USDA, ARS, Citrus and Subtropical Products Research Laboratory, 600 Avenue S, NW, Winter Haven, FL 33881, United States.
Bioresour Technol. 2010 Jul;101(14):5242-9. doi: 10.1016/j.biortech.2009.12.038. Epub 2010 Mar 1.
Citrus processing waste (CPW) pretreated under different times, pH and temperatures was investigated. Pretreatments at 160 degrees C for longer than 4 min with steam purging were needed to remove limonene, an inhibitor for fermentation, to below 0.1%. While hemicelluloses were solubilized well following all pretreatments at 160 degrees C, just 70% of the pectin was solubilized in natural CPW compared to over 80% after pretreatments using acid modified CPW (pH 2.8). Pretreatments at 160 degrees C on base modified CPW (initial pH 6.8) quickly destroyed pectin, had significantly lower dissolved solids, and were excessively viscous. Total sugars fermentable by Saccharomyces cerevisiae were not changed after pretreatment at 160 degrees C for up to 8 min in CPW between pH 2.2-8.2. Ethanol yields based on sugar content after enzymatic hydrolysis after 48h simultaneous saccharification and fermentation ranged from 76% to 94%. Ethanol yields were slightly lower but not statistically different using base modified pretreatments.
研究了不同时间、pH 值和温度下预处理的柑橘加工废物 (CPW)。需要在 160°C 下用蒸汽吹扫预处理超过 4 分钟，以将发酵抑制剂柠檬烯去除至低于 0.1%。虽然在 160°C 下所有预处理都能很好地溶解半纤维素，但与使用酸改性 CPW (pH 2.8)预处理后超过 80%的果胶溶解相比，天然 CPW 中仅溶解了 70%的果胶。在 CPW 中用碱改性 CPW (初始 pH 值 6.8)在 160°C 下预处理会迅速破坏果胶，使溶解固形物显著降低，且黏度过高。在 CPW 中 pH 值为 2.2-8.2 时，160°C 预处理 8 分钟内，可发酵糖的总糖含量不变。经 48 小时同步糖化发酵的酶水解后，基于糖含量的乙醇得率范围为 76%-94%。使用碱改性预处理时，乙醇得率略低，但无统计学差异。
