5. Conclusions
Plant protein concentrates and isolates are increasingly consumed and have become important ingredients in shaping future sustainable diets. Upcycling barley via its substantial side stream in the beer brewing industry would allow producers to repurpose protein-rich and nutrient-rich barley. In this study, we demonstrate that upcycled barley/rice protein from barley spent grain exhibits clear postprandial total AA uptake profiles. Although upcycled barley/rice protein had a slightly lower overall EAA uptake compared to that of pea protein, it showed higher uptake of methionine and tryptophane. Furthermore, the overall absorption speeds, as estimated by the time-2-max, were similar to both pea and whey proteins. The findings also highlight the complementarity of barley/rice and pea protein, which may offer future potential in blending approaches to optimize protein quality for overall health. Future research, including upcycled barley protein, should include examining the effects on health outcomes, such as skeletal muscle synthesis, as well as implications for product development, such as texture properties and sensory characteristics of different sources of BSG.