11个产地纽荷尔脐橙果实风味物质含量差异

2011年、2012年从11个脐橙产地收集到22份纽荷尔脐橙果实样品,采用气相色谱法对果实汁胞中的可溶性糖和有机酸进行检测,并采用高效液相色谱法检测2012年果实中的主要苦味物质。结果表明:(1)果实中的可溶性糖主要为果糖、葡萄糖和蔗糖,其中蔗糖含量最高(占可溶性总糖含量的51.01%~60.19%),肌醇含量最低;丹江口、桂林和衢州等不同产地的果实中可溶性糖含量在不同年份间有显著差异;(2)果实中的有机酸主要是苹果酸、柠檬酸和奎宁酸,其中柠檬酸含量最高(占总酸含量的73.74%~90.04%),奎宁酸含量最低;丹江口等产地的果实中有机酸含量在不同年份间有显著差异;(3)果实中的主要苦味物质为柠檬苦素和诺米林,吉首和雅安果实中的柠檬苦素含量(分别为670.0±293.2μg/g和652.1±217.0μg/g)显著高于其他产地;衢州果实中的诺米林含量最高(789.7±38.9μg/g),并显著高于其他产地。对11个产地纽荷尔脐橙果实中的糖、酸与苦味物质进行偏相关分析,结果表明果实中各风味物质具有一定的相关性,其中果糖和葡萄糖、苹果酸和奎宁酸、诺米林和肌醇各含量之间均呈显著正相关,蔗糖与奎宁酸含量呈显著负相关。纽荷尔脐橙果实风味物质在不同产地间有一定差异,气候因素可能是造成成熟果实酸和苦味物质含量差异的主要原因。

Contents of Flavor Components in Newhall Navel Oranges (Citrus sinensis) Harvested from Eleven Production Areas of China

Gas chromatography (GC) was applied to evaluate the contents of soluble sugars and organic acids in the juice sacs of mature Newhall navel orange fruits from 11 production areas of China in 2011 and 2012. The main bitter compounds, nomilin and limonin, were determined using high performance liquid chromatography (HPLC) in samples harvested in 2012. Results showed that fructose, glucose and sucrose were the three main soluble sugars. Among total soluble sugars, the content of sucrose accounted for 51.01% - 60.19%, ranking the highest, while the content of inositol accounted for 1.61% - 2.14%, ranking the lowest. Generally, the contents of soluble sugars in the juice sacs differed significantly between 2011 and 2012 in Danjiangkou, Guilin and Quzhou production areas. Citrate and malate were the two most abundant organic acids detected. Organic acid content in many production areas, including Danjiangkou, changed significantly between 2011 and 2012. The contents of limonin in the two most abundant production areas, Jishou and Ya'an, were 670.0±293.2 μg/g and 652.1±217.0 μg/g, respectively. The content of nomilin (789.7±38.9 μg/g) in Quzhou was significantly higher than that in the other production areas. Partial correlation analysis showed that the contents of fructose and glucose, malate acid and quinic acid, and nomilin and inositol were positively correlated (P < 0.05), with correlation coefficients of 0.98, 0.43 and 0.48, respectively; while the content of sucrose and quinic acid was negatively correlated, with r=-0.39 (P < 0.05). Our results showed differences between the quality of sugars, organic acids and bitter compounds in mature Newhall navel oranges in different production areas, with climate among the main determinants of organic acid and bitter compound content.