Research On Physicochemical Quality Analysis Of Different Blueberry Varieties And Juice Storage Stability

In order to investigate physical and chemical composition and functional properties of different varieties of blueberries,this study selected 10 different varieties of blueberry in Huaining County,Anqing City,Anhui Province,including 'O'Neal','Star','Emerald','Jewel','Legacy',‘Misty','Lanmei 1','Climax','Brightwell' and 'Baldwin' as the research objects,and analyzed the main quality parameters respectively.Including the appearance characteristics(100-grain weight,fruit shape index),sugar and acid content(total acid,total sugar)and other nutritional components(ash,minerals,amino acids and anthocyanins,et al.).The comprehensive evaluation models of physicochemical and nutritional characteristics of different varieties of blueberry fruits were established by combining principal component analysis and cluster analysis methods.Further,'Lanmei 1','Climax','Brightwell' and 'Baldwin' four varieties of blueberry were selected as raw materials to prepare blueberry juice respectively,and the effects of different varieties on the processing characteristics of blueberry juice were investigated.The main research results are as follows:(1)The results of 100-grain weight,sugar to acid ratio,protein,fat,ash,minerals,amino acids and total anthocyanins in different varieties of blueberry fruits showed,the100-grain weight(72-203 g),carbohydrate/acid ratio(7.45-45.97),protein(2.33-5.15g/100g),fat(2.0-3.7 g/100g),ash(1.1-1.7 g/100g)and mineral(634.90-1221 mg/kg)of the10 varieties of blueberry were measured,amino acids(2.43-9.26 mg/g)and anthocyanins(3-10 mg/g)were significantly different.Among them,'Star' has the highest weight of 100 grains and content of protein and amino acids.'Jewel' has the highest ratio of sugar to acid.The contents of fat,ash,minerals and anthocyanins of 'Lanmei 1' were the highest but the100-grain weight and the ratio of sugar to acid were the lowest.(2)The composition of anthocyanins in different varieties of blueberry was analyzed by Q-TOF-LC-MS.The results showed that a total of 15 anthocyanins were identified from 10 varieties of blueberry.They were delphinidin-3-O-galactoside,delphinidin-3-O-glucoside,cyanidin-3-O-galactoside,delphinidin-3-O-arabinoside,cyanidin-3-O-glucoside,petunidin-3-O-galactoside,petunidin-3-O-glucoside,cyanidin-3-O-arabinoside,peonidin-3-O-galactoside,peonidin-3-O-glucoside,malvidin-3-O-galactoside,malvidin-3-O-glucoside,malvidin-3-O-arabinoside,malvidin-3-O-acetylgalactoside,malvidin-3-O-acetylglucoside;Among them,the 'Jewel'identified thirteen kinds of anthocyanins,the variety is the richest of anthocyanins.'O'Neal','Climax','Brightwell' and 'Baldwin' identified twelve kinds of anthocyanins respectively.'Star' identified eleven different anthocyanins.'Lanmei 1',and 'Legacy'identified ten different anthocyanins respectively.'Misty' identified nine kinds of anthocyanins,and 'Emerald' only identified eight kinds of anthocyanins.(3)By principal component analysis of 16 physical and chemical indexes of different varieties of blueberry fruits,such as 100-grain weight,total sugar and anthocyanin et al.The results showed that the comprehensive quality of the 10 varieties of blueberries was ranked as: 'Jewel' has the highest sugar to acid ratio and the highest comprehensive score,and the fresh food quality is better,while 'Lanmei 1' has the lowest sugar to acid ratio and the lowest comprehensive score,and the fresh food quality is worse.According to the similarity of physical and chemical components of the 10 blueberry varieties,the results of quality cluster analysis showed that when Euclidean distance was 5,the 10 blueberry varieties could be divided into 4 categories.The class ? was 'Jewel',which had the best quality;The class ? were 'Misty' and 'Legacy',quality comes second;The class ? were'Star','Emerald','Baldwin','O'Neal','Brightwell' and 'Climax';The class ? was 'Lanmei1'.(4)The contents of total phenols and anthocyanins in different varieties of blueberry juice and their stability during storage were investigated by using 'Lanmei 1','Climax','Brightwell' and 'Baldwin' as raw materials.The results showed that the contents of total phenols and anthocyanins were 1637 mg GAE/kg and 346 mg GAE/kg respectively of'Lanmei 1'.The contents of total phenols and anthocyanins of 'Lanmei 1' were higher than'Baldwin'(1417 mg GAE/kg,326 mg GAE/kg),'Climax'(1094.47 mg GAE/kg,268.20 mg GAE/kg)and 'Brightwell'(1113.62 mg GAE/kg,153.81 mg GAE/kg).The storage stability of anthocyanins and total phenols inthe juice of 'Lanmei 1' was the highest,followed by 'Baldwin','Climax' after and 'Brightwell'.