What type of food preservation technique involves canning food with minimal oxygen?

Canning is a food preservation technique that effectively reduces oxygen levels, thus prolonging the shelf life of food by minimizing the potential for microbial growth and spoilage. Vacuum packing plays a similar role by removing air from packaging, significantly limiting oxygen exposure. This process helps in preserving the freshness and quality of food items, making them less prone to oxidation and spoilage.

On the other hand, freezing involves lowering the temperature to slow down microbial growth but does not specifically focus on oxygen levels. Dehydration removes moisture from food, which is beneficial for preserving items, but it does not involve canning with minimal oxygen. Salting draws moisture out of food and creates an environment that inhibits bacterial growth, but again, it does not involve canning or reducing oxygen in the same way.

Therefore, vacuum packing is the correct answer because it specifically addresses the minimization of oxygen in conjunction with food preservation.