Scholarlink

Objective <p>The aim of this study was to investigate the effects of different harvest times on phenolic compounds, organic acids, sugars, vitamin&#xa0;C content, and antioxidant capacity of ‘Şire’ grapes cultivated under Diyarbakır ecological conditions.</p> Methods <p>Grape samples were collected at three harvest times, representing early, mid, and full maturity stages. Organic acids, sugars, vitamin&#xa0;C, and individual phenolic compounds were analyzed using high-performance liquid chromatography. Antioxidant capacity was determined with the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization assay. Data were evaluated using one-way analysis of variance followed by Duncan’s multiple range test.</p> Results <p>Harvest time had a&#xa0;significant effect on most phytochemical parameters (<i>p</i> &lt; 0.05). The highest antioxidant capacity was observed at the mid-harvest stage. Vitamin&#xa0;C content was highest at early harvest, whereas glucose concentration was lowest at mid-harvest. Citric and tartaric acids increased with advancing maturity, while malic acid showed a&#xa0;temporary decrease. Individual phenolic compounds, including catechin, rutin, and chlorogenic acid, exhibited significant variations across harvest times, with early and late harvest stages generally showing higher concentrations.</p> Conclusion <p>The results demonstrate that harvest timing plays a&#xa0;crucial role in determining the phytochemical quality and antioxidant potential of ‘Şire’ grapes. Mid-harvest appears to be optimal for maximizing antioxidant activity, whereas early harvest is favorable for preserving vitamin&#xa0;C content. These findings provide valuable information for optimizing harvest strategies and improving the nutritional and functional quality of ‘Şire’ grapes and related products.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Harvest Time-Dependent Variation in Phenolic Compounds and Antioxidant Capacity of ‘Şire’ Grape (Vitis vinifera L.)

  • 期刊论文

  • 发表日期：

    2026年6月22日

查看全文
  • Melekşen Akin,
  • Fuat Atabey,
  • Mahmut Bodur,
  • Birsen Yilmaz,
  • Sadiye Peral Eyduran

摘要

Objective

The aim of this study was to investigate the effects of different harvest times on phenolic compounds, organic acids, sugars, vitamin C content, and antioxidant capacity of ‘Şire’ grapes cultivated under Diyarbakır ecological conditions.

Methods

Grape samples were collected at three harvest times, representing early, mid, and full maturity stages. Organic acids, sugars, vitamin C, and individual phenolic compounds were analyzed using high-performance liquid chromatography. Antioxidant capacity was determined with the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization assay. Data were evaluated using one-way analysis of variance followed by Duncan’s multiple range test.

Results

Harvest time had a significant effect on most phytochemical parameters (p < 0.05). The highest antioxidant capacity was observed at the mid-harvest stage. Vitamin C content was highest at early harvest, whereas glucose concentration was lowest at mid-harvest. Citric and tartaric acids increased with advancing maturity, while malic acid showed a temporary decrease. Individual phenolic compounds, including catechin, rutin, and chlorogenic acid, exhibited significant variations across harvest times, with early and late harvest stages generally showing higher concentrations.

Conclusion

The results demonstrate that harvest timing plays a crucial role in determining the phytochemical quality and antioxidant potential of ‘Şire’ grapes. Mid-harvest appears to be optimal for maximizing antioxidant activity, whereas early harvest is favorable for preserving vitamin C content. These findings provide valuable information for optimizing harvest strategies and improving the nutritional and functional quality of ‘Şire’ grapes and related products.