Valorização de subprodutos da indústria arrozeira para desenvolvimento de uma mix isenta de glúten para bases de pizza

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia

The present work has as purpose to develop a pizza base for a targeted customer suffering from the celiac disease, valuing by-products from the rice industry, namely flour of broken rice and rice bran. The aim of this study is to develop a mix, for pizza base, designed for home preparation, increasing the market supply of gluten-free products to lower the prices normally associated with this kind of products. Today Portugal can count with 15 permanent industries in rice milling (Ania, 2010). The by-products from the processing of the agro-industry raw materials from rice are usually considered as non-hazardous, abundant, easily biodegradable, cheap and potentially recoverable. However, there may be an economic problem, due to the large quantities processed, thus imposing a productivity burden significant in this sector. The production of gluten-free bakery products presents a technological challenge, due to the limited capacity of the gluten-free doughs in sustaining the CO2 produced during fermentation. We studied the effect of various ingredients added to the pizza dough. These studies were carried out at the level of texture - Texture Profile Analysis and Cutting test; rheology - test of stress and frequency sweep; aw (water activity), and the expandability of the dough throughout the fermentation (over-run percentage). A sensory testing was performed to the pizza bases with a panel of non-celiac tasters. From the results, the formulation F5 with 33% of rice bran and 4% of broken rice flour was emphasized, which led to better technological and sensory characteristics with rheological characteristics similar to commercial gluten-free pizza base. A comparison of nutritional formulation developed in this study was also performed with two commercial mixes, a gluten-free one and another whole meal with gluten