制糖脱色成本占糖浆精制成本的1/3,而酶促褐变是蔗汁颜色加深的一个主要原因。本文探讨了制糖压榨过程中褐变对蔗汁颜色变化的影响,进一步研究了亚硫酸盐对蔗汁酶促褐变的抑制。结果表明:褐变对蔗汁色值贡献率大于50%,前10 min褐变速度最快;蔗梢蔗汁相对于成熟蔗茎蔗汁酶促褐变程度高;压榨后立即预灰能减少酶促褐变色素生成;多酚氧化酶活性在蔗汁预灰pH大于9.5时为0,在pH6.0~6.5最高;3 mmol/L NaHSO3的添加量能完全抑制蔗汁酶促反应发生。研究可为甘蔗制糖工艺的改进提供依据。
The decolorization cost is about equal to one-third of the total syrup clarification cost, and enzymic browning is one main contribution to the color in sugarcane juice. In the paper, the effects of enzymic browing on the color of sugarcane juice in the squeezing processes of sugar indusry were discussed, and the inhibition of enzymic browning in sugarcane by sulphite was further studied. Results showed that①the contribution of browning to the color in sugarcane juice is greater than 50%, and the browing speed is the fastest in the first 10 minutes;②the enzymic browning degree in sugarcane juice from cane tops is greater than that from ripe cane stems;③the preliming of sugarcane juice right after the squeezing process can decrease enzymic browning;④the activity of polyphenol oxidase is zero at pH 9.5 while preliming sugarcane juice, and is the greatest at pH 6.0~6.5;⑤the enzymic browning was entirely inhibited using 3 mmol/L NaHSO3. The paper raised a possible way and basis to improve sugar technology.