Analysises Of Nutritional Components In Pear Fruits And The Effects Of Bagging And Salicylic Acid

Contents of main nutritional components in pear fruits of different varieties were measured, the effects of bagging and Salicylic Acid on contents of nutritional components were studied. In addition, changes of nutritional components content during process of maturation were studied. The main results were as follows:1. Analysis of nutritional components in pear fruits of different varieties showed that fructose, glucose and sucrose were predominant sugar in pear fruits, the content of which ranged from 3.40% to 9.24%, 0.21% to 2.72%, 0.10% to 1.69% , respectively; Content of titrable acid was the highest in Bayuehong Pear(0.286%) and lowest in Atago(0.078%); Content of Vitamin C was the highest in Beurre Bosc (9.50 mg/100g) and lowest in Lubaoshi Pear(1.89mg/100g); Content of protein ranged from 127 to 428 mg/100g, content of free amino acid ranged from 24.8 to 77.4 mg/100g; Contents of the same mineral element of different pear varieties were different. Contents of fructose, cellulose and vitamin C were higher and contents of protein and free amino acid were lower in fruits of western pear varieties as Bayuehong Pear, Beurre Bosc, Packham's Triamph, Bartlett Max Red and Red D' Ajou than that of fruits of other varieties.2. Effects of bagging were different on contents of nutritional components of different varieties. Contents of soluble sugar, fructose, glucose, sucrose, starch, titrable acid, vitamin C and mineral elements decreased in bagging fruits. In addition, content of soluble sugar decreased significantly in bagging fruits of Yali Pear, Beurre Bosc and Bayuehong Pear, content of fructose decreased significantly in bagging fruits of Xuehua Pear, Whangkeumbae, and Yali Pear, content of glucose decreased significantly in bagging fruits of Whangkeumbae and Beurre Bosc, content of titrable acid decreased significantly in bagging fruits of Xuehua Pear, Whangkeumbae and Beurre Bosc, content of vitamin C decreased significantly in bagging fruits of Xuehua Pear, Bartlett Max Red and Bayuehong Pear, content of mineral elements as K, Mg and Ca decreased significantly in Xuehua Pear and Yali Pear; Changes of protein and free amino acid contents in bagging fruits were different according to pear varieties.3. Whangkeumbae and Yali Pear were used in the determination of nutritional components contents during fruits maturation: contents of soluble sugar, fructose, glucose and sucrose gradually increased, contents of starch, vitamin C and cellulose gradually decreased, contents of protein and titrable acid increased first and then decreased, content of major elements decreased and content of minor elements showed different trends.4. Whangkeumbae and Huangguan Pear were used in the determination of SA immersion, 1mmol/L significantly delayed the degration of starch, titrable acid, vitamin C and cellulose and maitained higher contents of protein and free amino acid under both room and low temperature, and lmmol/L maintained higher content of soluble sugar during storage anaphase under room temperature.