Changes in Physicochemical Parameters during Storage of the Inflorescence Sap Derived from Four Coconut (Cocos nucifera L.) Varieties in Côte d’Ivoire
Konan N’guessan Ysidor *
Laboratory of Biochemistry and Food Sciences, Department of Biosciences, University Felix Houphouët-Boigny, Côte d’Ivoire and 2Marc Delorme Research Station for Coconut, National Agronomic Research Center (CNRA), Côte d’Ivoire.
Konan Konan Jean-Louis
Marc Delorme Research Station for Coconut, National Agronomic Research Center (CNRA), Côte d’Ivoire
Konan Brou Roger
Laboratory of Food Biochemistry and Technology of Tropical Products, Department of Food Sciences and Technologies, University Nangui Abrogoua, Côte d’Ivoire.
Assa Rebecca Rachel
Laboratory of Biochemistry and Food Sciences, Department of Biosciences, University Felix Houphouët-Boigny, Côte d’Ivoire.
Okoma Djeya Muriel Joelle
Marc Delorme Research Station for Coconut, National Agronomic Research Center (CNRA), Côte d’Ivoire
Issali Auguste Emmanuel
Marc Delorme Research Station for Coconut, National Agronomic Research Center (CNRA), Côte d’Ivoire
Biego Godi Henri Marius
Laboratory of Biochemistry and Food Sciences, Department of Biosciences, University Felix Houphouët-Boigny, Côte d’Ivoire.
*Author to whom correspondence should be addressed.
Abstract
Aim: The study investigated the changes in the main physicochemical parameters of the coconut inflorescence sap derived from MYD, WAT, PB 121+ and PB 113+ varieties during storage.
Place and Duration: Marc Delorme Research Station for coconut, National Agronomic Research Center, Abidjan, Côte d’Ivoire, between March and May, 2013.
Methodology: The coconut sap was collected from six coconut trees per variety, and then a sample for each variety was constituted by mixing the collected saps. Three samples of the coconut sap from each variety, each collected on a different day (repeated on three days of collection), were stored at 35±2°C. Then 10 parameters were assessed during 120 h (5 days) of storage.
Results: The results showed a significant effect of the storage duration upon the whole parameters. Specifically, important decrease was observed for the total sugars contents (from 16.08 to 0.93 g/100 mL), pH (7.32 to 4.17) and the relative density (1.055 to 1) of the coconut sap samples, without any differentiation between varieties. Also, the total soluble solids and the dry matter contents dropped respectively from 16.31 to 3.82% and 16.47 to 3.09 g/100 g. On the other hand, significant increases were recorded with the total titrable acidity (from 0.26 to 1.85 g/100 g) and the tannins contents (from 5.65 à 13.2 mg/L). Concerning reducing sugars and proteins, partial increasing of their contents (6.60 to 8.29 g/100 mL and 2.34 to 2.84 g/100 mL, respectively) was recorded after 24 hours of storage. The total polyphenols contents reached peaks of 606.84 mg/L to 1316.24 mg/L after 36 h, before decreasing. The WAT differed from the three other varieties with the highest content of total polyphenols and tannins during the 120 hours of storage.
Conclusion: The study evidenced similar changes in the physicochemical traits during 5 days of natural fermentation of the sap of different coconut varieties. The sap remained stable during the earlier 12 hours of storage, but up to 5 days the main nutrients were spoiled.
Keywords: Coconut sap, varieties, storage, fermentation, sugars