Lamberti Lorenzo, Grillo Giorgio, Gallina Lorenzo, Carnaroglio Diego, Chemat Farid, Cravotto Giancarlo
Dipartimento di Scienza e Tecnologia del Farmaco, University of Turin, Via P. Giuria 9, 10125 Turin, Italy.
Baladin S.S. Agricola, Via Carrù 23, 12060 Piozzo, Italy.
Foods. 2021 Nov 7;10(11):2726. doi: 10.3390/foods10112726.
Interest in essential oils has consistently increased in recent years. Essential oils have a large variety of applications in multiple fields, including in the food, cosmetics and pharmaceutical industries. The volatile fraction (VF) in hops ( L.) fits within this domain as it is primarily used in the brewery industry for the aromatization of beer, and is responsible for the floral and fruity tones. This work aims to design an optimized extraction protocol of the VF from hops, using microwaves. Microwave-assisted hydrodistillation (MAHD) has been developed to reduce energy and time consumption in lab-scale reactors up to industrial-scale systems. Hops are principally available in three forms, according to a brewery's applications: (i) fresh (FH); (ii) dried (DH) and (iii) pelletized (PH). In this work, all three forms have therefore been studied and the recovered volatiles characterized by means of GC-MS. The optimized lab-scale MAHD protocol gave the best extraction yield of 20.5 mL/kg for FH. This value underwent a slight contraction when working at the highest matrix amount (3 kg), with 17.3 mL/kg being achieved. Further tests were then performed in a pilot reactor that is able to process 30 kg of material. In this case, high yield increases were observed for PH and DH; quadruple and double the lab-scale yields, respectively. In addition, this industrial-scale system also provided marked energy savings, practically halving the absorbed kJ/mL.
近年来，人们对精油的兴趣持续增长。精油在多个领域有着广泛的应用，包括食品、化妆品和制药行业。啤酒花中的挥发性成分（VF）就属于这一范畴，它主要用于啤酒酿造行业为啤酒增添香气，赋予啤酒花香和果香。这项工作旨在设计一种利用微波从啤酒花中提取VF的优化方案。微波辅助水蒸馏（MAHD）技术已被开发出来，以减少从实验室规模的反应器到工业规模系统的能源和时间消耗。根据啤酒厂的应用，啤酒花主要有三种形式：（i）新鲜的（FH）；（ii）干燥的（DH）和（iii）制粒的（PH）。因此，在这项工作中，对这三种形式都进行了研究，并通过气相色谱 - 质谱联用（GC - MS）对回收的挥发物进行了表征。优化后的实验室规模MAHD方案对FH的提取率最高，为20.5 mL/kg。当处理量达到最高值（3 kg）时，该值略有下降，为17.3 mL/kg。随后在一个能够处理30 kg物料的中试反应器中进行了进一步测试。在这种情况下，观察到PH和DH的产量大幅增加；分别是实验室规模产量的四倍和两倍。此外，这个工业规模系统还显著节省了能源，每毫升吸收的千焦几乎减半。
