Institute of Food Engineering FoodUPV, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain.
Molecules. 2024 Oct 16;29(20):4897. doi: 10.3390/molecules29204897.
Of the three types of waste generated in beer processing, brewer's spent grain (BSG) is the most abundant and has a high potential for valorization. In this work, defatted BSG (DB) was subjected to an extraction process with subcritical water at different temperatures to obtain extracts rich in phenols and the cellulosic fractions, which were also purified by using hydrogen peroxide (HO). The results showed that the dry extracts obtained at 170 °C were richer in phenolics (24 mg Gallic Acid Equivalent (GAE) g DB), but with lower antioxidant capacity (71 mg DB·mg 2,2-diphenyl-1-pikryl-hydrazyl). This extract also showed the highest antibacterial potential against (80 mg·mL) and (140 mg·mL) than those obtained at lower temperatures. The purification of cellulose from the treated residues, using hydrogen peroxide, revealed that DB is a limited source of cellulose material since the bleached fractions showed low yields (20-25%) and low cellulose purity (42-71%), even after four bleaching cycles (1 h) at pH 12 and 8% HO. Despite this, the subcritical water extraction method highlights the potential of a simple process as a technological option to convert underutilized side streams like beer bagasse into added-value, potential ingredients for innovative food and pharmaceutical applications.
在啤酒加工过程中产生的三种废物中，啤酒糟（BSG）是最丰富的，具有很高的增值潜力。在这项工作中，脱脂啤酒糟（DB）在不同温度下进行亚临界水提取过程，以获得富含酚类物质和纤维素的提取物，并用过氧化氢（HO）对其进行纯化。结果表明，在 170°C 下获得的干提取物含有更丰富的酚类物质（24 毫克没食子酸当量（GAE）g DB），但抗氧化能力较低（71 毫克 DB·mg 2,2-二苯基-1-苦基肼）。与在较低温度下获得的提取物相比，该提取物对 和 （80 mg·mL 和 140 mg·mL）也表现出更高的抗菌潜力。用双氧水对处理后的残渣进行纤维素纯化表明，DB 是纤维素材料的有限来源，因为经过漂白的纤维素产量较低（20-25%），纤维素纯度较低（42-71%），即使在 pH 值为 12 和 8%HO 下进行四个漂白循环（1 小时）也是如此。尽管如此，亚临界水提取方法突出了简单工艺作为将啤酒糟等未充分利用的副产物转化为有价值的创新食品和制药应用的潜在成分的技术选择的潜力。
