Marchante Lourdes, Gómez Alonso Sergio, Alañón María Elena, Pérez-Coello María Soledad, Díaz-Maroto María Consuelo
Area of Food Technology Faculty of Chemical Sciences and Technologies University of Castilla-La Mancha Ciudad Real Spain.
Area of Food Technology Regional Institute for Applied Scientific Research (IRICA) University of Castilla-La Mancha Ciudad Real Spain.
Food Sci Nutr. 2018 Jul 14;6(6):1564-1574. doi: 10.1002/fsn3.697. eCollection 2018 Sep.
Winemaking by-products are a natural source of antioxidant components; however, due to their highly perishable and seasonal nature, they may require a prior conservation step before being processed. Natural extracts from fresh and oven-dried red grape agro-industrial by-products were obtained by ultrasound assisted extraction (UAE), using a hydroalcoholic solution as extracting solvent. Extracts were analyzed by HPLC-DAD-ESI-MS, to know the feasibility of winemaking by-products as natural sources of phenolic compounds, as well as the effect of the oven-drying treatment on the phenolic composition. Oven-drying at 45°C caused a significant decrease on the total phenolic content, which implied a reduction of the antioxidant capacity of the extracts. Also, it produced a decrease in total and individual flavan-3-ols, stilbenes, and flavonols, being greater in those extracts from stems. Respect to anthocyanins, which were only identified in grape pomace extracts, oven-drying caused an important decrease, being the peonidin-3-O-glucoside the more thermosensitive compound. Natural extracts from fresh or oven-dried winemaking by-products could be used in other food industries as a valuable source of phenolic compounds with antioxidant properties. However, further studies on other drying methods are required for addressing the preservation of phenolic compounds from winery by-products successfully.
酿酒副产物是抗氧化成分的天然来源；然而，由于其极易腐烂和季节性的特点，在加工之前可能需要进行预先保存步骤。采用水醇溶液作为提取溶剂，通过超声辅助提取（UAE）从新鲜和烘干的红色葡萄农工业副产物中获得天然提取物。提取物通过HPLC-DAD-ESI-MS进行分析，以了解酿酒副产物作为酚类化合物天然来源的可行性，以及烘干处理对酚类成分的影响。45°C烘干导致总酚含量显著降低，这意味着提取物的抗氧化能力下降。此外，它还导致总黄酮-3-醇、芪类和黄酮醇的总量及个别含量减少，茎部提取物中的减少更为明显。对于仅在葡萄皮渣提取物中鉴定出的花青素，烘干导致其显著减少，芍药色素-3-O-葡萄糖苷是最热敏的化合物。新鲜或烘干的酿酒副产物的天然提取物可作为具有抗氧化特性的酚类化合物的宝贵来源用于其他食品工业。然而，需要对其他干燥方法进行进一步研究，以成功解决酒厂副产物中酚类化合物的保存问题。
