School of Food Science, Washington State Univ., Pullman, WA 99164, USA.
J Food Sci. 2011 Aug;76(6):C884-90. doi: 10.1111/j.1750-3841.2011.02280.x.
The production of grape seed flour (GSF) from a waste product generated during winemaking, is of interest in product development applications due to its potential health benefits. However, before GSF can used in baking as a source of additional antioxidants, research on its heat stability is required. The overall objective of this study was to assess changes in phenolic content and antioxidant activity of GSF during heating. Merlot GSF was heated at 5 temperatures (120 to 240 °C) for 0 to 90 min. At each time/temperature combination, total phenolic content (TPC), total flavanoid content (TFC), Trolox equivalent antioxidant capacity (TEAC), 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, and ferric ion reducing antioxidant power (FRAP) of the extracts were determined. Specific polyphenolic compounds, including catechin, gallocatechin, epicatechin, and gallic acid were also measured. Results showed that when Merlot GSF was heated to ≥180 °C, significant decreases in the TPC and antioxidant activity, measured using FRAP, DPPH, and TEAC, were observed. Longer heating times also caused a reduction in antioxidant capability. Catechin and epicatechin content decreased with increasing heating temperature while gallocatechin and gallic acid content increased. Both catechin and epicatechin content had strong positive correlations (r > 0.91) with TPC and TFC, as well with FRAP and TEAC, suggesting that the GSF antioxidant activity is related to the presence of these particular compounds. Overall, while a decrease in antioxidant content was observed during heating, this occurred at higher baking temperatures. Thus GSF may be suitable for use as an ingredient in baked goods to bolster antioxidant content.
In order for Merlot grape seed flour (GSF) to be used in baking as a source of additional antioxidant compounds, the impact of heating on the polyphenolic compounds in the GSF needed to be examined. Thermal treatment of Merlot GSF caused significant decreases in the TPC, antioxidant power, and specific polyphenolic compounds when heated ≥180 °C. Thus while antioxidant content decreased with higher heating temperatures, this occurred at higher baking temperatures. Thus, GSF may be suitable for use as an ingredient in baked goods to bolster antioxidant content.
从酿酒过程中产生的一种废料中生产葡萄籽油（GSF），由于其潜在的健康益处，在产品开发应用中引起了人们的兴趣。然而，在 GSF 可以作为额外抗氧化剂的来源用于烘焙之前，需要对其热稳定性进行研究。本研究的总体目标是评估 GSF 在加热过程中酚类含量和抗氧化活性的变化。将梅洛 GSF 在 5 个温度（120 至 240°C）下加热 0 至 90 分钟。在每个时间/温度组合下，测定提取物的总酚含量（TPC）、总类黄酮含量（TFC）、Trolox 当量抗氧化能力（TEAC）、2,2-二苯基-1-苦基肼基（DPPH）自由基清除能力和铁离子还原抗氧化能力（FRAP）。还测定了特定的多酚化合物，包括儿茶素、没食子儿茶素、表儿茶素和没食子酸。结果表明，当梅洛 GSF 加热至≥180°C 时，使用 FRAP、DPPH 和 TEAC 测定的 TPC 和抗氧化活性显著降低。较长的加热时间也会降低抗氧化能力。随着加热温度的升高，儿茶素和表儿茶素的含量减少，而没食子儿茶素和没食子酸的含量增加。儿茶素和表儿茶素的含量与 TPC 和 TFC 以及 FRAP 和 TEAC 呈强正相关（r >0.91），表明 GSF 的抗氧化活性与这些特定化合物的存在有关。总体而言，尽管在加热过程中观察到抗氧化含量下降，但这种情况发生在较高的烘焙温度下。因此，GSF 可作为烘焙食品的成分，以增加抗氧化剂的含量。
为了使梅洛葡萄籽油（GSF）在烘焙中用作额外抗氧化化合物的来源，需要检查加热对 GSF 中多酚化合物的影响。梅洛 GSF 的热处理导致 TPC、抗氧化能力和特定多酚化合物在加热≥180°C 时显著降低。因此，尽管随着加热温度的升高，抗氧化含量下降，但这种情况发生在较高的烘焙温度下。因此，GSF 可作为烘焙食品的成分，以增加抗氧化剂的含量。
