Final answer:
The correct answer is D) Biguanides, which are not mentioned as a food preservative and are known for their use as antiseptics and disinfectants in medical applications.
Step-by-step explanation:
The question 'Which of the following is NOT used to preserve foods?' requires an understanding of chemical preservatives in food.
The options given are A) Sodium nitrite B) Nisin C) Potassium sorbate D) Biguanides.
From the reference material provided, we know that sodium nitrite is used to preserve meats, nisin is an antimicrobial peptide that is used in the preservation of cheeses, meats, and beverages, and potassium sorbate is used to control the growth of molds in acidic foods. However, biguanides are not mentioned as a food preservative.
Biguanides are better known for their use in medical applications, particularly as antiseptics and disinfectants.
In terms of food preservation, sodium nitrite is NOT used to preserve foods. Sodium nitrite is commonly used to preserve bacon and other meats, but it is not considered a food preservative in general.
Instead, chemical preservatives like sodium sorbate, potassium sorbate, and natural antimicrobial substances like nisin are used to inhibit microbial growth and minimize spoilage in various foods.