(P06-032-25) Assessment of Postprandial Amino Acid Response to Biscuits Fortified With Brewers’ Spent Grain (BSG) and Fermented BSG in Individuals With Metabolic Syndrome

Objectives: Brewers’ Spent Grain (BSG) is a food processing by-product from beer manufacturing rich in dietary fiber and protein, offering potential to be repurposed as a low-cost plant protein source. However, like many plant-derived proteins, BSG has limited protein digestibility. Fermentation with Rhizopus Oligosporus (RO) has been shown to improve protein quality of BSG by increasing crude protein content and breaking down heteropolymer compounds that hinder protein digestibility. However, resulting improvements in postprandial amino acid responses, especially in individuals with metabolic syndrome (MetS), who may have attenuated responses to protein digestion, have not yet been validated. This study aimed to evaluate the postprandial amino acid responses after consumption of BSG and fermented BSG (FBSG) fortified biscuits in individuals with MetS through a cross-over, randomized control trial.

Methods: BSG and FBSG (4% RO, 37°C, 3 days) biscuits were formulated by substituting 30% of wheat flour with BSG or FBSG flour, while control (CON) biscuits contained only wheat flour. Fifteen adults with MetS were recruited in Singapore and each participant consumed 90 g of CON, BSG or FBSG biscuits in random order, with a one-week washout period between visits. Blood samples were collected seven times over two hours post consumption and amino acids contents in the blood and biscuits were measured by an amino acid analyzer.

Results: A significant increase in free amino acids contents were observed in the FBSG biscuits compared to BSG and CON biscuits (FBSG vs BSG vs CON: 0.43 ± 0.05 g/100g vs 0.08 ± 0.01 g/100g vs 0.06 ± 0.01 g/100g, p ≤ 0.001). However, no significant differences in postprandial total amino acid response for incremental area under the curve were observed among the three biscuits (p = 0.447) in individuals with MetS.

Conclusions: Although fermentation of BSG as a pre-treatment appeared to improve protein quality when it is incorporated in the biscuits, there was no improvement in protein absorption in individuals with MetS during short-term consumption. The findings suggest that other factors, such as protein digestion kinetics and metabolic variability may limit absorption, and further research is needed to explain the observed clinical results.

Funding Sources: Ministry of Education, Singapore