DEAR DR. BLONZ: What part does palmitate play when added to powdered milk? -- A.P., Sonoma, Calif.

DEAR A.P.: Palmitate is a salt of palmitic acid, a saturated fatty acid. It is found in a number of foods, but its name comes from the fact that it comprises about 45 percent of the fats found in palm oil. Palmitic acid becomes "palmitate" when combined with other compounds. In milk, the vitamin A, or retinol, is combined with palmitic acid and the resulting compound can be called vitamin A palmitate, or retinol palmitate. You can also see palmitate in other compounds, such as ascorbyl palmitate, which is a combination of palmitic acid and vitamin C (ascorbic acid). In the human body, palmitic acid makes up about 25 percent of the fats found in breast milk. It's also present in lung surfactant, a substance that coats the insides of our lung surfaces and allows us to breathe. The amount of palmitate added to powdered milk is negligible. It is only there as an escort for the small amount of vitamin A added to the product.

DEAR DR. BLONZ: Do you have any preference of dietary supplement forms -- for instance, capsules vs. tablets? For someone getting up in years, can the body absorb one form better than the other? -- R.R., San Diego, Calif.

DEAR R.R.: It really comes down to a matter of personal preference. There are good powdered supplements, as well as products that are in capsule and tablet form. With few exceptions, taking supplements at mealtime makes sense. The mixing that goes on during digestion should give either form sufficient opportunity to dissolve and be absorbed. I have heard that some people don't "trust" tablets because they feel they will pass through without dissolving, but companies formulate their products to dissolve. You can always pose questions to a company you are considering, asking them to provide data on these issues. Such information should be readily available.

DEAR DR. BLONZ: I have some questions relating to sweeteners. I read that fructose is sweeter than sucrose, and so fewer grams of fructose would be needed to achieve an equivalent sweet taste. Is this the case? What is the difference between sugar, invert sugar and honey? -- K.E., Walnut Creek, Calif.

DEAR K.E.: There are definite differences in the level of perceived sweetness between the various sweet-tasting substances. Sucrose, or table sugar, is a double sugar made up of glucose linked to fructose. It is used as the sweetness standard, being assigned the value 1.0. Fructose, also called fruit sugar, has a relative sweetness of 1.7, which means it is 70 percent sweeter than sucrose. When compared to sucrose, less fructose would be needed to achieve the equivalent level of sweetness. This highlights one of the health advantages of eating fresh fruits: You get more sweetness per calorie, plus all the other nutrients found in the fruit. Glucose by itself is less sweet than sucrose, having a relative sweetness of 0.7. Invert sugar, honey and sucrose are similar in that they are all made up of glucose and fructose. The difference is that with invert sugar and honey, the glucose and fructose are not linked. This affects the degree of sweetness, with invert sugar and honey having a relative sweetness of 1.3, or 30 percent greater than sucrose.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 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: I recently watched a video on YouTube saying that the pasteurization process destroys critical enzymes needed to assimilate calcium from milk. Do you have any information as to whether this is true? -- E.B., Puma, Ariz.

DEAR E.B.: There are enzymes in raw (unpasteurized) milk, and some are indeed destroyed by the process of pasteurization. The question, though, is whether these enzymes are essential for the assimilation, or absorption, of the calcium in milk. The answer here is no -- or at least it has never been demonstrated in any study I have been able to find.

The enzymes in raw milk -- and there are a number of them -- come either from the cow or from bacteria that might be present. One of the main cow enzymes in milk, for example, is called plasmin. It is a protein-digesting enzyme that, if left to act, will eventually degrade the milk protein, leading to clumping and the development of "off" flavors and odors.

Please understand that while the pasteurization of milk does not make it a sterile product, it does help destroy potentially harmful microorganisms that can cause spoilage or disease. It does this by knocking out some, but not all, of the enzymes and bacteria. Pasteurized milk still needs to be refrigerated because the cold serves to slow bacterial growth and enzymatic action. All this explains why milk goes bad if it is allowed to sit too long or is stored at the wrong temperature. The storage time of milk can be extended if the milk product is processed with a higher temperature (ultra-pasteurized) and then packaged in aseptic containers.

The YouTube video you cite was incorrect if it stated that the enzymes in raw milk are needed for us to absorb calcium and other mineral elements. What you are hearing smacks of an unscientific milk attack. There are those who really do not like milk, and feel it is an unhealthy food.

It is up to each individual to decide whether he or she wants to consume milk or any dairy product. Not everyone wants to drink milk, and not everyone has to. Our freedoms allow us to make our own food choices. There is a growing amount of nonsense online, so when you encounter new information, I encourage you not to be influenced before checking out the facts from a reliable source. A good way to debunk claims is to investigate whether there is any scientific foundation to the concepts. Often, you can do this by searching among reliable sources such as government websites (ending in .gov) or academic ones (ending in .edu). I have a list of reliable sources at my blonz.com site (blonz.com/nut.htm).

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 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: Is there any problem with drinking salty soup? Our son has developed a taste for ramen and craves some every day. We know it's high in fat and salt, but since he is 14 and not overweight, should we be concerned about those issues? For a while he was using only half the flavoring packet, but lately he seems to want it saltier. What do you think? -- A.H., Watertown, Wis.

DEAR A.H.: It is not unusual for children and adolescents to develop preferences that oftentimes border on cravings. Regardless of how you try to instill balance in their diets, they insist on their favorites and you begin to wonder if they are getting the nourishment they need. Ramen-type soups provide convenience and a reliable flavor, and the flavoring packets of some brands can be high in sodium. Most, however, are relatively modest in fat.

Because there is brand-to-brand variety, you might be able to find an acceptable soup with better nutritional attributes. If he is stuck on a particular brand that offers little besides noodles and salty soup, I would take solace in the fact that your son will be eating other foods during the day and that they probably don't follow the same format. Another potential fix would be to give an OK on the ramen, but see if he would be amenable to adding some peas, corn or other vegetables to the soup. Perhaps you could strike a deal where points from the consumption of other "balancing" foods would have to be earned before the ramen is given the green light. In the end, keep in mind that these types of desires tend to pass with time.

DEAR DR. BLONZ: I recently bought packages of fish fillets that contained farm-raised catfish. When I got home, I noticed that the fish contained ingredients that I am questioning, especially since I watch my salt intake. They include sodium tripolyphosate, sodium hexametaphosate, acid pyrophosate, citric acid and salt. Since when is salt put on frozen fish fillets? All those sodium compounds sound like a no-no for a person with high blood pressure. I hate to toss them, but since I read the ingredients, I have lost my appetite for them. I would appreciate your help. -- J.P. Carlsbad, Calif.

DEAR J.P.: Chemical names can sound intimidating. A fresh or fresh-frozen fish wouldn't be using these additives, but the product wouldn't have much of a shelf life. As for your ingredients, the first four are there to help maintain quality of the product during its shelf life. They are often referred to as sequestrants: To put it simply, they keep the elements involved in spoilage reactions away from each other. This has the net effect of delaying the breakdown that makes food go bad. Although it may not be what you had intended on purchasing, there is no evidence that these compounds are harmful, and having them is certainly preferable to consuming a product that has begun to spoil.

There would only be minimal sodium supplied by these ingredients, as they are only there in very small amounts. Salt is added for flavor, and the amount added would depend on the manufacturer. If this is a packaged, processed fish fillet, the Nutrition Facts label will provide the total amount of sodium per serving, regardless of source.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 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.