Assessment of Changes in Beta-carotene Content and Sensory Attributes of Two Sweet Potato Varieties as Influenced by Organic and Inorganic Fertilizers and Storage Methods

Two field experiments were conducted at two seasons at the research fields of the University of Education, Winneba-Mampong campus from September, 2011 to January, 2012 and April to July, 2012 to assess changes in beta-carotene content and sensory attributes of two sweet potato varieties (Okumkom and Apomuden) grown under organic and inorganic fertilizers and three different storage methods in Ghana. Cooked samples of the harvested sweet potato roots were evaluated for their sensory attributes. In the storability studies, the harvested roots were sorted, cured and stored under three storage methods for 3 months. The beta- carotene changes in the stored roots were assessed. There was a significant difference (p<0.05) between Apomuden and Okumkom grown under amendment and the control in beta-carotene content at harvest and in pit store in both seasons. The beta- carotene content of Apomuden increased by 15-30% in pit store during the minor season than at harvest. Both varieties grown under amendment and the control and stored in pit was the most effective storage method in terms of beta-carotene over ash and grass storage in both seasons. There was a significant difference (p<0.05) between Okumkom and Apomuden in root texture and palatability at harvest and after cooking during the minor season. Apomuden differed significantly (p<0.05) from Okumkom in root colour and flavour at harvest and after cooking during the major season. The application of 30-45-45 kg/ha NPK to both varieties was more acceptable with regard to root taste, colour and palatability than the other treatments during the minor season.