Food Chemistry
Browning catalysed by polyphenol oxidase, which oxidises phenolic compounds to quinones that polymerise into brown melanins. It requires oxygen, the enzyme, and a phenolic substrate.
Why a cut apple or potato turns brown within minutes, and why a squeeze of lemon juice slows it down.
A copper-containing enzyme responsible for enzymatic browning in cut fruit and vegetables. Optimum pH is around 6–7 and it is largely inactivated above about 80 °C.
A short heat treatment, usually 70–100 °C, applied before freezing, drying or canning, primarily to inactivate enzymes.
A non-enzymatic browning reaction between a reducing sugar's carbonyl group and a free amino group of an amino acid or protein, producing melanoidin pigments and a wide range of flavour compounds.
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