Analysis Of Volatile Flavor Compounds And Their Genetic Characteristics In Malus Domestica ‘Ruixue'

The quality of the fruit was an important internal indicator,and the volatility component is an important factor in evaluating the fruit quality.‘Ruixue' is a late-maturing and high-quality new cultivar bred by the Northwest A&F University.It is widely concerned with its fleshy,crisp,juicy and unique flavor.In this experiment,seven cultivars of ‘Ruixue',‘Fuji',‘Cripp's Pink',‘Gala',‘Golden Delicious',‘Jonagold' and ‘Orin' were used as test materials to analyze the differences in volatility components in the mature period;The differences of volatile aroma components were analyzed in the ripening period,and the changes of volatile aroma component of ‘Ruixue' and their parents were determined during the storage.At the same time,the F1 generation of ‘Fuji' × ‘Cripp's Pink' was selected as the test material,and the genetic characteristics of the main volatile aroma components of apple were analyzed.The experiment achieved the following results:1: A total of 92 volatility components were detected in 7 apple cultivars,including 53 kinds of esters,12 kinds of aldehydes,6 kinds of alcohols,4 kinds of ketones,9 kinds of olefins,8 kinds of other kinds;‘Ruixue' had higher relative content of ?-farnesene(27.88 %),2-hexenal(17.65 %)and 2-methylbutanoate(15.24 %),1-Butanol,2-methyl-,acetate(0.00 %)and hexyl acetate(1.57 %)were relatively low in relative amounts.These volatility components had a great influence on the flavor of ‘Ruixue'.In general,the unique flavor of‘Ruixue' may be caused by the higher content of fruit-flavored Hexyl 2-methylbutanoate,the floral volatility of ?-farnesene and the green-flavored 2-hexenal and a lower content of1-Butanol,2-methyl-,acetate and hexyl acetate.2: At maturity,there was a significant difference in the volatility components and content of ‘Ruixue' and the parental fruit.The type of volatility component of ‘Ruixue' was similar to that of ‘Cripp's Pink',but it was significantly higher than ‘Fuji';The relative content of esters in ‘Ruixue' was lower than that of ‘Fuji' and ‘Cripp's Pink',in which the relative content of 2-methyl-1-butyl acetate and hexyl acetate was lower;and the relative content of 2-hexenal and guanidine-farnesene in ‘Ruixue' was significantly higher than that of ‘Fuji' and ‘Cripp's Pink'.3: After storage at room temperature for 0-50 d,it was found that: the volatility components of ‘Ruixue' and ‘Cripp's Pink' the volatility components reached the maximum in storage for 30 days,51 species and 62 species respectively,and the volatility component typesof ‘Fuji' was gradually increasing under the storage conditions at room temperature.The total relative content of ‘Ruixue' esters was lower than that of their parents at room temperature,and the relative content of hexyl acetate and hexyl hexanoate was significantly lower than that of their parents,while the content of 2-methylbutyrate was higher than that of the parent.The relative content of hexanal in the three cultivars showed a gradual increase trend,and the relative content of 2-hexenal showed a downward trend(except for ‘Fuji').In different storage periods,the relative contents of hexanal and 2-hexenal in ‘Ruixue' were higher,and the relative contents of ?-farnesene of ‘Ruixue' and ‘Cripp's Pink' reached the maximum at 40 days and 10 days respectively.The value of ?-farnesene in ‘Fuji' was gradually increasing.When the apple was stored for about 30 days,‘Ruixue' had the best flavor.4: After the fruit was refrigerated for 0-150 days,the experiment found that the volatility components of the three cultivars all increased first and then decreased.‘Ruixue'reached the maximum value after 150 days of storage,‘Fuji' and ‘Cripp's Pink' reached the maximum value when stored for 120 days.The number of esters in the three cultivars increased first and then decreased.Both ‘Fuji' and ‘Cripp's Pink' reached the maximum value after 120 days of storage;while the total relative content of esters decreased first and then increased.The minimum was reached after 120 d of storage.‘Ruixue',‘Fuji' and‘Cripp's Pink' were reduced by 48.74 %,31.88 % and 46.36 % respectively.With the prolongation of storage period,the relative content of aldehydes in the three cultivars gradually decreased,and the relative content of ?-farnesene increased first and then decreased,reaching a maximum at 120 days of storage.In general,the relative content and number of esters in ‘Ruixue' were small,and the relative content of aldehydes and olefins in‘Ruixue' was relatively high during each storage period.When the fruit was stored for about120 days,the ‘Ruixue' had the best flavor.5: Through the analysis of the volatility components of some strains of ‘Fuji' × ‘Cripp's Pink',it was found that there were 6 kinds of volatility components that were not separated by the parents.There were 21 kinds of volatility components which were separated by the parents,12 kinds of volatility components which were contained in one of the parents,and the separation ratios between the different components were different.