Formulation of Foxtail Millet Probiotic Powder Enriched with High Protein and Fibre

Abstract

Aims: The study aimed to formulate a foxtail millet probiotic powder enriched with high protein and fibre. Study Design: This was an experimental, laboratory-based study. Place and Duration of Study: The study was conducted at the Department of Dairy Microbiology, Dairy Science College, Hebbal, Bengaluru, Karnataka, India, between January 2024 and October 2024. Methodology: Foxtail millet was sterilized by autoclaving at 121°C for 15 minutes, while chia seeds and whey protein concentrate (WPC) were sterilized via autoclaving and UV treatment, respectively. Microbiological analysis for contaminants, including aerobic spores, yeasts, and molds, was performed using the pour plate method. The incorporation levels of probiotic cultures into the millet flour were optimized based on their viability. The resulting millet-probiotic powder was enriched with protein (from WPC) and fibre (from chia flour) to meet the Recommended Dietary Allowance (RDA) for these nutrients using trial and error method. The protein and fibre contents were quantified using the micro Kjeldahl method and crude fibre estimation, respectively. Statistical analyses were conducted using ANOVA, with a critical difference (CD) at a 5% significance level employed to assess the significance of differences between treatments. Results: Sterilization methods significantly reduced microbial counts in foxtail millet flour, chia flour, and whey protein concentrate. Autoclaving at 121°C for 15 minutes completely sterilized millet and chia flours, while UV-C treatment effectively sterilized WPC, reducing microbial contamination to undetectable levels. The mixed culture of Lactobacillus acidophilus LA-5, Bifidobacterium bifidum BB-12, and Streptococcus thermophilus demonstrated the highest viable counts across various inoculation levels. A 5% inoculation rate was selected for further studies due to its optimal balance of viability and resource efficiency. Whey protein concentrate (WPC) with 80.04% protein content and chia flour with 24.6% fibre were incorporated into the probiotic millet dry mix, enhancing both protein and fibre content to meet Recommended Dietary Allowances (RDA) for adults. A formulation of 74.5g foxtail millet, 68g chia flour, and 7.5g WPC per 150g was optimized, yielding 27.05g of protein (50.09% of the RDA) and 20.39g of fibre (50.99% of the RDA), resulting in a nutritionally dense and functional product. Conclusion: The sterilization methods successfully reduced microbial contamination in foxtail millet flour, chia flour, and whey protein concentrate, ensuring a safe base for probiotic inclusion. The optimized formulation, combining foxtail millet, chia flour, and whey protein concentrate, resulted in a nutritionally dense dry mix, providing 50.09% of the Recommended Dietary Allowance for protein and 50.99% for fibre. This approach demonstrates the potential for developing a functional product that enhances both nutritional value and probiotic viability.