O trigo é um cereal que pode ser utilizado na elaboração de produtos, como pães, bolos, biscoitos e massas, razão por que seu consumo é incentivado. A composição química do grão de trigo (umidade, carboidratos, proteínas, lipídeos, minerais) afeta as características funcionais tecnológicas e, juntamente com as propriedades estruturais, define a qualidade da farinha de trigo. Dentre os constituintes do trigo as proteínas de reserva são o principal responsável pela funcionalidade do trigo, a fonte de destaque das propriedades viscoelásticas da massa, ou seja, o glúten, que tem papel fundamental na panificação. A composição química determina o comportamento reológico da massa que pode ser verificado através de análises reológicas, como: análise do glúten, farinografia, extensografia, análise da atividade α-amilásica e análise rápida de viscosidade.

Food texture is one of the most widely measured quality attributes during processing and consumption, being measured by instrumental and sensory means. The aims of this study were to measure the textural parameters of the crumb of 14 whole-wheat bread loaves made with whole-wheat flour and fat replacer using instrumental methods and a sensory trained panel, and to determine the relationship between instrumental and sensory assessments. The data of instrumental and sensory texture were individually subjected to analysis of variance and correlated using principal component analysis. The analyses showed that for both (instrumental and sensory texture), the less firm, more elastic and more cohesive bread loaves have <60% whole-wheat flour, regardless of the content of fat replacer. The hardness attribute, measured with a texturometer, was consistent with the results of other published works and with our sensory evaluation as the matrix showed correlation coefficients with high values.

The cellular structure of healthy food products, with added dietary fiber and low in calories, is an important factor that contributes to the assessment of quality, which can be quantified by image analysis of visual texture. This study seeks to compare image analysis techniques (binarization using Dtsu's method and the default ImageJ algorithm, a variation of the iterative intermeans method) for quantification of differences in the crumb structure of breads made with different percentages of whole-wheat flour and fat replacer, and discuss the behavior of the parameters number of cells, mean cell area, cell density, and circularity using response surface methodology. Comparative analysis of the results achieved with the Dtsu and default ImageJ algorithms showed a significant difference between the studied parameters. The Dtsu method demonstrated the crumb structure of the analyzed breads more reliably than the default ImageJ algorithm, and is thus the most suitable in terms of structural representation of the crumb texture.Keywords: Dtsu and default algorithms; binarization; ImageJ. Practical Application:The structural elements of food products such as breads can be quantified by image analysis, contributing to the understanding of quality-related properties such as texture, because to prepare bread with whole-wheat flour (whole grain milled) and fat-replacer (enzymatically modified corn starch) is a challenge. To quantify the differences in crumb structure features of 14 different types of whole-wheat breads made with fat replacer, was used two different image thresholding techniques (binarization using Dtsu's method and the default ImageJ algorithm), using free softwares (GIMP and ImageJ).

No abstract

Bread characteristics are dependent upon the chemical composition and fiber content of the wheat flour used. A healthy diet can help prevent chronic diseases, where whole grains and fewer calories from fat are components of a healthy diet. The aims of this study were to determine the centesimal composition of wheat flour samples (whole, refined, and flour blends) along with their farinographic parameters (water absorption, development time and stability) and also to verify the specific volume, crumb texture profile and digital imaging of bread loaves made with 60% whole wheat flour and 3% fat or fat replacer. Increasing the whole wheat flour percentage in the blends also increased levels of protein, ash and insoluble fiber. All the farinographic parameters were also increased. Enzymatically modified starch was found to be an effective fat replacer in whole wheat loaves. The loaves made using fat replacer had the same specific volume and higher cell density as those made with fat, but exhibited different texture profile parameters such as higher hardness value and lower springiness value.Uniterms: Wheat flour/centesimal composition. Whole wheat bread/characteristics. Fat/replacers. Food fibers.A composição química da farinha de trigo e a presença de fibras afeta as características dos pães. Uma forma de contribuir com a prevenção de doenças crônicas não transmissíveis é através de alimentação saudável, incluindo grãos integrais na dieta alimentar e reduzindo as calorias de determinado alimento, substituindo a gordura. Assim, este trabalho tem como objetivo determinar a composição centesimal das amostras de farinha de trigo integral, refinada e as misturas entre elas; bem como os parâmetros farinográficos (absorção de água, tempo de desenvolvimento e estabilidade) das mesmas. Além disso, verificar volume específico, perfil de textura do miolo e análise de imagem de pães elaborados com 60% de farinha de trigo integral e com 3% de gordura ou com substituto de gordura. Os dados foram submetidos à análise de variância. À medida que aumenta o percentual de farinha integral, os teores de proteína, cinzas e fibra insolúvel alcançam valores significativamente maiores e a absorção de água fica maior na farinografia, bem como o tempo de desenvolvimento e a estabilidade. O amido modificado enzimaticamente utilizado na elaboração de pão com 60% de farinha de trigo integral funcionou como um efetivo substituto de gordura. O pão integral elaborado com substituto de gordura apresentou volume específico significativamente igual ao pão integral elaborado com gordura, porém com diferenças em relação a parâmetros do perfil de textura, maior firmeza e menor elasticidade além de maior densidade celular do que o pão elaborado com gordura.Unitermos: Farinha de trigo/composição centesimal. Pão de trigo integral/características. Gordura/ substitutos. Fibras alimentares. INTRODUCTIONWheat is one of the ten most important commodities globally (FAO, 2010) and numbers among the world's 'big three' cereal crops in terms of harvested area. Whe...