鲜切红薯酶促褐变影响因素研究

The influencing factors of enzymatic browning of fresh cut sweet potato

以鲜切红薯为材料,通过测定一定条件下其多酚氧化酶(polyphenol oxidase,PPO)与邻苯二酚反应产物的吸光度值,研究pH值、温度、反应时间以及肉桂酸、L-半胱氨酸、柠檬酸、抗坏血酸4种抑制剂对红薯PPO活性的影响.结果表明,在波长为410 nm的测量条件下,以0.01 mol/L的邻苯二酚为底物测得红薯PPO反应产物吸光值分别在pH值为6.5、温度为10℃和反应时间为5 min时最高,相对活性最强.4种抑制剂中,只有抗坏血酸对红薯多酚氧化酶的活性有显著抑制效果,且0.1%抗坏血酸的抑制效果最佳.研究为鲜切红薯贮藏加工提供了有效的保鲜方法,有利于提高红薯的食用品质及商品价值.

The effect of pH,temperature,reaction time and 4 inhibitors including cinnamic acid,L-cysteine,citric acid and ascorbic acid on the viability of polyphenol oxidase(PPO)in sweet potato were investigated by determining the absorbance of PPO and catechol under certain reaction conditions.The results showed that,with the 0.01 mol/L catechol as the substrate and the wavelength of 410 nm,the PPO in sweet potato had the highest activity at pH 6.5 and the reaction time of 5 min as well as at the temperature of 10℃.Under certain conditions,only ascorbic acid had significant inhibitory effects on the activity of PPO in sweet potato among the four inhibitors,and the inhibition effect of 0.1%ascorbic acid was the most remarkable.This study provides an effective method for fresh cut sweet potato storage and processing,which is conducive to improve the eating quality and commodity value of sweet potato.