Mixed gels formed by casein and pea protein: structure and interactions

• Ano de defesa: 2023
• Autor(a) principal: Silva, Raiane Rodrigues da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa; Ciência e Tecnologia de Alimentos
• Palavras-chave em Português: Caseína; Proteínas vegetais; Hidrogéis; Raios X; Ervilha; Ciência e Tecnologia de Alimentos
• Link de acesso: https://locus.ufv.br//handle/123456789/31941; https://doi.org/10.47328/ufvbbt.2023.469

Protein hydrogels are responsible for the structure of various types of food products. The wide variety of products available is made possible by the ability to modify proteins, facilitated by factors such as pH, temperature, and ionic strength. These modifications allow proteins to interact with themselves or with proteins of different origins. However, many times the association of different types of proteins may not occur in synergism, modifying the structure of the gel. Due to this, it is necessary to study to understand the interactions responsible for the structuring of the different protein gels and the structural differences caused by the incorporation of different proteins in the same system. Thus, this dissertation aimed to understand the structure and interaction of mixed gels formed from casein and pea protein. When initially analyzing the suspensions containing different proportions of casein and pea protein, it was observed that the proteins have a preference for forming isolated systems. However, when applying heat treatment, the interactions between proteins increased, but only among those from the same source. In the formation of hydrogels through the acidification of the system, it was observed that the interactions between proteins of the same origin were more evident compared to the interactions between proteins of different origins. With the application of heat treatment before the acidification process, pea proteins were more affected than caseins, making the gels with higher amounts of pea protein even stronger due to pea-pea interactions. Through analyses using temperature variation, the gels formed by acidification were studied concerning their structure and interactions. It was possible to conclude that gels consisting mostly of casein are more sensitive to temperature changes, presenting less strong interactions. On the other hand, gels formed by pea protein are less sensitive to temperature changes and have strong interactions. Additionally, it was observed that the substitution of 20% casein can result in several changes in the gel structure, such as the approximation of protein chains, favoring interactions, and conferring new characteristics to mixed gels. However, proteins of different origins still have a preference for interacting with proteins of the same origin, forming independent systems. Therefore, future studies are necessary to increase the interaction between these proteins and promote the formation of new systems, enabling the application of these gels in the formulation of new products. Keywords: Casein. Pea protein. USAXS. Chemical interactions. Mixed gels.