RESUMO

Gluten-free batters, in general, require the incorporation of agents to control their rheology; this role is commonly played by hydrocolloids. New natural sources of hydrocolloids are under permanent research. In this regard, the functional properties of the galactomannan extracted from the seed of Gleditsia triacanthos (Gledi) have been studied. In this work, we evaluated the incorporation of this hydrocolloid, alone and in combination with Xanthan gum, in gluten-free batters and bread and compared it with Guar gum. The incorporation of hydrocolloids increased the viscoelastic profile of the batters. Gledi addition at 0.5% and 1.25% increased the elastic modulus (G') by 200% and 1500%, respectively, and similar trends were observed when Gledi-Xanthan was used. These increases were more pronounced when Guar and Guar-Xanthan were used. The batters became firmer and more elastically resistant because of the addition of hydrocolloids; batters containing Gledi had lower values of these parameters than batters containing Gledi-Xanthan. The addition of Gledi at both doses significantly increased the volume of the bread compared to the control by about 12%, while when Xanthan gum was included, a decrease was observed, especially at higher doses (by about 12%). The increase in specific volume was accompanied by a decrease in initial crumb firmness and chewiness, and during storage, they were significantly reduced. Bread prepared with Guar gum and Guar-Xanthan gum combinations was also evaluated, and the trends observed were comparable to that of bread with Gledi gum and Gledi-Xanthan gum. The results showed that Gledi addition favors the production of bread of high technological quality.

RESUMO

The aims of this work were to assess the influence of the physicochemical composition of whole flour from soft and hard wheat genotypes on cookie and bread properties, as well as the ability of the prediction tests to estimate the whole meal flour end-use. Flours from hard and soft wheat genotypes proved to have different chemical composition and particle size distribution. Flours from hard wheat had lower particle average size and dietary fiber content, and higher lipid and wet gluten contents than flours from soft wheat. Particle size distribution, water absorption capacity and chemical composition of whole flours strongly influenced bread and cookie making performance. Considering prediction tests, flours from different wheat types were successfully discriminated using SDS-SI, SRC lac, and GI. However, rather weak correlations were found between the prediction test and the cookie and bread quality parameters. The prediction test, standardized for refined flours, showed a poor performance when whole flours were used. Nevertheless, grain texture and whole flour physicochemical properties did affect bread and cookie quality parameters, thus classical prediction tests should be modified in order to estimate the end-use performance of whole flours. Moreover, a standardization of the milling process should be considered.

RESUMO

The selection of lactic acid bacteria strains is interesting for the development of sourdough to obtain wheat bread with improved technological and nutritional properties. In this work, the performance of ten different LAB strains isolated from diverse cereals in wheat sourdough was evaluated. Five facultative heterofermentative (Lactobacillus pentosus ES124, Lactobacillus paralimentarius ES259, Lactobacillus plantarum ES137, Lactobacillus plantarum ATCC8014 and Lactobacillus plantarum ES147), three obligately heterofermentative (Lactobacillus brevis ES253, Lactobacillus fermentum ES142 and Lactobacillus fermentum ES148) and two homofermentative (Pediococcus acidilactici ES22 and Enterococcus faecium ES74) lactic acid bacteria strains were evaluated in ten single strain fermentations. Sugar profile, volatile compounds and proteolytic ability of sourdoughs were analyzed. The microbiological counts showed that facultative heterofermentative strains presented higher counts than homofermentative sourdoughs. Monosaccharides (glucose and fructose), maltose and sucrose, isomaltose and dextrin were detected in fermentations with homofermentative strains whilst in those with heterofermentative strains maltose/sucrose, isomaltose and dextrin were found. L. paralimentarius ES259 and L. pentosus ES124 showed the highest diversity of volatile compounds. L. plantarum ES137 and P. acidilactici ES22 were the strains with the highest proteolytic activity. The technological performance allowed us to select LAB as starters to develop breads with specific rheological properties and final quality.

Assuntos

Lactobacillales , Triticum , Pão/análise , Fermentação , Microbiologia de Alimentos , Lactobacillus

RESUMO

Studies on Argentinian soft wheat cultivars are scarce, although the flours obtained from these wheats are the most suitable for cookie making. This work studies the behavior of the flours obtained from 44 adapted soft wheat lines harvested in two consecutive years for cookie making, focusing on starch properties. Starch granule size distribution, and thermal and pasting properties of flour samples were studied. Large variations in flour and starch characteristics were found between all experimental lines, indicating a wide variability among wheat genotypes and a noticeable effect of crop year conditions. Starch granule size distribution showed the typical bimodal distribution observed for wheat. Flours with higher proportion of large A-type granules were associated with lower damaged starch (DS). As expected, the lower the DS content, the lower the solvent retention capacity, gelatinization temperature and enthalpy, with a positive impact on cookie diameter. Flours from soft wheat genotypes with higher proportion of large A-type granules were associated with lower DS content and reduced water absorption capacity. Both genotype and environment exert an effect on soft wheat flour characteristics.