Processing of Rice Husk Autohydrolysis Liquors for Obtaining Food Ingredients

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• 作者：Rodolfo Vegas ; José ; Luis Alonso ; Herminia Domí ; nguez ; and Juan Carlos Parajó
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2004
• 出版时间：December 1, 2004
• 年：2004
• 卷：52
• 期：24
• 页码：7311 - 7317
• 全文大小：77K
• 年卷期：v.52,no.24(December 1, 2004)
• ISSN：1520-5118

文摘

Rice husks are of a lignocellulosic nature, with a hemicellulose fraction made up of substitutedarabinoxylan. Rice husks were treated with hot, compressed water (autohydrolysis reaction) underoptimized conditions to cause the hydrolytic degradation of arabinoxylan. The reaction productscontained volatile components and nonvolatile components (NVC), which were made up ofhemicellulose-derived products (substituted oligosaccharides and monosaccharides) and othernonvolatile solutes (ONVS). To decrease the content of ONVS, concentrated autohydrolysis liquorswere first subjected to ethyl acetate extraction and then subjected to various alternative treatments(solvent precipitation, freeze-drying solvent extraction, or ion exchange). The resulting liquors wereassayed for composition and yield determination. Material balances are presented for the severalprocesses considered. The best results in terms of purification were obtained with sequential stagesof ethyl acetate extraction and ion exchange, which led to concentrates with hemicellulose-derivedcompounds (sugars and substituted sugar oligomers) accounting for 92 wt % of the NVCs.Keywords: Autohydrolysis; rice husks; hemicelluloses; purification; refining; xylooligosaccharides