Variation of free Sugar and Amino Acid Contents of Pears During the Ripening Period

배의 성숙 중 유리당과 유리아미노산 함량 변화

A variation of free sugar and amino acid contents of pears during the ripening period was determined by HPLC and amino acid analyzer. The research results are as follws: Fructose, glucose and sucrose were present in the pears. The contents of fructose was the highest, followed by glucose and sucrose in order. The contents of total sugar in Shingo and Youngsan was similar, but the contents of frucose in Shingo was lower and the contents of sucrose was higher than that of Youngsan (p＜.001). During the ripening period, the contents of fructose and glucose gradually increased during the harvesting season and then somewhat decreased. The contents of sucrose increased continually, while the contents of total free sugar reached the maximum during the harvesting season, it was 10.41%, 10.29% in Shingo and Youngsan and then decreased gradually. The contents of total free amino acid in Shingo was higher than that of Youngsan. A variation ratio and the composition of amino acid in Shingo and Youngsan during the ripening period didn＇t make a significant difference. The major free amino acid of the pears was in the order of aspartic acid, serine, threonine, histidine, glutamic acid, valine, arginine, and alanine. During the ripening period, aspartic acid, threonin, serine, methionine, isoleucine, leucine, histidine, and Iysine increased gradually. Glutamic acid, alanine, valine, arginine didn＇t show much change. The contents of total free amino acid increased during the ripening period.