Development of a Method to Produce Granulated Sugar from the Inflorescences Sap of Coconut (Cocos nucifera L.) in Ivory Coast: Case of Hybrid PB113+

Abstract

Aims: To develop a method for transforming inflorescences sap of coconut into crystalline sugar, with a view to diversifying coconut exploitation in Côte d'Ivoire. Study Design: The sap was extracted from inflorescences of row 8 of PB113 hybrid and harvested 03 times a day (07h, 12h and 17h). Three processes for transforming sap into crystalline sugar have been gradually tested, taking into account the quality of the sap, the temperature-treatment time combination and the physical constraints applied to the sap. Place and Duration of Studies: Marc Delorme Station for Coconut Research at the National Centre for Agricultural Research, between May 2015 and July 2016. Methodology: Six coconuts was selected from those that showed no evidence of a history of disease or pest attack. Then, in their leaf corona, the unopened inflorescences, rank 8, were used for sap extraction [12]. On each coconut tree, the sap was collected in a plastic container previously sanitized with water heated to 100°C in a boiling bath and was collected 03 times a day (07h, 12h and 17h). The collected samples were placed in an isothermal cooler before being sent to the laboratory for processing. The transformation of sap into derived products was carried out by thermal spraying of the raw material. The experiments were performed on an electric hot plate (TRIOMPH) equipped with a temperature and time regulator. Heating the sap also required a frying pan and stainless-steel spatulas. A pH meter, a 0.01 electronic precision balance (METTLER BD 202, made in USA) and a refractometer were also used to measure physico-chemical parameters of the sap before and during its transformation. Three (3) processes were tested in this study for the transformation of inflorescences sap into coconut sugar. In each process, variable time-temperature heating combinations were used. Results: Both first one’s processes tested did not produce sugar crystals. Their deficiencies were improved in the 3rd process which resulted in the clear crystallization of the sap. With this process, a first vaporization of the sap was carried out with gradually increasing temperatures up to 140°C for 30 min giving a fairly firm coconut syrup. The syrup was sprayed for a second time at 60°C for 30 minutes to obtain a massecuite, which was then destemmed, crumbled and dried at ambient temperature to provide crystalline coconut sugar. This sugar comes in the form of crystals of irregular grain size with a red coloring, similar to brown cane sugar. The results reveal that the production of 1 kg of crystalline coconut sugar requires the treatment of 6.25 L of coconut inflorescences sap. Conclusion: The extension of the method of production of crystalline coconut sugar must be encouraged and represents an important support for the development of coconut sap in Côte d'Ivoire. However, further studies must be carried out to determine the biochemical characteristics of the coconut sugar produced.