M. W. Muthee*, J. O. Anyango and J. W. Matofari
1Department of Dairy and Food Science Technology,
Egerton University, P.O Box 536, Egerton: +254705554038
*Corresponding Author: firstname.lastname@example.org
Over the recent years, there has been a change in consumption patterns. As a result, consumers are gearing towards convenience foods. This has led to the rise in demand for ready-to-eat (RTE) foods. Potato has been found to be a preferred crop for ready-to-eat foods, for instance, potato chips and crisps because of its ease of preparation and convenience. These are prepared from different varieties, and different processing methods. Research shows that processing methods and variety have an effect on the physicochemical properties such as the size and structure of the starch, gelatinization temperatures, viscosity and starch composition, which affects starch digestibility which is a nutritional quality parameter. Starch digestibility influences the glycaemic index (GI) of foods, which is an indicator of the potential of a food to raise blood glucose. RTE foods in Kenya have been found to have a high glycaemic index (>70%)which may be associated with the high type 2 diabetes prevalence in Kenya (5.6%), where potato is the third most consumed staple crop. Nyandarua County, being a major producer and consumer has a high type 2 diabetes prevalence at 10.8%. Different ready-to-eat potato products exhibit different glycemic responses once consumed since processing methods employed affect the amount of resistant starch formed, rate and extent of starch digestibility, and amylase inhibition. Continued intake of high GI foods has been reported to increase the risk of contracting cardiovascular diseases and conditions such as type 2 diabetes and obesity. Boiled and mashed potatoes have been found to have a higher glycaemic index, 78% and 70% respectively. Fried potatoes have been found to have high resistant starch (7%) as a result of formation of amylose-lipid complexes which hinder enzymatic digestion, hence reduced starch digestibility. However, there is limited information on the effect of combining a particular variety and processing method.
Keywords: Nyandarua, ready-to-eat, potato, starch digestibility