Development and Nutritional Evaluation of High-Protein Millet-Based Snack Products Fortified with Pea Protein and Soy Protein

Abstract: The purpose of the current study was to develop high-protein millet-based snack products fortified with pea protein and soy protein. Millet is well known for its high dietary fiber and mineral contents; however, it has relatively low amounts of bioactive compounds and poor protein quality which can be improved by incorporating complementary plant protein sources. Therefore, the objective of the study was to use millet flour as the base ingredient and add varying levels of pea protein and soy protein to produce high-protein, nutritionally-enhanced millet-based snack formulations. Four fortified treatment formulations were developed and tested along with a control formulation for both the physical and functional characteristics (e.g., bulk density, hardness, water absorption capacity, and oil absorption capacity) and the sensory characteristics (i.e., taste, color, and appearance) of the formulations. Results from the study demonstrated a statistically significant increase in the protein content of the fortified formulations when compared to the control formulation; conversely, a statistically significant decrease in the carbohydrate proportion occurred because of the partial substitution of millet flour with the added protein ingredients. The addition of protein resulted in some changes to the physical properties (e.g., bulk density, hardness, water absorption capacity, and oil absorption capacity) of the formulations, although moderate additions of protein to the millet flour resulted in formulations with desirable textures and expansion characteristics. The results of the sensory evaluations of the formulations, which used a nine- point hedonic scale, indicated that the optimal formulation had the highest overall acceptability based on the responses of the panelists. Overall, the study demonstrates that millet-based snack products that have been fortified with both pea and soy proteins are nutritious, plant-based, high-protein snack options that have good sensory qualities and may provide opportunities for the development of functional foods.

Keywords: Pea protein, Soy protein, High-protein snack, Fortification, Nutritional evaluation, Sensory analysis