添加肉桂醛的海藻酸钠/蟹壳粉双交联水凝胶吸水衬垫对冷却肉的保鲜效果

Effect of Sodium Alginate/Crab Shell Powder Bi-Crosslinked Water Absorbent Pad Added with Cinnamaldehyde on Preservation of Chilled Meat

托盘包装的冷却肉在4℃贮藏过程中会流出血水并聚积在包装盒底部,血水与肉长时间接触不仅易滋生微生物,还会影响肉的色泽,加速冷却肉的腐败变质,缩短货架期。以脱乙酰基蟹壳粉为天然交联剂,不同体积分数的肉桂醛(0.3%、0.6%、0.9%、1.2%)为抑菌剂,获得了高强度、高吸水性的双交联海藻酸钠抑菌水凝胶吸水衬垫,用于吸收冷却肉在贮藏过程中渗出的血水。结果表明:脱乙酰基蟹壳粉与海藻酸钠之间发生了Ca^(2+)交联和聚电解质相互作用,肉桂醛的加入可显著改善材料的性能,当肉桂醛体积分数为0.6%与0.9%时,水凝胶吸水衬垫的结构更加致密并具有优异的溶胀性能、机械强度和抑菌能力。与未用吸水衬垫和使用木纤维吸水纸的处理组相比,海藻酸钠/蟹壳粉抑菌水凝胶吸水衬垫处理组冷却肉的pH值、挥发性盐基氮值、菌落总数与挥发性气味等指标的增幅显著降低(P<0.05),且汁液流失率少,汁液封存率为100%。海藻酸钠/蟹壳粉抑菌水凝胶吸水衬垫使用天然来源的蟹壳粉作为交联剂,脱乙酰基蟹壳粉与海藻酸钠形成双交联网络结构,不仅提高了材料的机械性能与凝胶强度,而且可提高废弃物的综合利用率,显示出了高于商业吸水衬垫的溶胀率,吸收冷却肉渗出物时可将渗出物封存于网状结构内部而不溢出,在减缓冷却肉微生物增殖和延长保质期方面具有一定优势。

In the process of chilled meat packaged in trays and storaged at 4℃,the exudate at the bottom will accelerates the growth of microorganisms,affect the color of meat,speed up the spoilage of chilled meat and shorten its shelf life.In this study,deacetylated crab shell powder(dCSP)were used as natural crosslinking agents to obtain bi-crosslinked sodium alginate antibacterial hydrogel water absorbent pads with high strength and high water absorption,which contained different volume fraction(0.3%,0.6%,0.9%,1.2%)of cinnamyl aldehyde.Those water absorbent pads can be used to absorb exudation from the chilled meat during storage.The results indicated that the dCSP in the system could realize both Ca^(2+)crosslinking and polyelectrolytes interactions with sodium alginate.The addition of cinnamyl aldehyde could significantly enhance the performance of water absorbent pads.The hydrogel water absorbent pads showed denser structure,better swelling property,mechanical strength and antibacterial activity,when the cinnamyl aldehyde volume fraction was 0.6%or 0.9%.The pH value,total volatile basic nitrogen value,total viable count and volatile odor indicators of chilled meat with antibacterial hydrogel water absorbent pads were lower than the group without water absorbent pad and the group with wood fiber absorbent paper(P<0.05).The juice loss rate of chilled meat with antibacterial hydrogel water absorbent pads was low and the juice storage rate was 100%.The bi-crosslinked network formed between sodium alginate and crab shell powders which could enhance the mechanical properties and gel strength of water absorbent pads.In addition,the use of crab shell powders also could improve the comprehensive utilization rate of waste.The swelling ratio of hydrogel water absorbent pads were higher than that of commercial absorbent pads.The hydrogel water absorbent pads could not only effectively absorb the meat exudate,but also could trap those liquids inside the three-dimensional network.The hydrogel water absorbent pads have certain advantages of inhibiting the growth of microorganisms and extending the shelf life of chilled meat.