With too little headspace, liquid is more likely to

With too little headspace, liquid is more likely to cook out of the jars during heat sterilization. With too much headspace, air remaining the jar can cause darkening ot the food, oxidized flavor, and lower vitamin retention.

Pressure canning low-acid foods is receiving increased emphasis today, mainly based on the greater safety of this technique. The method also offers an additional advantage—improved quality and nutrient retention. Lowacid foods include asparagus, shelled beans, snap beans, beets, carrots, corn, hominy, mushrooms, okra, peas, potatoes, pumpkin, spinach and other greens, squash, and sweet potatoes.

Property managed heat sterilization has a great deal to do with the quality of canned food. If the temperature is too high or the time of sterilization too long, the result is a product with poor color, soft texture, and less flavor. Tomatoes canned in the pressure canner are an example.

Jars must be air-cooled naturally after heat sterilization to maintain quality as well as for safety. Delayed cooling in tightly enclosed areas, such as cardboard cartons, will decrease quality of the product.

Storage conditions are vital to quality of canned foods. If stored in a light, rather than a dark place, light-sensitive colors will darken gradually.

Storage temperaures between 40 to 50 degrees F (4.5 degrees to 10 degrees C). if the spot is dry , are best for qua ty retention. Quality losses are increased when canned foods are stored at higher temperatures. For example, about a third of the vitamin C is lost if foods are stored a year at temperatures ot 80 degreees F (26 degress C) or higher.

Storage temperatures between 50 degrees to 70 degrees F (10 degrees to 21 degrees C) are acceptable.

Properly canned and stored foods should be safe to eat for more than two years. However, for top quality, it is best to can only the amount to be used in one year.