Step 1: Caramelization
Caramelization is the process of heating sugars at high temperature, leading to complex flavor and brown pigment formation.
$⇒$ P – 2 (Sugar).
Step 2: Denaturation
Denaturation refers to the structural unfolding of proteins or enzymes, leading to loss of biological activity.
$⇒$ Q – 4 (Enzyme).
Step 3: Oxidation
In food systems, oxidation usually refers to the degradation of lipids (lipid peroxidation), which causes rancidity.
$⇒$ R – 1 (Lipid).
Step 4: Bleaching
Bleaching is the removal or lightening of pigments in food (like chlorophyll, carotenoids).
$⇒$ S – 3 (Pigment).
Therefore, the correct matching is:
P-2, Q-4, R-1, S-3.