Final answer:
The microbial activity on lipid food like 'dodol/dothal' and 'kavum/paniyaram' causing fats to smell and taste bad is known as rancidity, which can be prevented by antioxidants.
Step-by-step explanation:
The microbial activity on lipid food such as 'dodol/dothal' and 'kavum/paniyaram' is known as rancidity. This occurs when fats are contaminated with enzymes like lipase, which cause partial hydrolysis and oxidation of unsaturated fatty acids at the double bonds. The process is accelerated by atmospheric moisture and temperature, leading to the release of hydrogen peroxide, which gives the fat a bad odour and taste. Rancidity can be combated with the use of antioxidants such as vitamin E and vitamin C.