Improvement of Gelation of Peanut Protein Isolate

Abstract

Peanut protein isolate (PPI) has a variety of functional characteristics such as emulsibility, water-binding capacity, gelation, solubility, foamability, and film-forming property, so it can be used in meat products, aquatic products, baked food, dairy products, beverages, ice cream, candy, and other food treatment areas. Among them, as one of the major functional characteristics of PPI, gelation can make the protein have high viscosity, plasticity, and springiness, so that the gel formed by protein can be used as the carrier for water, flavor agents, sugar, and other compounds. Over the years, the study in this field has been the focus of food treatment research, and a majority of scholars have attached much attention to it. In order to further improve the gelation of PPI and expand its applications in the field of food treatment, modification method is often used for improvement. Physical modification (microwave, ultrahigh pressure, and other technologies) is simple, safe, and fast with low treatment costs, and it is able to maintain the nutritional value of protein to the largest extent, so it has gained popularity from the majority of scholars. There are a large number of study reports on the physical modification of peanut protein, but the study progress is slow due to the complexity of the globular structure of peanut protein. Although the functional characteristics of peanut protein can be improved in different degrees, the specific physical modification for gelation and its mechanism and other problems have not been described clearly, and thus the use of gelation of peanut protein has not been really industrialized. Therefore, it is urgent to deeply study the new technology, new methods, and related basic theories of the physical modification of peanut protein. High-pressure technology has been widely used in the modification studies of food protein (Messens et al. 1997; Wang et al. 2008; Apichartsrangkoon 2003; Molina et al. 2001, 2002; Puppo et al. 2004, 2005; Hongkang Zhang et al. 2003). Studies showed that the emulsibility, solubility, gelation, and other functional characteristics of soy protein, soy protein components, whey protein, and other protein might change due to high pressure. There are few studies on the ultrahigh-pressure modification of the functional characteristics of peanut protein, and the change laws of functional characteristics after modification and its structure-function relationship are not clear, and there is no ultrahigh-pressure modification technology suitable for deep treatment. Therefore, the author’s study team took the ultrahigh-pressure technology as the supporting point to modify the PPI and reveal the change law of its gelation and its structure-function relationship, so as to provide theoretical guidance to the deep treatment and utilization of peanut protein.