DEAR DR. BLONZ: I try hard to limit my daily salt intake, but some foods need a little extra flavor. I tend to use seasonings such as onion powder and garlic powder in place of onion salt and garlic salt, but what exactly is the difference between the powder and the salt? Is there any salt in the “powders,” and am I doing any good at all by making the substitution? Any other suggestions? -- I.D., Walnut Creek, California

DEAR I.D.: As a general rule, if a seasoning has “salt” in the name, expect there to be salt (sodium chloride) in the product. But whatever the name, the way to know for sure is to consult the ingredients statement and check the level of sodium on the Nutrition Facts label.

Individuals concerned about salt/sodium need to shift away from a mindset where a desire to add flavor automatically translates to “more salt.” As you indicate, seasonings such as garlic or onion powders (or granules) can be helpful. They contain no salt, and in addition to their flavors, they will contain the naturally occurring phytochemicals found in these healthful foods.

It is difficult to make generalizations about what types of seasonings work with what foods or methods of preparation. It would be nice if we each had an experienced chef nearby to provide needed advice! Absent this, we can consult a cookbook, magazine or online recipe resource. Every week, the food sections of local newspapers present new ways of preparing foods. It helps to acquaint yourself with the variety of flavors available through herbs and spices, and how they work. There are many resources out there, but one I continue to recommend is “The Spice Lover’s Guide to Herbs and Spices” by Tony Hill.

DEAR DR. BLONZ: What is white distilled vinegar made from, and how is it made? Is it healthy or harmful? -- F.T., Hayward, California

DEAR F.T.: Vinegar has been used as a flavor enhancer, preservative and folk remedy since 5000 B.C. Vinegar comes from fermented carbohydrate, and there are many varieties, their particular flavors depending on the type of carbohydrate used. White distilled vinegar comes from the distillation of grains -- mostly corn, but also rye and barley.

The acid in vinegar is acetic acid, and it is usually present in solution at about four parts in 100 (4 percent acidity). White distilled vinegar’s main failing is that it has a strong acidic taste. It can be used in foods, but it is perhaps best suited for pickling.

Vinegar does not provide any needed nutrients. It is not unsafe or harmful if used appropriately. For more on vinegar’s possible health attributes, see tinyurl.com/yaxcedxq.

DEAR DR. BLONZ: Quick question: I was wondering about the nutritional content of frozen vegetables. I eat them daily, heated up in a microwave for a minute or two. Are these a good source of vitamins, or am I kidding myself? -- S.J., Dover, New Jersey

DEAR S.J.: Assuming it is stored properly, the nutrition of a frozen food is up there with the fresh version’s.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: At a recent lecture, a doctor of natural medicine touched on the topic of milk homogenization, saying that it could be a major cause of heart disease and should be avoided. As it was explained, this theory was put forth by the chief of cardiology at a hospital. Proponents of this theory point to the fact that heart disease rates are much lower in countries, such as France, that don’t homogenize most of their milk, and higher in countries, such as Finland, that do. Do you know if any studies have been done, or are in progress, to substantiate the damaging effects of homogenization?

Also, are dairy products such as yogurt and cheese subject to homogenization? -- J.L., Casa Grande, Arizona

DEAR J.L.: Hearing something at a lecture does not make it so. There is little scientific support for these charges.

Milk is about 3.7 percent fat by weight as it comes out of the cow. The fat exists in globules of various sizes. If allowed to sit, these fat globules would rise to the top because fat is less dense than water. Homogenization is a physical process that changes the size of the milk-fat globules into a smaller, more uniform size. This is accomplished by forcing the milk through a small opening under pressure. After that, the milk fat remains evenly distributed throughout the milk, and the globules do not rise to the top.

One exception to this would be if the milk were frozen: When that happens, the water forms into ice crystals that separate from the fat. Upon defrosting, the fat globules will once again rise to the top as they did before the milk was homogenized.

Most commercial milk products, including yogurt and cheese, are made from homogenized milk.

DEAR DR. BLONZ: I am hoping you can explain something for me. The front label of a product I use says “sweetened only with malted barley,” but the nutrition label says the product has “13 grams of sugars.” Can both be correct? This is important for me to know, as I am a diabetic. I like the product, and I would like to keep using it. -- F.D., Berkeley, California

DEAR F.D.: Malted barley is produced by allowing the barley grain to sprout. This causes the grain to produce higher levels of a starch-digesting enzyme that breaks the grain down to simpler sugars. The 13 grams of “sugar” are probably maltose, a double-sugar that breaks into two molecules of glucose upon digestion. As a diabetic, you should treat maltose as you would any sugar.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: Could you explain freezer burn, and whether foods that have suffered from it are safe to eat? I am particularly interested in whether it is safe to use freezer-burned foods such as beef, chicken or shrimp for soups or stews. -- S.T., Las Vegas

DEAR S.T.: Freezer burn describes the physical effect of a food losing moisture content from being in the freezer. In nature, there is a physical drive for substances in adjacent pools to mix and equilibrate. This even happens, albeit slower, at frozen temperatures.

In an attempt to equilibrate with the dry air of the freezer, the water content of a frozen food gets drawn to the surface and then pulled out. This involves sublimation: the process of a solid going directly to a vapor state without first passing through a liquid phase. Sublimation is integral to the freeze-drying process used with certain foods, but in the case of freezer burn, it is an undesirable side effect of frozen storage. This also explains why the ice in your ice cube tray shrinks over time.

The surface of an affected food will take on an “off” color and a leathery texture. Affected portions are safe to eat, but they won’t taste right. The formation and departure of the sharp-edged water/ice crystals are responsible for the rough texture in the “burned” foods.

The best way to protect against freezer burn is to pack your frozen foods in heavyweight, moisture-resistant wrap, such polyethylene freezer bags, aluminum foil, freezer film wraps or well-sealed plastic containers. Although they can hold liquids, standard plastic wraps can “breathe” a tiny bit, and that’s all it takes for moisture to escape in a dry, frozen environment. Brief uses of such wraps may be OK, but don’t trust them for longer than a week of freezer storage. Consider using plastic bags specifically labeled for freezer storage, since they have an additional barrier to prevent moisture loss.

You may, however, notice that even when using appropriate freezer containers or bags, some ice crystals will form in the non-food space during longer periods of storage. Do your best to make sure the bag or container is well sealed, with a minimum of dead space around the food. If you know it’s going to be there for a while, consider double-bagging.

Back to your issue: Depending on the degree of damage, you should be able to salvage these foods if you trim away the freezer-burned portions before cooking. If, as you say, all you want to do is to cut it up and use it in stocks, soups and stews, you may be able to salvage more, but I would proceed carefully to be sure you don’t have some undesirable textures in the final dish.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.