Brenes-Álvarez Mercedes, García-García Pedro, Ramírez Eva María, Medina Eduardo, Brenes Manuel, Romero Concepción
Food Biotechnology Department, Instituto de la Grasa (IG), CSIC, Ctra. Utrera km 1, Building 46, 41013 Seville, Spain.
Foods. 2024 Oct 7;13(19):3180. doi: 10.3390/foods13193180.
Olive leaves are generated in large quantities in olive oil and table olive factories. This waste is currently used for multiple purposes, one of them being the extraction of bioactive substances, in particular phenolic compounds. The aims of this study were (i) to obtain a new polyphenolic extract from potassium hydroxide (KOH) -treated olive leaves; and (ii) to reduce acrylamide formation in black olives by using this extract. The results showed that olive leaves and leafless branches of the Manzanilla cultivar treated with 10 g/L KOH provide a solution that, concentrated under vacuum, had >6000 mg/L hydroxytyrosol and >2000 mg/L of hydroxytyrosol 4-glucoside. Moreover, the residual material generated after the treatment with KOH could be used for agronomic purposes, due to its high potassium content. The employment of this non-bitter extract during the darkening step of black ripe olive processing then resulted in darker fruits with higher potassium content. Likewise, the addition of the extract into the packing brine reduced the acrylamide formation by up to 32%, although this effect was batch-dependent. KOH olive extract could be useful for the reduction in acrylamide in black ripe olives along with the enrichment of this product in phenolic compounds and potassium.
橄榄油和食用橄榄加工厂会产生大量橄榄叶。这种废弃物目前有多种用途，其中之一是提取生物活性物质，特别是酚类化合物。本研究的目的是：（i）从经氢氧化钾（KOH）处理的橄榄叶中获得一种新的多酚提取物；（ii）使用该提取物减少黑橄榄中丙烯酰胺的形成。结果表明，用10 g/L KOH处理的曼萨尼拉品种的橄榄叶和无叶枝条可提供一种溶液，在真空浓缩后，其羟基酪醇含量>6000 mg/L，羟基酪醇4-葡萄糖苷含量>2000 mg/L。此外，KOH处理后产生的残余物质因其高钾含量可用于农业用途。在黑熟橄榄加工的变黑步骤中使用这种无苦味提取物，会使果实颜色更深，钾含量更高。同样，将提取物添加到包装盐水中可使丙烯酰胺的形成减少多达32%，不过这种效果因批次而异。KOH橄榄提取物可用于减少黑熟橄榄中的丙烯酰胺，同时使该产品富含酚类化合物和钾。
