真空贴体和高氧气调包装对冷鲜猪肉贮藏期品质和微生物的影响

Effect of Vacuum Skin Packaging and High-Oxygen Modified Atmosphere Packaging on the Quality and Microbial Properties of Chilled Pork during Storage

分析真空贴体包装(vacuum skin packaging,VSP)和高氧气调包装(high-oxygen modified atmosphere packaging,HiOx-MAP)冷鲜猪肉贮藏期间的pH值、肉色、总挥发性盐基氮含量、硫代巴比妥酸反应物(thiobarbituric acid reactive substance,TBARS)值、羰基含量、巯基含量、菌落总数、微生物多样性等指标,研究猪肉在0~4℃条件下VSP和HiOx-MAP贮藏过程中品质的变化。结果表明:在整个贮藏期内HiOx-MAP猪肉亮度值(L)和黄度值(b)始终显著高于VSP猪肉(P<0.05);相较于VSP猪肉,贮藏前期的HiOx-MAP猪肉显示出更高的红度值(a),但贮藏后期HiOx-MAP猪肉a显著低于VSP猪肉(P<0.05),颜色稳定性较差,并具有更高的TBARS值、羰基含量和更低的巯基含量(P<0.05);在货架期方面,VSP猪肉和HiOx-MAP猪肉的微生物货架期均为20~25 d,但是从贮藏10 d开始HiOx-MAP猪肉的菌落总数显著高于VSP猪肉(P<0.05);微生物多样性分析结果显示,随着贮藏时间的延长,2种包装猪肉的微生物多样性均呈下降趋势,但HiOx-MAP猪肉的α多样性(操作分类单元数、Chao1指数、Shannon指数)更高,说明相较于VSP猪肉,HiOx-MAP猪肉中的微生物种类和多样性更为丰富;当菌落总数接近国家标准规定上限时,HiOx-MAP猪肉中的优势菌群为明串珠菌属、沙雷氏菌属和假单胞菌属,而VSP猪肉的优势菌群为肉食杆菌属。总体而言,在短期贮藏销售(10 d内)时使用HiOx-MAP能够维持良好的肉色,VSP能更好维持猪肉品质并延长货架期。

This study analyzed the effect of vacuum skin packaging(VSP)and high-oxygen modified atmosphere packaging(HiOx-MAP)on the quality changes of pork during chilled storage(0–4℃),which were evaluated in terms of pH,color,total volatile basic nitrogen(TVB-N)content,thiobarbituric acid reactive substances(TBARS)value,protein carbonyl and sulfhydryl content,total viable count(TVC)and microbial diversity.The results showed that the brightness(L)and yellowness(b)values of pork were always higher in the HiOx-MAP group than those in the VSP group during the whole storage period(P<0.05).Compared with the VSP group,the HiOx-MAP group showed a higher redness(a)value at the early stage but a significant lower a value at the late stage of storage(P<0.05),indicating that the HiOx-MAP group had poor color stability.Furthermore,the HiOx-MAP group had higher TBARS value and lower protein carbonyl and sulfhydryl content(P<0.05).Additionally,the shelf lives of both groups were 20–25 days,but the TVC of the HiOx-MAP group was significantly higher than that of the VSP group starting from day 10(P<0.05).With increasing storage time,the microbial diversity of both groups showed a decreasing trend,but theαdiversity in terms of the number of operational taxonomic units(OTU),Chao1 index and Shannon index of the HiOx-MAP group was higher,indicating more abundant microbial species and diversity compared with the VSP group.When the TVC was close to the upper limit of the national standard,the dominant bacteria in the HiOx-MAP group were Leuconostoc,Serratia and Pseudomonas,while Carnobacterium was the dominant bacteria in the VSP group.In conclusion,HiOx-MAP is recommended to maintain better meat color for short-term storage(within 10 days),while VSP can be used for maintaining pork quality and extending the shelf life.