2. Methodology
2.1. Procurement of materials
The tuber of elephant foot yam (A. paeoniifolius) was procured from local market in Pondicherry.
2.2. Preparation of elephant foot yam flour
2.2.1. Pre-treatment
drained and blotted dry with a paper towel.
2.2.2. Drying process
2.2.2.1. Freeze drying
Yam slices were dried in a freeze dryer (Delvac Lyodel Shelf Freeze Dryer) for 24 h. The temperature range in which freeze drying was carried out was −30 °C to 30 °C.
2.2.2.2. Solar drying
a.
Direct solar drying
Yam slices were loaded on a direct solar dryer (LP471 Pyranometer) and dried for 8 h.
b.
Indirect solar drying
Yam slices were loaded on indirect solar dryer for 8 h (LP471 Pyranometer).
2.2.3. Grinding of flour and storage
Dried yam slices were ground in laboratory grinder and sieved through a 60 mesh screen to obtain yam flour. Samples were then stored in air tight plastic containers in a cool, dark and dry place at room temperature.