维生素C和复合维生素中维生素C稳定性的比较研究

Comparative Study on the Stability of Vitamin C and Vitamin C in Complex Vitamins

探究复合维生素中维生素C(CVC)的稳定性,对指导含复合维生素的食品体系中,提高维生素C(VC)的稳定性具有实际意义。本研究采用荧光分析法测定维生素C含量,比较CVC和VC在不同温度、pH值、金属离子、光照、氧化还原剂和碳水化合物等条件下的稳定性差异。结果表明,CVC相较于VC具有更强的耐热性、耐碱性和抗光照稳定性。氧化剂过氧化氢显著降低CVC和VC残留率,用体积分数2.7%的过氧化氢处理后,CVC和VC的残留率接近于0;不同浓度的抗氧化剂表没食子儿茶素没食子酸酯对提高CVC和VC稳定性不显著,而降低CVC稳定性的效果强于VC。金属离子对CVC和VC影响效果不一,Mg^2+和Zn^2+对CVC残留率影响较小,Fe^3+和Na^+影响较大;Na^+对VC残留率的影响较小,而Zn^2+的影响最大。低葡萄糖含量(≤5%)仅能提高CVC稳定性,而高葡萄糖含量(≥10%)可同时提高CVC和VC的稳定性。结论:CVC和VC表现出差异化稳定性,说明在食品加工过程中应根据添加维生素C的种类,调整相应的加工条件。

It is of practical significance to investigate the stability of vitamin C in complex vitamins(CVC)under different conditions,which will be helpful to improve the stability of vitamin C(VC)in the food system containing complex vitamins.In the present study,the content of vitamin C was determined by fluorescence analysis,and then the stability of CVC and VC was compared in different conditions including temperature,pH value,metal ions,light,redox reagents and carbohydrates,etc.The results showed that CVC displayed stronger heat resistance,alkali resistance and light stability than VC.The residue rate of CVC and VC decreased significantly as the hydrogen peroxide level increased,and was close to 0%after incubation with volume fraction 2.7%hydrogen peroxide.Moreover,epigallocatechin gallate didn't show concentration-dependence on improving the stability of CVC and VC,but lessened more CVC content than VC.Additionally,the effect of metal ions on CVC and VC stability was diverse,the residue rate of CVC was minimally affected by Mg^2+and Zn^2+,but maximally by Fe^3+and Na^+.However,the residue rate of VC was minimally affected by Na^+,but maximally by Zn^2+.Low concentration of glucose(≤5%)could only improve CVC stability,and high concentration of glucose(≥10%)could improve both CVC and VC stability.Together,these results indicated that CVC and VC exhibited different stability.Therefore,it should be adjusted processing conditions according to addition of the type of vitamin C in the food industry.