Dados do Trabalho

Título

EVALUATION OF THE TECHNO-FUNCTIONAL PROPERTIES OF COWPEA PROTEIN ISOLATE SUBJECTED TO DIFFERENT PHYSICAL TREATMENTS

Introdução

Pea protein isolates have been widely used as ingredients in the food industry. However, beans are underexplored in terms of their technological potential, despite the large number of species consumed in Brazil. Therefore, this study determined some techno-functional properties of cowpea protein isolate (IPC) obtained through different treatments.

Material e Métodos

The cowpea protein isolate was obtained by solubilization and precipitation of the protein fraction using established procedures. IPC suspensions (20%, w/v) underwent thermal treatments (80 and 100 °C for 15 minutes) or ultrasound (40 kHz for 15, 30, and 45 minutes). Subsequently, techno-functional properties were evaluated. Mean results were analyzed using analysis of variance (ANOVA) and compared using Tukey's test (p ≤ 0.05).

Resultados e Discussão

The untreated IPC showed an Emulsifying Activity Index (IAE) of 39.9±1.7 m²/g, with stability of 40.4±1.4 minutes. IPCs treated with ultrasound maintained the emulsion activity (28.3±0.4 m²/g, 41.3±1.6 m²/g, 39.5±1.19 m²/g for treatments of 15, 30, and 45 minutes, respectively). The 45-minute treatment notably increased emulsion stability by 50%. IPC treated at 80 °C maintained emulsification capacity (27.4±1.0 m²/g) but suffered a considerable 70% loss in stability. Conversely, treatment at 100 °C resulted in total loss of this property. The untreated IPC had a foam formation capacity of 269.4±3.4%, with stability exceeding 70% after 1 hour. IPC treated with ultrasound for 45 minutes increased foam stability to 82% after 1 hour, whereas thermal treatments at 80 and 100 °C impaired both capacity and stability (66% and 57%, respectively). There was an increase in hydrophobic surface area (between 28% and 43%) in all treatments compared to the control IPC, suggesting protein denaturation in all treated samples. However, the denaturation caused by thermal treatment was detrimental to the functional properties of a protein ingredient, which is significant given that this method is often used to deactivate antinutritional factors, something that needs to be studied with ultrasound.

Conclusão

Thus, the results suggest the potential use of ultrasound as an effective method to enhance the stability of emulsions and foams formed by IPC, thereby optimizing the functionality of protein ingredients.