Effect of Genotype on the Properties of Flours and Protein Isolates Derived From Wrinkled and Round Peas

Gelation properties of salt-extracted pea protein induced by heat treatment

Pea protein isolates (PPI) and rice protein isolates (RPI) were used as meat extenders at different concentration levels (3%, 6%, 9%, and 12%) for the development of chicken nuggets and evaluation of their physicochemical and sensory properties. Protein value of pea and rice protein-enriched nuggets ranged between 32.84%–39.31% and 39.23%–48.49%, respectively, which was high as compared to the control (34.99%). Moisture level ranged between 53.72% and 59.02%. Addition of proteins did not show any effect on pH and ash contents of nuggets. All the treatments displayed significant increase in water holding capacity and decrease in cooking loss compared to the control samples. Cooking loss in PPI and RPI extended nuggets was found between 5.01%–11.12% and 3.85%–7.54%, respectively. There was no significant difference in the textural characteristics of extended nuggets. All treatments involving RPI gave high scores for “overall acceptability” of sensory score. However, PPI showed substantial issue in flavor in nuggets. Practical application Food insecurity has become the biggest challenge of the developing countries as about 60% of the world population is suffering from protein deficiency. The leading factor responsible for the unavailability of meat to poor peoples is the high cost of meat and meat products. Increasing population, uncertain crop yield, and high cost of animal-based products have prompted the food industry to identify non-meat protein sources to incorporate in traditional meat formulations. So, inclusion of vegetable proteins like rice and pea proteins in meat formulations not only enhance the nutritional value but also provide a vehicle to promote the use of plant proteins to maintain target protein intake. There is a need to find economical sources of protein having positive impact on sensory properties of meat. In this regard, pea and rice protein isolates were used in order to prepare good quality and nutritious product with acceptable sensory score.

In this study, the effect of different isolation techniques on the isolated proteins from pigeon pea was investigated. Water, methanol, ammonium sulfate, and acetone were used for the precipitation of proteins from pigeon pea. Proximate composition, and antinutritional and functional properties of the pigeon pea flour and the isolated proteins were measured. Data generated were statistically analyzed. The proximate composition of the water‐extracted protein isolate was moisture 8.30%, protein 91.83%, fat 0.25%, ash 0.05%, and crude fiber 0.05%. The methanol‐extracted protein isolate composition was moisture 7.87%, protein 91.83%, fat 0.17%, and ash 0.13%, while crude fiber and carbohydrates were not detected. The composition of the ammonium sulfate‐extracted protein isolate was moisture 7.73%, protein 91.73%, fat 0.36, ash 0.13%, and crude fiber 0.67%. The acetone‐extracted protein isolate composition was moisture 8.03%, protein 91.50%, ash 0.67%, and fat 0.30%, but crude fiber and carbohydrates were not detected. The isolate precipitated with ammonium sulfate displayed the highest foaming capacity (37.63%) and foaming stability (55.75%). Isolates precipitated with methanol and acetone had the highest water absorption capacity (160%). Pigeon pea protein isolates extracted with methanol and ammonium sulfate had the highest oil absorption capacity of 145%. Protein isolates recovered through acetone and methanol had the highest emulsifying capacity of 2.23% and emulsifying stability of 91.47%, respectively. The proximate composition of the recovered protein isolates were of high purity. This shows the efficiency of the extraction techniques. The isolates had desirable solubility index. All the isolation techniques brought significant impact on the characteristics of the isolated pigeon pea protein.

A closed cavity rheometer was employed to assess the properties of concentrated protein materials before, during and after thermal treatment, using conditions that are relevant to the production of meat analogues. Pea and soy protein isolate and wheat gluten were used as model matrices. The analysis was done using Lissajous curves, both for small and large amplitude oscillatory shear deformation. The energy dissipation ratios based on the enclosed area inside the Lissajous curves characterize the plasticity of the materials. The results show that the modulus of wheat gluten increases during heating and remains elevated after cooling. In contrast, the moduli of pea and soy protein isolates decrease during heating. Subsequent cooling leads to properties that are similar to the rheological properties of unheated pea and soy protein isolates. Lissajous curves and energy dissipation ratios provide insight in the non-linear response. At 30 °C, pea and soy protein isolate have a higher dissipation ratio than wheat gluten. Upon a heat treatment and even after cooling, the dissipation ratio was smaller at similar strain amplitude compared with 30 °C. This indicates that heating induced more elasticity. Upon heating, pea protein isolate loses its elastic properties faster than soy protein isolate, while wheat gluten showed abrupt dissipation after extensive deformation. The observed characteristics are consistent with the behaviour during extrusion and shearing, in which wheat gluten forms extended filaments, while soy and pea protein isolates form a homogeneous matrix. Studying the large oscillatory shear behaviour during and after thermal treatment provides a more detailed picture of the rheological changes during processing, than one would obtain through classical rheology. The dissipation ratio summarizes the information in the Lissajous curves. These insights help to better identify material-structure-process relationships for concentrated plant protein materials during thermomechanical conversions, such as extrusion.

