Effect of Thermal Processing Methods on the Quality of Xuehua Pear Decoction

In order to compare the differences in nutritional quality and volatiles of Xuehua pear decoction prepared by two thermal processing technology. The decoction was prepared from Xuehua pear using two thermal processing methods, namely stewed and roasted, and the sensory quality, physicochemical properties, antioxidant capacity, and volatile composition of the decoction were analyzed. The results showed that roasted pear decoction with a yield of 67.24% had higher sensory score, solid-acid ratio and higher hydroxyl radical scavenging ratio,and lower browning and turbidity values; stewed pear decoction with a yield of 74.41% had bright color and larger L*and a*value. There was no significant differences between the two pear decoctions in soluble sugars components,total phenols, total flavonoids content and 1,1-diphenyl-2-picrylhydrazyl（DPPH） radical scavenging ratio. Electronic nose test results showed that the odor of two types of pear decoction could be completely separated. Electronic tongue test showed that the acidity, bitterness, astringency, saltiness, and sweetness played a major role in the distinction of the taste. A total of 52 volatiles were detected in the two pear decoctions, including 8 esters, 11aldehydes, 9 alcohols, 19 alkanes, 2 ketones, two other types of substances and α-farnesenes, among which, the roasted pear decoction possessed the more varieties of volatiles（43） and higher total contents（38.00 μg/m L）. There were some differences in the sensory quality, physicochemical properties, functional and active components of pear decoction prepared with two thermal processing method, and the flavor characteristics and volatile components were obviously different.