运用气相色谱检测数据定量评价加工果蔬汁的香气协调性变化

为了建立加工果蔬汁香气协调性变化程度的定量评价模式,运用数学方法归纳果蔬汁样品的气相色谱(GC)检测数据,以原果蔬汁为基准,计算经浓缩或其他加工处理后样品中含有的各挥发性组分的百分含量相对于原果蔬汁的整体变化值(即样品偏差值),用以定量描述果蔬汁处理前后香气组分的整体变化程度。当需要比较不同加工方法或工艺对果蔬汁香气协调性的影响时,可对其进行相同条件的GC检测获取数据并计算比较样品偏差值。用此方法将冷冻浓缩柠檬汁、真空蒸发浓缩柠檬汁与原汁进行了比较,结果显示冷冻浓缩柠檬汁不仅能够很好地保持柠檬汁香气成分的绝对含量,同时也很好地保持了天然柠檬汁原有的香气协调性。

Quantitative Evaluation of the Variation of Aroma Harmony in Processed Fruit and Vegetable Juices with Gas Chromatographic Data

To develop a quantitative evaluation model for the variation of aroma harmony in processed fruit and vegetable juices, gas chromatographic data from juice samples were summed up by mathematic modeling. Based on the original fruit and vegetable juices, the total change in volatile compounds expressed in term of percentage between the treated samples by various processes and the original juice, that is, the deviation of samples, are calculated. They were then used to describe the total change of aroma compounds in the fruit and vegetable juices before and after the processing. To compare the influences of different processes on aroma harmony in fruit and vegetable juices, the samples were analyzed by gas chromatography under the same conditions and the data were obtained by comparing the deviations of the samples. The lemon juices concentrated either by freeze-concentration or by vacuum evaporation were compared against the original lemon juices. The results showed that the freeze-concentration well retained not only the absolute contents of aroma compounds but also the aroma harmony of natural lemons.