SummaryImitated meat product (nuggets) has been a major influence on vegans since time immemorial. Pea protein isolates (PPIs) and lentil protein isolates (LPIs) are identified as ingredients for their indigenous color, flavor, taste, texture, and functional properties. This study was aimed to investigate the potential use of pea and lentil PI as a meat substitute in nugget preparation to replace meat usage. Chemical characteristics of pea and lentil powder and functional properties of PPI and LPI were determined. Furthermore, the nutritional profile, textural property, and sensory attributes of imitated meat products (nuggets) were compared with chicken‐based nuggets. Results showed that functional properties of PPI and LPI were almost similar to each other, and NG2 (40%PPI: 60%LPI) was selected as the most acceptable nugget with desired nutritional, textural, and sensory attributes. PPI and LPI can be successfully used nutritionally and functionally as valuable substitutes for meat‐based nuggets, even in NG2 (40%PPI: 60%LPI), without significant deterioration of overall acceptability of nuggets. PPI‐ and LPI‐based nuggets could be introduced to the market as a potential marketable non‐meat product with indigenous color, flavor, taste, texture, and overall acceptability.

Recently, legume protein isolates are increasingly of interest as ingredients for the food industry; however, in spite of their health benefits, there is a limited information about the presence of bioactive compounds in the protein isolates. The objective of this study was to establish the phytochemical composition and selected techno-functional properties of pea and bean flours and their protein isolates obtained applying different drying methods. Regarding proximate composition, bean flour contained higher amounts of total protein (23%) and fat (44%) than pea flour; bean protein isolate (BPI) contained higher total and soluble protein, fat and starch than the pea protein isolate (PPI). Both protein isolates showed a similar emulsifying capacity (around 27%). Emulsion stability and foaming capacity were higher in the PPI (around 36%). Bean flour contained lower amounts of α-galactosides (31.64mg/g) but a higher trypsin inhibitors content (21.95 TIU/mg) than pea flour. The preparation procedure of the protein isolates affected the bioactive compound content. The PPI showed a reduction of inositol phosphates (13%), galactosides (76%), trypsin inhibitors (90%) and total phenolic compounds (35%) compared to its whole flour. The BPI contained higher amounts of inositol phosphates (137%) and total phenolic compounds (135%) than its flour, while it showed a lower content of galactosides (54%) and a similar amount of trypsin inhibitors. Thus, the bioactive compound content and the functional properties studied indicate that protein isolates can be used as ingredients with added-value in the development of new formulated food products, allowing their increasing use in the food industry.

Comparative structural and emulsifying properties of ultrasound-treated pea (Pisum sativum L.) protein isolate and the legumin and vicilin fractions

Bread-making potential of pea protein isolate produced by a novel ultrafiltration/diafiltration process

Binding of carbonyl flavours to canola, pea and wheat proteins using GC/MS approach

Pea protein dry-fractionated (PDF), pea protein isolated (PIs), soy protein isolated (SIs) and oat protein (OP) were combined in four mixes (PDF_OP, PIs_OP, PDF_PIs_OP, SIs_OP) and extruded to produce meat analogues. The ingredients strongly influenced the process conditions and the use of PDF required higher specific mechanical energy and screw speed to create fibrous texture compared to PIs and SIs. PDF can be conveniently used to produce meat analogues with a protein content of 55 g 100 g−1, which is exploitable in meat-alternatives formulation. PDF-based meat analogues showed lower hardness (13.55–18.33 N) than those produced from PIs and SIs (nearly 27 N), probably due to a more porous structure given by the natural presence of carbohydrates in the dry-fractionated ingredient. PDF_OP and PIs_PDF_OP showed a significantly lower water absorption capacity than PIs OP and SIs_OP, whereas pea-based extrudates showed high oil absorption capacity, which could be convenient to facilitate the inclusion of oil and fat in the final formulation. The sensory evaluation highlighted an intense odor and taste profile of PDF_OP, whereas the extrudates produced by protein isolates had more neutral sensory characteristics. Overall, the use of dry-fractionated protein supports the strategies to efficiently produce clean-labeled and sustainable plant-based meat analogues.

