Dry fractionated faba bean protein-rich flour (FPR) produced by milling/air classification, and faba bean protein isolate (FPI) produced by acid extraction/isoelectric precipitation were compared in terms of composition, techno-functional properties, nutritional properties and environmental impacts. FPR had a lower protein content (64.1%, dry matter (DM)) compared to FPI (90.1%, DM), due to the inherent limitations of air classification. Of the two ingredients, FPR demonstrated superior functionality, including higher protein solubility (85%), compared to FPI (32%) at pH 7. Foaming capacity was higher for FPR, although foam stability was similar for both ingredients. FPR had greater gelling ability compared to FPI. The higher carbohydrate content of FPR may have contributed to this difference. An amino acid (AA) analysis revealed that both ingredients were low in sulfur-containing AAs, with FPR having a slightly higher level than FPI. The potential nutritional benefits of the aqueous process compared to the dry process used in this study were apparent in the higher in vitro protein digestibility (IVPD) and lower trypsin inhibitor activity (TIA) in FPI compared to FPR. Additionally, vicine/convicine were detected in FPR, but not in FPI. Furthermore, much lower levels of fermentable oligo-, di- and monosaccharides, and polyols (FODMAPs) were found in FPI compared to FPR. The life cycle assessment (LCA) revealed a lower environmental impact for FPR, partly due to the extra water and energy required for aqueous processing. However, in a comparison with cow’s milk protein, both FPR and FPI were shown to have considerably lower environmental impacts.

Similarly prepared protein isolates from blue lupin (Lupinus angustifolius) and white lupin (L. albus) were assessed in relation to their composition, functional properties, nutritional attributes and environmental impacts. Blue lupin protein isolate (BLPI) and white lupin protein isolate (WLPI) were found to be quite similar in composition, although differences in the electrophoretic protein profiles were apparent. Both lupin protein isolates (LPIs) had good protein solubility (76.9% for BLPI and 69.8% for WLPI at pH 7) and foaming properties. However, a remarkable difference in heat gelation performance was observed between BLPI and WLPI. WLPI had a minimum gelling concentration of 7% protein, whereas BLPI required 23% protein in order to form a gel. WLPI also resulted in stronger gels over a range of concentrations compared to BLPI. Nutritional properties of both LPIs were similar, with no significant differences in in vitro protein digestibility (IVPD), and both had very low trypsin inhibitor activity (TIA) and fermentable oligo-, di- and monosaccharides, and polyols (FODMAP) content. The amino acid profiles of both LPIs were also similar, with sulfur-containing amino acids (SAAs) being the limiting amino acid in each case. Environmental impacts revealed by the life cycle assessment (LCA) were almost identical for BLPI and WLPI, and in most categories the LPIs demonstrated considerably better performance per kg protein when compared to cow’s whole milk powder.

Partial replacement of animal protein sources with plant proteins is highly relevant for the food industry, but potential effects on protein digestibility need to be established. In this study, the in vitro protein digestibility (IVPD) of four protein sources and their mixtures (50:50 w/w ratio) was investigated using a transient pepsin hydrolysis (1 h) followed by pancreatin (1 h). The protein sources consisted of napin-rich rapeseed (Brassica napus L.) protein concentrates (RPCs; RP1, RP2) prepared in pilot scale and major bovine whey proteins (WPs; α-LA, alpha-lactalbumin; β-LG, beta-lactoglobulin). IVPD of individual protein sources was higher for WPs compared to RPCs. The RP2/β-LG mixture resulted in an unexpected high IVPD equivalent to β-LG protein alone. Protein mixtures containing RP1 showed a new IVPD response type due to the negative influence of a high trypsin inhibitor activity (TIA) level. Improved IVPD of RP1 alone and in protein mixtures was obtained by lowering the TIA level using dithiothreitol (DTT). These results showed that napin-rich protein products prepared by appropriate processing can be combined with specific WPs in mixtures to improve the IVPD.

