Abstract The present study focuses on the fractionation of cashew apple bagasse via a pretreatment using acetic acid as a delignifying agent and sulfuric acid as an external catalyst. As expected, the concentrations of both acids and the incubation time dramatically affected delignification and hemicellulose solubilization. Under the optimal pretreatment conditions, recycling of the spent liquor had no apparent impact on the chemical composition of the pretreated material, yield of sugar produced via enzymatic hydrolysis (∼37 g/L reducing sugars at 7.5% (w/v) solid loading), or yield of ethanol obtained via fermentation with Saccharomyces cerevisiae (∼16 g/L at 10% (w/v) solid loading). The lignin recovered from the spent liquor showed a good ultraviolet protective effect; the addition of 5% (w/w) of the biopolymer increased the sun protection factor of a commercial sunscreen lotion from 21.62 to 40.71. The combined use of hydrogen peroxide and ultraviolet radiation reduced the organosolv lignin color (absorbance at 450 nm was four times lower) owing to aromatic ring cleavage, but cosmetics containing whitened organosolv lignin had low sun protection factor values. In summary, the results obtained in this study demonstrate the utility of organic acid pretreatment in the valorization of lignocellulosic materials.

中文翻译：

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使用乙酸预处理腰果苹果蔗渣的价值化：生产纤维素乙醇和木质素以用作防晒成分

摘要 本研究的重点是通过使用乙酸作为脱木素剂和硫酸作为外部催化剂的预处理来分馏腰果苹果蔗渣。正如预期的那样，酸的浓度和孵育时间显着影响了脱木素和半纤维素溶解。在最佳预处理条件下，废液的回收对预处理材料的化学成分、酶水解产生的糖产量没有明显影响（约 37 g/L 还原糖，7.5% (w/v) 固体负载）或通过酿酒酵母发酵获得的乙醇产量（约 16 g/L，10% (w/v) 固体负载）。从废液中回收的木质素表现出良好的紫外线防护效果；添加 5% (w/w) 的生物聚合物将商业防晒乳液的防晒系数从 21.62 增加到 40.71。由于芳环断裂，过氧化氢和紫外线辐射的联合使用降低了有机溶剂木质素的颜色（450 nm 处的吸光度降低了四倍），但含有增白有机溶剂木质素的化妆品防晒系数值较低。总之，本研究中获得的结果证明了有机酸预处理在木质纤维素材料增值中的效用。但含有增白有机溶剂木质素的化妆品防晒系数值较低。总之，本研究中获得的结果证明了有机酸预处理在木质纤维素材料增值中的效用。但含有增白有机溶剂木质素的化妆品防晒系数值较低。总之，本研究中获得的结果证明了有机酸预处理在木质纤维素材料增值中的效用。