Fried foods can absorb up to 40% of oil by weight. The moisture loss from the substrate (whether a vegetable or meat) during frying influences the degree of oil absorption, with generally higher moisture losses associated with increased oil absorption. It is known that forming a barrier during the flash-fry step reduces oil uptake, and eliminating the flash-fry step (if possible) helps to reduce oil uptake. Starches (e.g., high amylose), dextrins and some proteins (e.g., whey) have been shown to reduce the oil uptake, explained Chandani Perera, Ph.D., senior project coordinator, Roquette America Inc., in the presentation “Formulating Batters and Breading for Reduced Fat Absorption in Fried Foods,” during Prepared Foods’ 2011 R&D Applications Seminar-East.

For example, in one research study (by Ann Dragich and John Krochta, University of California, Davis), it was determined that coating chicken strips with wheat flour; dipping them in a batter, then a 10% solution of whey protein isolate; and frying at 160°C for five minutes resulted in chicken strips with 31% less fat than control chicken strips fried without the whey protein isolate dip.

Perera provided an overview of research investigating the use of resistant dextrin, pea starch or bread crumbs made with corn, rice, potato and tapioca starch to coat foods—and their effectiveness at reducing fat uptake during frying.

Resistant dextrin can be made from corn or wheat starch through the steps of dextrinification and separation, followed by purification, drying and agglomeration. The ingredient can be labeled “dextrin,” “corn dextrin” or “wheat dextrin.” The indigestible 1,2 and 1,3 glucose linkages of resistant dextrin result in a high dietary fiber content. The water-soluble ingredient has a low viscosity, neutral taste and allows processing stability under conditions of heat (including sterilization), low pH and extrusion. It has excellent digestive tolerance and a low glycemic index (GI), and can function as a probiotic. It also can be used in beverages, bars, soups, baked goods and fruit preps, notes Perera.

Bread was prepared with resistant dextrin vs. all-purpose wheat flour (both at 46.9% of the formula), then processed into breadcrumbs and used to coat fish nuggets dipped in an egg wash. When fried at 195°C for three minutes, the prototype breaded fish with resistant dextrin was found to be less oily and crispier than the control fish.

When breadcrumbs were formulated with 42% corn, pea, tapioca, potato or rice starch plus 7.3% pea protein, breadcrumbs from rice were found to be the densest; those from corn and potato were the lightest; while pea and tapioca breads were in-between, in terms of crumb texture. “Upon frying, the breadcrumbs from rice became brown rapidly and provided very hard texture. Tapioca crumbs remained very soft upon frying and did not contribute to the crispiness. Pea starch-based crumbs had the highest crispiness upon frying,” Perera added.

Pea starch is of higher amylose content (about 35%) than standard corn or wheat starches; has good film forming properties and gel formation; demonstrates strong retrogradation; and requires less heat during processing due to its lower swelling temperature.

Pea starch gives greater crispiness and a longer bowl-life (crunchiness when liquid is added) in cereals. It provides crispiness and less softening in coated French fries; preserves crispiness of the crumb when battered microwaveable foods are heated; and helps prevent breaking in transparent noodles.

Finally, a combination that was 33% pea starch and 67% resistant dextrin was used to replace all-purpose flour in an application where chicken was dusted, then received an egg wash, then dusted again and fired in canola oil at 195°C for three minutes. The pea starch/dextrin coating reduced fat uptake by 30% compared to the control, Perera said.
Potato chips formulated with resistant dextrin showed reduced fat absorption compared to a control, and even less when a pea starch/dextrin combination was used.

Perera summarized the results by saying both resistant dextrin and pea starch in breading provide crispier texture to fried foods, and resistant dextrin helps to reduce fat absorption upon frying. Although pea starch itself does not provide significant reduction in fat absorption, a combination of resistant dextrin and pea starch does give improved crispiness and reduced fat absorption. Finally, she noted that breadcrumbs with rice and tapioca starches also had some effect on reducing fat absorption in fried foods.
 
