Koliastasi Aikaterini, Kompothekra Vasiliki, Giotis Charilaos, Moustakas Antonis K, Skotti Efstathia P, Gerakis Argyrios, Kalogianni Eleni, Ritzoulis Christos
Department of Food Science and Technology, International Hellenic University, Sindos Campus, 57400 Thessaloniki, Greece.
Department of Food Science and Technology, Ionian University, Vergoti Avenue, 28100 Argostoli, Greece.
Foods. 2019 Jul 20;8(7):271. doi: 10.3390/foods8070271.
Partial (one month) composting of solid olive processing waste is shown to produce extractable emulsifiers. Size exclusion chromatography (SEC) and Fourier-transform infra-red spectroscopy (FTIR) show that these consist of polysaccharides and proteins from the composted waste. Aqueous extraction at pH 5, pH 7, and pH 9 all yield extracts rich in oligosacchrides and oligopeptides which derive from the break-down of the macromolecules under composting, with the extract obtained at pH 5 being the richer in such components. Fourier-transform infra-red (FTIR) spectroscopy also confirms that these materials consist of proteinic and poly/oligosaccharidic populations. These materials can emulsify stable oil-in-water emulsions at pH 3 for a few days, while the same emulsions collapse in less than 24 h at pH 7. Confocal microscopy and droplet size distribution data suggest that Ostwald ripening, rather than coalescence, is the major course of emulsion instability. The above point to a short-process alternative to full composting in producing a high added value product from solid olive processing waste.
固体橄榄加工废弃物的部分（一个月）堆肥显示可产生可提取的乳化剂。尺寸排阻色谱法（SEC）和傅里叶变换红外光谱法（FTIR）表明，这些乳化剂由堆肥废弃物中的多糖和蛋白质组成。在pH 5、pH 7和pH 9下进行水相萃取，均能得到富含寡糖和寡肽的提取物，这些提取物源自堆肥过程中大分子的分解，其中在pH 5下获得的提取物中此类成分更为丰富。傅里叶变换红外（FTIR）光谱也证实这些物质由蛋白质和多/寡糖群体组成。这些物质能够在pH 3下乳化形成稳定的水包油乳液，并持续几天，而同样的乳液在pH 7下不到24小时就会破乳。共聚焦显微镜和液滴尺寸分布数据表明，奥斯特瓦尔德熟化而非聚结是乳液不稳定的主要过程。上述情况表明，在从固体橄榄加工废弃物生产高附加值产品方面，有一种替代完全堆肥的短流程方法。
