Postharvest Proximate and Mineral Compositions of Orange-Fleshed Sweet Potato Treated with Different Concentrations of Calcium Chloride

Abstract

Freshly harvested orange-fleshed sweet potato (OFSP) starts deteriorating after about one week of storage, unless treated, even at 18°C.  Postharvest chemical treatment has been found to prolong the shelf-life of the root. In this study, treatment with different concentrations (1, 2, 3, 4,  5 and 6 %) of CaCl₂ were used to investigate the effect of storage time (0,2 and 4 weeks) on the proximate and mineral contents of UMUSPO 3  variety of OFSP in triplicates. Results showed that among the different concentrations, 4 % had more positive effect on the OFSP root minerals (Ca,  Na, Mg, P, K, Zn) compositions which were significantly different ≤(P 0 .05) between 0 -2 weeks, and 0- 4 weeks of storage but was not scientifically  different between week 2 and week 4. Also, the minerals were significant ≤(0P.05) between CaCl₂ concentrations. While, in all the proximate analysis  significant (P≤0.05) difference was found. The effect of CaCl₂ concentrations did not negatively affect the proximate and mineral  compositions despite the level of concentrations. It could be deduced that minimal deterioration occurred at the cell wall of the roots and extended  to the starchy parenchyma regions as a result of CaCl₂ applications. The high retention of stored OFSP (UMUSPO 3) quality could be as a result of  the accumulation of Ca in the cell walls which led to facilitation in the cross linking of the pectic polymers that increases the wall strength and cell  cohesion. Finally, postharvest application of 4 % of CaCl₂ is advisable to farmers in storing and maintaining a healthy and nutritious OFSP roots for  consumptions.