Lactic acid (LA) is a high-value chemical with growing demand for the production of polymers and plastics and in the food and pharmaceutical industries. However, production costs remain a significant constraint when using conventional food-grade substrates. This study investigates Ivorian sugarcane molasses, an abundant agro-industrial by-product, as a low-cost carbon source for LA production via batch fermentation with Limosilactobacillus fermentum ATCC 9338. Molasses was pretreated by acid hydrolysis to improve fermentability, increasing glucose and fructose concentrations. Comparative fermentations using raw and pretreated molasses showed a 75% increase in LA production (32.4 ± 0.03 g/L) after pretreatment. Optimisation using Box–Behnken design revealed that the initial sugar concentration, inoculation rate, and stirring speed significantly influenced lactic acid production. Under optimal conditions, a maximum LA concentration of 52.4 ± 0.49 g/L was achieved with a yield of 0.95 g/g and productivity of 0.73 g/L·h. Kinetic analysis confirmed efficient sugar utilisation under the optimised conditions, and polarimetry revealed a near-racemic lactic acid. A simplified cost analysis showed that molasses could reduce carbon source costs by over 70% compared to refined sugars, supporting its economic viability. This work demonstrates the potential of pretreated molasses under robust fermentation conditions as a sustainable and cost-effective substrate for LA production in resource-limited contexts. The approach aligns with circular bioeconomy principles and presents a replicable model for decentralised bioproduction in a developing country like Côte d’Ivoire.

Côte d’Ivoire, the global leader in cashew nut production, largely abandons cashew apples after harvest. Similarly, sugarcane molasses, a by-product of sugar production, is underutilized. This study proposes an innovative method to valorize these two agricultural residues by producing lactic acid using the bacterium Lactobacillus casei NRRLB-441. The approach combines cashew apple juice and sugarcane molasses to create an optimized culture medium, offering promising economic and ecological opportunities. To achieve this, an I-optimal mixture design was implemented, with cashew apple juice proportions ranging from 50% to 90%, and sugarcane molasses from 10% to 50%. An experimental matrix of 13 trials, based on the Scheffé model, was developed to determine optimal combinations and measure lactic acid yields. This approach aims to maximize the utilization of these agricultural residues while providing promising economic and environmental prospects. Biochemical and mineralogical analyses revealed that cashew apple juice and sugarcane molasses are rich in glucose (82.78 g/L), fructose (66.65 g/L), and minerals (calcium, magnesium, iron, sodium, and potassium). The results showed a significant lactic acid concentration (78.57 g/L) when cashew apple juice and sugarcane molasses are in equal proportions (50%), with a yield of 69.22% and a productivity of 1.09 g/L/h. These findings confirm the bio-convertibility of these agro-resources into other economically significant products such as lactic acid, citric acid, and bioethanol.

In Côte d'Ivoire, most cashew apples remain unprocessed due to their astringency and certain taboos. These taboos suggest that consuming cashew apples with milk is considered incompatible. This study aims to characterize cashew apple wine enriched with Hibiscus sabdariffa calyxes. Three formulations incorporating Hibiscus calyxes were assessed for their physical, biochemical, and mineral composition. Color intensity analysis using a spectrometer revealed that wine formulations 1 and 2 exhibited superior color intensity at 6.109 and 6.531 nm, with polyphenolic compound content ranging from 0.940 ± 0.086 to 1.06 ± 0.529 g EAG.L-1. Antioxidant activity, as determined by ABTS inhibition rate, ranged from 31.86% to 38.42%. Inductively coupled plasma analysis indicated a variety of minerals, with potassium (2548.494 to 2962.914 mg/L), sodium (1153.265 to 1260.049 mg/L), and calcium (1649.299 to 1749.172 mg/L) being the most abundant. No heavy metals, such as lead or cadmium, were detected. The resulting cashew apple wine formulations exhibited a diverse nutritional profile.