Browning
Not due Microorganisms spoil slower,not found inside apple
Soak apple into phenol(kills microorganisms)and compare-no change in browning
Temperature destroys enzymes-heated apple doesn't brown
needs air-quinone is formed from oxygen
ascorbic acid prevents browning because reduces(antioxidant)
Enzyme active pH 6-8.Citric acid occurs naturally&doesn't affect taste.SO2 is an enzy.inhibitor
Browning control:
1Reduce concentration of substrate by selecting apples or genetically
2Excluding oxygen+adding antioxidant
3Inactivating enzyme by heating,adjusting pH,adding inhibitors,altering conc.of reaction soln