金力新,维生素C的稳定性研究(毕业论文),终稿.doc

嘉 应 学 院 本科毕业论文(设计) (维生素C的稳定性研究 ：维生素 C（Vitamin C）又叫 L-抗坏血酸（Ascorbic Acid，AA），是一种水溶性维生素，广泛作为一种食品添加剂运用于饮料，乳制品，快餐食品，肉制品。常态下不稳定，受光照容易被氧化，也非常容易受温度，值，以及氧化剂的影响。这几种因素也常常存在于日常的含抗坏血酸的制品中。 本实验运用紫外光吸收光谱仪(UV absorbance spectrometry)，利用抗坏血酸在265nm处有最大吸收峰，测量不同条件下标准溶液（10g/ml），包括光照条件，温度条件，，氧化剂，抗氧化剂，糖类，模拟出日常食品制品中的变化，通过其吸光度残留率，对其稳定性进行研究。 结果：1.在持续日光照射10小时下，抗坏血酸标准溶液的的残留率仅为14.1%2.在恒温25°C，40°C，60°C，80°C，100°C中放置180min，吸光度残留率随之温度的升高与时间的增加而下降。 3.抗坏血酸标准溶液在不同的下，10小时内的残留率： 4.抗坏血酸标准溶液在加入不同浓度氧化剂(H2O2)下，30min后的残留率（扣除氧化剂本身的吸光度） 5，抗坏血酸标准溶液在加入不同抗氧化剂（）下，30min后的残留率（扣除抗氧化剂本身的吸光度） 抗坏血酸标准溶液加入不同浓度蔗糖溶液，2小时内的残留率 关键词：抗坏血酸；紫外吸收光谱仪； Study on the Stability of Vitamin C Abstract: Vitamin C, （vitamin C) also known as L-ascorbic acid (ascorbic acid, AA) is a water soluble vitamin, widely used as a food additive used in beverages, dairy products, snack foods, meat products. Normal unstable, light is easily oxidized nor often easily affected by temperature, pH and oxidant effect. These factors often exists in the daily ascorbic acid containing products.This experiment using UV absorption spectroscopy (UV absorbance spectrometry), using ascorbic acid has a maximum absorption peak at 265nm, measured under different conditions of vitamin C standard solution (10 mg / ml), including light, temperature, pH, oxidants, antioxidants, sugar, simulating the changes of vitamin C daily food products, by its absorbance residual rate, the stability were studied.Results: 1. In under 10 hours of continuous exposure to sunlight, ascorbic acid standard solution of the residual rate is only 14.1% that the Illuminati destruction of vitamin C.2. In different constant temperature water bath at a temperature of 25°C, 40°C, 60°C, 80°C, 100°C placed 180min absorbance residual rate along with the increase of temperature and the increase of the time decreased.3. Ascorbic acid standard solution at different pH, 10 hours the residual rate of change: environment more tends to alkaline, vitamin C residual rate was also decr