Starch Lab Report

1016 Words 5 Pages
In experiment 2.1, absorbance readings for both heated and unheated corn and tapioca starch were taken. For both starch’s the heated results came to be much higher then the un-heated as seen in Table 2.1. Iodine reacts with the amylose compound in starch where it gets trapped in the amylose coils and blue-ish colour is formed after the addition of Lugols reagent (Fennema and others 2008). The absorbance readings came out higher for heated corn starch because iodine had more amylose to react with. As corn-starch is heated gelatinization occurs where amylose is released since the starch granule is disrupted. With absorbance readings 0.100 and 0.013 implications that amylose is located in starch granules are clear but still can be available …show more content…
This used the already gelatinized starch from Experiment 2.1, where amylase is 25% present. The production of saliva, is when α-amylase is secreted to start the digestion process (Bailey and Howard 1963). Glucose, maltose, malotriose are all low molecular weight products that that are formed through hydrolysis of amylase of internal α-1,4 and α-1,6-glycosidic linkages (Fenemma and others 2008). Through gelatinization both amylose and amylopectin are realised making it easier for α-1,4 and α-1,6-glycosidic linkages to hydrolyze to form glucose products (Rogers 2015). With the formation of glucose and addition of Benedict’s solution hydrolysis occurred and there was formation of reducing sugars (Fenemma and others 2008). The presence of reducing sugars led to colour change in the test tube with amylase solution. An error that may have occurred in this experiment was the amount of time that the test tubes were kept in the water bath. The manual stated to only keep the hydrolyzed solution incubated for 10 minutes but never stated how long to keep the reaction part of the experiment in the water bath for. We kept the test tubes in boiling water bath for about 15 minutes and came out with only reaction with our amylase solution. If we kept the test tubes in the water bath for a little longer the saliva may have reacted and changed colour too. 15 minutes seemed like it was not enough time for the full hydrolysis reaction to take place for saliva. The amylase in the amylase solution would be more concentrated then the α-amylase in the saliva showing that the amylase solution would have a faster reaction time then

Related Documents

Related Topics