微波纳米解冻技术对秘鲁鱿鱼汁液流失的抑制机制

Drip loss of frozen squid can result in the decline of quality and processing ability during thawing, which will lead to severe economic losses. Microwave nano-thawing technology solves the problem of instant thawing, and realize the fast and uniform thawing of frozen products. Previous research found that microwave nano-thawing technology could reduce thawing loss of squid. However, the exact mechanism of reducing juice loss and improving muscle quality is still unclear. The project selects Dosidicus gigas mantle as the experimental material and combines the theory of drip channel. Macroscopic research and microscopic exploration will be conducted from multiple perspectives, such as structure, biochemistry and charge effect. The effects of microwave nano-thawing technology on the formation and recrystallization of ice crystals will be analyzed. Molecular dynamics (MD) will be used to simulate the inhibitory effect of magnetic nanoparticles on ice crystal formation. The development of drip channel will be fully analyzed by modern instrumental analysis techniques during the process of thawing. The reason of inhibiting the outflow of thawed juice will be expounded. Protein denaturation will be studied. Zeta potential analysis, Raman spectroscopy and H/D replacement techniques will used to study the changes in the binding capacity of proteins to water. The effect of microwave nano-thawing on protein resorption of thawed juice will be studied. Low field nuclear magnetic resonance (LF-NMR) and hydrogen proton magnetic resonance imaging (MRI) will be applied to track the state, distribution and constitute of myowater to demonstrate the migration dynamics in Dosidicus gigas. Thus, the mechanism of inhibition of juice loss during thawing of Dosidicus gigas by microwave nano-thawing technology will be clarified. The project will provide theoretical basis application value for controlling drip loss and improving the quality of squid processing.

鱿鱼解冻过程中汁液流失严重，导致其品质和加工性能下降，造成严重经济损失。微波纳米解冻技术攻克了瞬间解冻难题，实现了冻品的快速均匀解冻。申请人前期研究发现微波纳米解冻技术能够减少鱿鱼解冻损失，但其抑制汁液流失的机制尚不明确。本项目拟以冷冻秘鲁鱿鱼为研究对象，从结构、生化和电荷效应等多重角度进行宏观研究和微观探索。结合滴水通道学说，分析细胞内外冰晶及冰晶重结晶的情况，采用分子动力学模拟磁性纳米粒子对冰晶重结晶的抑制效应；利用现代仪器分析技术观察滴水通道的形成发展，阐明抑制解冻汁液流出的原因；研究蛋白质变性情况，运用zeta电位分析、拉曼光谱和H/D置换技术等研究蛋白质和水结合能力的变化，阐明微波纳米解冻对蛋白回吸解冻汁液的影响；借助LF-NMR、MRI技术分析水分“态变”规律，从而揭示微波纳米解冻技术对秘鲁鱿鱼汁液流失的抑制机制，对控制鱿鱼解冻汁液损失、改善加工品质，具有重要的理论和应用价值。

鱿鱼解冻过程中汁液流失严重，导致其品质和加工性能下降，造成严重经济损失。微波纳米解冻技术攻克了瞬间解冻难题，实现了冻品的快速均匀解冻。本项目以冷冻秘鲁鱿鱼为研究对象，从结构、生化和电荷效应等多重角度进行宏观研究和微观探索。具体研究结果如下：1）与冷藏解冻（CST）和微波解冻（MT）相比较，微波纳米解冻处理组（MNPMT）的肌原纤维小片化指数显著降低（P < 0.05），同时减少了肌纤维的损伤，保持肌纤维的完整性。分子动力学模拟过程中构象变化、质心距离和均方根位移结果表明磁性纳米粒子有逐渐贴近冰晶表面的趋势，且MNPs与冰晶结合会诱导冰晶面发生一定程度的破坏，从而抑制冰晶再结晶。2）与CST和MT相比较，MNPMT可以降低蛋白质的浊度和粒径，减少解冻过程中的蛋白质分子聚集，提高肌原纤维蛋白和肌球蛋白的溶解度。MNPMT-100 W和MNPMT-500 W处理组蛋白质有较强的荧光强度，较好的维持了蛋白质的三级结构，说明微波纳米解冻可以有效减缓蛋白质变性，维持蛋白质高级构象，较好地维持了秘鲁鱿鱼蛋白质与水的结合能力。3）与CST相比较，MNPMT的解冻损失率显著降低（P < 0.05），MNPMT解冻时间较短，解冻速率较快，能够快速通过最大冰晶溶解带（-5-0℃），减少了蛋白质的降解和对肌纤维的损伤，提高了蛋白质的水合作用，较好的保持鱿鱼的水分。MT和MNPMT样品的蒸煮损失显著低于CST样品 （P < 0.01）。MNPMT可减少肌纤外水，增加肌纤外水的结合水，提高秘鲁鱿鱼的品质。4）研究了MNPs联合超声-微波解冻(NUMT)对巨型鱿鱼膜保水能力、蛋白质和脂肪氧化以及蛋白质构象的影响。结果表明NUMT处理具有较高的WHC，较低的氧化，有效减少肌原纤维蛋白的聚集和降解，稳定了秘鲁鱿鱼的蛋白质结构。经NUMT处理的巨型鱿鱼膜肌纤维结构致密有序，表面光滑，纤维网络间隙小且分布均匀。本项目对控制鱿鱼解冻汁液损失、改善加工品质，具有重要的理论和应用价值。