Faculty of Bioscience and Technology for Agriculture, Food and Environment, University of Teramo, Teramo, Italy.
Department of Soil, Plant and Food Sciences, Food Science and Technology Unit, University of Bari Aldo Moro, Bari, Italy.
J Sci Food Agric. 2019 Nov;99(14):6620-6627. doi: 10.1002/jsfa.9949. Epub 2019 Aug 26.
Most olive by-products, like olive leaves, are still undervalued despite their strong potential as a source of healthy and functional components. To exploit their potential use as active ingredients in complex food systems, it is of primary importance the knowledge of their composition and technological functionality which represented the objective of this work.
Phenolic extracts from olive leaves, obtained by extraction with pure water (Eth0) and two different water-ethanol solutions (Eth30, Eth70), were characterized for their composition and technological properties such as water- / oil- holding ability, air/water surface activity, and emulsifying capacity at pH 4.5 and 7. Their chemical stability over time, at constant temperature, was also investigated. The technological properties were affected by extraction media and pH. Phenolic extracts displayed significant surface activity, showing dose-dependent behavior. Surface properties were affected by pH and this result was confirmed by the emulsifying capacity. The extracts showed good oil-holding capacity but limited water-binding capacity. Eth70 showed the highest chemical stability, which was confirmed by the rate parameters obtained by modeling data using a Weibull model.
The results of this study highlight that olive leaves extracts can represent a useful ingredient in acidic lipid-containing foods. © 2019 Society of Chemical Industry.
尽管橄榄叶等大多数橄榄副产物具有成为健康和功能性成分的巨大潜力，但它们仍然被低估。为了利用它们作为复杂食品体系中活性成分的潜在用途，了解其组成和技术功能至关重要，这是这项工作的主要目标。
用纯水（Eth0）和两种不同的水-乙醇溶液（Eth30、Eth70）提取橄榄叶得到的酚类提取物，对其组成和技术性能（如持水/持油能力、空气/水表面活性和在 pH4.5 和 7 时的乳化能力）进行了表征。还研究了它们在恒温下随时间的化学稳定性。提取介质和 pH 影响技术性能。酚类提取物表现出显著的表面活性，呈剂量依赖性。表面性质受 pH 影响，这一结果通过乳化能力得到了证实。提取物具有良好的持油能力，但持水能力有限。Eth70 表现出最高的化学稳定性，这通过使用 Weibull 模型对数据进行建模得到的速率参数得到了证实。
本研究结果表明，橄榄叶提取物可以成为含酸性脂质食品中的有用成分。© 2019 英国化学学会。
