[关键词]
[摘要]
冷冻豆腐经常出现质地粗糙、孔径不均、甚至断面等品质问题。本研究采用冰球结合磷酸盐缓冲液法提取寒地冬小麦冰结构蛋白(winter wheat ice structural proteins,WISPs),经检测热滞性为0.46 ℃,其溶液的冰晶形态小、数量多,具有一定的抗冻活性。在不同添加量WISPs各组冷冻豆腐中,当添加量为1.00%时,其持水率、复水性、耐煮性及弹性、拉伸性较对照组分别提高了115.00%、52.17%、53.06%、21.79%、23.71%,硬度、剪切力降低了24.83%、23.75%;结合水、半结合水、不易流动水含量增加了133.77%、137.78%、26.41%;横截面光滑细腻,蜂窝均匀,孔径大小适中。此时冷冻豆腐蛋白游离疏基含量较对照组增加了37.50%,二硫键含量减小了41.43%;对照和0.25%组中90kDa以上的组分全部降解;除0.75%和1.00%组外,其余各组的BS亚基中低分子量组分降解;各组中AS、BS亚基含量均少于1.00%组,说明1.00%组的蛋白组分最稳定。WISPs作为抗冻保护剂,改善了冷冻豆腐的品质和蛋白质结构特性,对其具有抗冻保护作用,为抗冻蛋白在冷冻食品中的应用提供了理论基础。
[Key word]
[Abstract]
Frozen tofu often has quality problems such as coarse texture, inconsistent hole sizes, and even discontinuity among its parts. In this study, WISPs were extracted by puck combined with phosphate buffer solution (PBS) method. According to the result of our test, its thermal hysteresis activity THA was 0.46 ℃, and the ice crystals in the solution were small and abundant and It has a certain anti-freezing activity. In the frozen tofu with different WISPs addition levels, when the WISPs addition level was 1.00%, the water holding capacity, rehydration capacity, cooking resistance, elasticity and elongation increased by 115.00%, 52.17%, 53.06%, 21.79% and 23.71%, respectively, compared with the control group, and the hardness and shear force decreased by 24.83% and 23.75%. The content of bound water, semi-bound water and non-flowing water increased by 133.77%, 137.78% and 26.41%. The cross section is smooth and exquisite, the honeycomb is uniform and the aperture is moderate. Compared with the control group, the free group content of frozen tofu protein increased by 37.50% and the disulfide bond content decreased by 41.43%. All the components above 90kDa in control group and 0.25% group were degraded. Except for 0.75% and 1.00% groups, the low molecular weight components of BS subunit in other groups were degraded. The content of AS and BS subunit in each group was lower than that in 1.00% group, indicating that protein components in 1.00% group were the most stable. WISPs, as an antifreeze protective agent, improved the quality and protein structure characteristics of frozen tofu, and had antifreeze protective effect on it, which provided a theoretical basis for the application of antifreeze protein in frozen food.
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[基金项目]
黑龙江“百千万”工程科技重大专硕(2021ZX08B01)