Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, 5 rue Bommel, Z.A.E. Robert Steichen, Hautcharage, L-4940, Luxembourg.
PM-International AG, 15 Wäistroos, Schengen, L-5445, Luxembourg.
J Food Sci. 2021 Mar;86(3):892-900. doi: 10.1111/1750-3841.15652. Epub 2021 Feb 16.
Four different wine grape pomaces (GP) (Vitis vinifera) varieties, Auxerrois, Pinot Blanc, Gamay and Pinot Noir, and obtained from white, rosé or red wine vinification, were considered for possible valorization in food supplement industry. Stabilization of GP by drying is paramount prior to further processing in the valorization chain, as GP might suffer spoilage over time. The objectives of this work were therefore to: evaluate the effect of microbiological spoilage and drying on the polyphenol profile and antioxidant capacity of GP; define a drying procedure by comparing kinetics of freeze-drying (FD) and vacuum oven (VO) (at 60 °C and 40 °C). Microbiological spoilage led to significant losses (P < 0.01) of antioxidant capacity (40% to 87%) and total phenolic content (70% to 90%), while drying had no significant effect. FD and VO at 60 °C drying kinetics exhibited similar drying curves, and a dry weight (DW) plateau was reached by 48 hr. In contrast VO at 40 °C required 170 hr to reach similar DW values, pointing out the importance of temperature when opting for VO technology. Antioxidant capacity of GP extracts did not differ between drying methods. Interestingly, GPs from white and rosé wines (AUX, PB, and GAM) had up to 3.5 times higher content (P < 0.001) of total polyphenols compared to PN, obtained from red wine. These results reinforce the importance of drying of GP as a pretreatment, which otherwise could result in significant product degradation. Additionally, we propose white and rosé GP as more interesting sources for valorization, with higher phenolic content, compared to red wine GP.
四种不同的酿酒葡萄渣（GP）（Vitis vinifera）品种，包括奥塞瓦、白比诺、佳美和黑比诺，分别来自白葡萄酒、桃红葡萄酒或红葡萄酒酿造，被认为具有在食品补充剂行业中进行增值利用的潜力。在增值链中进一步加工之前，通过干燥对 GP 进行稳定化至关重要，因为 GP 随着时间的推移可能会变质。因此，这项工作的目的是：评估微生物变质和干燥对 GP 多酚谱和抗氧化能力的影响；通过比较冷冻干燥（FD）和真空烤箱（VO）（60°C 和 40°C）的动力学，定义干燥程序。微生物变质导致抗氧化能力（40%至 87%）和总酚含量（70%至 90%）显著损失（P < 0.01），而干燥没有显著影响。FD 和 60°C 的 VO 干燥动力学表现出相似的干燥曲线，在 48 小时内达到干重（DW）平台。相比之下，VO 在 40°C 下需要 170 小时才能达到类似的 DW 值，这表明在选择 VO 技术时温度的重要性。GP 提取物的抗氧化能力在干燥方法之间没有差异。有趣的是，来自白葡萄酒和桃红葡萄酒的 GP（AUX、PB 和 GAM）的总多酚含量比来自红葡萄酒的 PN 高 3.5 倍（P < 0.001）。这些结果强调了 GP 干燥作为预处理的重要性，如果不进行干燥，可能会导致产品严重降解。此外，与红葡萄酒 GP 相比，我们提出白葡萄酒和桃红葡萄酒 GP 是更有价值的增值来源，因为它们具有更高的酚类含量。
