Mathematical Modeling of Lactobacillus paracasei CBA L74 Growth during Rice Flour Fermentation Performed with and without pH Control

Abstract

The mathematical modeling of fermentation processes allows for the formulation of predictions about the kinetics of biomass growth and metabolite production as well as setting or verifying the best operative conditions in view of the economical convenience of the process. For this purpose, we performed a kinetic study of a rice flour fermentation process using Lactobacillus paracasei CBA L74 with and without pH control; the pH value was set to 5.8 under pH control. Monod, Logistic, and Contois models were proposed to describe the bacterial growth rate in both conditions. The best mathematical model, which was able to describe the experimental data obtained without pH control, was the Contois model, as the specific growth rate was influenced by both the glucose reduction (from 14.31 g/L to 10.22 g/L) and the biomass production (2 log growth) that occurred during fermentation. Conversely, when pH control was implemented, both Monod and Contois models satisfactorily described the specific growth rate trend. The estimated kinetic parameters confirmed that biomass production (2 log growth) and glucose consumption (from 14.31 g/L to 6.06 g/L) did not affect the microorganism’s growth capacity when the fermenting medium was maintained at an optimal pH. The lactic acid production rate described by the Luedeking–Piret model did not appear to be linked to growth in the absence of pH control while, on the other hand, this model was unsuitable for describing the experimental lactic acid concentration when pH control was applied. The kinetic modeling of lactic acid production and the percentage of added glucose in the protocol with controlled pH will be optimized in the future.

Banana Puree Lactic Fermentation: The Role of Ripeness, Heat Treatment, and Ascorbic Acid

“…Most of these types of functional foods are dairy-based products [20][21][22], but products of a different nature are also on the rise. The ability of the bacterial strain that was used in the present study to ferment food matrices, such as cereals and legumes, has previously been demonstrated [17,[23][24][25][26][27][28][29], and its probiotic activity has also been confirmed in previous studies [30][31][32][33]; in the present work, its ability to ferment an industrial product, such as banana puree, was investigated. Banana, both as a fresh or processed fruit, is one of the most consumed fruit crops worldwide, starting from infancy.…”

Functional Properties of an Oat-Based Postbiotic Aimed at a Potential Cosmetic Formulation

“…Conversely, th mum bacterial load of 9.48 log (CFU/g) found by controlling pH was similar achieved during the uncontrolled pH process (9.74 log(CFU/g) [28]. Furtherm demonstrated by Colucci Cante et al [34], pH control allows the microorganism t a better duplication capacity and improved kinetic performances.…”

“…The fermentation process was carried out on a hydrolyzed oatmeal suspension under controlled conditions of temperature and pH, previously identified as optimal for LP's growth and its metabolic activity [34,35], and a subsequent mild heat treatment was performed to achieve the microbial inactivation. The effect of each single process step on selected functional properties of interest, as lactic acid concentration, total polyphenol content, antioxidant activity, anti-tyrosinase activity, and photoprotection activity (Sun Protection Factor, SPF, estimation) was investigated to confirm the potential of the resulting oat-based postbiotic.…”

Gut health benefits and associated systemic effects provided by functional components from the fermentation of natural matrices

“…(2019) and Colucci Cante et al. (2021) studied the impact of controlling pH at an optimal value of 5.8 on the growth kinetics and the lactic acid production during a rice flour fermentation process using Lacticaseibacillus paracasei CBA L74.…”