Study On Volatile Components Of The Featured Pears In Cold Areas

Featured pears in cold areas is special variety in China. Its components are different from pears in southern parts of china because of the temperature of locations. Not only have different taste flavor, but also the volatile compounds are different. Featured pears in cold areas have unique flavor, suitable for processing. However, due to volatile components often losses in the processing and storage, lead the flavor change. So the systematic study the volatile compounds in featured pears in cold areas can improve the quality of their products, provide the theoretical basis and technical support.In this study, the featured pears in cold areas as the research object, determine the best extraction method of volatile components in the featured pears in cold areas. On this basic, discusses on the development process of volatile components in fruit varieties, including 520, chou-heung, LongYuan pears, 1273, winter honey, and compare the volatile compounds in different varieties. The results were as follows:The best conditions by SPME / GC-MS were:extraction head is PDMS, extraction solution volume 20ml, extraction temperature 40℃, extraction time 30min, the best electrolyte is sodium chloride ( 0.366g/ml).There are 22 kinds of volatile compounds in green fruit of 520, including 10 kinds of esters, 4 kinds of alcohols 3 kinds of aldehydes and 4 kinds of ketones. Half ripe fruit contains 32 substances, including 17kinds of esters, 5 kinds of alcohols, 3 kinds of aldehydes and 7 kinds of other compounds. Ripe fruit contains 35 kinds of substances, which contains 18 kinds of esters, 5 kinds of alcohols, 3 kinds of aldehydes, 3 kinds of ketones, and 6 kinds of other substances such as acid. But after ripe fruit contains 36 kinds of substance, contains 19 kinds of ester material , 2 kinds of aldehydes, 8 kinds of alcohols , 2 kinds of ketone, and 6 kinds of other substances.The green fruits of Chou-heung contain 29 kinds of substance, including 18 kinds of esters, 4 kinds of alcohols, 2 kinds of aldehydes,, 1 kinds of ketone, and 4 kinds of other substances. Half ripe fruit containing 30 kinds of volatile components, including esters 19 kinds of material 2 kinds of aldehydes, 4 kinds of alcohols ,2 kinds of material similar substance, and 3 ki- nds of the other material. Ripe fruit contains 43 kinds of substances, including 25 kinds of esters, 2 kinds of aldehydes 3 kinds of ketones, 5 kinds of alcohols and 8 kinds of other substances. After cooked fruit contains 40 kinds of substance, including 22 kinds of esters accounted for,2 kinds of aldehydes,3 kinds of ketones, 5 kinds of alcohols and 8 kinds of other substances. In maturation process of chou-heung, we can found that the esters are the most and mature process is the synthesis process of ester.The green fruit of 1273 have 14 kinds of volatile compounds, including 5 kinds of esters, 5 kinds of alcohols and 1 kind of other substances. Half ripe fruit contains 16 kinds of volatile components, including 7 kinds of esters, 5 kinds of alcohols and 1 kind of other substances. Ripe fruit contains 17 kinds of substances, which contains 10 kinds of esters, 4 kinds of alcohols, 1 kind of aldehydes, and 2 kinds of ketone. Overripe fruit contain 20 substances, which contains 13 kinds of ester, 1 kind of aldehydes, and 2 kinds of ketone.The green fruit of freshly pears contain 17 kinds of volatile components, including 11 kinds of esters, 2 kinds of alcohols, 2 kinds of aldehydes, and 2 kinds of the other material. Half ripe pears contain 19 kinds of substance, 13 kinds of esters, 2 kinds of alcohols, 2 kinds of aldehydes and 2 kinds of other substances. And ripe fruit contain 20 kinds of substances, which contain 13 kinds of esters, 3 kinds of alcohols, 2 kinds of aldehydes, and 2 kinds of material. Over ripe pears contains 22 kinds of substances, including 15 kinds of substances esters of material, 3 kinds of alcohols, 2 kinds of aldehydes, 2 kinds of material.The green fruit winter honey contains 8 kinds of volatile compounds, including 4 kinds of esters, 2 kinds of alcohols, 2 kinds of aldehyde. Half ripe fruit contains 9 kinds of volatile compounds, including 6 kinds of esters, 4 kinds of alcohols, 1 kind of aldehydes. But ripe fruit contains 14 kinds of substance, which contains 6 kinds of esters, 2 kinds of alcohols, 2 aldehydes 1 kind of ketones, 3 kinds of r substances. After the winter fruit contains boiled honey, including 15 July esters, alcohols, aldehydes 2 kinds of two, ketone, 3 kinds of other substances.The QiuZi have most types of material, followed is western pear, and then is Pyrus bretschneideri communis L. The most contents of aromatic substances are the western pear. QiuZi is the secondly, finally is Pyrus bretschneideri.