Physicochemical, nutritional, antioxidant properties and stability monitoring of coconut (Cocos nucifera L.) water from two localities in Cameroon

Abstract

The nutritional value of a food is linked to the quality and quantity of the nutrients it contains. It offers a major advantage in establishing a food table composition (FTC) which is a tool that provides information on the quantity of nutrients contained in a food. Furthermore, certain natural beverage are not taken into account in the FTC. This is the case of the water of <i>Cocos nucifera</i> nuts, although widely consumed around the world. The aim of this study was to valorise the water of <i>Cocos nucifera</i> nuts (mature and mid-mature) to contribute to the enrichment for the cameroonian FTC. Physicochemical, nutritional and antioxidant parameters were assessed by standard methods. Physicochemical analyses showed that mid-mature nuts from Edea and Bafia, have respectively an average of 0.2 ± 0.04 and 0.19 ± 0.05 mL of water/g of nut, with soluble dry extract of 4.3 ± 0.28 and 5 ± 0.0°B for a pH of 5.01 ± 0.01 and 5.11 ± 0.0. The total titratable acidity was of 0.113 ± 0.0 and 0.117 ± 0.0 mg citric acid per 100 mL water. The mean contents of total and reducing sugars, proteins, free amino acids and lipids in the same samples were 5.49 ± 0.05 and 5.56 ± 0.04; 5.09 ± 0.6 and 4.99 ± 0.7; 0.12 ± 0.0 and 0.15 ± 0.0; 0.06 ± 0.0 and 0.09 ± 0.0; 0.07 ± 0.0 and 0.10 ± 0.0g/100 mL of water, respectively. These data showed that from mid-maturity to full maturity, there was a significant increase (p < 0.05) in pH, lipid, protein, free amino acid, and phenolic contents and decrease in water volume, total titratable acidity, total and reducing sugars contents. In general, mineral contents increased significantly (p < 0.05), while total antioxidant power decreased with maturity. As for stability, degradation processes are more intense at room temperature than in the refrigerator.