Bonifácio-Lopes Teresa, Catarino Marcelo D, Vilas-Boas Ana A, Ribeiro Tânia B, Campos Débora A, Teixeira José A, Pintado Manuela
CBQF-Centro de Biotecnologia e Química Fina-Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal.
CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
Foods. 2022 Jul 30;11(15):2279. doi: 10.3390/foods11152279.
Brewer's spent grain (BSG) solid residues are constituted by dietary fibre, protein, sugars, and polyphenols, which can have potential effects on human health. In this study, for the first time, the flours obtained from solid residues of solid-liquid extraction (SLE) and ohmic heating extraction (OHE) were applied throughout the gastrointestinal digestion simulation (GID), in order to evaluate their prebiotic potential and in vitro human gut microbiota fermentation. The results showed that the digestion of BSG flours obtained by the different methods lead to an increase throughout the GID of total phenolic compounds (SLE: from 2.27 to 7.20 mg gallic acid/g BSG-60% ethanol:water (); OHE: 2.23 to 8.36 mg gallic acid/g BSG-80% ethanol:water ()) and consequently an increase in antioxidant activity (ABTS-SLE: from 6.26 to 13.07 mg ascorbic acid/g BSG-80% ethanol:water (); OHE: 4.60 to 10.60 mg ascorbic acid/g BSG-80% ethanol:water ()-ORAC-SLE: 3.31 to 14.94 mg Trolox/g BSG-80% ethanol:water (); OHE: from 2.13 to 17.37 mg Trolox/g BSG-60% ethanol:water ()). The main phenolic compounds identified included representative molecules such as vanillic and ferulic acids, vanillin and catechin, among others being identified and quantified in all GID phases. These samples also induced the growth of probiotic bacteria and promoted the positive modulation of beneficial strains (such as spp. and spp.) present in human faeces. Moreover, the fermentation by human faeces microbiota also allowed the production of short chain fatty acids (acetic, propionic, and butyric). Furthermore, previous identified polyphenols were also identified during fecal fermentation. This study demonstrates that BSG flours obtained from the solid residues of SLE and OHE extractions promoted a positive modulation of gut microbiota and related metabolism and antioxidant environment associated to the released phenolic compounds.
啤酒糟固体残渣由膳食纤维、蛋白质、糖类和多酚组成，这些成分可能对人体健康产生潜在影响。在本研究中，首次将通过固液萃取（SLE）和欧姆加热萃取（OHE）的固体残渣获得的面粉应用于整个胃肠道消化模拟（GID），以评估它们的益生元潜力和体外人体肠道微生物群发酵情况。结果表明，通过不同方法获得的啤酒糟面粉在整个GID过程中导致总酚类化合物增加（SLE：从2.27毫克没食子酸/克啤酒糟-60%乙醇：水；OHE：从2.23毫克没食子酸/克啤酒糟-80%乙醇：水），从而抗氧化活性增加（ABTS-SLE：从6.26毫克抗坏血酸/克啤酒糟-80%乙醇：水；OHE：从4.60毫克抗坏血酸/克啤酒糟-80%乙醇：水-ORAC-SLE：从3.31毫克 Trolox/克啤酒糟-80%乙醇：水；OHE：从2.13毫克 Trolox/克啤酒糟-60%乙醇：水）。鉴定出的主要酚类化合物包括代表性分子，如香草酸和阿魏酸、香草醛和儿茶素等，在所有GID阶段都进行了鉴定和定量。这些样品还诱导了益生菌的生长，并促进了人粪便中存在的有益菌株（如某些菌属和某些菌属）的正向调节。此外，人粪便微生物群的发酵还能产生短链脂肪酸（乙酸、丙酸和丁酸）。此外，在粪便发酵过程中也鉴定出了先前确定的多酚。这项研究表明，从SLE和OHE萃取的固体残渣中获得的啤酒糟面粉促进了肠道微生物群的正向调节以及与释放的酚类化合物相关的代谢和抗氧化环境。
