Laboratório Associado para a Química Verde (LAQV-REQUIMTE), Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Colab4Food-Collaborative Laboratory, 4485-655 Vairão, Portugal.
Molecules. 2022 Apr 12;27(8):2493. doi: 10.3390/molecules27082493.
Essential oil (EO), hydrolate, and nondistilled aqueous phase (decoction) obtained from the hydrodistillation of lemongrass byproducts were studied in terms of their potential as food ingredients under a circular economy. The EO (0.21%, dry weight basis) was composed mainly of monoterpenoids (61%), the majority being citral (1.09 g/kg). The minimal inhibitory concentrations (MIC) of lemongrass EO against , , and , were 617, 1550, and 250 μg/mL, respectively. This effect was dependent on the citral content. Particularly for Gram-negative bacteria, a synergism between citral and the remaining EO compounds enhanced the antimicrobial activity. The polymeric material obtained from the nondistilled aqueous phase was composed of phenolic compounds (25% gallic acid equivalents) and carbohydrates (22%), mainly glucose (66 mol%). This polymeric material showed high antioxidant activity due to bound phenolic compounds, allowing its application as a functional dietary fiber ingredient. Matcha green tea formulations were successfully mixed with lemongrass hydrolate containing 0.21% EO (dry weight basis) with 58% of monoterpenoids, being citral at 0.73 g/kg, minimizing matcha astringency with a citrus flavor and extending the product shelf life. This holistic approach to essential oils' hydrodistillation of byproducts allows for valorizing of the essential oil, hydrolate, and decoction for use as food ingredients.
从香茅草副产物的水蒸馏中获得的精油、水蒸馏液和非蒸馏的水相（浸剂），在循环经济的背景下，被研究作为食品成分的潜力。精油（以干重计为 0.21%）主要由单萜类化合物组成（占 61%），其中大部分是柠檬醛（1.09g/kg）。香茅草精油对 、 、 的最小抑菌浓度（MIC）分别为 617、1550 和 250μg/mL。这种效果取决于柠檬醛的含量。特别是对于革兰氏阴性菌，柠檬醛和其余精油化合物之间的协同作用增强了抗菌活性。非蒸馏的水相得到的聚合材料由酚类化合物（25%没食子酸当量）和碳水化合物（22%）组成，主要是葡萄糖（66mol%）。由于结合了酚类化合物，这种聚合材料具有很高的抗氧化活性，允许其作为功能性膳食纤维成分应用。抹茶绿茶配方成功地与含有 0.21%精油（以干重计）的香茅草水蒸馏液混合，其中含有 58%的单萜类化合物，柠檬醛含量为 0.73g/kg，最小化了抹茶的涩味，带有柑橘味，并延长了产品的保质期。这种对香茅草副产物水蒸馏的整体方法允许对精油、水蒸馏液和浸剂进行增值，作为食品成分使用。
