FOOD SCIENCE AND PROCESSING 3 (2+1)

Lesson 14 : Vegetables

Enzymes

Enzymes are found in plants cells. They function as chemical reactions. Enzymes bring ripening of tomatoes and bananas. If this enzymatic reaction continues the fruit gets spoilt. They also bring browning in potato, brinjal and plantain. Two of enzymes namely ascorbic oxidase and phenoloxidase are important as the former oxidises ascorbic acid and the latter causes oxidation of polyphenols and enzymic browning in vegetables.

Raw papaya contains an enzyme called papain. Papain is used as a stabilizer in beer and other beverages and as a meat tenderizer.

Enzymes also can cause detrimental changes in anthocyanin pigments. Peroxidases and phenolases naturally present in some fruits and vegetables can catalyse oxidative reactions that are harmful.