Formulation, pilot-scale preparation, physicochemical characterization and digestibility of a lentil protein-based model infant formula powder.

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 µm) than LF (31.9 µm), 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 µm) after 18 h reconstitution in water, compared with the SF and RF (5.82 and 4.55 µm, 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. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Formation and thermal and colloidal stability of oil-in-water emulsions stabilized using quinoa and lentil protein blends.

BACKGROUND: The amino acid composition, and rheological, thermal and colloidal stability of plant protein-based oil-in-water emulsion systems containing 1.90, 3.50 and 7.70 g 100 mL-1 protein, fat and carbohydrate, respectively, using quinoa and lentil protein ratios of 100:0 and 60:40 were investigated. The emulsion containing lentil protein showed lower initial, peak and final viscosity values (22.7, 61.7 and 61.6 mPa s, respectively) than the emulsion formulated with quinoa protein alone (34.3, 102 and 80.0 mPa s, respectively) on heat treatment. RESULTS: Particle size analysis showed that both samples had small particle sizes (~1.36 µm) after homogenization; however, the sample with 60:40 quinoa:lentil protein ratio showed greater physical stability, likely related to the superior emulsifying properties of lentil protein. However, upon heat treatment, large aggregates (~100 µm) were formed in both samples, reducing the physical stability of the samples. This physical stability was increased with the addition of 0.20% sodium dodecyl sulfate (SDS), whereas it was negatively affected by the addition of α-amylase. Addition of α-amylase led to lower viscosity for both emulsion samples, with measured values of 41.8 and 46.0 mPa s for the 100:0 and 60:40 samples, respectively. This suggests that the heat-induced increases in particle size were partially due to hydrophobic interactions between the proteins as SDS disrupts hydrophobic bonds between proteins. CONCLUSION: These results demonstrated that using a mixture of lentil and quinoa proteins positively affected the physical stability of plant protein-based emulsions, in addition to contributing to a more nutritionally complete amino acid profile - both important considerations in the development of plant-based beverages. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Thermal and Mineral Sensitivity of Oil-in-Water Emulsions Stabilised using Lentil Proteins.

Oil-in-water emulsion systems formulated with plant proteins are of increasing interest to food researchers and industry due to benefits associated with cost-effectiveness, sustainability and animal well-being. The aim of this study was to understand how the stability of complex model emulsions formulated using lentil proteins are influenced by calcium fortification (0 to 10 mM CaCl2) and thermal processing (95 or 140 °C). A valve homogeniser, operating at first and second stage pressures of 15 and 3 MPa, was used to prepare emulsions. On heating at 140 °C, the heat coagulation time (pH 6.8) for the emulsions was successively reduced from 4.80 to 0.40 min with increasing CaCl2 concentration from 0 to 10 mM, respectively. Correspondingly, the sample with the highest CaCl2 addition level developed the highest viscosity during heating (95 °C × 30 s), reaching a final value of 163 mPa·s. This was attributed to calcium-mediated interactions of lentil proteins, as confirmed by the increase in the mean particle diameter (D[4,3]) to 36.5 µm for the sample with 6 mM CaCl2, compared to the unheated and heated control with D[4,3] values of 0.75 and 0.68 µm, respectively. This study demonstrated that the combination of calcium and heat promoted the aggregation of lentil proteins in concentrated emulsions.

Composition, Physicochemical and Sensorial Properties of Commercial Plant-Based Yogurts.

The aim of this study was to determine the key physicochemical, sensory and quality attributes of plant-based yogurts made from soy, coconut, cashew, almond and hemp, including a dairy benchmark yogurt. The soy, coconut and cashew-based yogurts showed textural parameters comparable to the dairy yogurt, with firmness values of 0.46, 0.44, 0.51 and 0.36 N, respectively. Rheological analysis showed that one of the soy-based yogurts was similar to the dairy yogurt in terms of apparent viscosity, in addition to water-holding capacity (82.8% and 75.7%, respectively). Other plant-based yogurts, e.g., hemp, showed different rheological and textural parameters to the other plant-based products, relating this to the agar and rice starch components of the hemp formulation. The sensory analysis demonstrated that some plant-based yogurts were similarly appreciated to dairy-based products. This was due mainly to the presence of specific hydrocolloids, sweeteners and flavours in the formulations; for example, the acceptability of the soy- and dairy-based yogurts were identical (5.95). The results obtained in this study allowed identification of key quality attributes of plant-based yogurt products and highlighted relationships between such attributes and formulation, which can be exploited in future product development.

Composition, Protein Profile and Rheological Properties of Pseudocereal-Based Protein-Rich Ingredients.

The objectives of this study were to investigate the nutrient composition, protein profile, morphology, and pasting properties of protein-rich pseudocereal ingredients (quinoa, amaranth, and buckwheat) and compare them to the more common rice and maize flours. Literature concerning protein-rich pseudocereal ingredients is very limited, mainly to protein profiling. The concentrations of macronutrients (i.e., ash, fat, and protein, as well as soluble, insoluble and total dietary fibre) were significantly higher for the protein-rich variants of pseudocereal-based flours than their regular protein content variants and the rice and maize flours. On profiling the protein component using sodium dodecyl sulfate⁻polyacrylamide gel electrophoresis (SDS-PAGE), all samples showed common bands at ~50 kDa and low molecular weight bands corresponding to the globulin fraction (~50 kDa) and albumin fraction (~10 kDa), respectively; except rice, in which the main protein was glutelin. The morphology of the starch granules was studied using scanning electron microscopy with quinoa and amaranth showing the smallest sized granules, while buckwheat, rice, and maize had the largest starch granules. The pasting properties of the ingredients were generally similar, except for buckwheat and amaranth, which showed the highest and lowest final viscosity, respectively. The results obtained in this study can be used to better understand the functionality and food applications of protein-rich pseudocereal ingredients.