Stamatopoulos Konstantinos, Katsoyannos Evangelos, Chatzilazarou Arhontoula, Konteles Spyros J
Department of Food Technology, Faculty of Food Technology and Nutrition, Technological Educational Institute of Athens, 12 Ag. Spyridonos St., Egaleo, 122 10 Athens, Greece.
Department of Food Technology, Faculty of Food Technology and Nutrition, Technological Educational Institute of Athens, 12 Ag. Spyridonos St., Egaleo, 122 10 Athens, Greece.
Food Chem. 2012 Jul 15;133(2):344-51. doi: 10.1016/j.foodchem.2012.01.038. Epub 2012 Jan 28.
Impact of steam, hot water blanching and UV-C irradiation as pre-treatments on extraction of oleuropein and related biophenols from olive leaves (OLs), was investigated. Moreover, particle size effect of olive leaves and steam blanching duration were selected as independent variables to optimise steam blanching process in terms of oleuropein content (OC) and antioxidant activity (AC) of ethanolic extracts, by using response surface methodology. Optimum conditions for OC and AC were 10 min steam blanching of 20-11 and 3-1mm olive leaf fraction, respectively. Depending on the extraction procedure, at optimum conditions of steaming the results indicate that steam blanching of OL prior to extraction can significantly increase oleuropein yield from 25 to 35 times compared to non-steam blanched sample, whereas the antioxidant activity increased from 4 to 13 times. No significant UV-C effect was observed in OC and AC, while hot water blanched samples showed significantly higher oleuropein yields and antioxidant activity compared to untreated samples.
研究了蒸汽、热水烫漂和紫外线-C照射作为预处理对从橄榄叶（OLs）中提取橄榄苦苷及相关生物酚的影响。此外，选择橄榄叶的粒径效应和蒸汽烫漂时间作为自变量，采用响应面法，根据乙醇提取物中橄榄苦苷含量（OC）和抗氧化活性（AC）优化蒸汽烫漂工艺。OC和AC的最佳条件分别是对20-11目和3-1mm的橄榄叶部分进行10分钟的蒸汽烫漂。根据提取程序，在最佳蒸汽处理条件下，结果表明，与未蒸汽烫漂的样品相比，提取前对OL进行蒸汽烫漂可使橄榄苦苷产量显著提高25至35倍，而抗氧化活性提高4至13倍。在OC和AC方面未观察到紫外线-C的显著影响，而热水烫漂的样品与未处理的样品相比，显示出显著更高的橄榄苦苷产量和抗氧化活性。
