Improving the sensorial properties of pea protein through fermentation

Abstract: Lactic acid fermentation has been a widely used process for many years, offering nutritional and sensory benefits to plant proteins. In this study, the objective was to produce a fermented pea powder with enhanced sensory properties by combining previous research from FrieslandCampina. A screening was performed on a set of cultures obtained from a contract research organization (CRO), starter Culture A, Culture B and Culture C. The best combination was determined based on the volatiles obtained from GC analysis, pH kinetics, and their effects on physicochemical and sensorial properties, with the Culture B being the most suitable. Pre-treatments such as pasteurization and the combination of pasteurization and homogenization were used, and the intensity of stirring during fermentation was found to play a crucial role in the physicochemical properties of the pea protein medium. After that the product was again homogenized and pasteurized, with viscosity measurements taken for each process. SDS-PAGE analysis showed signs of albumin hydrolysis. By comparing the reference with the fermented protein chemically, there is a major drop in the protein level, while glycose was mostly utilized for the growth of microorganisms. Sodium and potassium displayed a huge increase due to the caustics used for neutralization. GC analysis was performed in various stages of the process, to determine the volatile compounds and the effect of each process stage. Overall, fermentation had a huge impact on the volatile compound profile, reducing the off flavors of the pea protein. Spray drying mitigates some compounds and increases the levels of hexanal. The use of a lower inlet temperature during spray-drying resulted in decreasing the levels of benzaldehyde. Comparing the proteins that were developed in this experiment with the protein that was developed in CRO they had enhanced volatile profiles. However, during the sensory analysis, the CRO protein was preferred. This is due to the fact of the caustics’ effect that were used during neutralization. From that experiment a process diagram is proposed. Further research needs to be done for the combination of caustics that should be used for neutralization, the optimization of the production process, reduction of the fermentation time and the increase of the production yield.