A freshly cut potato turns reddish- brown when left standing. why do mashed potatoes stay white?
Lemon juice is sometimes sprinkled on freshly cut fruit to prevent the fruit from turning reddish-brown. Explain how lemon juice can prevent the reddish -brown reaction?
3 responses so far ↓
1 zdolphinsz // Nov 3, 2008
THIS I KNOW!
the freshly cut potato turns reddish brown due to oxidation. what exactly happens i’m not so sure. Anyway, it is an enzyme that catalyses the oxidation reaction.
Mashed potato are potatoes are are being mashed.. lol.. but which means that the likelihood of enzymes being denatured is high.
when enzymes are denatured, they cannot function properly, thus unable to catalyse the oxidation of potato, thus potato stays white.
and then..
lemon juice is acidic, when added to the potato, it denatures the enzyme in potato, thus making the enzyme unable to catalyse the oxidation reaction.
Lemon juice denatures the enzyme by disrupting tertiary and secondary bonds, mainly, hydrogen bonds and ionic interactions.
Hope it helps ((:
2 racefish68122 // Nov 3, 2008
Cooking destroys the enzyme as does the acid in the lemon juice. Lemon or lime does the same thing. It won;t work with avocado though.
3 Ollie Tabooger // Nov 3, 2008
MMMM, mashed lab potatoes . Do you serve that with in a petrie dish?