Some Quality Indices of Gnetum Africanum (Afang) Leaves as Affected by Drying Methods

Abstract

Gnetum africanum is a tropical plant with origin in the rain forest of Nigeria and contains valuable nutrients but susceptible to speedy spoilage due to its high moisture content. This necessitates its preservation, through drying, as it is not readily available for consumers in parts of Nigeria where it is not grown. This research, therefore, was carried out to evaluate the effect of three drying methods (solar drying, sun drying and oven drying) on some quality indices of Gnetum africanum leaves with a view to determine the most appropriate drying method for maximum nutrient retention. Fresh Gnetum africanum leaves were obtained from the local market, defoliated, washed, drained and sliced. The sliced vegetable was divided to four portions of 200g each. With the initial properties of the fresh vegetable (sample A) determined, samples B, C and, D were subjected to solar, sun and oven drying respectively. The properties evaluated were analyzed and the results showed that sun dried vegetable (sample C) had the least overall quality retention. Moreover, solar dried vegetable (sample B) had the highest quality retention in terms of protein (3.92%), fat content (6.67%) and carotene (6.10IU) while oven dried one (sample D) had the highest quality retention of crude fiber (0.63%), ash content (7.87%), carbohydrate (72.49%) and sensory properties (taste, colour, aroma and texture). These results indicated that drying, especially solar and oven drying can be used to preserve Gnetum africanum leaves with considerable retention in its nutritional and sensory properties.

Keywords

• Gnetum africanum;
• Drying;
• Drying methods;
• Nutritional properties
• Sensory properties