Refrigeration Storage Effect on Nutritive Value and Antioxidant Properties of Five Leafy Vegetables Consumed in Northern Cote d'Ivoire (Ivory Coast)

摘要

Storage and processing technologies have been utilized for centuries to prevent post harvest losses of vegetables and to transform them into safe, delicious and stable products. The aim of this study was to evaluate the effect of refrigeration storage (4℃) on the nutritional value of five leafy vegetables (Hibiscus sabdariffa, Amaranthus hybridus, Andasonia digitata, Vigna unguiculata and Ceiba patendra) that are consumed in Northern Cote d'Ivoire. The selected samples were subjected to storage at 4℃ for 5, 10 and 15 days and the physicochemical properties were determined using standard methods. Fresh selected samples were used as the control. The result of the study revealed that increased storage time affected the nutritional value of the selected leafy vegetables. The registered losses at 15 days of refrigeration storage were as follow: ash (2.41-9.70%), proteins (5.66- 18.97%), vitamin C (11.43- 41.29%), carotenoids (25.44- 41.29%), oxalates (12.43- 14.55%), phytates (35.03- 44.10%). It was observed an increase (0.17- 2.41%) in total phenolic content during storage. In addition, a small increase (0.88- 2.66%) of fibres content was also observed in the studied leafy vegetables stored under refrigeration at 4℃. Furthermore, after 15 days of storage at 4℃ the residual contents of minerals were: calcium (308.30- 858.75mg/100g). Magnesium (213.64- 610.14 mg/100g), potassium (565.32-1844.08 mg/100g), iron (49.29- 160.53 mg/100g) and zinc (17.95-34.06 mg/100g). The result of the present study suggests that vegetables should be stored in cold storage for a short time (less to five days) in order to avoid loss of essential nutrients.