The demand for pulse proteins as alternatives to soy protein has been steeply increasing over the past decade. However, the relatively inferior functionality compared to soy protein is hindering the expanded use of pulse proteins, namely pea and chickpea protein, in various applications. Harsh extraction and processing conditions adversely impact the functional performance of pea and chickpea protein. Therefore, a mild protein extraction method involving salt extraction coupled with ultrafiltration (SE-UF) was evaluated for the production of chickpea protein isolate (ChPI). The produced ChPI was compared to pea protein isolate (PPI) produced following the same extraction method in terms of functionality and feasibility of scaling. Scaled-up (SU) ChPI and PPI were produced under industrially relevant settings and evaluated in comparison to commercial pea, soy, and chickpea protein ingredients. Controlled scaled-up production of the isolates resulted in mild changes in protein structural characteristics and comparable or improved functional properties. Partial denaturation, modest polymerization, and increased surface hydrophobicity were observed in SU ChPI and PPI compared to the benchtop counterparts. The unique structural characteristics of SU ChPI, including its ratio of surface hydrophobicity and charge, contributed to superior solubility at both a neutral and acidic pH compared to both commercial soy protein and pea protein isolates (cSPI and cPPI) and significantly outperformed cPPI in terms of gel strength. These findings demonstrated both the promising scalability of SE-UF and the potential of ChPI as a functional plant protein ingredient.

Exploring novel food proteins and processing technologies : a case study on quinoa protein and high pressure –high temperature processing

Proteins originating from dry legumes are not that much used in food formulations, yet, they are interesting components from a sustainability point of view, and could have interesting functional properties, e.g. for emulsion preparation. Therefore, this work focuses on the potential of the water soluble part of pea, chickpea and lentil protein isolates under acidic emulsions (pH 3.0) using a novel mild technique: premix membrane emulsification. Pea proteins (PP) and chickpea proteins (CP) lower the interfacial tension in the same way as whey protein isolate (WPI), which suggests that they could facilitate emulsion droplet formation similarly as WPI, while lentil proteins (LP) are slightly less effective. It is possible to make oil-in-water (O/W) emulsions with an average droplet diameter (d4,3) of ~5 μm after 5 cycles in the premix system. The droplet size distribution of the emulsions remained constant during one day of storage, indicating that legume proteins are able to form and kinetically stabilize O/W emulsions. CP and PP exhibited emulsifying properties comparable to those of WPI, whereas LP is slightly less efficient, therewith indicating the great potential and that pea and chickpea protein isolates hold as emulsifiers in acidic food formulations.

Impact of interactions between soy and pea proteins on quality characteristics of high-moisture meat analogues prepared via extrusion cooking process

For several commercial plant-protein stabilisers, we investigated how surface shear and dilatational properties affect dynamic emulsion stability under high bulk shear conditions. Potato protein isolates Potato-1 (rich in patatin) and Potato-2 (rich in protease inhibitors) showed a stiffer, more solid-like response than soy and pea protein isolates in large amplitude oscillatory surface shear. Soy protein isolates had the weakest interfaces and showed a more liquid-like behaviour. Potato-2 had the highest stiffness and most brittle interface in large amplitude oscillatory dilatational deformations. It also showed more significant softening, evident from both the shear and dilatational Lissajous plots. Only the Potato-1-stabilised emulsion was stable against coalescence at high bulk shear (although that emulsion was unstable against flocculation because of its low zeta potential). The low stiffness imparted to the interface by the pea and soy protein isolates was not suitable for preparing emulsions with high dynamic stability. In the linear regime, both Potato-1 and Potato-2 produced interfaces with similar surface shear moduli, and in dilatation, Potato-2 gave a higher modulus. The lower stability of the Potato-2 emulsions appears to be linked to the higher brittleness and stronger softening effect for increasing deformation amplitude. Both in surface shear and dilatation, the maximum linear strain for the Potato-1-stabilised interface is larger. The lower maximum linear strain and stronger softening effect at high deformations for Potato-2 may have resulted in more disruption of the interfacial microstructure, and this induced (partial) coalescence.