Impact of alkalization on the antioxidant and flavanol content of commercial cocoa powders
Impact of alkalization on the antioxidant and flavanol content of commercial cocoa powders
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DOI：
10.1021/jf801670p
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发表时间：
2008-09-24
影响因子：
6.1
通讯作者：
Ou, Boxin
中科院分区：
文献类型：
--
作者：
Miller, Kenneth B.;Hurst, William Jeffery;Ou, Boxin
可可是一种食品成分，它对食品风味的贡献很重要，但也与潜在的健康益处有关。被认为对心血管健康有益的化学物质是黄烷醇（黄烷-3-醇）抗氧化剂。来自文献的证据表明，天然可可的黄烷醇含量很高，但当可可用碱加工时，也称为荷兰加工或Dutching，黄烷醇大大减少。本文介绍了具有代表性的天然可可和轻度、中度和重度碱化可可的理化组成。作为调查的一部分，测量了棕色/黑色和红色/棕色碱加工可可。天然可可粉具有5.3-5.8的可提取pH。将碱化可可粉分为轻度处理（pH 6.50-7.20）、中度处理（pH 7.21-7.60）和重度处理（pH 7.61和更高）。天然的非碱化粉末具有最高的ORAC和总多酚和黄烷醇（包括原花青素）。这些化学测量结果表明，随着可可粉的可提取pH值的增加，呈线性下降。同样，黄烷醇单体、低聚物和聚合物都显示出随着最终可可粉的pH增加而线性降低。当棕色/黑色可可粉相比，红色可可粉，黄烷醇类似的减少，观察到增加碱化。天然可可的平均总黄烷醇含量为34.6 +/- 6.8 mg/g，轻度加工可可的平均总黄烷醇含量为13.8 +/- 7.3 mg/g，中度加工可可的平均总黄烷醇含量为7.8 +/- 4.0 mg/g，重度加工可可粉的平均总黄烷醇含量为3.9 +/- 1.8 mg/g。所观察到的线性和可预测的影响碱化黄烷醇含量进行了讨论，在文献中的其他报告，以及它可能对饮食和食品制造的影响。
Cocoa is a food ingredient that is important for the contribution of flavor to foods but is also associated with potential health benefits. The chemistry thought to be responsible for its cardiovascular health benefits is the flavanol (flavan-3-ol) antioxidants. Evidence from the literature indicates that natural cocoas are high in flavanols, but when the cocoa is processed with alkali, also known as Dutch processing or Dutching, the flavanols are substantially reduced. This paper provides a survey of the physical and chemical composition of representative natural cocoas and lightly, medium, and heavily alkalized cocoas. As part of the survey, both brown/black and red/brown alkali-processed cocoas were measured. Natural cocoa powders have an extractable pH of 5.3-5.8. Alkalized cocoa powders were grouped into lightly treated (pH 6.50-7.20), medium-treated (pH 7.21-7.60), and heavily treated (pH 7.61 and higher). The natural, nonalkalized powders had the highest ORAC and total polyphenols and flavanols (including procyanidins). These chemical measurements showed a linear decrease as the extractable pH of the cocoa powder increased. Likewise, the flavanol monomers, oligomers, and polymers all showed a linear decrease with increasing pH of the final cocoa powder. When brown/black cocoa powders were compared to red cocoa powders, similar decreases in flavanols were observed with increased alkalization. The average total flavanol contents were 34.6 +/- 6.8 mg/g for the natural cocoas, 13.8 +/- 7.3 mg/g for the lightly processed cocoas, 7.8 +/- 4.0 mg/g for the medium processed cocoas, and 3.9 +/- 1.8 mg/g for the heavily processed cocoa powders. The observed linear and predictable impact of alkalization on flavanol content is discussed with respect to, other reports in the literature as well as what implications it may have on diet and food manufacturing.