Analysing Indian Yam (Dioscorea) Varieties Based on Starch Viscosity: A Comparative Scientific Study

Abstract

Background: yam (dioscoreae) stands as a crucial crop, rich in fiber and starch, widely utilized in food and pharmaceutical industries. This research delved into three indian yam cultivars: potato, elephant yam, and cassava.

Aim: the aim of the present study is to isolate the starches from potato, elephant yam, and cassava and their viscosity properties.

Objective: to isolate starches from potato, elephant and cassava starch by using alkaline extraction. To evaluate the viscosity properties of the isolated starches using brookfield viscometer.

Methods and methodology: The three different yams cultivars viz., potato, cassava and elephant yam were processed in the present investigation for isolation of starch and % yield of obtained starch was compared. The viscosity of the yam starches of three different varieties was studied by the brookfield viscometer. The viscosity, determined by using standard type of viscometer at 100 rpm, of the starch samples of the different varieties. Potato starch exhibited the highest viscosity, trailed by cassava and elephant yam. A comparative analysis of viscosity, depicted in the plot of % starch solution versus viscosity highlighted slight differences among varieties.

Results: Starch isolation via alkali extraction method was followed by characterization for viscosity using a brookfield viscometer. Starch yield ranged from 81% to 90% on a fresh weight basis. Potato exhibited the highest starch yield at 90%, while elephant yam showed the lowest at 81%, and cassava stood at 85%. For viscosity analysis, gruels were prepared from 1%, 2%, 3%, and 4% starch solutions in distilled water. After boiling and cooling, viscosity was measured using a standard viscometer at 100 rpm, expressed in centipoise. Results indicated a clear influence of processing pre-treatment on starch properties. Viscosity varied among cultivars and was concentration-dependent. Potato starch solution demonstrated the highest viscosity at 21.6 centipoise, followed by cassava at 18.5 centipoise, and elephant yam at 16.5 centipoise, all measured at 4% concentration.

Conclusion: These findings underscore the distinct rheological characteristics of starch from different yam cultivars and highlight the potential for tailored applications in various industries.