Legumes are a source of health-promoting macro- and micronutrients, but also contain numerous phytochemicals with useful biological activities, an example of which are saponins. Epidemiological studies suggest that saponins may play a role in protection from cancer and benefit human health by lowering cholesterol. Therefore, they could represent good candidates for specialised functional foods. Following the consumption of a soya-rich high-protein weight-loss diet (SOYA HP WL), the concentrations of Soyasaponin I (SSI) and soyasapogenol B (SSB) were determined in faecal samples from human volunteers (n = 10) and found to be between 1.4 and 17.5 mg per 100 g fresh faecal sample. SSB was the major metabolite identified in volunteers’ plasma (n = 10) after consumption of the soya test meal (SOYA MEAL); the postprandial (3 h after meal) plasma concentration for SSB varied between 48.5 ng/mL to 103.2 ng/mL. The metabolism of SSI by the gut microbiota (in vitro) was also confirmed. This study shows that the main systemic metabolites of soyasaponin are absorbed from the gut and that they are bioavailable in plasma predominantly as conjugates of sapogenol. The metabolism and bioavailability of biologically active molecules represent key information necessary for the efficient development of functional foods.

The volatile profile was monitored during an optimized salt extraction process (salt solubilization coupled with membrane filtration) to produce a pea protein isolate (PPI). Aroma compounds from samples collected at different steps of the manufacturing process were isolated using solvent-assisted flavor evaporation (SAFE) and analyzed by gas chromatography–mass spectrometry–olfactometry (GC–MS–O) and GC–time-of-flight mass spectrometry (GC–TOF-MS). A sensory evaluation of pea flour (PF) and PPI aqueous solutions was also conducted. Twelve aroma compounds were perceived with a “moderate” odor intensity by panelists from the sniffing port of GC–MS–O. From the sensory evaluation, the aroma descriptors used to describe the PF and PPI testing solutions were also used to describe individual compounds eluting from the sniffing port. This observation supports the hypothesis that the 12 compounds identified in this study by GC–MS–O are likely to be the main contributors to the aroma profile of the samples analyzed.

The aroma profile was monitored during an optimized pH-extraction method (alkaline solubilization coupled with isoelectric precipitation) to produce pea protein isolates (PPIs). Samples were taken at different steps throughout the protein extraction. The aroma compounds were isolated from these samples using solvent-assistant flavor evaporation (SAFE) and were identified by gas chromatography-mass spectrometry-olfactometry (GC-MS-O) and gas chromatography-time-of-flight-mass spectrometry (GC-TOF-MS). A sensory evaluation of pea flour (PF) and PPI aqueous solutions was also conducted. From the instrumental analysis, 13 compounds were found to be likely the main contributors to the aroma profile of the samples examined. This hypothesis was also supported by the sensory data, which showed that the PF and PPI aqueous solutions were described with some of the odor descriptors used during the instrumental analysis. No new aroma compounds appear to be produced via the optimized pH-extraction and no existing compounds were completely removed from making a sensory contribution as determined by the olfactory analysis.