Zheng Zhenxiao, Zhu Kai, Dai Zhiyuan
Institute of Seafood, Zhejiang Gongshang University, Hangzhou 310012, China.
State Key Laboratory of Aquatic Products Processing of Zhejiang Province, Hangzhou 310012, China.
Foods. 2021 Nov 13;10(11):2797. doi: 10.3390/foods10112797.
Making Antarctic krill oil into emulsion is a good way to utilize Antarctic krill, but proliferation of microorganisms cannot be ignored. HO is widely used in the sterilization of liquid food since its decomposition products are environmentally friendly, although residual HO should be removed for food safety. Adding catalase (CAT) is an effective means to do this. However, the enzyme activity center of CAT is the iron porphyrin group, which has the risk of accelerating lipid oxidation in the oil emulsion. Therefore, we hypothesized that CAT might not be suitable for the removal of HO in Antarctic krill oil emulsion. In this paper, Antarctic krill oil emulsion was prepared, and then the effect of CAT on the emulsion was studied through visual observation, microscopic morphology observation, turbidity and stability, particle size, and ζ-potential; finally, the mechanism of CAT destroying the emulsion was explored from the perspective of lipid oxidation. The results showed that a stable Antarctic krill emulsion was prepared using Tween-80 as the emulsifier, with the oil concentration of 1% (/) and the ratio of surfactant to oil phase of 1:5 (). The emulsion treated with CAT had undergone demulsification, stratification, and coagulation after 2 days of incubation, while the emulsion treated with superoxide dismutase (SOD) and bovine serum albumin (BSA) changed little. In addition, the thiobarbituric acid reactive substances (TBARS) value and the content of hydroxyl radicals in the CAT group increased significantly. The preliminary research results indicated that the effect of CAT on the emulsion related to the lipid oxidation caused by the iron porphyrin group at the center of the enzyme activity. All these results indicated that CAT was not suitable for the removal of residual HO in Antarctic krill oil emulsion. Moreover, it is helpful to avoid the contact of Antarctic krill oil emulsion and CAT during the processing of the krill.
将南极磷虾油制成乳剂是利用南极磷虾的一种好方法，但微生物的增殖不容忽视。过氧化氢（HO）因其分解产物对环境友好而被广泛用于液体食品的杀菌，不过出于食品安全考虑，应去除残留的HO。添加过氧化氢酶（CAT）是实现这一目的的有效手段。然而，CAT的酶活性中心是铁卟啉基团，这存在加速油乳剂中脂质氧化的风险。因此，我们推测CAT可能不适用于去除南极磷虾油乳剂中的HO。本文制备了南极磷虾油乳剂，然后通过肉眼观察、微观形态观察、浊度与稳定性、粒径以及ζ电位研究了CAT对该乳剂的影响；最后从脂质氧化的角度探讨了CAT破坏乳剂的机制。结果表明，以吐温-80为乳化剂，油浓度为1%（/），表面活性剂与油相比例为1:5（）时，制备出了稳定的南极磷虾乳剂。用CAT处理的乳剂在孵育2天后发生了破乳、分层和凝聚，而用超氧化物歧化酶（SOD）和牛血清白蛋白（BSA）处理的乳剂变化不大。此外，CAT组的硫代巴比妥酸反应物（TBARS）值和羟基自由基含量显著增加。初步研究结果表明，CAT对乳剂的影响与酶活性中心的铁卟啉基团引起的脂质氧化有关。所有这些结果表明，CAT不适用于去除南极磷虾油乳剂中的残留HO。此外，在磷虾加工过程中避免南极磷虾油乳剂与CAT接触是有益的。
