Study On The Quality Stability Of NFC Fruit And Vegetable Juice Based On Raw Material Characteristics

Yunnan Province is rich in fruit and vegetable resources,but most of them are sold fresh and lack of high value-added deep processing.As an important product of fruit and vegetable processing,fruit juice can not only effectively solve the problem of excess fruit and vegetable after harvest,but also greatly improve its added value.From the perspective of raw materials,this study combined Yunnan's characteristic fruit and vegetable resources with high pressure processing(HPP)to explore the quality stability of not from concentrate(NFC)fruit and vegetable juices.The research is divided into a composite system and a single system.The specific content includes 3 parts:(1)Study on the quality stability of HPP treated NFC juices with different natural formulation during storage.(2)The effect of variety and late-ripening stages on the cloudy stability of NFC apple juice.(3)Evaluation of volatile aroma components of NFC apple juice between different varieties and analysis of changes in different late ripening stages.The main conclusions are as follows:(1)Based on sensory evaluation,3 kinds of compound systems with sharp contrast in color,composition and ratio were constructed: yellow compound juice(orange-mango-kiwi),orange compound fruit and vegetable juice(pineapple-carrot)and green compound fruit and vegetable juice(spinach-mint-cucumber-pear).After the HPP treatment(550 MPa,5 min),the comprehensive evaluation of the quality of juices during the storage period(90 days,4 ?)was conducted through multivariate data analysis and kinetic model fitting.The results showed that the orange juice with fruit and vegetable exhibited the highest quality stability,while the green juice based on vegetables had the lowest quality stability during storage.Generally,mixing ingredients with target quality characteristics(such as ingredients with high viscosity,high ascorbic acid concentration,multi-fruit aromatic compounds,etc.)is an effective method to improve the quality stability of HPP juice during storage.(2)Variety and late-ripeness have significant effects on the cloud stability of NFC apple juice.In the early stage of picking,NFC apple juice had a high concentration of insoluble starch and phenolic substances as well as a low content of pectin.The uneven distributuion of the large particles in juices resulted in the law turbidity and serious precipitation.With the increase of late-ripening the turbidity and cloud stability of NFC apple juices increased,but trended significantly differences: Gala and Golden Delicious apple juices had the highest turbidity and the best cloud stability in the second late-ripening stage.The precipitation of t Fuji and Australian Green Ping apple juices was most improved at the third late-ripening stage.The stratification and precipitation of Huashuo apple juice remianed unimproved during the 3 late-ripening stages.This type of apple was therefore unsuitable for juice production.The combination of variety and post-maturity can improve the turbidity and stability of apple juice.(3)The aroma profile of NFC apple juice was scanned by HS-SPME-GC-MS fingerprint technique.The results showed that a total of 73 volatile compounds were detected in NFC apple juice,including 29 esters,19 alcohols,13 aldehydes,7 terpenes,3ketones and 2 furans.Esters,alcohols and aldehydes were the main volatile aroma components in NFC apple juice.There were significant differences in the volatile aroma components of NFC apple juices produced from different varieties.4,6,1,and 3characteristic volatile aroma components were detected in Huashuo,Fuji,Gala,and Golden Delicious apple juice.Granny Smith had the lowest total content of volatile aroma components but was rich in aldehydes which had a grassy taste.Fuji,Gala and Golden Delicious apple juices showed similar characteristics of aroma components.They were rich in esters,aldehydes and alcohols,with a strong sweet fruit smell and green fruit flavor.The late-ripening raw materials promoted the accumulation of aroma components in Fuji,Granny Smith,Gala and Golden Delicious NFC apple juice.However,Huashuo apple juice demonstrated the most abundant volatile matter in terms of content and types during the early stage of picking.