Essay About Non Enzymatic Browning And Enzymatic Browning

Non Enzymatic Browning and Enzymatic Browning
Laboratory No. 5    Class no.: HPCC 02Non enzymatic browning and enzymatic browningName: Lui Cheuk Him   IntroductionBrowning food can be desirable, as in caramelization or undesirable, as in the browning in the skin of an apple and banana. Food can have the browning process through either enzymatic or non-enzymatic processes due to sugars or enzymes. Non-enzymatic browning may follow the Maillard or caramelization pathway. When the high concentration of sugar is heat, caramelization can occurs. The Maillard reaction can provide desirable flavor for browned food. It involves the condensation of reducing sugars with free amine groups of amino acids, peptides or protein. Enzymatic browning occurs when raw unheated plant tissues are cut or peeled. Normally, the enzyme polyphenol oxidase (PPO) involves in many fruits and vegetables such as potatoes or apple. After the catalyzing the oxidation of compound in plant tissues, it would form brown melanins and may lead to wastage off raw materials. ObjectivesTo investigate the effect of sugar and amino acid on the Maillard browning reactionTo determine the enzyme activity of polyphenol oxidase (PPO) by To determine the effect of temperature on enzymatic browningMethodAs in the manualResults Experiment 1: The effect of sugar and amino acid on the Maillard browning reactionSamplesObservation (Deepest color/Choking in ascending order)Color (Deepest color→3Flavor Choking→3Glycine + FructoseBrown (3)3Glycine + GlucosePale brown (2)2Glycine + SucroseColorless (1)1Experiment 2: Determination of enzyme activity[pic 1]Experiment 3: effect of temperature on enzymatic browning[pic 2]Temperature(℃)Tangent of equationSlopePPO activity (%)Standard y=0.169x+0.03760.16910050y=0.1122x+0.00780.112266.3960y=0.0981x+0.00320.098158.0570y=0.0368x+0.00520.036821.7880y=0.0178x+0.01070.017810.53[pic 3]