HORTICULTURE SCIENCE
FRUIT SCIENCE
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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carbon dioxide in the air
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water
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oxygen
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sugar
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Detailed explanation-1: -The enzyme responsible for the browning is called polyphenol oxidase (or PPO). In the presence of oxygen the PPO enzyme changes substances known as phenolic compounds (through a process of oxidation) into different compounds called quinones. The quinones then react with other compounds to form melanin.
Detailed explanation-2: -Browning in fruits and vegetables is caused mainly by the enzyme PPO, which in the presence of oxygen catalyzes the oxidation of o-diphenols to o-quinones. Brown pigments are produced by the polymerization of o-quinones.
Detailed explanation-3: -Enzymatic browning is one of the most important reactions that occur in fruits and vegetables, usually resulting in negative effects on color, taste, flavor, and nutritional value. The reaction is a consequence of phenolic compounds’ oxidation by polyphenol oxidase (PPO), which triggers the generation of dark pigments.