Effect of Cell Wall Neutral Sugars and Uronic Acid Compounds on Cassava (Manihot esculenta Crantz) Retting Ability

Aims: Evaluate the effect of cassava cell wall neutral sugars and uronic acids on the ability of cassava to be retted by a traditional starter (sta_96).

Place and Duration of Study: Sample: collected from a farm in the Center region in Cameroon. All the analysis were performed at the Department of Microbiology of the University of Yaounde 1 in Cameroon, between June 2024 and December 2024.

Methodology: height (08) different local cassava varieties 12 months aged were submitted to fermentation with Sta_96 and their retting kinetic parameters (retting rate and retting times) were assessed by penetrometry. Furthermore, their parietal compounds (neutral sugars and uronic acids) and non-parietal compounds (reducing and total sugars) were analyzed by spectrophotometry and the data obtained were submitted to correlation analysis.

Results: It was observed that the roots of the VB 3, CB 1, CB 2, sweet, 6M, and CR varieties softened more easily, with fermentation rates ranging from 1.04 ± 0.88 to 1.75 ± 0.23 cm/h and retting times ranging from 42.64 ± 7.07 to 50.64 ± 0.44 h. The roots of the VB 1 and VB 4 varieties softened with greater difficulty. Negative correlations (-0.79 and -0.881 respectively for neutral sugars and uronic acids) were observed between neutral sugars, uronic acids and softening rate, suggesting that these compounds increase cassava’s retting time by decreasing it fermentation rate. This study shows that the cassava’s softening ability is linked to the neutral sugars and uronic acids content in cassava root walls.

Conclusion: Taking into account the cell wall composition in the formulation of starters can lead to a standardization of the cassava roots retting time.