To test for starch and glucose in maize meal suspension after heated up for 20 minutes does the meal need to have heat during testing

For the starch test (using iodine solution): No, the meal suspension does not need additional heat during the testing phase. The iodine solution reacts with starch at room temperature, producing a blue-black color if starch is present.

For the glucose test (using Benedict's solution): Yes, the meal suspension does need heat during the testing phase. After adding Benedict's solution, the mixture must be heated (usually in a hot water bath) for the reaction to occur and for any color change (from blue to green, yellow, orange, or brick-red) to indicate the presence of reducing sugars like glucose.