Enzymes structure and functionality Flashcards
actions that can disrupt the structure of food and impact the functionality of enzymes
cutting, peeling, mashing, pureeing, mastication
how does physcial disruption affect enzyme activity
enzymes that arent found with thier substrate in the food matrix can interact
example enzyme in cabbage
myrosinase
-also found in the gut
function of myrosinase
hydrolysis of glucosinates
where is myrosinase found
cell wall
where are glucosinates found
inside plant cells
what reaction occurs between myrosinase and glucosinolates
hyrolysis
what does the hydrolysis of hydrosinolates produce
glucose + active products
-isothiocynaat
-nitrill
-thiocyanaat
what do active products supply
health benefit
sensory atributes (sulphuric smell)
how can you stop the action of myrosinase
cook it
co factor for myrosinase
vitamin C
role of ascorbic acid in food
regulate redox balance inside the cell
what enzyme regulates ascorbic acid
ascorbic acid oxidase
product from L-ascorbic acid oxidation
dehydroxyascorbic acids (DHAA)
oxidising agents for LAA
AAO (ascorbic acid oxidase)
light
heat
oxygen
pH
metal ions
two types of oxidation that can happen to LAA
enzymatic
chemical
describe the active site of AAO
multicopper oxidase glycoprotein
function of AAO
control cell growth
indirectly control L-AA pool
what effects AAO
light
temperature
oxygen
pH
maturity
where is AAO found
bound to the cell wall
where is L-AA found
cytosol
vacuole
cell wall
organelle
why is there less DHAA in leaves that have received higher heat treatment
the heat inactivates AAO so less conversion is occuring
optimal pH for AAO
around 6
optimal pH of pectinase
around 6
temperature AAO will inactivate/denature
70-80C
when frozen carrots are cooked what is the best temperature to maintain the vitamin C content
20-30
lower is better
