Does microwaving reduce the nutrients in vegetables? Are the microwaveable bags of vegetables designed to prevent nutrient loss?

Rick Webdale, United Kingdom

Microwaves form part of the electromagnetic spectrum, and their frequency is situated between infrared waves and radio and television waves. The energy makes the water molecules in the food vibrate at 2.5 billion times a second and heating occurs due to rotation of the water molecules.

As with all food preparation, whether conventional or micro waved, there is a loss and/or change of nutrients. Vitamin retention in some cases of micro waved foods can be even better than in conventionally cooked foods. This improvement is due to the higher energy levels and thus shorter cooking time required in a microwave oven.

Minerals cannot be destroyed during food treatment, they can however, be lost in cooking water or meat juices. The vegetables in microwave bags have no contact with water. That is an advantage regarding to the washout from nutrients.

Studies of a variety of vegetables cooked conventionally, and in a microwave oven, for various lengths of time, revealed a negligible change in mineral content regardless of cooking method.