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The objective of this work was to evaluate the effects of drying, grinder type, and moistening conditions on the interparticle porosity of feed material and the torque supplied to the screw during the single-screw extrusion processing of brown rice. The grains were dried at 60 °C up to moisture contents of 9 and 6% and then milled using two grinder types (disc and roller). The milled products were moistened at levels to produce extruded snacks (11 and 14%). Irrespective of drying the grains, lower particle diameters in the fine and coarse fractions, and narrower distributions were obtained by grinding brown rice in a roller mill than in a disc mill. The disc mill products presented lower interparticle porosity and generated higher torque values than the roller mill products. A reduction in grain moisture from 9 to 6% only decreased the interparticle porosity of disc mill products and increased the torque. An increase in feed moisture from 11 to 14% only increased the interparticle porosity of roller mill products and decreased the torque regardless of grain moisture. This work contributed to understanding the impact of the morphology of the particles in the torque variability during the extrusion processing of brown rice. Few published works correlate physical properties of the feed material with extrusion dependent variables. In the present study, feed materials with high interparticle porosity were produced with roller mill and when extruded they generated low variabilities in the torque.

The aim of the present study concerns the development, characterization and sensory evaluation of a dual-functional whey hydrolysate. Four concentrations of commercial pepsin (0.48%, 0.95%, 1.43%, 1.91% w/w) were evaluated. The hydrolyses curves and the Reversed-Phase High Performance Liquid Chromatography analyses showed a direct relationship between enzyme concentration and degree of hydrolysis. Through mass spectrometry 21 peptides were identified and 5 of them have never been described in the literature before. The hydrolysate produced (PC3) induced a vascular relaxation of 65.02% in phenylephrine-contracted rat aortic rings. PC3 powder presented a homogeneous aspect with a mean particle size of 86.39 μm, high water solubility (>92%) in a wide pH range (1−12) and an increase of 33% in oil absorption capacity, when compared to the unhydrolyzed product. Sensory analysis showed a high acceptance (7.6 in a 9-point hedonic scale) of the hydrolysate among 100 consumers. The results brought the possibility of developing a whey hydrolysate with high vasorelaxant activity, great technological properties and sensory appeal, as an interesting dual-functional ingredient to be incorporated into food products.

International audience; Sorghum is a potential substitute for corn/wheat in cereal-based extruded products. Despite agronomic advantages and its rich diversity of phenolic compounds, sorghum kafirins group together and form complex with tannins, leading to a low digestibility. Phenolic content/profile by UPLC-ESI-QTOF-MSE and kafirins polymerization by SE-HPLC were evaluated in wholemeal sorghum extrudates; tannin-rich (#SC319) and tannin-free (#BRS330) genotypes with/without turmeric powder. Total phenolic, proantocyanidin and flavonoid contents were strongly correlated with antioxidant capacity (r > 0.9, p < 0.05). Extrusion increased free (+60%) and decreased bound phenolics (−40%) in #SC319, but reduced both (−40%; −90%, respectively) in #BRS330, which presented lower abundance after extrusion. Turmeric addition did not significantly impact antioxidant activity, phenolic content and profile and kafirins profile. Tannins presence/absence impacted phenolic profiles and polymerization of kafirins which appears related to the thermoplastic process. The extrusion improved proteins solubility and can positively enhance their digestibility (phenolic compounds-proteins interactions), making more accessible to proteolysis in sorghum extrudates.

Millet (Pennisetum glaucum) is a small gluten-free cereal originated from Africa that is not currently introduced in the Western diet. It is an interesting source of dietary fiber, vitamins, minerals, proteins and phenolic compounds superior to the most traditional consumed cereals. It is very effective crop adopted in no tilling farming system planted in a vast cultivated area in Brazil. Bread is a food product of high acceptance that is traditionally made from wheat, particularly from refined flours. However, it is known to present a high glycemic index and low levels of dietary fiber and naturally contains gluten proteins. The objective of this work was to develop whole grain bread using blends of raw and extruded flours from millet and to evaluate the physicochemical parameters in comparison to commercial whole bread products with and without gluten. The use of extrusion increased antioxidant capacity (215.2 ± 1.9 μM Trolox/g) and enzymatic inhibition (96.31 ± 0.005) in relation to the product elaborated from raw flour. Millet is presented as potential food interesting for the production of bread considered in the diet of Brazilian population, particularly to those suffering from gluten allergy and diabetes.

