Effect Of Ice Temperature And Ice Water Mixture Storage On Quality Of Lotus Root And Its Quality After Brine

Lotus root is one of the most important aquatic vegetables in China,which is deeply loved by consumers because of its unique taste and rich nutritional value.However,there are more prominent problems in the production and processing of lotus root,that is the growth of lotus root has obvious periodicity,and the market cannot provide high-quality lotus root raw materials in the non-harvest season,which cannot meet the needs of consumers and lotus root enterprises for production and processing.Therefore,it is necessary to find a way to maintain the storage quality and brine quality of postharvest lotus root,so that lotus root can meet the market supply in non-harvest period.In recent years,ice temperature storage of postharvest fruits and vegetables has attracted people’s attention,which can maintain cell activity,reduce metabolism,delay cell aging,and effectively maintain the nutrition,taste and quality of postharvest fruits and vegetables.Ice water mixture is widely used in the food industry because of its characteristics of clean and pollution-free,rapid heat exchange and small physical damage to food.However,the use of ice temperature and ice water mixture in postharvest storage of lotus root is less studied.Centralized segmented peeling of lotus root can improve the processing efficiency of the factory,reduce labor costs,and conduct storage experiments for segmented peeled lotus root to determine the storage effect and storage time.Storage experiments on whole lotus root can determine the effect of two ways to maintain the storage quality of postharvest lotus root and brine quality,as well as the time to extend the shelf life.In this study,“Elian No.5”was used as the experimental material to preserve postharvest lotus root by means of ice-temperature storage and ice-water mixture storage,so as to analyze the difference between fresh quality and marinated quality of lotus root during storage,clarify the different characteristics and storage effects of the two methods,and provide the basis for the storage and freshness preservation of postharvest lotus root.The results are as follows:(1)The storage experiment of segmented peeled lotus root showed that the shelf life of segmented peeled lotus root was 25 d for ice temperature storage,and the shelf life of segmented peeled lotus root for ice-water mixture storage was 20 d.Ice temperature storage and ice water mixture storage can maintain the appearance quality of lotus root,delay aging,effectively maintain the water content of lotus root,delay the decline of soluble solids content,reduce the metabolism of fruit and vegetable phenolic substances by maintaining total phenolic content and delaying the rise of PPO activity,and delay the browning of lotus root.Ice temperature storage can better maintain the elasticity and chewiness of lotus root,and ice-water mixture storage can better maintain hardness and brittleness.The texture and sensory scores of lotus root stored by two methods were better than those of fresh lotus root.Short-term storage(within 5 days)using ice water mixture will not affect the appearance quality of lotus root and the sense after brine,so the storage effect is better.Long-term storage(after 15 days)using ice temperature storage effect is better.(2)The storage experiment of whole lotus root showed that the shelf life of whole lotus root could be achieved for 60 days after ice temperature storage,and the quality of whole lotus root could be maintained for 45 days after ice water storage.The effect of ice water mixture storage on the appearance quality of lotus root is better.Both storage methods can reduce the accumulation of MDA content and delay the aging.Ice temperature storage can inhibit PPO activity and maintain the stability of total phenol content,while the PPO activity of lotus root stored in ice-water mixture is higher,but it can better inhibit the accumulation of total phenol.Both storage methods can better maintain the texture characteristics of lotus root before and after marinade.Similar to the segmented peeled lotus root storage experiment,the ice-water mixture was more suitable for short-term storage(30 days),and the storage effect was better,and the ice temperature storage effect after 30 days of storage was better than that of ice-water mixture.(3)In the experiment of restorage of lotus root after brine,the peeled lotus root was stored for 5 days after halogenated at the 10th day,the L*value decreased slightly,and the initial moisture content and the proportion of free water in the ice-water mixture group were both higher,but the decreasing range was also higher than that in the ice-temperature storage.On the 15th day of storage,after the whole section of lotus root brine was stored for 5 days,the brightness of bittern lotus root was higher and the moisture content showed a trend of decreasing.Short-term storage of bittern lotus root has little effect on the proportion of bound water,immovable water and free water.The total number of colonies in the 5 days of storage of halo root was not higher than 10~3CFU/g,which was within the safe range.The volatile flavor substances of lotus root changed with the storage time,and the difference between different storage time was higher than that of different groups.