OTHER INGREDIENTS AND THEIR EFFECT ON STARCH

VII. OTHER INGREDIENTS AND THEIR EFFECT ON STARCH

A. Water

Water may be the most common ingredient utilized with starch. It is also one of the most underestimated ingredients affecting starch negatively. Water as a food ingredient has been emphasized as essential to make starch, both native and modified multifunctional, in food products. This being true, then the variety of water must be considered, not only from home to home but also the differences around the globe. Water obtained from a well has certain measurable properties and constituents. The same can be said about water taken from a city water system. However, these two waters are significantly different, which could dramatically alter the functional properties of added starch.

Consider the treatment facility for any city and the number of cities around the Consider the treatment facility for any city and the number of cities around the

a complete reformulation is necessary. What is often thought to be the simplest ingredient for foods is seen to be a very complex supply of components.

B. Sweeteners

Sweeteners (see Fig. 33 and Table 11) offer a lot more to the food product than just sweetness. Sweeteners for this review include maltodextrins, sweetener solids greater than

20 DE, high-fructose syrup, syrups classified as medium and high conversion, as well as sucrose. The high-intensity sweeteners contribute sweetness in foods, but are predomi- nately carried by maltodextrins. Therefore, I will forgo discussion about their effect, as it relates primarily to that of maltodextrins. When utilizing maltodextrins with starch, the food technologist is attempting to increase solids, control sweetness, or generate a desired color. In some instances a maltodextrin may be added to assist with stickiness (tackiness). This is best done with very low-DE (⬍5) maltodextrin products. These same maltodextrins have proven to provide fatlike properties. Because of the blandness and solubility of malto- dextrins, they are very compatible with the incorporation of instant starches. They conve- niently offer a method for premixing without affecting the functionality of the added starch. In fact, the low-DE maltodextrins are somewhat similar to modified starches pro- cessed with enzyme. Sweetener solids having a DE greater than 20 are not classified as maltodextrins. In fact, those derived from maize starches are called corn syrup solids. Similar products are commercially available today, derived from other starch sources, i.e., rice, tapioca, potato, etc. They now represent a small but reasonable share of the dry solids and liquid sweetener market. A primary functional characteristic is that of adding

Table 11 Conventional Corn Syrups Common Name

Confectionery Functionality Low D.E. Syrup

25 5 77.5 High viscosity . . . low hygroscopicity 35 15 80 Limited use in hard candy

Regular Corn Syrup 42 20 80 All purpose syrup . . . high cooked candies ‘‘Glucose’’

. . . soft candies, when blended with dex- trose, fructose, or invert sugar

High Maltose Syrup 42 7 80 Low dextrose content . . . good color stabil- ity . . . low hygroscopicity . . . special hard candy uses

Intermediate Syrup 55 30 81 ‘‘Comparative syrup’’ used in both hard &

soft candies

Sweetose (high 64 40 82 Best choice for soft candies . . . good mois- conversion)

84 ture affinity . . . best economics 84 ture affinity . . . best economics

C. Salts

Most technologists consider this ingredient predominately sodium chloride. For many food systems this may be correct. However, salts can complex with a number of compounds creating unique structures, thus resulting in very unique eating quality. An example of such a complex is the preparation of instant puddings. Many food scientists as well as consumers consider the starch as the building block for producing the set and eating quality for instant mix puddings. The starch however is added to control the water phase of the mixture, enhance mouth-feel, and provide stability during storage. The structure and eating quality is generated from the salt complex created with the protein from the dairy portion of the mixture and added salts. The protein can come from added liquid milk or dry milk solids. Quantity and blend ratio of the added salts influence the rate of set, strength of the gel, and the mouth-feel of the finished pudding. Calcium and potassium salts, either phosphate or chloride derivatives, significantly add to or detract from the quality of the puddings. Calcium usually increases gel strength and shortens set time, whereas potassium has the reverse effect. The chloride derivatives generally produce a distinct off-flavor and are considered unacceptable for commercial products, however the effect is worth noting.

D. Other Food Ingredients

Many food ingredients (spices, fruits, flavors, etc.) can contribute to soluble solids of the food matrix. This includes ingredients that compete for water. Ingredients competing for water typically retard the hydration of the added starch. However, many ingredients are added for flavor, particulate characteristics, or enhancement of other functional ingredi- ents. Many times these unique additives contain α-amylase. α-Amylase is an enzyme utilized in degrading starches for the production of sweeteners. It is also the type of enzyme utilized by the body to break down carbohydrates. Starch is a carbohydrate and there- fore will be digested by this enzyme. Peppers, some smoke flavors, fruits such as pine- apple, and fresh blueberries are known to contain significant quantities of α-amylase. Dairy products such as cheeses (blue cheese) and low heat processed milk solids can be

a source. In the early 1990s the flour industry experienced a significant setback with flour. For a 2-year period the wheat crop experienced a very wet season and a second growth occurred within the crop prior to harvest. Not only were protein-related enzymes formed, but so was α-amylase. Many bakery products experienced breakdown of the starch phase of the flour as well as the digestion of added starches. In many products the effect was not noticed until the product (e.g., refrigerated and frozen dough) reached the consumer. There are test procedures available to assist with analysis. Many contract laboratories assay for enzyme presence. A simple nonquantitative test can be utilized using triplicate containers of a control starch paste and inoculating with suspect material. It only requires

24 h at room temperature to study the effect, or at elevated temperatures (140 °F) about 4–6 h yields an indication of enzyme activity. As with all tests always use a control sample

E. Proteins and Other Starches

Ingredients that contain proteins typically contain carbohydrates. Therefore, always con- sider the source of the protein and its anticipated contribution to to the food product. Proteins, as mentioned earlier, complex very easily with salts. These complexes can create gray to dark particulates. These particulates can create undesirable textures. Foods that will be fried, baked, or subjected to long-term processing at high temperatures can poten- tially produce dark spots on the surface (Mallard reaction). Protein can also contribute to texture. In breads it may be desirable, however the elastic effect of glutenlike dough in some foods is not acceptable. Agglomerated proteins generate small to large particulates that can create uneven surface texture as well as a gray color.

Starch added from other sources or as another ingredient, not intended to yield func- tional properties, are often overlooked. One source that can contribute a significant per- centage of starch that has already been mentioned is that found in powdered sugar. The 3% starch allowed in powdered sugar could significantly alter the cook, flavor, clarity, texture, and shelf-life of a food product.

When a technologist has identified all sources of starch or other hydrophilic com- pounds prior to formulating the final product, a relative amount of correctly modified starch can be added allowing for the effect from the other ingredients. In many cases the technologist may need to seek advice from suppliers as to ingredient composition and potential functionality when mixing with other ingredients. Some ingredients utilized can

be preblended compounds from many sources. A supplier may not quantify the amounts, and in some instances not disclose the detailed listing, of ingredients. An example of such

a mixture could be a blend of common and waxy corn starches. The supplier of such a product may only identify the product as containing ‘‘corn starch’’. The supplier would

be correct in doing so.