Abstract：
Brewers\' spent grain (BSG) is the main byproduct from the brewing industry, which accounts for 85 % of the total waste generated during beer production. This lignocellulosic material is traditionally used as livestock feed and sold at a low price. However, BSG can be used as a low-cost feedstock for the production of bioactive molecules and chemicals precursors, upgrading the value of this byproduct. In this context, BSG is a promising feedstock for the extraction of antioxidants like ferulic acid (FA) and p-coumaric acid (p-Cu). The effectiveness of three hydrolysis treatments were evaluated for the extraction of FA and p-Cu from BSG, namely enzymatic (based on the synergistic cooperation between a feruloyl esterase and an endo-1,4-β-xylanase), alkaline and hydrothermal. The hydrothermal treatment produced the highest extraction yields (7.2 g/kgBSG and 1.4 g/kgBSG for FA and p-Cu, respectively) in a short extraction time (an hour). On the other hand, enzymatic hydrolysis extracted 4.3 g/kgBSG for FA and negligible yields for p-Cu in 4 h of incubation at 25 °C. Yields of 5.5 g/kgBSG for FA and 0.6 g/kgBSG for p-Cu were obtained in more than 5 h of alkaline treatment at 120 °C. The mass and energy balances revealed the high dependence of the operating costs on the concentration of BSG used during the extraction process, with costs of 34.5 €, 6607 € and 205.5 € per kg of FA for the chemical, enzymatic and hydrothermal extraction methods at 100 kg BSG/m3.
摘要：
酒糟（BSG）是酿酒行业的主要副产品，占啤酒生产过程中产生的总废物的85%。这种木质纤维素材料传统上用作家畜饲料并以低价出售。然而,BSG可用作生产生物活性分子和化学品前体的低成本原料，提升这种副产品的价值。在这种情况下，BSG是用于提取抗氧化剂如阿魏酸(FA)和对香豆酸(p-Cu)的有前途的原料。评估了三种水解处理从BSG中提取FA和p-Cu的有效性，即酶（基于阿魏酸酯酶和内切-1,4-β-木聚糖酶之间的协同合作），碱性和热液。水热处理产生了最高的提取率（FA和p-Cu的7.2g/kgBSG和1.4g/kgBSG，分别)在较短的提取时间(一小时)内。另一方面,在25°C孵育4小时内，酶水解提取了4.3g/kgBSG的FA，p-Cu的产量可忽略不计。在120°C下碱处理超过5小时，FA的产率为5.5g/kgBSG，p-Cu的产率为0.6g/kgBSG。质量和能量平衡表明，操作成本对提取过程中使用的BSG浓度的高度依赖性。费用为34.5欧元，该化学品每公斤FA为6607欧元和205.5欧元，100kgBSG/m3的酶和水热萃取方法。
