Department of Food Science and Technology, University of Tuscia, Viterbo, Italy.
J Agric Food Chem. 2010 Jul 14;58(13):7557-64. doi: 10.1021/jf100331z.
Clusters of Aleatico winegrape were picked at 18 degrees Brix and placed at 10, 20, or 30 degrees C, 45% relative humidity (RH) and 1.5 m/s of air flow to dehydrate the berries up to 40% of loss of initial fresh weight. Sampling was done at 0, 10, 20, 30, and 40% weight loss (wl). Selected polyphenols and sugar content (expressed as SSC = soluble solids content) both measured on dry weight basis, polyphenol oxidase (PPO), and phenylpropanoid pathway gene expression were analyzed. Phenolic acids increased significantly at 20% wl at 20 degrees C, while at 10 degrees C the increase was lower. Stilbenes (trans-resveratrol and trans-piceid) and catechins rose more than double to 100 mg/kg and more than 3-fold to 135 mg/kg at 20 degrees C and 10% wl. At 10 degrees C the increase of these compounds was less, but higher than initial values. At 30 degrees C, except for a significant rise at 10% wl for catechins and stilbenes, all the rest of the compounds diminished. Anthocyanins increased at 10 and 20 degrees C, but decreased at 30 degrees C. PPO rapidly increased at 20 and 30 degrees C at 10% wl and then declined, while at 10 degrees C the activity lasted longer. Relative gene expression of phenylalanine ammonia lyase (PAL), stilbene synthase (STS), chalcone isomerase (CHI), dihydroflavonol reductase (DFR) were upregulated at 10 degrees C more than at 20 degrees C, at 20% wl, while at 30 degrees C the gene expression was downregulated.
Aleatico 葡萄串在 18 度白利糖度时被采摘，并在 10、20 或 30 摄氏度、45%相对湿度（RH）和 1.5 米/秒的空气流速下放置，以将浆果脱水至初始鲜重损失 40%。在 0、10、20、30 和 40%的重量损失（wl）时进行采样。测定干重基础上的多酚和糖含量（表示为 SSC=可溶性固形物含量）、多酚氧化酶（PPO）和苯丙烷途径基因表达。在 20 摄氏度和 20%wl 时，酚酸显著增加，而在 10 摄氏度时增加较低。白藜芦醇（反式-白藜芦醇和反式-白藜芦醇苷）和儿茶素增加了一倍以上，达到 20 摄氏度和 10%wl 时为 100mg/kg 以上，增加了 3 倍以上，达到 135mg/kg。在 10 摄氏度时，这些化合物的增加较少，但高于初始值。在 30 摄氏度时，除了儿茶素和白藜芦醇苷在 10%wl 时显著增加外，其余所有化合物均减少。在 10 和 20 摄氏度时，花色苷增加，但在 30 摄氏度时减少。PPO 在 20 和 30 摄氏度和 10%wl 时迅速增加，然后下降，而在 10 摄氏度时，活性持续时间更长。苯丙氨酸解氨酶（PAL）、白藜芦醇合酶（STS）、查尔酮异构酶（CHI）、二氢黄酮醇还原酶（DFR）的相对基因表达在 10 摄氏度时比在 20 摄氏度时上调更多，在 20%wl 时，而在 30 摄氏度时基因表达下调。
