Semester of Graduation

Summer 2019

Degree

Master of Science (MS)

Department

Nutrition and Food Sciences

Document Type

Thesis

Abstract

Gluten sensitivities and intolerance disorders such as Celiac disease are being diagnosed more every day which has opened a huge market for gluten-free foods that is expected to reach nearly $7.6 billion by 2020. About 30% of the US population says they are trying to cut-down on or avoid gluten completely, with only 7% doing so for medical reasons. Although there are gluten-free alternatives available to use in cooking and baking, simple substitution of these flours for wheat does not produce acceptable texture characteristics. Gluten-free baked goods suffer from being low in nutritional value such as protein and fiber content while having a high glycemic index, which is driving the need for further research. Rice is the third most globally produced cereal and is being used regularly in gluten-free product development due to its hypoallergenicity, white color, bland taste, and easy digestibility. Rice is not a good source of protein with an average of only 6.4 percent per serving. New rice varieties are being cultivated to yield higher protein contents and overall nutritional value. The purpose of this study was to survey products in the market that contain rice flour as a predominant ingredient and replacement for wheat, in order to determine which products to focus on re-formulating with higher protein rice flour.

Grocery stores in the Baton Rouge, Louisiana area ranging from low-cost to premium were examined and product details were documented and analyzed. A total of 393 products among 5 stores listed rice flour as a primary ingredient and most were certified gluten-free. The most common product types were chips, crackers, cookies, and cakes. Thirty-five percent of the items surveyed contained one to three different gums. Sorghum flour, rice starch, potato starch, tapioca starch, and/or cornstarch were used in 60% of products in addition to rice flour. Pasta and protein bars were among the most protein dense foods with averages of 5.03 and 4.77 grams of protein per serving. There is a need for acceptable gluten-free foods that are more nutrient rich, especially with protein. Results indicated that baked goods should be the focus for development of higher protein rice flour-based products.

High protein rice flours were compared to commercial rice flours containing regular protein levels. Flour analyses included pasting properties by RVA, starch, protein, fat, and fiber content. Muffins and bread were prepared with standard bakery ingredients, a hydrocolloid, and combined in a specific manner to achieve a desirable texture. Color and texture analyses were conducted on products made with high protein rice flours and compared to commercial brown rice flour. A sensory study was done with consumers who were asked to rate their liking of the appearance, aroma, texture, and taste of the products. The only difference between the muffins was the type of rice flour used. The brown and white high protein rice flours were found to have protein contents of 8.43% and 7.12%, respectively. Results of the sensory study favored products made with high protein rice flour over commercial brown rice flour. Utilization of rice flour with greater protein content may result in comparable flavor and texture characteristics to traditional rice flour baked goods while also adding nutritional value in terms of protein for gluten-free foods.

Committee Chair

King, Joan

DOI

10.31390/gradschool_theses.4967

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