有机酸浸渍处理对苹果片冻干品质的影响

Effects of different organic acid impregnating treatments on the quality of freeze-dried apple slices

采用浓度为1%,2%,3%,4%的柠檬酸、乙酸、苹果酸和抗坏血酸浸渍苹果片,以冻干苹果片色泽、产出率、复水比、形变率、质地特性及微观结构为检测指标,分析不同酸浸渍对真空冷冻干燥苹果片品质的影响。结果表明:柠檬酸、抗坏血酸和苹果酸处理冻干苹果片的总色差值△E随酸浓度的增加而增加,乙酸处理冻干苹果片△E值相对较小,护色效果好;经柠檬酸、抗坏血酸、苹果酸处理冻干苹果片形变率随浓度的增加有增加的趋势,且显著高于乙酸处理组和未浸渍组(P<0.05),而乙酸处理组的形变率较未浸渍组略有降低;酸浸渍处理冻干苹果片的复水比均显著高于未浸渍组(P<0.05)。在浓度为1%的条件下,苹果酸和乙酸较其他酸处理冻干苹果片后的组织细胞较为完整,细胞壁较厚,表现出较高的硬度和较小的形变率。因此乙酸可以较好地保持冻干苹果片的综合品质。

The fresh-cut apple slices were impregnated with different concentrations(1%,2%,3%and 4%)of organic acid including citric acid,ascorbic acid,malic acid and acetic acid.The color,yield,rehydration,deformation rate,texture characteristics and microscopic pore structure of freeze-dried apple chips were used as indicators to analyze the effect of different acid immersion on the quality of vacuum freeze-dried apple chips.The results showed that the △E value of freeze-dried apple slices treated with citric acid,ascorbic acid and malic acid increased with the increase of acid concentration,with relatively small△E value treated with acetic acid,and the color protection effect was good.The deformation rate of freeze-dried apple slices treated with citric acid,ascorbic acid and malic acid increased with increasing concentration,and was significantly higher than that in the acetic acid treated group and the non-impregnated group(P<0.05),slight reduction in dipping group.The rehydration ratios of freeze-dried apple slices treated with acid impregnated were significantly higher than those in the non-dipping group(P<0.05).At a concentration of 1%,the malic acid and acetic acid impregnation freeze-dried apple slices showed more completed tissue cells and thicker cell walls, which contributed to high hardness and small deformation rate.It was found that acetic acid could effectively improve the comprehensive quality of freezedried apple slices.