气调包装对冷却猪肉菌相影响与货架期预测模型
发布时间：2018-07-17 17:19
【摘要】：冷却肉在加工、流通和销售过程中始终保持0~4℃,微生物生长繁殖在一定程度受到抑制。但目前我国肉类冷链尚处于起步阶段,在物流过程经常出现冷链断链、温度波动的状况;传统冷却肉在物流各环节以暴露在空气中为主,易受二次污染;及目前冷却猪肉品质指标检测方法费时耗力,并且结果具有滞后性。冷却肉营养丰富,含水量高,是微生物繁殖的良好基质。因此,冷却肉易腐败变质,货架期短。本文研究了不同包装方式和不同气体配比的气调包装对冷却猪肉的影响,确定最佳包装方法和气体配比。主要结果如下:1.通过监测气调包装内O_2与CO_2含量的变化,选择阻气性较高的PE/PA复合包装袋(长110mm×宽150mm×厚0.19mm)为真空包装和气调包装的材料。2.不同包装的冷却猪肉在4℃贮藏过程中品质与货架期不同。无包装和托盘包装货架期不超过4d,高氧气调包装(80%O_2+20%CO_2)货架期为6d,真空包装和低氧气调包装(35%O_2+65%CO_2)货架期长达9d。真空和气调包装均有利于延长冷却猪肉货架期,但真空包装使肉呈暗红色,影响感官品质。因此,4℃下冷却猪肉的最佳包装方式为低氧气调包装,即35%O_2+65%CO_2。3.采用四组不同气体配比(35%O_2+65%CO_2、55%O_2+45%CO_2、15%O_2+80%CO_2+5%N2和35%O_2+55%CO_2+10%N2)对贮藏在4℃下冷却猪肉进行包装,根据冷却猪肉贮藏过程中微生物指标(菌落总数、假单胞菌、热杀索丝杆菌、乳酸菌和肠杆菌科)、TV B-N值和MDA值的变化,筛选出最优气体配比。气调包装(35%O_2+65%CO_2)能抑制腐败菌繁殖,减缓脂质氧化,延长冷却猪肉的货架期,保鲜效果最佳。气调组35%O_2+65%CO_2对猪肉保鲜效果最好。4.在贮藏过程中,气调包装内O_2含量下降,CO_2含量上升。O_2浓度与优势腐败菌呈正相关,CO_2浓度与之呈负相关;其相关性和显著性因O_2和CO_2配比不同而异。采用多元回归法分析保鲜效果最好的气调组(35%O_2+65%CO_2)中O_2、CO_2对优势菌影响,并建立拟合方程。其中O_2和CO_2对假单胞菌、菌落总数、热杀索丝杆菌影响的回归方程拟合较好,分别为:Y=9.580-0.0093X1+0.10X2,相关系数R2=0.92(P0.01);Y=8.032-0.0067X1+0.75X2,相关系数R2=0.90(P0.01);Y=2.169-0.067X1+0.079X2,相关系数R2=0.84(P0.01),其中X1为O_2浓度值,X2为CO_2浓度值。5.研究了气调包装(35%O_2+65%CO_2)下的冷却猪肉在不同温度下菌落总数的生长曲线,并通过修正的Gompertz方程可以较好地拟合菌落总数的动力学模型,其R2均大于0.95。建立了货架期预测模型(SL),模型参数为:bμ=0.016,Tminμ=-36.8012,bλ=0.013,Tminλ=-50.715,Nmax=7.0933 lg(cfu/g),N0=3.0340 lg(cfu/g)。将4℃下冷却猪肉菌落总数实测值与预测值对比,验证了此预测模型(SL)的准确性。分析表明:实测值和预测值的相对误差为-4.28%,这说明该预测模型(SL)可以有效预测-2~20℃下低氧气调包装(35%O_2+65%CO_2)冷却猪肉的货架期。
[Abstract]:In the process of processing, circulation and sale of chilled meat, the microorganism growth and reproduction were inhibited to a certain extent. But at present, the cold chain of meat in our country is still in the initial stage, the cold chain breaks the chain and the temperature fluctuates frequently in the logistics process, the traditional cooling meat is exposed to the air in every link of the logistics, and is vulnerable to secondary pollution. And the present method of measuring the quality index of chilled pork is time consuming, and the result is lagged. Chilled meat is rich in nutrition and high in water content. It is a good substrate for microbial reproduction. As a result, chilled meat is prone to spoilage and short shelf life. In this paper, the effects of different packaging methods and different gas ratios on the chilled pork were studied, and the optimum packing method and gas ratio were determined. The main results are as follows: 1. By monitoring the changes of the contents of O _ 2 and CO _ 2 in the modified atmosphere packaging, PEP / PA composite bag (long 110mm 脳 wide 150mm 脳 thick 0.19mm) with high gas resistance was selected as the material of vacuum packaging and modified atmosphere packaging. The quality and shelf life of chilled pork in different packaging were different during storage at 4 鈩，
本文编号：2130381
[Abstract]:In the process of processing, circulation and sale of chilled meat, the microorganism growth and reproduction were inhibited to a certain extent. But at present, the cold chain of meat in our country is still in the initial stage, the cold chain breaks the chain and the temperature fluctuates frequently in the logistics process, the traditional cooling meat is exposed to the air in every link of the logistics, and is vulnerable to secondary pollution. And the present method of measuring the quality index of chilled pork is time consuming, and the result is lagged. Chilled meat is rich in nutrition and high in water content. It is a good substrate for microbial reproduction. As a result, chilled meat is prone to spoilage and short shelf life. In this paper, the effects of different packaging methods and different gas ratios on the chilled pork were studied, and the optimum packing method and gas ratio were determined. The main results are as follows: 1. By monitoring the changes of the contents of O _ 2 and CO _ 2 in the modified atmosphere packaging, PEP / PA composite bag (long 110mm 脳 wide 150mm 脳 thick 0.19mm) with high gas resistance was selected as the material of vacuum packaging and modified atmosphere packaging. The quality and shelf life of chilled pork in different packaging were different during storage at 4 鈩，
本文编号：2130381
本文链接：https://www.wllwen.com/shoufeilunwen/boshibiyelunwen/2130381.html