“Formulating Batters and Breading for Reduced Fat Absorption in Fried Foods,” Chandani Perera, Ph.D., senior project coordinator, Roquette America Inc., Chandani. perera@roquette.com, 630-463-9431, www.Roquette.com
--Summary by Claudia D. O’Donnell, Contributing Editor

 

Formulating Cleaner Labels

Many consumers desire “cleaner” labels on the packaged foods and beverages they purchase. They generally are looking for a variety of characteristics, including: products taste as good as they look; they contain ingredients consumers know and recognize; products are convenient (e.g., can be reheated in the microwave), yet still have flexibility of preparation. Additionally, these products must have textures and flavors with which consumers are familiar, and they need to be of high quality. Desired products typically have traditional, authentic, home-style characteristics and/or are of restaurant quality. And, adds Leslie Drew, senior applications technologist for National Starch Food Innovation/Corn Products International, safety is a given. Drew presented “Use of Functional Native Starches” at the 2011 Prepared Foods’ R&D Applications Seminar in Chicago.
Drew continued to explain that the length of the ingredient list and the complexity of the actual ingredient label consistently influence consumers, with the result of “less being more.” The focus on health and well-being has resulted in a genuine desire to understand food better, she added. “Consumers welcome explanation of the origin and purpose of unusual or unpronounceable ingredients in, or next to, the ingredients’ label on the pack.” These are drivers behind clean labels.

Ingredients currently used in commercial seafood soup, a sweet cake-type dessert and a tartar sauce were shown by way of example. Drew placed certain ingredients consumers typically question into four functional categories: texturizing systems; emulsifiers; flavors, flavor enhancers and colors; and preservatives. She illustrated alternatives for the currently used ingredient systems and indicated how challenging replacement efforts can be. For example, natural flavor enhancers can relatively easily replace monosodium glutamate (MSG), but replacing DATEM (diacetyl tartaric acid ester of mono- and diglycerides) and polysorbate 80 emulsifiers with more “natural” sounding ingredients is difficult. Using functional native starches to replace modified food starch is of intermediate difficulty.

Traditional native starches can have consumer-friendly names, but they also have less desirable properties, such as a narrow peak viscosity range, highly limited process tolerance, undesirable textures and limited functional properties. In contrast, the benefits of functional native starches include tolerance to temperature, pH and shear. They have a smooth, short texture with a non-pasty mouthfeel. Lastly, they can be labeled according to their base description, i.e., “corn starch,” “maize starch” or “tapioca starch.”

Drew presented four application case studies in which foods were reformulated to have cleaner ingredient legends. The studies included “all-natural” salad dressing, fruit preparation, retorted soup and beef gravy.

In pourable creamy dressing, an instant functional native corn starch can be used to replace instant modified corn starch (a texturizer). Rosemary and green tea extract can replace EDTA (a chelating agent to prevent oxidation). Cultured dextrose can replace potassium sorbate (a microbial preservative), and natural flavor enhancer can replace MSG.

When the reformulated product was evaluated over the course of a year, sensory attributes—including flavor, color, microbial stability and granular integrity—“were similar or identical for control and ‘all-natural,’” said Drew. (See chart, p.52, “Control vs. ‘All Natural’ Salad Dressings.”)
In the case of a 40-42˚Bx (degree Brix) fruit preparation (such as is used in yogurt), the objective was to replace modified food starch with a functional native starch. The formulation challenge was that the all-natural fruit preparation needed to retain both textural stability (viscosity) and sensory attributes of flavor and texture over an 18-week shelflife, whether stored under ambient or refrigerated temperature, or put through 18 freeze/thaw cycles.

In the formulation, 5.0% functional native starch replaced 4.5% modified starch. A sensory ballot was then used to evaluate surface and edge syneresis, gelling, graininess and overall score, as well as flavor and overall appearance and texture. The end result was that the fruit prep with functional native starch was comparable to the original product with modified food starch. (A microscopy evaluation also showed both modified starch and functional native starch exhibited a “good cook.”)

Additional applications for functional native starches include chilled ready meals; soups and sauces; frozen ready meals/meal solutions; fruit preparations for pie fillings, yogurts/dairy applications; bakery fillings; creams/cooking creams; baby foods; and processed meat. pf

“Use of Functional Native Starches,” Leslie Drew, senior applications technologist, National Starch/Corn Products International, leslie.drew@nstarch.com, www.nationalstarch.com 
—Summary by Claudia D. O’Donnell, Contributing Editor