Is it really true that adding mayonnaise to a salad won't hasten the rate at which it spoils?
If you are talking about commercial mayonnaise, yes. Adding mayonnaise actually retards the growth of spoilage organisms. But obviously that does not mean you should throw safe food-handling procedures to the wind. Two key ingredients contribute to retarding bacterial growth. The lemon and/or lime juice and vinegar raise the acidity of a salad to a level where bacteria do not multiply as rapidly as they do on, for example, cooked egg or cubed turkey. Salt, an optional but common ingredient in mayonnaise, also interferes with their growth.
The acid content of homemade mayonnaise may not be as high as in commercial brands (which must adhere to a federally specified standard), and may not be as effective in retarding spoilage.
Whether you buy mayonnaise or make your own, it is still essential to follow these important rules for preparing salads. Refrigerate cooked foods once they have stopped steaming, and wait until they are thoroughly chilled before mixing with items such as celery, onions and mayonnaise. As soon as it is mixed, return the salad to the refrigerator. And it goes without saying that work surfaces and utensils should be kept scrupulously clean.
Last summer I canned fruit for the first time. Although I followed directions carefully, two bad things happened. After a time, the fruit on top in some of the jars became discolored. And in some jars, the fruit is rising, leaving the liquid at the bottom.
I used a pressure canner and there were no indications of bulging lids or spurting liquid, which I know can be signs of gas formation and spoilage. Also there was no mold present, so I assumed the fruit was safe. But is was esthetically unattractive and I would like to know what I did wrong before I try again this season.
Floating can occur for one of three reasons: if fruits are packed too loosely; if the fruits are packed in syrup which is too heavy; and if some air remains in the tissues before the food is heated and processed. Running a sterilized implement such as a long, narrow spatula between the fruit and the wall of the jar before sealing should get rid of excess air bubbles.
Color changes, which can signal spoilage, also occur for other reasons. Darkening of the fruit at the top of the container, such as you describe, can be the result of oxidation from air left in the jar.
But other types of darkening, which do not spell danger, can also occur. For example, overprocessing can lead to discoloration throughout the container. And brown, black and gray off-colors can come from containers or cooking utensils or, in some areas, from the water used in preparation.
In a pamphlet on food storage I read that freezing cured meats is not recommended. Can you explain why?
Freezing causes the flavor of ingredients used in the curing process to get stronger, affecting both the taste and texture of these foods adversely. In addition, seasonings in the meat speed up the rate at which rancidity develops.
To ensure top quality, cured meats should be eaten fresh. If you happen to find yourself with leftovers that must be frozen to avoid spoilage, keep corned beef and frankfuters in the freezer just two weeks, bacon for a month, cured hams no more than two months, and fresh sausage for a maximum of three months.
It is generally suggested that bologna and other luncheon meats, as well as smoked sausage, not be frozen.