Generation of phenolic-rich extracts from brewers' spent grain and characterisation of their in vitro and in vivo activities. (March 2021)

• Record Type: Journal Article
• Authors: Connolly, Alan; Cermeño, Maria; Alashi, Adeola M.; Aluko, Rotimi E.; FitzGerald, Richard J.
• Is Part Of: Innovative food science & emerging technologies. Volume 68(2021)
• Publication Date: 2021-03
• Subjects: Brewers' spent grain -- BSG -- SHR -- Phenolics -- ACE -- DPP-IV -- Antioxidant -- Bioactive; Food -- Biotechnology -- Periodicals; Food industry and trade -- Technological innovations -- Periodicals; Aliments -- Biotechnologie -- Périodiques; Food -- Biotechnology; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.ifset.2021.102617
• Languages: English
• ISSNs: 1466-8564

Abstract

Abstract: Brewers' spent grain (BSG) is a co-product of the brewing industry, which is rich in phenolic acids. This study compared the in vitro bioactive properties of aqueous, aqueous pH-shift and enzyme-aided phenolic extracts from pale (unroasted) wet BSG. Overall, the pH-shift extracts showed higher oxygen radical absorbance capacity (ORAC), trolox equivalent antioxidant capacity (TEAC) and ferric-reducing antioxidant power (FRAP) values compared with the enzyme-aided extracts. A selected enzyme-aided extract showed highest in vitro ACE inhibitory activity (ACE IC50 : 0.133 ± 0.032 mg mL −1 ) and mediated significant ( p < 0.05) reductions in blood pressure markers in vivo following ingestion by spontaneously hypertensive rats (systolic blood pressure; −35.35 ± 9.04 and diastolic blood pressure; −28.55 ± 4.22 mmHg). The results demonstrated that the observed in vitro activity of phenolic-rich extracts may be translated into an in vivo hypotensive effect. Enzyme-assisted extraction has potential as an alternative solvent-free approach for generating phenolic-rich extracts from BSG that may find use in the management of hypertension. Graphical abstract: Unlabelled Image Highlights: Phenolic-rich extracts were obtained from brewers' spent grain. The aqueous, pH-shift extraction method resulted in highest phenolic extraction. Ferulic and p-coumaric acid were identified within the phenolic extracts. In vitro bioactivities were higher in enzyme-aided phenolic extracts. An enzyme-aided extract had hypotensive effects in spontaneously hypertensive rats.