Plant-based milk alternatives (PBMA) are a new popular food trend among consumers in Europe and North America. The forecast shows that PBMA will double their value by 2023. The objective of this study was to analyze the nutritional value of commercial products in terms of their fatty acid profile and protein digestibility from commercial PBMA. Eight commercially available PBMA were selected for fatty acid analysis, performed with gas chromatography of methylated fatty acids (GC-FAME), and, from these, four commercial products (almond drink, hemp drink, oat drink, and soy drink) were selected for a short-term in vitro protein digestibility (IVPD) analysis. The fatty acid analysis results showed that most of the products predominantly contained oleic acid (C18:1 ω-9) and linoleic acid (C18:2 ω-6). Hemp drink contained the highest omega-6/omega-3 (ω6/ω3) ratio among all tested products (3.43). Oat drink and almond drink were the PBMA with the highest short-term protein digestibility, non-significantly different from cow’s milk, while soy drink showed the lowest value of protein digestibility. In conclusion, PBMA showed a significant variability depending on the plant source, both in terms of fatty acid composition and protein digestibility. These results provide more in-depth nutritional information, for future product development, and for consumer’s choice.

Highlights Two lentil protein isolates (LPIs) and a lentil flour (LF) were prepared in pilot-scale. Nutritional and anti-nutritional properties of LPIs were examined in comparison to LF. Total galacto-oligosaccharides (GOS) contents of LPIs were reduced by 58–91%. Trypsin inhibitor activity (TIA) levels of LPIs were reduced by 81–87%. In vitro protein digestibility (IVPD) values of LPIs were improved by 35–53%.

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BACKGROUND: Infant formula is a human milk substitute for consumption during the first months of life. The protein component of such products is generally of dairy origin. Alternative sources of protein, such as those of plant origin, are of interest due to dairy allergies, intolerances, and ethical and environmental considerations. Lentils have high levels of protein (20-30%) with a good amino acid profile and functional properties. In this study, a model lentil protein-based formula (LF), in powder format, was produced and compared to two commercial plant-based infant formulae (i.e., soy; SF and rice; RF) in terms of physicochemical properties and digestibility.Results: The macronutrient composition was similar between all the samples; however, RF and SF had larger volume-weighted mean particle diameters (D[4,3] of 121-134 ∼m) than LF (31.9 ∼m), which was confirmed using scanning electron and confocal laser microscopy. The larger particle sizes of the commercial powders were attributed to their agglomeration during the drying process. Regarding functional properties, the LF showed higher D[4,3] values (17.8 ∼m) after 18 h reconstitution in water, compared with the SF and RF (5.82 and 4.55 ∼m, respectively), which could be partially attributed to hydrophobic protein-protein interactions. Regarding viscosity at 95 °C and physical stability, LF was more stable than RF. The digestibility analysis showed LF to have similar values (P < 0.05) to the standard SF.Conclusion: These results demonstrated that, from the nutritional and physicochemical perspectives, lentil proteins represent a good alternative to other sources of plant proteins (e.g., soy and rice) in infant nutritional products.

BV, biological value; DF, dietary fi bre; DH, degree of hydrolysis; DM, dry matter; E:S ratio, enzyme to substrate ratio; IDF, insoluble dietary fi bre; IVPD, in vitro protein digestibility; IVPD PT, overall protein digestibility; NSP, non-starch polysaccharides; PD, protein digestibility; RE, rapeseed embryo fi bres; RH, rapeseed hulls; RP(2), rapeseed protein concentrate (2) rich in napin proteins; SDF, soluble dietary fi bre; TD, true protein digestibility; TDF, total dietary fi bre; TDF-RE, total dietary fi bre isolated from rapeseed embryo fi bres; TDF-RH, total dietary fi bre isolated from rapeseed hulls; TNBS, trinitrobenzenesulfonic acid; U-samples, untreated samples; UPT-samples, uncorrected overall protein digestibility samples.