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Barley is rarely used in the food industry, even though it is a main source of β-glucans, which have important health benefits and a technological role in food. This work evaluated the humid extraction of barley β-glucans and partially characterized them. The extraction was studied using surface response methodology with both temperature and pH as variables. The extracted β-glucans were characterized by chemical and rheological analysis, infrared spectroscopy and scanning electron microscopy. The effect on extraction of linear and quadratic terms of pH and temperature corresponding to the regression model was significant, and we obtained a maximum concentration of 53.4% at pH 7.56 and temperature 45.5°C, with protein and mainly starch contamination. The extracted β-glucans presented a higher apparent viscosity than the commercial ones, the behavior of the commercial and extracted samples can be described as Newtonian and pseudoplastic, respectively. The results of infrared spectroscopy and scanning electron microscopy were characteristic of commercial β-glucans, indicating that this method is efficient for extracting β-glucans.

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The present work aimed to evaluate the effectiveness of whole grain consumption in preventing colorectal cancer. A systematic review with meta-analysis of 11 cohort studies was carried out. The age group of the population studied (1,719,590 participants) was between 25 and 76 years of age. The review evaluated the relative risks with the Cox proportional hazard model. The period of study varied from 6 to 16 years, where 7,745 persons developed colorectal cancer during the follow-up period. In the multivariate analysis, the highest quintile relative risk was 0.94 (95% confidence interval, 0.85-1.03), whereas that for the lowest quintile was 0.96 (95% confidence interval, 0.88-1.04). The location of tumors was also evaluated, with tumors in the colon demonstrating a relative risk of 0.93 (95% confidence interval, 0.83-1.02) and tumors in the recto a relative risk equal to 0.89 (95% confidence interval, 0.79-1.00). In this multivariate analysis, consumption of whole grains was inversely associated with the risk of developing colorectal cancer.

Plant sources are receiving special attention as feedstuffs in aquafeeds because of fish meal and oil shortage. However, studies about the effects of dietary fibre in fish are scarce. The inclusion of plant ingredients containing different levels of dietary fibre -broken rice (BR), ground corn (GC), wheat bran (WB), citrus pulp (CP) and soybean hulls (SH) were evaluated for the omnivores jundia´catfish and Nile tilapia. Tilapia is a typical omnivore with long intestines, whereas jundia´has short intestines and no pyloric ceca. Fibrous sources (CP, WB and SH) were less digestible for both species than the starchy ones (BR and GC). However, jundia´presented less ability to utilize the starch and protein from plant sources than tilapia. Growth of tilapia followed plant sources digestibility but no significant differences were detected for jundia´, probably because of its slower growth rate. Muscle layer was thicker in the distal intestine of jundia´fed CP diet, which possibly indicates an adaptation to propel the large volume of viscous digesta along the intestine. Therefore, despite its lower ability to utilize starchy plant sources, jundia´showed an adaptive capacity to utilize fibrous diets, which is in agreement with its omnivorous feeding habit.

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High oat content may be efficiently processed by optimizing the extruder conditions (temperature, screw speed, and profile), improving the nutritional properties of the final product. © 2017 Society of Chemical Industry.

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.