Changes in the biochemistry and flavor of Shine Muscat grapes at different ripening stages (RS) were analyzed to identify factors affecting these characteristics. The yellowness index values were 45.1, 49.4, and 50.2 in the ripening stage 1 (RS1), ripening stage 2 (RS2), and ripening stage 3 (RS3) groups, respectively, representing the different ripening stages. The yellowness of the grape berries tended to increase with ripening due to the gradual breakdown of chlorophylls and the evolution of carotenoids. The total content of monoterpenes, on the other hand, was approximately two-fold higher at RS3 than RS1 and RS2. Moreover, linalool was the most abundant compound contributing to the total content of monoterpenes. The highest correlation was observed between the linalool content and °Brix/acid ratio (r = 0.9981), followed by the monoterpene content and °Brix/acid ratio (r = 0.9933). These findings indicate that changes in the contents of linalool and its oxidized forms may be used as a quality index and an indicator of the timing of harvest for Shine Muscat grapes.

中文翻译：

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马斯喀特不同成熟时期生化和挥发性风味物质的变化

分析了不同成熟阶段（RS）的Shine Muscat葡萄的生化和风味变化，以确定影响这些特征的因素。在成熟阶段1（RS1），成熟阶段2（RS2）和成熟阶段3（RS3）组中，黄度指数分别为45.1、49.4和50.2，代表了不同的成熟阶段。由于叶绿素的逐渐分解和类胡萝卜素的进化，葡萄浆果的黄度趋于随着成熟而增加。另一方面，在RS3，单萜的总含量比RS1和RS2高约两倍。此外，芳樟醇是最丰富的化合物，有助于单萜的总含量。芳樟醇含量与白利糖度/酸比之间的相关性最高（r = 0.9981），其次是单萜含量和白利糖度/酸比（r = 0.9933）。这些发现表明，芳樟醇含量及其氧化形式的变化可用作质量指数和Shine Muscat葡萄收获时机的指标。