超声-热处理鲜切莲藕贮藏期间品质变化的研究

Study on the quality change of fresh-cut lotus root during storage with ultrasound-heat treatment

使用超声-热处理鲜切莲藕,研究其护色保鲜的作用及可能机制,旨在提供一种鲜切莲藕保鲜的方法。该实验通过感官评价和风味成分分析、酶活测定、扫描电镜等方法,对鲜切莲藕在贮存9 d内的生理生化指标进行了测定,以蒸馏水处理作为对照。结果表明,使用50℃联合超声(300 W,40 kHz)处理9 min,贮存9 d后测得鲜切莲藕的总色差比对照低55.22%(P<0.05);酯、醛、酮等主要风味成分损失较少,是对照的92.34%;失重率和硬度下降缓慢,同时可降低多酚氧化酶和过氧化物酶活性,提高苯丙氨酸解氨酶活性及总酚含量;丙二醛含量降低了38.78%(P<0.05),从而减少对细胞的损伤并增加抗氧化能力,延长货架期。扫描电镜结果显示,超声-热处理在鲜切莲藕细胞间产生更多的微通道,为超声-热作用的可能机制提供了佐证,为鲜切莲藕了提供一种温和高效的保鲜方法,具有良好的应用前景。

Ultrasonic-heat treatment of fresh-cut lotus roots was used to study the effect and possible mechanism of its color preservation and fresh-keeping,aiming to provide a method for fresh-cutting fresh-cut lotus roots.The experiment measured the physiological and biochemical indexes of fresh-cut lotus roots stored for 9 days through sensory and flavor component analysis,enzyme activity determination,scanning electron microscopy,and other methods,and distilled water treatment was used as a control.Results showed that the total color difference of fresh-cut lotus roots was 55.22%lower than the control(P<0.05)after being treated with 50℃combined with ultrasound(300 W,40 kHz)for 9 min and stored for 9 days.The loss of main flavors such as esters,aldehydes and ketones was less,which was 92.34%of the control.The weight loss rate and hardness decreased slowly.It could also reduce the activities of polyphenol oxidase and peroxidase and increase the activity of phenylalanine ammonia-lyase.And the total phenol content,while the malondialdehyde content was reduced by 38.78%(P<0.05),thereby reducing the damage to the cells and increasing the antioxidant capacity and prolonging the shelf life.Scanning electron microscopy observed that ultrasound-heat treatment produced more microchannels between fresh-cut lotus root cells,which provided evidence for the possible mechanism of ultrasound-heat interaction.This study provides a gentle and efficient preservation method for fresh-cut lotus roots and has good application prospects.