Evaluation of the technological, nutritional and sensory qualities of bakery products produced with partial substitution of the wheat flour by whole rice flour

AUTOR(ES)
FONTE

Braz. J. Food Technol.

DATA DE PUBLICAÇÃO

01/09/2016

RESUMO

Summary The objective of this work was to determine the technological, nutritional and sensory characteristics of bread produced by substituting 25 and 50% of conventional wheat flour by whole rice flour (Oryza sativa L). The final products were evaluated in terms of specific loaf volume, appearance of the central slice, crumb firmness, moisture content, dietary fibre, phytates, minerals, kinetics of amylopectin retrogradation determined by differential scanning calorimetry, and a sensory evaluation using a 9-point hedonic scale. In general, the addition of whole rice flour to the formulation showed significant differences in the kinetics of amylopectin retrogradation as comparing to the control sample (retrogradation enthalpy changed from 2.4 to 1.8-2.1 J/g). It also caused a decrease in the specific volume of the bread (from 4.48 to 2.26-2.86 cm3/g) which was directly related to an increase in crumb firmness (from 0.77 to 1.90-3.85 N). However, good overall sensory consumer acceptance (7.2-7.3) was observed. As for the minerals, calcium and zinc may be bioavailable in the 25% formulation and in the control samples. In products with whole rice flour, a significant increase in the triphosphate myo-inositol level (from negligible values to 0.38-0.44 μmoles/g) was observed, which is considered to exert positive biological activity in the body. It is important to consider that mineral bioavailability in whole grain products is related to the formulation and the bread-making process, basically due to the presence of phytates. In fact, a high proportion of phytates was present in the formulation with 50% of whole rice flour, so low mineral bioavailability was expected as predicted by phytate/mineral molar ratios above the threshold for the inhibition values for iron and zinc absorption.

ASSUNTO(S)

whole rice flour bread quality mineral availability phytates sensory evaluation amylopectin retrogradation

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