The global demand for protein is increasing year by year. At present, about one billion people in the world cannot obtain enough protein. In order to meet this demand, it is very meaningful to use vegetable protein to partially replace animals. Compared to animal proteins, plant proteins exhibit environmental friendliness, sustainability, ethical selectivity, and a more balanced amino acid composition. Likewise, high yield and low living environment requirements are also a major advantage of soy protein replacing animal protein. Pea is the second most important legume crop, and its annual output is second only to soybean. Pea protein is hypoallergenic and has a balanced amino acid ratio, making it the preferred vegetable protein to replace animal protein. However, the application of pea protein in food and beverage is still a difficult task for the food industry due to its inherent beany taste and processing technical characteristics.
Pea protein needs to undergo pretreatment steps before extraction, such as washing, drying, sorting, shelling or splitting, so that the extraction of pea protein is not affected by other components. Oxidation of fatty acids is the main cause of beany flavor in pea protein, and the unpleasant flavor can be removed by removing lipids in pea flour by supercritical extraction combined with solvent. Germination treatment is an effective means to improve functionality, nutritional value, processing characteristics and improve undesired flavor. Studies have shown that sprouting for longer than a day increases bean-related odors, possibly from increased lipoxygenase activity or the release of protein-bound bean-related volatiles. The fermentation process of pea can be used to improve protein digestibility, reduce anti-nutrients, and increase the bioavailability of minerals, therefore, fermentation process may also be a promising treatment method for pea.
Wet extraction is a common method for commercial pea protein at present, mainly alkaline extraction-isoelectric point precipitation. Although wet extraction can extract pea protein with sufficient purity, the natural structure and functional properties of the protein will be damaged. Therefore, it is necessary to Conduct further optimization studies. Dry extraction mainly involves two key steps, milling and air classification. Grinding is mainly to separate protein and starch by grinding pea seeds, but the grinding strength can separate starch and protein matrix, and also make starch granules be damaged, so that protein and starch cannot be separated. Air classification refers to the use of air power to separate flour according to particle size distribution to achieve the purpose of separating protein and starch, and dry extraction is green, efficient, cost-effective, and sustainable. The main disadvantage is that the obtained protein is low in purity. In addition to dry and wet extraction, there are currently mild mixed extraction methods to separate proteins. The mixed method refers to the separation of the fine components that cannot be separated layer by layer using centrifugal force or other purification methods after dry separation. Improve purity. After protein extraction, the structure, processing properties and nutritional properties of the protein can be improved by subsequent processing methods, such as fermentation, enzymatic, chemical and thermal processing.
Yellow pea protein consists of albumin (10-20%) and globulin (70-80%), pea albumin is a rich source of essential amino acids with higher nutritional value, while pea globulin has greater functional properties application value. Pea protein promotes an increase in muscle thickness, especially for those building muscle strength. In addition, pea protein exhibits specific functional benefits including solubility, emulsifying and foaming ability, stability of emulsions and foams, and gelling and film-forming ability. Incorporating pea protein into staple foods can increase the protein content of the diet and provide certain functions to the formula. Currently, the reported foods using pea protein are bread, noodles, baked goods, snacks, meat products and beverages. Although pea protein can improve certain properties of foods, such as improving the texture of snacks, making puffed snacks more crisp. However, there are still major challenges. For example, the beany smell leads to a low score of the food, and the addition of pea protein to the beverage leads to a decrease in the nutritional value, which is not suitable for long-term drinking.
Pea protein is a potential ingredient in food and beverage research. It can be added to food to supplement the protein intake in the diet, and can also impart some special properties to the food. The huge challenges are mainly sensory and functional properties. At present, some new formulas and new processes have been proposed, and preliminary results have been achieved, which can meet the requirements of food and the expectations of consumers. However, theoretical underpinning studies on the interaction between pea protein and other components in the food matrix are still lacking. Future directions mainly lie in the study of new technologies to improve the functional and sensory properties of pea protein, as well as the study of the interaction between pea protein and other components.