Extruded products were prepared from a corn flour and dehulled carioca bean (Phaseolus vulgaris, L.) flour blend using a single-screw extruder. A central composite rotate design was used to evaluate the effects of extrusion process variables: screw speed (318.9–392.9 rpm), feed moisture (10.9–21.0 g/100 g) and bean flour level (4.8–55.2 g/100 g) on the specific mechanical energy (SME), sectional expansion index (SEI), longitudinal expansion index (LEI), volumetric expansion index (VEI) and density (D) of the extrudates. The instrumental texture was also analyzed. The independent variables had significant effects on the physical properties (SEI, VEI and density) of extrudates, with the exception of SME and LEI. SEI increased with increasing screw speed, but a higher moisture and bean flour content resulted in decreasing SEI and VEI. The increase of moisture and bean flour increased the density of extrudates. According to texture analysis, some treatments with 30 and 45 g/100 g bean flour did not show significant differences when compared to commercial brand snacks. However, when combined with higher moisture content (≥19 g/100 g) and lower screw speed (≤333 rpm), the results of the expanded product were not satisfactory.

The diversity of sorghum grainsis relatedto their intrinsic properties, which include starch type,non-starch components and phenolic compounds. The latter are genotype dependent and affect the pericarp characteristics such as color and presence of a pigmented testa. This diversity can be valuable for developing new food products by thermoplastic extrusion intended for human consumption. Flours from sorghum grains from the genotypes of varied pericarp color: white (CMSXS180; 9010032), red (BRS 310; BRS 308) and light brown (BRS 305; 9929034) were processed in a co-rotating twin-screw extruder. Changes promoted by extrusion cooking were evaluated via specific mechanical energy (SME), die pressure, apparent density, sectional expansion index (SEI), water absorption index (WAI) and water solubility index (WSI). Pericarp color affected diepressure, apparent density and WSI values of extrudates. Light brown genotypes, rich in tannin and fiber content, generated the lowest die pressure and SEI values. Red genotypes presented the lowest SME and the highest WAI values. White genotypes presented intermediate SME and the highest die pressure values. These results reflect differences in starch conversion induced by the pericarp type. These results further suggest the potential use of pigmented sorghum extrudates for human consumption. Made available in DSpace on 2018-05-10T01:03:21Z (GMT). No. of bitstreams: 1 Physicochemicalproperties.pdf: 2413559 bytes, checksum: bbc0c369210dfb5a60600b95befc2684 (MD5) Previous issue date: 2014-01-23

In the production of oil from sesame (Sesamum indicum L.) seeds, a coproduct is obtained which is rich in protein and fiber contents. Mixtures of semi-defatted sesame cake (SDSC) (0–20%) and corn grits were processed in a single screw extruder at screw speed ranging from 324 to 387 rpm to improve the nutritional value of corn expanded extrudates. Chemical composition of raw and extruded materials, sectional expansion index (SEI), texture properties, color, paste viscosity, microstructure and sensory analysis of the extrudates were performed. The addition of SDSC increased protein, fat and ash content of corn extrudates, whereas carbohydrate content was reduced. The addition of SDSC reduced the sectional expansion of the corn extrudates and increased puncture force. SDSC–corn extrudates were darker than non-SDSC–corn extrudates. Increasing SDSC increased the number of cells similar to those of commercial corn extrudates with small cells. Sensory analysis showed 20% SDSC-corn extrudates to be acceptable and nutritional balanced. The use of SDSC on corn extrudates up to 20% is an alternative to improve nutritional value keeping good sensory characteristics.

The aim of this work was to formulate cookies using extruded flour from by-products of rice and common beans industries, such as broken rice and split old bean grains, in order to make available foods with added nutritional value as other options to consumers. The market of ready to eat and high quality products is increasing in the world considering the new habits and life style of modern consumers. Different proportions of rice and black bean (whole – WBF or peeled grain - PBF) pre-gelatinized flours were used to prepare the cookies by partially replacing the corn starch in the original recipe. The samples were characterized for physicochemical and sensory parameters. The final products showed an interesting nutritional composition. The increase of mixed flour on cookies formulation contributed to an increase of vitamin B content. There was no tannin content detected in the final products and the level of phytate was very low with no significant difference among samples. A significant difference between products was observed for some colour parameters. The sensory analyses showed that consumers “liked lightly” the cookies with 15% and 30% PBF and 15% WBF. Cookies formulated with WBF had lower acceptance by consumers in terms of appearance and only those with 30% WBF had an intermediate score (“neither like, neither dislike”) for global acceptability. Regarding texture, when a higher amount of both flour (PBF and WBF) was applied it was observed an increase of cookie hardness and fracturability values. In conclusion it is viable to produce acceptable cookies using a rice and black bean extruded flour and then diversify the application of these by-products generated by their processing industries.

