Her skin is working to protect her because of her sweat glands, which are producing sweat as a mechanism to cool your body during the intense heat. Also, there are melanocytes in your skin which produce melanin, which give your skin its pigmentation, and this also helps protect from the sun. In addition, if you apply sunscreen with a SPF higher than 15, that is pretty healthy protection from the sun as well, even though it isn't a natural defense.
Cooling, freezing, fermentation, sun-drying, etc., are few age-old food preservation techniques. With the advent of technology, modern methods of food preservation were developed. Chemicals and other natural substances were used for preservation. These substances are known as preservatives.
Adding preservatives is the chemical method of food preservation. Conventional antimicrobial preservatives include <em>calcium propionate</em>, <em>sodium nitrite</em>, <em>sodium nitrate</em>, <em>sulphites</em> (<em>sulfur dioxidepotassium hydrogen sulfite</em>, <em>sodium bisulfite</em>, etc.) and <em>disodium EDTA</em>. <em>BHA </em>and <em>BHT </em>are antioxidants.
