Biochemical and Functional Properties of Yam Flour during the Post-harvest Conservation of Dioscorea alata Cultivar « Azaguié »

Aims: To be follow the biochemical and functional properties of yam flour during the post-harvest conservation of yam « Azaguié » (Dioscorea alata) tubers.

Study Design: Analysis of variance (ANOVA) was carried out in this work.

Place and Duration of the Study: Food Science and Technology Training and Research Unit, Nangui Abrogoua University, Abidjan, Côte d’Ivoire, from December 2014 to February 2016.

Methodology: The yam tubers stored after harvest in a warehouse were kept for 6 months. Tubers were randomly taken for the preparation of flour every two months. Flours were obtained after grinding and sieving the pulp pieces and dried at 45°C for 48 h. Thereafter, the biochemical and functional analyses were performed on these different flours.

Results: except for the lipid contents, all biochemical properties that were measured vary significantly (P ≤ 0.05) with post- harvest conservation time of the yam tubers. Dry matter, total sugars and reducing sugars increased. By cons, protein, phenolic compound, ash and minerals (calcium, copper, potassium, magnesium and zinc) decreased with post- harvest conservation time of the yam species tubers. With regard to functional properties studied, water absorption capacity (WAC), oil absorption capacity (OAC) and wettability increased significantly (P ≤ 0.05) with post-harvest conservation time of the yam tubers. However, the water absorption index (WSI), hydrophilic lipophilic index (HLI), bulk density, foaming capacity and foam stability decreased significantly (P ≤ 0.05) during post-harvest conservation of yam tubers.

Conclusion: This study shows the importance of post-harvest conservation time of the yam tubers in the use of these categories of flours in food technology.