Physicochemical, Microbiological and Sensory Characterization of Juice Produced from Watermelon (Citrullus lanatus) Consumed in Côte d’Ivoire

Abstract

Watermelon (Citrullus lanatus) is one of the most commonly consumed tropical fruits by humans, especially Ivorians. The present study was initiated to evaluate the physicochemical, microbiological and sensory properties of watermelon juice produced in an artisanal way. For this purpose, the effect of pasteurization (82°C for 20 s) and storage (8°C for four days) on different parameters were evaluated. The pH decreases from 4.83 to 3.78 (unpasteurized juice) and from 5.13 to 3.84 (pasteurized juice), the acidity increases from 0.09 to 0.34 g/L (unpasteurized juice) and from 0.09 to 0.25 g/L (pasteurized juice), the Brix values drop from 5.95 to 4.65°B (unpasteurized juice) and from 6 to 4.80°B (pasteurized juice), and the dry matter and reducing sugars respectively varied from 4.49 to 2.12%, 0.069 to 0.06% (unpasteurized juice) and from 5.25 to 2.21%, 0.064 to 0.06%. No change was observed in the ash content in the two juices. It varied from 0.32 to 0.08%. Regarding vitamin C and lycopene, the average contents were respectively 7.57 g/mL and 0.055 mg/100 mL (unpasteurized juice) and 2.45 g/mL and 0.047 mg/100 mL (pasteurized juice). Microbiological analyzes of unpasteurized and pasteurized juices have shown the absence of coliforms and staphylococcus aureus. However, the number of mesophilic aerobic germs is lower than that of the standard. The sensory test shows that watermelon juice products have a good acceptance by the panelists. Finally, this study showed that heat treatment influences the antioxidant content and not the physicochemical parameters and ensures a healthy juice. Keywords: