Abstract

Commercial production of inulooligosaccharides (IOS) relies largely on chicory roots. However, Jerusalem artichoke (JA) tubers provide a suitable alternative due to their high inulin content and low cultivation requirements. In this study, three inulin-rich substrate preparations from JA were investigated to maximize IOS production, namely powder from dried JA tuber slices (Substrate 1), solid residues after extracting protein from the JA powder (Substrate 2) and an inulin-rich fraction extracted from protein extraction residues (Substrate 3). The preferred temperature, pH and inulin substrate concentration were determined after which enzyme dosage and extraction time were optimized to maximize IOS extraction from the three substrates, using pure chicory inulin as benchmark. Under the optimal conditions, Substrate 3 resulted in the highest IOS yield of 82.3% (w/w_inulin). However, IOS production from the Substrate 1 proved more efficient since it renders the highest overall IOS yield (mass of IOS per mass of the starting biomass). In the case of co-production of protein and IOS from the JA tuber in a biorefinery concept, IOS production from the Substrate 2 is preferred since it reduces the inulin losses incurred during substrate preparation. For all the inulin-rich substrates studied, an enzyme dosage of 14.8 U/g_inulin was found to be optimal at reaction time less than 6 h. JA tuber exhibited excellent potential for commercial production of IOS with improved yield and the possible advantage of a reduced biomass cost.

摘要

菊糖低聚糖 (IOS) 的商业生产很大程度上依赖于菊苣根。然而，菊芋 (JA) 块茎因其菊粉含量高和栽培要求低而提供了合适的替代品。在这项研究中，研究了来自 JA 的三种富含菊粉的底物制剂，以最大限度地提高 IOS 产量，即来自干燥 JA 块茎切片的粉末（底物 1）、从 JA 粉末中提取蛋白质后的固体残留物（底物 2）和富含菊粉的部分从蛋白质提取残留物中提取（底物 3）。确定优选的温度、pH 和菊粉底物浓度，然后优化酶剂量和提取时间，以最大限度地从三种底物中提取 IOS，使用纯菊苣菊糖作为基准。在最优条件下，含_菊粉）。然而，来自底物 1 的 IOS 生产证明更有效，因为它提供了最高的整体 IOS 产量（每质量起始生物质的 IOS 质量）。在生物精炼概念中从 JA 块茎联合生产蛋白质和 IOS 的情况下，优选从底物 2 生产 IOS，因为它减少了底物制备过程中发生的菊粉损失。对于所有研究的富含菊粉的底物，发现14.8 U/g_菊粉的酶剂量在反应时间小于 6 小时时是最佳的。JA 块茎在 IOS 的商业生产方面表现出优异的潜力，具有提高的产量和降低生物质成本的可能优势。