【作者】 裴家伟；

【导师】 张柏林；

【作者基本信息】 河北农业大学 ， 农产品加工及贮藏工程， 2004， 硕士

【摘要】 羊肉在我国居民的日常消费中所占的比重越来越大。然而，我国的羊肉制品的加工技术仍然非常滞后，羊肉制品粗糙，品种单一。小包装分割肉是国际肉制品加工的流行趋势之一，本项研究旨在研究开发新型的复配型防腐剂，以期能运用于小包装分割羊肉制品上，延长羊肉产品的货架期。 对屠宰后羊肉的微生物区系进行了调查，成功地分离出引起冷却羊肉腐败的主要革兰氏阳性菌和阴性菌8种，其中含芽孢的革兰氏阳性杆菌有3种，占整个微生物区系的30％；革兰氏阳性球菌1种，占整个区系的2％；革兰氏阴性螺旋杆菌3种，占整个区系的63％；革兰氏阴性杆菌1种，占整个区系的5％。 分别运用山梨酸钾、EDTA和Nisin对7种主要引起羊肉腐败的微生物进行了抑菌实验，结果显示，0.25‰以上山梨酸钾能够有效抑制5×10~4 cfu／mL以下的革兰氏阳性短芽孢杆菌的生长；1‰以下的山梨酸钾不能完全抑制5×10~4 cfu／mL革兰氏阴性粗短杆菌的生长，对10~4 cfu／mL革兰氏阳性球菌菌株、革兰氏阴性螺旋菌菌株和肠杆菌菌株抑制效果不太明显。1mmoL EDTA能完全抑制住小于10~5 cfu／mL革兰氏阳性短芽孢杆菌菌株、革兰氏阳性球菌菌株的生长，能明显的抑制10~5 cfu／mL的革兰氏阴性粗短杆菌菌株生长，对10~5 cfu／mL的革兰氏阴性螺旋菌菌株有一定的抑制作用。10mmoL EDTA能完全抑制住10~5 cfu／mL革兰氏阴性螺旋菌菌株的生长；能明显抑制10~5 cfu／mL的革兰氏阴性粗短杆菌菌株的生长，而20 mmoL EDTA能很明显抑制10~5 cfu／mL肠杆菌菌株的生长。25mg／mL、50 mg／mL、75 mg／mL和100 mg／mL的Nisin几乎对所有引起羊肉的腐败菌有抑制作用，但抑制程度不同，抑菌活性有一定的变化。大于75 mg／mL的Nisin对10~5 cfu／mL的革兰氏阳性短芽孢杆菌菌株、革兰氏阴性粗短杆菌菌株、肠杆菌菌株、革兰氏阴性螺旋菌菌株和革兰氏阳性球菌菌株有明显的抑制作用，对10~5 cfu／mL的革兰氏阳性短芽孢杆菌菌株抑制作用尤为明显。 根据单一抑菌剂的抑菌结果，选择不同浓度的抑菌剂组成复配型防腐剂，对引起羊肉腐败的主要微生物种类进行了抑菌实验，获得了一组最佳复配型防腐剂(25mg／mL Nisin-20mmoL EDTA-1‰山梨酸钾)。应用该复配型防腐剂对真空小包装分割羊肉进行保藏防腐，研究表明，能使其货架期达到28d，较不加防腐剂的可以延长货架期5～7d。更多还原

【Abstract】 Mutton meat, as a popular food in China, has been consumed for a long time. In recent decades, the consumption of small vacuum-packaged fresh meat has grown rapidly. However, one of the main problems facing the fresh lamb meat product is a short shelf-life and fast spoilage. The purpose of this study was how to use food-grade preservatives to improve the shelf-life of fresh mutton meat packaged.It was seen that the main microflora causing the spoilage of fresh mutton meat consisted of 3 gram-positive bacilli with spore (about 30% of the micro flora), 1 gram-positive coccus (about 2% of the whole microflora), 3 gram-negative spirilla (about 63% of the whole microflora), and 1 gram-negative bacillus (about 5% of the whole microflora).Potassium sorbate, EDTA and nisin were used as preservatives to inhibit the growth of the main strains representative for the spoilage of fresh lamb meat. It was found that 0.25%o potassium sorbate produced a positive inhibition against short G+ spore bacillus with a concentration less than 5xl04cfu/ml. A concentration less than \%o potassium sorbate hardly exerted a complete control towards short G- plump bacillus having a population density of 5x104cfu/ml. It was proved that use of l% potassium sorbute never controlled the growth of G+ coccus, G~ spirilla and enterobacter with a population density of 104cfu/ml.1mmol EDTA completely controlled the growth of G+ short spore bacillus and G+ coccus whose cell density was 5xl04cfu/ml. A level of lmmol EDTA showed a limited inhibition against the growth of G- spirilla with a population density of 105 cfu/ml. However, a level of 10mmol EDTA completely controlled the growth of the G- spiral bacteria having a population density of 105cfu/ml. lOmmol EDTA produced a very significant control towards the growth of G" plump short bacillus with 105cfu/ml. 20mmol EDTA showed a remarkable inhibition against the enterobacter with a population density of 105cfu/ml.Different concentrations of nisin including 25mg/mL, 50mg/mL, 75mg/mL and 100mg/mL were used as bio-preservative to examine its effects against the growth of allstrains leading to the spoilage of fresh mutton meat. It was seen that there was a big difference in nisin’s concentrations in inhibiting the spoiling bacteria. Generally speaking, as more as 75mg/mL of nisin significantly inhibited the growth of G+ short spore bacillus, G-plump short bacillus, enterobacter, G’spiral bacteria and G+ coccus having a population density of 105cfu/ml. The growth of G+ short spore bacillus with a population density of 105cfu/ml was almost controlled in the presence of 75mg/mL nisin.Different combined preservatives including potassium sorbate, EDTA and nisin, based on the information from individual preservatives, were tested for their inhibitions against all the strains spoiling fresh mutton meat. The compound preservative consisting of Nisin(25mg/mL)-EDTA(20mmol)-potassium sorbate(l %) showed the most strong inhibition against the growth of the bacteria causing the spoilage of fresh mutton meat. Furthermore, this preservator was employed to improve the quality of small vacuum-packaged mutton meat. A 28-d shelf life of fresh mutton meat was maintained. Compared to controlling samples, an extended shelf life of 5 to 7 days was produced if the combined preservative was used to practice.更多还原