【摘要】：冷卻肉在加工、流通和銷售過程中始終保持0~4℃,微生物生長繁殖在一定程度受到抑制。但目前我國肉類冷鏈尚處于起步階段,在物流過程經(jīng)常出現(xiàn)冷鏈斷鏈、溫度波動的狀況;傳統(tǒng)冷卻肉在物流各環(huán)節(jié)以暴露在空氣中為主,易受二次污染;及目前冷卻豬肉品質(zhì)指標(biāo)檢測方法費(fèi)時耗力,并且結(jié)果具有滯后性。冷卻肉營養(yǎng)豐富,含水量高,是微生物繁殖的良好基質(zhì)。因此,冷卻肉易腐敗變質(zhì),貨架期短。本文研究了不同包裝方式和不同氣體配比的氣調(diào)包裝對冷卻豬肉的影響,確定最佳包裝方法和氣體配比。主要結(jié)果如下:1.通過監(jiān)測氣調(diào)包裝內(nèi)O_2與CO_2含量的變化,選擇阻氣性較高的PE/PA復(fù)合包裝袋(長110mm×寬150mm×厚0.19mm)為真空包裝和氣調(diào)包裝的材料。2.不同包裝的冷卻豬肉在4℃貯藏過程中品質(zhì)與貨架期不同。無包裝和托盤包裝貨架期不超過4d,高氧氣調(diào)包裝(80%O_2+20%CO_2)貨架期為6d,真空包裝和低氧氣調(diào)包裝(35%O_2+65%CO_2)貨架期長達(dá)9d。真空和氣調(diào)包裝均有利于延長冷卻豬肉貨架期,但真空包裝使肉呈暗紅色,影響感官品質(zhì)。因此,4℃下冷卻豬肉的最佳包裝方式為低氧氣調(diào)包裝,即35%O_2+65%CO_2。3.采用四組不同氣體配比(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)對貯藏在4℃下冷卻豬肉進(jìn)行包裝,根據(jù)冷卻豬肉貯藏過程中微生物指標(biāo)(菌落總數(shù)、假單胞菌、熱殺索絲桿菌、乳酸菌和腸桿菌科)、TV B-N值和MDA值的變化,篩選出最優(yōu)氣體配比。氣調(diào)包裝(35%O_2+65%CO_2)能抑制腐敗菌繁殖,減緩脂質(zhì)氧化,延長冷卻豬肉的貨架期,保鮮效果最佳。氣調(diào)組35%O_2+65%CO_2對豬肉保鮮效果最好。4.在貯藏過程中,氣調(diào)包裝內(nèi)O_2含量下降,CO_2含量上升。O_2濃度與優(yōu)勢腐敗菌呈正相關(guān),CO_2濃度與之呈負(fù)相關(guān);其相關(guān)性和顯著性因O_2和CO_2配比不同而異。采用多元回歸法分析保鮮效果最好的氣調(diào)組(35%O_2+65%CO_2)中O_2、CO_2對優(yōu)勢菌影響,并建立擬合方程。其中O_2和CO_2對假單胞菌、菌落總數(shù)、熱殺索絲桿菌影響的回歸方程擬合較好,分別為:Y=9.580-0.0093X1+0.10X2,相關(guān)系數(shù)R2=0.92(P0.01);Y=8.032-0.0067X1+0.75X2,相關(guān)系數(shù)R2=0.90(P0.01);Y=2.169-0.067X1+0.079X2,相關(guān)系數(shù)R2=0.84(P0.01),其中X1為O_2濃度值,X2為CO_2濃度值。5.研究了氣調(diào)包裝(35%O_2+65%CO_2)下的冷卻豬肉在不同溫度下菌落總數(shù)的生長曲線,并通過修正的Gompertz方程可以較好地?cái)M合菌落總數(shù)的動力學(xué)模型,其R2均大于0.95。建立了貨架期預(yù)測模型(SL),模型參數(shù)為:bμ=0.016,Tminμ=-36.8012,bλ=0.013,Tminλ=-50.715,Nmax=7.0933 lg(cfu/g),N0=3.0340 lg(cfu/g)。將4℃下冷卻豬肉菌落總數(shù)實(shí)測值與預(yù)測值對比,驗(yàn)證了此預(yù)測模型(SL)的準(zhǔn)確性。分析表明:實(shí)測值和預(yù)測值的相對誤差為-4.28%,這說明該預(yù)測模型(SL)可以有效預(yù)測-2~20℃下低氧氣調(diào)包裝(35%O_2+65%CO_2)冷卻豬肉的貨架期。
[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，

本文編號：2130381