Chances are that your kitchen cabinets or refrigerator contains at least one food product that has been changed in order to improve its nutritional profile. Fat-free cheeses, reduced-fat baked goods, fortified cereals and juices, and sugar-free beverages are all examples of products that showcase the nutritional benefits of food technology. Most food product development is complicated, and these types of products listed above are no exception. In fact, more times than not it’s a long, drawn-out process of research and development, testing and re-testing, and heading back to the “drawing board” for another try at development of the food product being sought. Here, in the second part of Food Insight’s two-part series on food ingredients, we provide the answers to some of your technical food development questions. Consider it “food for thought.”
Q Why do some sugar-free foods use more than one type of sugar substitute?
A Sugar substitutes, also known as “very low-calorie sweeteners” or “intense sweeteners,” are often combined in order to produce a taste that most closely mimics that of real sugar and because together they produce an improved simulation of a sugar-like taste than either one could achieve alone. “By combining sweeteners, a very precise taste can be achieved, aftertastes can be controlled, and costs can be optimized,” says Mark Kantor, Ph. D., associate professor in the department of nutrition and food science at the University of Maryland. Combining sweeteners can result in a synergistic effect that also allows the food manufacturer to use less total sweetener overall— up to 40 percent less—without compromising taste. Sometimes sweeteners are blended to obtain the best qualities of each, such as heat stability and the ability to retain sweetness over time. “It is possible that no one sweetener alone would result in the same desirable attributes that are achieved by using a combination,” adds Kantor.
Q Why are some reduced-fat products not much lower in calories than their regular-fat versions?
A “When replacing fat in a food with something else, there is a net decrease in caloric value—after all, fat packs 9 calories per gram—more than proteins or carbohydrates” says Manfred Kroger, Ph. D., professor emeritus of food science at The Pennsylvania State University. However, there are a few reasons why reduced-fat foods aren’t necessarily much lower in calories than their full-fat counterparts. First, reduced-fat products are not the same as fat-free products—some may have only a slight reduction in fat compared to a reference food. Second, although some ingredients used to reduce the amount of fat in foods are truly fat- and calorie-free (such as olestra, which is not absorbed by the body and which therefore contributes no calories), most of these ingredients contain from 1 to 5 calories per gram. Finally, in order to make a reduced-fat food have the same weight per serving as the regular- fat version (as required by the Food and Drug Administration), other ingredients must be added to the product, or a larger portion of the product must be considered as a serving. The additional ingredients contribute calories, and naturally, a larger portion of food per serving would also increase the number of calories per serving. Here’s a simple example: removing 1 gram of fat from a typical cracker would lower the number of calories by 9. However, in reality, the inclusion of a fatreplacer ingredient would add calories back, resulting in a net reduction of perhaps 4 calories per gram of fat removed.
Q Do reduced-fat baked goods have extra sugar added to them?
A Sugar does make up a larger percentage of reduced-fat and fat-free foods. Why? One reason is that when an ingredient is removed from a product, the remaining ingredients in the product become, in effect, more “concentrated.” In other words, even though the total amount of sugar is the same in both the regular and reduced- fat or fat-free version of a food, the proportion of sugar in the lower-fat version is greater. In some cases, when fat is removed from a food, a carbohydrate-based fat-replacer ingredient is added, which may also contribute to a higher “sugars” value on the product’s nutrition label.
Q What are fat substitutes made of?
A Fat-reduction ingredients may be classified into three categories: carbohydrate-based, proteinbased, or fat- based. Polydextrose, modified food starch, maltodextrins, xanthan gum, and cellulose gel are examples of carbohydrate-based fat replacers, which provide 0 to 4 calories per gram. They contribute bulk, creaminess, thickening, and stabilization to reduced-fat and fatfree foods such as frozen desserts, baked goods, salad dressings, and dairy products. Protein-based fat replacers, such as those from whey or egg white, are produced by simultaneously heating and blending them to make protein emulsions that mimic the creamy mouth feel of fat. Soy and corn are also sources of protein for the production of these ingredients. Protein-based fat-reduction ingredients provide 1 to 4 calories per gram, and are used in such foods as mayonnaise, salad dressings, baked goods, and a variety of dairy products. The fat-based substitutes simulate real fat in taste, texture, and mouth feel. Some of these products can be used just like regular oils, such as for frying, while others are more suitable as food ingredients. Depending on the degree to which fat-based fat-reduction ingredients are absorbed by the body, they can provide between 0 and 5 calories per gram. Olestra, salatrim, and mono- and diglycerides are examples of fat-based fat-reduction ingredients.
Q How is reduced-fat peanut butter made?
A Regular peanut butters contain a minimum of 90 percent peanuts, whereas the reduced-fat varieties contain approximately 60 percent peanuts. The peanuts that are taken out in reduced-fat products are replaced by corn syrup solids, which give “body” to the product. Unlike the peanuts that they are replacing, the corn syrup solids have no fat, thereby reducing the overall fat content of the peanut butter. (The numbers of calories in reduced- fat peanut butters are not necessarily lower than the numbers of calories in regular versions of peanut butter, however.) Soy protein, vitamins, and minerals are also added to reduced-fat peanut butters in order to make them nutritionally equivalent to regular peanut butter.
Q What’s in those new cholesterol-lowering spreads that makes them work?
A Today you can find two new types of products on the market—cholesterol-lowering spreads—and plant compounds are the keys to these products. One type of product contains a soybean extract called a plant sterol, whereas the other type contains a plant stanol ester found in small amounts in corn, wheat, and wood oils. Both types of the two new cholesterol-lowering table spreads function similarly to inhibit cholesterol absorption, decrease low-density lipoprotein (LDL) cholesterol (or “bad” cholesterol) levels, and maintain highdensity lipoprotein (HDL), cholesterol (or “good” cholesterol) levels and thereby promote healthy blood cholesterol levels.
Q How do they get all those vitamins and minerals into fortified cereals?
A Adding nutrients to a cereal can cause taste and color changes in the product. This is especially true with added minerals. Since no one wants cereal that tastes like a vitamin supplement, a variety of techniques are employed in the fortification process. In general, those nutrients that are heat stable (such as vitamins A, and E and various minerals) are incorporated into the cereal itself: they’re baked right in. Nonheat- stable nutrients (such as B-vitamins) are applied directly to the cereal after all heating steps are completed. Each cereal is unique—some can handle more nutrients than others can, which is one reason why fortification levels are different across all cereals.
