What is the main function of packaging to protect food from?

The primary function of packaging in food preservation is to protect food from various external factors that can lead to spoilage, deterioration, or loss of quality. Rancidity specifically refers to the spoilage of fats and oils, which can occur when food is exposed to oxygen, light, and heat. Proper packaging helps to create a barrier that limits the exposure of food to these elements, thereby preserving its freshness and extending its shelf life.

By using materials that are specifically designed to be oxygen impermeable or that can block harmful light, packaging plays a crucial role in preventing the oxidation of fats, which is a key factor leading to rancidity. In addition, some types of packaging may also incorporate materials that can absorb moisture or contain antioxidants, offering additional protection against rancidity.

While other factors such as microbial growth, mold, and moisture loss are also important concerns in food preservation, the question focuses specifically on the protection against rancidity, highlighting the packaging's role in maintaining the quality of fatty and oily foods.