Q: Enclosed is a favorite bran muffin recipe to which I would like to add oatmeal. Are any formula changes necessary?

A: When mixed into a batter, oatmeal absorbs some water as the batter bakes. This produces a very moist texture, which detracts from the crunchy nuttiness of the bran. To give the muffins more flavor, I increased their sweetness and added orange peel. % BRAN AND OATMEAL MUFFINS (Makes 18 muffins)

1/2 cup raisins

2 cups water

1 teaspoon baking soda

3 tablespoons honey

1 teaspoon salt (optional)

1/2 stick (2 ounces) butter, softened

1/4 cup dark molasses

1 egg

2 cups all-purpose flour sifted with 1 teaspoon baking powder

1 1/2 cups bran cereal

1/2 cup oatmeal

1 teaspoon fresh orange peel

1 teaspoon ground cinnamon

Bring raisins and water to a boil. Let soak 5 minutes and drain through colander into a pan or bowl. Measure out 1 1/3 cups of this water and let cool. Add baking soda and mix briefly to dissolve. Blend honey, salt, butter, molasses and egg until smooth. Add flour, bran, oatmeal, orange peel and cinnamon to mixture in bowl, blend with mixer on low speed, then add raisin water. Blend only until well incorporated. Stir in raisins. Fill paper-lined cupcake molds 2/3-full. Bake at 400 degrees until puffed and firm on top, about 15 minutes.

Q: How long can yogurt be kept unrefrigerated in a lunch box?

A: Yogurt (pH of 4.5) is a rather acidic food populated by two or three species of lactic acid-producing bacteria numbering between 14 million and 140 million per tablespoon. Few spoilage or food-producing bacteria can compete under or even survive in such conditions. Yeasts and molds, however, withstand the acidity and eventually grow, producing off-colors, flavors and odors. These cause changes in flavor, color and odor that are sometimes apparent after three or four weeks of refrigerated storage.

One cannot make a firm statement that yogurt kept in a lunch box would not spoil before nightfall, as spoilage rate depends on how long you stored the yogurt after buying it. It is, however, very unlikely that any would occur and even less likely that one could contract food poisoning from spoiled yogurt.

Q: Is it possible to make a poundcake with Egg Beaters? I have several recipes and most call for about 5 eggs. I am trying to reduce cholesterol, so I would like to replace all the eggs with this cholesterol-free substitute and the butter with shortening.

A: Egg Beaters is an all-egg white product and therefore contains none of the emulsifiers present in egg yolk. An emulsifier is a substance that allows the intimate association of water and fat in a cake batter.

In a poundcake batter, water is dispersed as minute droplets within the creamed fat. So is air. The more finely dispersed either is, the silkier, moister and more tender the cake. Since comparable emulsifiers are lacking from Egg Beaters (and from the egg whites with which it is made), cakes produced with it are heavier and more chewy than those made with whole eggs or egg yolks.

A cake made with Egg Beaters still rises, however, and, despite its coarser and chewier texture, is an acceptable substitute for those who must reduce cholesterol and saturated-fat intake but still want to eat cake.