Corn meal of various particle sizes ranging from 180 to 710 lm were processed in a twin-screw extruder to produce directly expanded extrudates. The extrusion process effects on the specific mechanical energy (SME), expansion indexes (radial, longitudinal and volumetric), pasting viscosity, water absorption index (WAI) texture properties, and microstructure were determined. Increasing the particle size decreased the SME input. Extrudates produced with corn meal of higher particle sizes expanded more than extrudates produced with smaller particle sizes. For all treatments there was no peak viscosity at 95 C. But expanded corn meal extrudate from the 180 lm fraction showed a discontinuous gel matrix phase. Increasing corn meal particle size decreased WAI values. The mechanical resistance of the extrudates from the smallest particle size was significantly higher (p < 0.05) than that of the largest particle size. The microstructure of raw corn meal revealed large fractured particles with small rounded particles adhering to the surface.

Maltodextrins show increasing industrial applications depending on the extent of the starch hydrolysis. This paper reports a relationship between morphological and physico-chemical characteristics of different maltodextrins (A, B, and C) in order to establish appropriate uses. The moisture content of the maltodextrins varied from 2.82 to 6.47% and true and bulk density, average particle size, and porosity of the maltodextrins ranged from 1.14–1.44 g/mL, 0.33–0.49 g/mL, 39.44–289.17 μm, and 59.70–67.58%, respectively. Spherical, irregular, and filamentous shapes conduct to low values of wetting times. The increase in the DE level of maltodextrins from the same botanical source caused a decrease in the dissolution time. Results demonstrated that products obtained by supplier B showed the best performance and regularity in the dissolution/dispersion characteristics in water meanwhile maltodextrins manufactured by supplier A would be favored by an agglomeration process.

Pereskia aculeata Miller is a native cactus that can be found in Brazil and is called 'ora-pro-nobis' (OPN). Many people from poor communities consume the dark green leaves of OPN as a vegetable. The objective of the present work was to evaluate the nutritional components in terms of proximate composition, minerals, vitamins, protein content and their in vitro protein digestibility. OPN leaves showed remarkable levels of total dietary fiber (39.1% dry basis), minerals (calcium, magnesium, manganese and zinc) and vitamins (vitamin A, vitamin C and folic acid). Among amino acids, tryptophan was the most abundant (20.5% of the total amino acids) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed small peptides, inferior to 6.5 kDa, and four major bands (61 kDa, 53 kDa, 33 kDa, and 15 kDa). The protein digestibility corrected amino acid score showed the lowest value of sulfur-amino acids (Met+Cys). OPN leaves could be considered a good source of minerals, vitamins and amino acids, and may serve as a potential functional ingredient.

The physical and physicochemical characteristics of blueberry (Vaccinium myrtillus) fruits produced in Brazil were analyzed. Rheological properties were measured at 5, 25, 45 and 65 °C, on a stress controlled rheometer equipped with grooved a stainless-steel parallel-plate in a shear rate range of 0-300 s-1, with the objective of determining the influence of temperature on the rheological properties. The pseudoplastic behavior with yield stress was well described by the Ostwald-de-Waele (Power Law), Herschel-Bulkley (HB) and Mizhari Berk models. The yield stress and behavior index decreased with the increase in the temperatures for 5, 25, and 45 °C whereas for the temperature of 65 °C the effects were the opposite exhibiting elevated values. The viscosity decreased with an increase in temperature, and the Arrhenius equation described adequately the effect of temperature on the apparent viscosity of the puree, in which the activation energy (Ea) determined at a shear rate of 100 s-1 was 9.36 kJ.mol-1. As características físicas e físico-químicas do mirtilo (Vaccinium myrtillus) produzido no Brasil foram analisadas. As propriedades reológicas foram medidas em 5, 25, 45 e 65 °C, em um reômetro de tensão controlada equipado com geometria rugosa de placas paralelas com taxa de deformação variando de 0-300 s-1 com o objetivo de verificação da influência da temperatura no comportamento do fluido. O comportamento pseudoplástico com tensão residual foi bem descrito pelos modelos de Ostwald-de-Waele (Lei da Potência), Herschel-Bulkley (HB) e Mizhari Berk. A tensão residual diminuiu com o aumento da temperatura para 5, 25 e 45 °C, enquanto que para 65 °C os efeitos foram contrários, exibindo elevados valores. A viscosidade diminuiu com o aumento da temperatura e a equação de Arrhenius apresentou uma boa descrição do efeito da temperatura na viscosidade aparente do mirtilo, e a energia de ativação (Ea) determinada para uma taxa de deformação de 100 s-1 foi 9,36 kJ.mol-1.