基因组学与应用生物学

通过测定变化前后的维生素Ｃ的紫外吸收光谱，发现利用其差别的程度，即用３３０ｎｍ处的ＯＤ值（ｏｐｔｉｃａｌｄｅｎｓｉｔｙ）可判断有效维生素Ｃ的变化情况。模拟食品加工中的一些条件，运用此法及Ｉ２定量法考察了有效维生素Ｃ的稳定性。结果观察到：碱性下有效维生素Ｃ通过形成新的物质而被破坏；虽然溶液中还原态维生素Ｃ在自然状态下不断损失，且第１０ｄ后损失速度加快，但２０ｄ内有效维生素Ｃ保存还较多；中性盐对有效维生素Ｃ有保护作用，而氨基酸与维生素Ｃ作用产生色变，加速维生素Ｃ的破坏；冻藏能保护维生素Ｃ，加热则破坏维生素Ｃ；由氧化剂Ｉ２介导氧化形成的氧化态维生素Ｃ极不稳定。

The ultraviolet absorptions of vitamin C and its changeable products were studied, it was found that the change of effective vitamin C can be determined by the optical density at 330 nm (OD330), In some imitative conditions of food processing, the stability of effective vitamin C was tested. Vitamin C was destroyed by forming a new unstable compound in basic condition. The level of reduced vitamin C dissolved in water decreased with the days going and declined more rapidly after 10 days , but the greater part of vitamin C was still effective in 20 days. The cold storage and neutral salt might play a role in protecting vitamin C. The heating and amino acids accelerated the change of vitamin C. Oxidized vitamin C formed by the oxidation of I2, was very unstable.