College of Information Engineering, Northwest A&F University, Yangling 712100, China.
College of Enology, Northwest A&F University, Yangling 712100, China.
Food Chem. 2017 Dec 15;237:811-817. doi: 10.1016/j.foodchem.2017.06.007. Epub 2017 Jun 2.
Phenolics contents in wine grapes are key indicators for assessing ripeness. Near-infrared hyperspectral images during ripening have been explored to achieve an effective method for predicting phenolics contents. Principal component regression (PCR), partial least squares regression (PLSR) and support vector regression (SVR) models were built, respectively. The results show that SVR behaves globally better than PLSR and PCR, except in predicting tannins content of seeds. For the best prediction results, the squared correlation coefficient and root mean square error reached 0.8960 and 0.1069g/L (+)-catechin equivalents (CE), respectively, for tannins in skins, 0.9065 and 0.1776 (g/L CE) for total iron-reactive phenolics (TIRP) in skins, 0.8789 and 0.1442 (g/L M3G) for anthocyanins in skins, 0.9243 and 0.2401 (g/L CE) for tannins in seeds, and 0.8790 and 0.5190 (g/L CE) for TIRP in seeds. Our results indicated that NIR hyperspectral imaging has good prospects for evaluation of phenolics in wine grapes.
葡萄酒葡萄中的酚类物质是评估成熟度的关键指标。近红外高光谱图像在成熟过程中已经被探索出来，以实现一种预测酚类物质含量的有效方法。分别建立了主成分回归（PCR）、偏最小二乘回归（PLSR）和支持向量回归（SVR）模型。结果表明，SVR 的表现总体上优于 PLSR 和 PCR，除了在预测种子中单宁含量方面。对于最佳预测结果，皮中单宁的平方相关系数和均方根误差分别达到 0.8960 和 0.1069g/L（+）-儿茶素当量（CE），皮中总铁反应性酚（TIRP）达到 0.9065 和 0.1776（g/L CE），皮中花色苷达到 0.8789 和 0.1442（g/L M3G），种子中单宁达到 0.9243 和 0.2401（g/L CE），种子中 TIRP 达到 0.8790 和 0.5190（g/L CE）。我们的结果表明，近红外高光谱成像在评估葡萄酒葡萄中的酚类物质方面具有良好的前景。
