冷冻处理对香水梨香气成分的影响

Effect of Freezing and Thawing on Aromatic Compounds of Pyrus ussuriensis

采用顶空固相微萃取(HS-SPME)及气质联用(GC-MS)技术,利用面积归一化法对常温和冷冻(-20℃,60d)后酸、甜两种品系香水梨果肉的香气成分进行提取及分析鉴定。常温酸梨共检出21种香气成分,其中酯类(89.07%)、醇类(4.49%)、胺类(3.30%)的相对含量较高;冷冻酸梨共检出18种香气成分,其中酯类(82.73%)、酮类(11.75%)、醇类(2.22%)的相对含量较高;在冷冻酸梨中未检测到常温酸梨中的胺类,但检测到了常温酸梨中未发现的酮类、醋酸酐(0.77%)成分。常温甜梨共检出20种香气成分,其中酯类(88.00%)、胺类(1.98%)、醋酸酐(1.62%)的相对含量较高;冷冻甜梨同样检出20种香气成分,其中酯类(88.22%)、醇类(4.21%)、酸类(3.76%)的相对含量较高;在冷冻甜梨中未检测到常温甜梨中的胺类,但检测到了常温甜梨中未发现的醇类、酮类(1.47%)成分。两种品系梨酯类含量均很高,说明酯类可能是香水梨果肉的主要呈香物质,冷冻处理梨的香味物质较常温梨总量变化不大,并未影响香水梨风味。

Abstract： SPME-GC/MS combined with Area Normalization Method were employed to evaluate the effects of freezing （-20 ℃, 60 d）on the relative contents of aromatic compounds in sour and sweet cultivars of Pyrus ussuriensis （‘Xiangshui Pear＇）. Twenty-one volatile compounds were found in the fresh sour pear, with sorted relatively high contents of ester （89.07%）,alcohol （4. 49%）and amine （3. 30%）. Among 18 kinds of aroma components detected in the frozen and thawed sour pear, ester （82. 73%）, ketones （11. 75%）and alcohol （2. 22%）possess relatively high content. In the frozen and thawed sour pear,amine from fresh sour pear was not found, whereas ketones and acetic anhydride （0. 77 %）were detected. Twenty kinds of volatile compounds were found in the fresh sweet pear, with sorted relatively high contents of esters （88.00 %）, amines （1.98%）and acetic anhydride （1.62 %）. Among 20 kinds of aroma components detected in the frozen and thawed sweet pear,ester （88. 22%） ,alcohol （4. 21%）and acid （3.76%）possess relatively high content. In the frozen and thawed sweet pear, amine from fresh sweet pear was not found, whereas alcohols and ketones （1.47%）were detected. The biggest similarity of two cultivars was that they were both high in esters, the main aroma substances of pear pulp. Total amount of flavoring substances changed slightly after freezing and thawing, which means that freezing treatment affects the flavor and taste of nears very little.