Name: Jaroslava Baranová
Candidate number: 000771-
Examination session: May 2012
Date of elaboration: 2.2.2011
What is the effect of enzyme bromelain contained in pineapple on the process of gelatinization of gelatine?
Enzymes are proteins that speed up or catalyze chemical reactions. Gelatine consists of gelatin(84-90%),mineral salts(1-2%) and water, and is free of fat cholesterol. Gelatin is a protein produced by partial hydrolysis of collagen (structural protein found in all animals) obtained by boiling bones. It can dissolve in hot water and after being cooled forms a semi-solid gel. Pineapple belong to a group of plants called Bromeliads. Also papaya and kiwi belong to this group. They all contain proteases which are able to break down proteins. In this case, pineapple contains bromelain. It also why bromelain is used in many meat tenderizers. Thus, since gelatine is mainly consisted of protein, they are broken down by bromelain and gelatine is not able to solidify. I expect the fresh pineapple to have the best effect, because it was not heated like, e.g. canned pineapple, whose enzymes denatures during the canning process, thus will not be able to break down the proteins. Cold temperature decreases the activity of enzymes, thus I think the degree of gelatinization will be lower in comparison to fresh pineapple.
Independent variable: Different types of pineapple (fresh, canned, dried ) Dependent variable: Degree of gelanitization
Constant variables: Other enzymes contained in pineapple (acid phophatase, ananain, carboxypeptidase, cellulase, comsain, peroxidase, phosphatase), temperature of the enviroment, pH of water used on the experiment, mineral salt conatined in gelatine,
Pineapple- fresh, canned, frozen,
Gelatine (Dr.Oetker - sheets),
Pot of cold water,
1. Prepare gelatine by...