变温液氮速冻结合复合抗冻剂对冻藏预制调理黄鳝品质的影响

Effect of Variable Temperature Liquid Nitrogen Quick-Freezing Combined with Composite Cryoprotectant on the Quality of Frozen Prepared Monopterus albus

为提高冻藏预制调理黄鳝液氮冻结效率和品质,采用预冷-变温液氮(-80℃→-50℃)速冻结合新型复合抗冻剂(4%低聚木糖+4%山梨糖醇+0.3%碳酸氢钠)处理预制调理黄鳝,测定中心温度、水分含量、解冻损失、离心损失、水分状态、硫代巴比妥酸反应物(thiobarbituric reactive substances,TBARS)值、酸价(acid value,AV)、荧光化合物含量、总挥发性盐基氮(total volatile base nitrogen,TVB-N)含量,并观察冰晶形态和微观形貌,研究预冷-变温液氮速冻结合新型抗冻剂对黄鳝品质的影响。结果显示,变温液氮速冻的黄鳝解冻损失(3.80%)、离心损失(11.6%)、自由水占比(24.4%)均显著低于冰柜冻结(P<0.05),且相较传统恒温液氮速冻的黄鳝解冻损失显著降低(P<0.05);采用新型抗冻剂处理的黄鳝冻藏24周,冰晶尺寸、解冻损失、离心损失、TBARS值、AV、荧光强度比值和TVB-N含量显著低于对照(未添加抗冻剂)(P<0.05),肌纤维微观结构更加完整,且与传统商用抗冻剂处理的黄鳝品质无显著差异(P>0.05)。这些结果表明,预冷-变温液氮速冻结合新型复合抗冻剂处理可提升冻藏预制调理黄鳝的品质,为黄鳝预制调理产品高效冷冻保鲜技术开发提供理论支撑。

To enhance the liquid nitrogen freezing efficiency and improve the quality of frozen prepared Monopterus albus,the effect of variable temperature liquid nitrogen quick-freezing combined with composite cryoprotectant treatment on the quality of prepared M.albus was investigated.Deep-fried cured M.albus was treated with a novel composite cryoprotectant consisting of 4%xylooligosaccharides,4%sorbitol and 0.3%sodium bicarbonate before precooling followed by liquid nitrogen freezing at variable temperatures(from-80 to-50℃).Internal temperature,moisture content,thawing loss,centrifugal loss,moisture state,thiobarbituric reactive substances(TBARS)value,acid value(AV),fluorescent compound content,and total volatile basic nitrogen(TVB-N)content were measured,and ice crystal morphology and microstructure were observed.The results indicated significantly lower thawing loss(3.80%),centrifugal loss(11.6%)and free water percentage(24.4%)under variable temperature liquid nitrogen quick-freezing compared with freezer freezing(P<0.05),and significantly lower thawing loss under variable temperature liquid nitrogen quick-freezing compared with constant temperature liquid nitrogen quick-freezing(P<0.05).After freezing for 24 weeks,prepared M.albus treated with the cryoprotectant exhibited significantly lower ice crystal size,thawing loss,centrifugal loss,TBARS value,AV,fluorescent compound content,and TVB-N content as well as more complete microstructure of muscle fibers,and its quality did not significantly differ from that of M.albus treated with a commercial cryoprotectant(P>0.05).These findings suggested that pre-cooling followed by variable temperature liquid nitrogen quick-freezing combined with the novel composite cryoprotectant could enhance the quality of prepared M.albus during frozen storage,which will offer theoretical support for the development of highly efficient freezing and preservation technology for prepared M.albus products.