The bioavailability and postprandial utilisation of sweet lupin (<I>Lupinus albus</I>)-flour protein is similar to that of purified soyabean protein in human subjects: a study using intrinsically <SUP>15</SUP>N-labelled proteins

Abstract

Sweet lupin (Lupinus albus), a protein-rich legume devoid of anti-nutritional factors, is considered to have a high potential for protein nutrition in man. Results concerning the nutritional value of lupin protein are, however, conflicting in animals and very scarce in human subjects. Furthermore, where fibre-rich protein sources are concerned, the long-term nutritional results are often obscured, particularly since fibre-promoted colonic fermentation may bias the energy supply and redistribute N flux. We therefore studied, during the postprandial phase, the bioavailability and utilisation of lupin-flour protein in nine healthy men who had ingested a mixed meal containing intrinsically 15N-labelled lupin flour as the protein source (Expt 1). The real ileal digestibility (RID) and ileal endogenous N losses (IENL) were assessed using a perfusion technique at the terminal ileum, and the N content and 15N enrichment of ileal samples. Lupin flour exhibited a high RID of 91 (SD 3)% and low IENL (5-4 (SD 1.3) mmol N/h). Postprandial dietary deamination was also assessed from body dietary urea and urinary dietary N excretion, and compared with results in nine healthy men following an iso-energetic meal containing a 15N-soyabean-protein isolate with a similar RID, as a control (Expt 2). Postprandial dietary deamination was similar after lupin and soyabean meals (17 (SD 2) and 18 (SD 4)% ingested N respectively). We therefore conclude that lupin protein is highly bioavailable, even if included in fibre-rich flour, and that it can be used with the same efficiency as soyabean protein to achieve postprandial protein gain in healthy human subjects.

Rapeseed and milk protein exhibit a similar overall nutritional value but marked difference in postprandial regional nitrogen utilization in rats

“…The similarities of digestive kinetics, regional tissue distribution and dietary N losses under acute or chronic conditions of consumption of the two protein sources suggest that these parameters initially responded to the immediate effect of dietary protein after ingestion and were not driven by any phenomenon related to metabolic regulation, which would occur after a chronic consumption of these protein sources. This finding lends further credence to the findings of studies on the postprandial metabolism of meal protein under acute condition [4,40-42]. Although obtained in two series of experiments, we could combine data on dietary N distribution and regional protein synthesis rates to estimate the contribution of dietary N to the amount of protein deposited in each tissue, which, to our knowledge, constitutes a novel finding.…”

Protein content and amino acid composition of commercially available plant-based protein isolates

“…In addition, we included lupin, hemp, and microalgae in the current analyses. Lupin is a native European legume with a protein quality score similar to soy, and has become of interest as an alternative to the import of soy (Lucas et al 2015 ; Mariotti et al 2002 ). Microalgae have received considerable attention due to their high protein content (similar to meat, egg, soybean, and milk), presence of other beneficial nutrients, and a production that requires less water and land than other crops or animal foods (Bleakley and Hayes 2017 ).…”

Identification of QTLs associated with resistance to Phomopsis pod blight (<i>Diaporthe toxica</i>) in <i>Lupinus albus</i>

“…It has potential for increased inclusion in the human diet (Erbas et al 2005, Mariotti et al 2002), although allergies have been reported (Quaresma et al 2007). …”