Pulse Protein Isolates as Competitive Food Ingredients: Origin, Composition, Functionalities, and the State-of-the-Art Manufacturing

Abstract

The ever-increasing world population and environmental stress are leading to surging demand for nutrient-rich food products with cleaner labeling and improved sustainability. Plant proteins, accordingly, are gaining enormous popularity compared with counterpart animal proteins in the food industry. While conventional plant protein sources, such as wheat and soy, cause concerns about their allergenicity, peas, beans, chickpeas, lentils, and other pulses are becoming important staples owing to their agronomic and nutritional benefits. However, the utilization of pulse proteins is still limited due to unclear pulse protein characteristics and the challenges of characterizing them from extensively diverse varieties within pulse crops. To address these challenges, the origins and compositions of pulse crops were first introduced, while an overarching description of pulse protein physiochemical properties, e.g., interfacial properties, aggregation behavior, solubility, etc., are presented. For further enhanced functionalities, appropriate modifications (including chemical, physical, and enzymatic treatment) are necessary. Among them, non-covalent complexation and enzymatic strategies are especially preferable during the value-added processing of clean-label pulse proteins for specific focus. This comprehensive review aims to provide an in-depth understanding of the interrelationships between the composition, structure, functional characteristics, and advanced modification strategies of pulse proteins, which is a pillar of high-performance pulse protein in future food manufacturing.

Keywords: composition; food application; functional property; non-covalent complexation; physical modification; pulse protein; structure–property relationship.

Figure 1

(A): The annual production quantity of pulse crops worldwide from 1961 to 2020 (FAO, 2020); (B): The distribution of bean production worldwide in 2020; (C): The distribution of pea production worldwide in 2020 (data obtained from Our World in Data, https://ourworldindata.org/, accessed on 17 July 2023).

Figure 2

Diagram of the crystal structure of pea globulin from the PDB database (http://www.rcsb.org/pdb, accessed on 17 July 2023); (A): legumin (PDB entry: 3KSC); (B): vicilin (PDB entry: 7U1I); (C): convicilin (PDB entry: 7U1J).

Figure 3

(A): Solubility of protein isolates under different pH; (B): Foam property (i.e., foam volume vs. time) of protein isolates. ■: White lentil protein isolate, □: Yellow lentil protein isolate, ●: Green mung bean protein isolate, ○: Yellow mung bean protein isolate, ◆: Soybean protein isolate, ◇: Commercial soybean protein isolate, ▲: Pigeon pea protein isolate, △: Cowpea protein isolate, ◊: Yellow pea protein isolate, -: Chickpea protein isolate [27]. Reproduced with permission from the copyright owner, published by Elsevier, 2021.

Figure 4

Antihypertensive mechanism (A), anticancer mechanism (B), and antidiabetic mechanism (C) of pulse bioactive peptides [78]. Reproduced with permission from the copyright owner, published by KLUWER ACADEMIC PUBLISHERS (DORDRECHT), 2021.

Figure 5

Main applications of pulse protein isolates in food industry [38].

Figure 6

Simplified reaction process of various chemical modifications. (a) Acylation; (b) Phosphorylation; (c) Amidation; (d) Esterification; (e) Glycation (Maillard reaction) [9]. Reproduced with permission from the copyright owner, published by INSTITUTE OF FOOD TECHNOLOGISTS, 2021.

Figure 7

Schematic of the effect of physical modification (ultrasonication, cold plasma, pulsed electric fields, and high hydrostatic pressure) on pulse protein conformation. p = pressure, c = concentration [16]. Reproduced with permission from the copyright owner, published by Elsevier, 2023.

Figure 8

The schematic of pulsed electric field modification applied to enhance EGCG-binding capacity of pea protein isolate [111]. Reproduced with permission from the copyright owner, published by Elsevier, 2023.