Effect of pretreatment with microwaves on mechanical extraction yield and quality of vegetable oil from Chilean hazelnuts (Gevuina avellana Mol)
Effect of pretreatment with microwaves on mechanical extraction yield and quality of vegetable oil from Chilean hazelnuts (Gevuina avellana Mol)
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DOI：
10.1016/j.ifset.2008.05.004
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发表时间：
2008-10-01
影响因子：
6.6
通讯作者：
Ortiz, Jaime
中科院分区：
文献类型：
--
作者：
Uquiche, Edgar;Jerez, Marcia;Ortiz, Jaime
研究了微波辐射对榛子籽压榨提油前的预处理效果。使用微波炉在2450 MHz的频率下对样品进行MW处理。建立了6个MW预处理，结合两个效力（400 W和600 W）和三次预处理（120，180和240 s）。相对于未处理的种子，作为对照，提取油产量增加与分子量预处理的榛子种子。选择了400 W、240 s的萃取条件（萃取油得率为45.3%）。在光学显微镜下观察表明，经400 W和240 s处理的样品的微观结构与未经处理的样品相比发生了改变，从而提高了萃取效率。测定了其品质特性（如酸值、过氧化值）、油脂组成（如脂肪酸、α-生育三烯酚含量）和油脂氧化稳定性（如诱导时间）。将这些结果与未处理的油样品的结果进行比较。MW预处理对氧化油稳定性（诱导时间为23.9小时）相对于未处理的油（8.8小时）有积极的影响。工业相关性：智利榛子（Gevuina avellana Mol）是山龙眼科澳洲坚果族（Macadamieae）最南端的物种，主要生长在智利南部和阿根廷。油主要由不饱和脂肪酸组成，占总量的93%。其主要成分是油酸和棕榈油酸，占脂肪酸的70%。传统的植物油提取是通过压榨或溶剂提取进行的。溶剂油萃取是最有效的方法;然而，其应用存在一些工业缺点，例如工厂安全问题，挥发性有机化合物排放到大气中，高操作成本和高加工温度导致的产品质量差。机械压榨法在技术上比萃取溶剂法更不广泛，劳动强度也更低。整个过程的安全性和简单性优于更有效的溶剂萃取设备。此外，压出的材料通常具有更好的天然特性，最终产品不含化学品，这是一个更安全的过程。然而，仅仅通过挤压种子来提取相对低效。建议研究用于预处理基质的新方法，该方法还允许更好地保留和利用所需的植物代谢物。在这些预处理中，包括辐射微波。有没有太多的信息在文献中的应用微波辐射作为预处理智利榛子和其影响的微观结构的基板，提取率和油的质量。本研究旨在探讨微波辐射预处理对智利榛子种子（G. avellana Mol）。(c)2008爱思唯尔有限公司保留所有权利。
The effect of microwave (MW) radiation on hazelnut seed (Gevuina avellana Mol) was studied as a substrate pretreatment prior to oil extraction by pressing. Samples were MW-treated at a frequency of 2450 MHz using a microwave oven. Six MW pretreatments were established, combining two potencies (400 W and 600 W) and three times of pretreatment (120, 180 and 240 s). Extraction oil yield increased with MW pretreatments of hazelnut seed with respect to untreated seeds, as a control. Conditions of 400 W and 240 s were selected (45.3% of extraction oil yield). Observations under light microscopy showed that the microstructure of treated samples to 400 W and 240 s, was modified comparing with that of untreated samples, thereby improving the extraction efficiency. The quality characteristics (e.g. acid value, peroxide value), oil composition (e.g. fatty acids, alpha-tocotrienol content) and oil oxidative stability (e.g. induction time) were measured. These results were compared to those of an untreated oil sample. MW pretreatment had a positive effect on oxidative oil stability (induction time of 23.9 h) with respect to untreated oil (8.8 h). Industrial relevance: Chilean hazelnut (Gevuina avellana Mol) is the southernmost Macadamieae species of the family Proteaceae that grows mainly in the southern part of Chile and Argentina. The oil is composed mainly of unsaturated fatty acids, which represent 93% of the total. Its main components are oleic and palmitoleic acids, which represent 70% fatty acids. Conventional vegetable oil extraction is carried out by pressing or solvent extraction. Solvent oil extraction is the most efficient method; however, its application presents some industrial disadvantages such as plant security problems, emissions of volatile organic compounds into atmosphere, high operation costs and poor quality products caused by high processing temperatures. Mechanical pressing oil extraction is technically less extensive and less labor-intensive than the extraction solvent method. The safety and simplicity of the whole process is advantageous over the more efficient solvent extraction equipment. Furthermore, materials pressed out generally have better preserved native properties, end products are free of chemicals and it is a safer process. However, extraction by just pressing the seeds is relatively inefficient. It is advisable to research new methodologies for pretreating substrates that also allow for better retention and availability of desirable plant metabolites. Within these pretreatments, the radiation microwave is included. There is not much information in the literature about the application of microwave radiation as a pretreatment for Chilean hazelnut and its effect on the microstructure of the substrate, extraction yield and quality of oil. The aim of the present study was to investigate the impact of pretreatment by microwave radiation prior to the oil extraction by pressing on the microstructure, recovery of oils and oil quality of Chilean hazelnut seeds (G. avellana Mol). (c) 2008 Elsevier Ltd. All rights reserved.