation practices. Results as follows:(1) Changes of the total number of bacteria:All of the six products total number of bacteria did not exceed the national standard of 1.0 x 104 in their shelf life. In the earlier stage the total number of bacteria growth relatively slow, then the growth rate gradually speed up, some of the products slower growth in the latter. This may be because the nutrient of the products has been excessive consumption. Both the growth speed and the final total number of bacteria at 0-4℃are less than 6-10℃. Shows low storage temperatures have significant effect in inhibition the microbial growth.(2) Changes of pH value:The pH value of the six products declined steadily during storage. The products pH value at 6-10℃environment have greater variation than the 0-4℃storage environments, the pH value of the product is relatively stable. The pH value of three kinds of dish sausage have no significant changes, late in the storage have noticeable downward trend. This may be related to the increase of the microorganisms in the late-stage.(3) Changes of water holding capacity:The water holding capacity of the six products have no significant changes during storage. Shineway luncheon ham and Yurun luncheon ham declined steadily during storage and 6-10℃temperature conditions have a large range of fluctuation, Meihao luncheon ham have greater variation during storage and have no significant trend. Three kinds of dish sausage products’water holding capacity under different temperatures showed an upward trend, there have no significant difference between different storage conditions.(4) Changes of moisture content:The moisture content of the six products declined steadily during storage. The products moisture content at 6-10℃environment have greater variation than the 0-4℃storage environments, but the overall difference was not significant.In the three luncheon ham, Yurun moisture content declined most obvious, All products during the storage have no obvious dry phenomenon, no significant product quality changes.(5) Changes of sensory evaluation:The sensory evaluation of the three kinds of luncheon ham declined steadily during storage, under different temperature conditions, the early stage sensory score difference is little difference; temperature effects on the sensory evaluation for products need to be further studied. In the early stage of storage, all of the three kinds of dish sausage have a rising trend in sensory score, this may be a release process of the product’inherent flavor. In the late, over time, the product of sensory score began to decline, and 6-10℃taste began to deteriorate, resulting in ratings decline.(6) Changes of coliform bacteria:The detection of the product throughout the storage period did not detect coliform bacteria, indicating that the product quality to maintain good health, no serious contamination of raw materials.(7) Changes of color:The L* of the six products declined steadily during storage, and the products L* at 6-10℃environment have greater variation than the 0-4℃storage environments, shows low-temperature help to protect the brightness of meat products, L* does not significantly changes. During storage, the product’ a* have no clear trend changes in different storage environments, and different storage environments is not significant difference; it is need a further study for the impact of time and temperature. The products b* no clear trend changes in different storage environments, the product’ b* at 6-10℃environment have greater variation than the 0-4℃storage environments.(8) Changes of texture value:The hardness of the six products declined steadily during storage, in the early stage hardness slow decline or no changes, over time, the rate of decline gradually accelerating; At 6-10℃storage temperature hardness changes faster than 0-4℃, Decline in water content led to a decline in the hardness. The springiness of the three kinds of luncheon ham declined steadily during storage, but have not significant decrease; The springiness of the three kinds of dish sausage have no significant changes during storage. In the adhesiveness side, throughout the six products during storage were significantly rise, the products adhesiveness at 6-10℃environment have greater rise than the 0-4℃storage environments. It can be seen that the temperature has significant effect in inhibition adhesiveness’rise. During storage, the product’resilience have no clear trend changes in different storage environments, and different storage environments is not significant difference; it is need a further study for the impact of time and temperature. Throughout the storage period, the six products’ chewiness upward trend, at 6-10℃storage temperature chewiness changes faster than 0-4℃, This may be because in the higher temperatures, more water loss related.更多还原