Brewer’s spent grain (BSG) is a nitrogen and fiber rich waste generated in high volumes in beer manufacturing. Here we have investigated the use of fermentation for value addition to this waste material. In this study we use solid-state fermentation (SSF) using food grade Rhizopus oligosporus to enhance its nutrient content by valorization of BSG. Subsequently, untargeted GC–MS (Gas chromatography mass spectrometry) based metabolomics was used to analyse the constituents. We investigated different solvents to extract extracellular metabolites and best derivatization method, where methanol and silylation provided best results. We observed significant levels of metabolite changes in amino acids, citric acid, vitamins and antioxidants. This data provided insight on metabolites variations during fermentation, proving that fermentation enhanced BSG’s nutrient content. Hence, data from metabolomics studies can be used to find novel applications for food wastes and innovative processing methods for valorization of waste materials.

啤酒厂的废谷物（BSG）是富含氮和纤维的废物，在啤酒制造过程中会大量产生。在这里，我们研究了利用发酵来增加废料的价值。在这项研究中，我们使用食品级根瘤菌（Rhizopus oligosporus）进行固态发酵（SSF）通过平衡BSG来提高其营养成分。随后，基于目标的GC-MS（气相色谱质谱）代谢组学被用于分析成分。我们研究了不同的溶剂以提取细胞外代谢物和最佳衍生化方法，其中甲醇和甲硅烷基化可提供最佳结果。我们观察到了氨基酸，柠檬酸，维生素和抗氧化剂中代谢物水平的显着变化。这些数据提供了发酵过程中代谢物变化的见解，证明了发酵增强了BSG的营养成分。因此，来自代谢组学研究的数据可用于寻找食品废物的新应用和创新的加工方法，以对废物进行价值评估。