This work aims to evaluate the starch/water concentrations (3.6%, 7.1%, 10.7% and 14.3%) effect of different commercial starch sources (namely cassava, maize, high-amylose maize, waxy maize and potato) regarding their pasting properties by using a Rapid Visco Analyser (RVA), gel strength, and intrinsic characteristics (such as morphology, granules size and distribution). The results showed that the 10.7% concentration (standard concentration usually used for evaluating starch properties) is not always predictive for the starches rheological behaviour. Meanwhile, the characteristics of the formed gels were not only related to RVA properties. For instance, decisions based on the results using the concentration of 10.7% can be far different from those used in industrial applications. The data reported can be useful to demonstrate how conditions, properties and starches characteristics are c...

ABSTRACT This work aimed to automate the most popular method to determine the cooking time of grains: the Mattson Bean Cooker apparatus. The proposed system is a low-cost and a simple approach, offering the possibility of calibration according to the size of the analyzed grains. The automation is based on the use of magnets, Hall effect sensors, potentiometers, and an operational amplifier to monitor the plungers' positions. The time required for each grain to be cooked is shown in a LCD display, and the connection among all the components is made by an ATmega328 microcontroller from the Arduino UNO R3 board. The proposed system can be assembled in an already existent device, costing ~US$200. Its validation was made with two different grains: carioca beans (Phaseolus vulgaris) and lentils (Lens culinaris). Despite the differences between sizes, both grains were suitably analyzed with the...

This work aims to evaluate the starch/water concentrations (3.6%, 7.1%, 10.7% and 14.3%) effect of different commercial starch sources (namely cassava, maize, high-amylose maize, waxy maize and potato) regarding their pasting properties by using a Rapid Visco Analyser (RVA), gel strength, and intrinsic characteristics (such as morphology, granules size and distribution). The results showed that the 10.7% concentration (standard concentration usually used for evaluating starch properties) is not always predictive for the starches rheological behaviour. Meanwhile, the characteristics of the formed gels were not only related to RVA properties. For instance, decisions based on the results using the concentration of 10.7% can be far different from those used in industrial applications. The data reported can be useful to demonstrate how conditions, properties and starches characteristics are c...

ABSTRACT Different drying accelerators were studied to improve vegetable drying: acetone (AC), ethanol (ET), isopropanol (ISO) and acetic acid (AA). Pre-treatments were performed by immersion of pumpkin cylinders. Convective drying was performed at 40 °C and air velocity 1 m/s. Different aspects were evaluated: drying kinetics, structural changes (microstructure and macrostructure), thermal profile and viscoelastic and rehydration behaviours. The microstructure was modified by pre-treatments, being more pronounced with AC and AA. Thinner cell walls, changes on turgor and extraction of components and air were reported, affecting the mass transfer. Moreover, the microstructural changes reinforced anisotropy and also affected the macrostructure, changing the viscoelastic behaviour. All pre-treatments resulted in a super-diffusive behaviour, decreasing the drying time from 9% (ISO) to 22% (...

ABSTRACT This work aimed studied the effect of ionizing irradiation on the nutritional and technological properties of cooked Carioca beans (Phaseolus vulgaris). The dry beans were irradiated with different doses (1, 5 and 10 kGy) of γ-radiation using 60Co as source. The composition and nutritional properties (protein, fat, ash, tannin, phytic acid content and protein in vitro digestibility) of the cooked beans were analyzed, with and without previously soaking process. In addition, the technological properties (hydration index, cooking time and color) of the beans were also evaluated. The results showed that protein, fat, ash and tannin content, as well as color, were not affected by irradiation, while the phytic acid was significantly reduced by the irradiation. Further, hydration index was slightly reduced only by using 10 kGy suggesting probable structure changes. Irradiation re...

ABSTRACT Ultrasound was combined with ethanol to improve different aspects of carrot convective drying, evaluating both processing and product quality. The ultrasound in water treatment resulted in cellular swelling and small impact on texture. Differently, the ultrasound in ethanol and ethanol treatments modified both carrot microstructure (cell wall modifications of parenchymatic tissue) and macrostructure (shrinkage and resistance to perforation). Pre-treatments with ultrasound in ethanol and ethanol improved the drying kinetics, reducing the processing time (~50%) and the energy consumption (42–62%). These pre-treatments also enhanced rehydration, whose initial rate and water retention were higher than the control. In addition, the carotenoid content was preserved after drying, for all the treatments. Any impact on shrinkage was observed. A mechanistic discussion, based on structur...

Ultrasound was combined with ethanol to improve different aspects of carrot convective drying, evaluating both processing and product quality. The ultrasound in water treatment resulted in cellular swelling and small impact on texture. Differently, the ultrasound in ethanol and ethanol treatments modified both carrot microstructure (cell wall modifications of parenchymatic tissue) and macrostructure (shrinkage and resistance to perforation). Pre-treatments with ultrasound in ethanol and ethanol improved the drying kinetics, reducing the processing time (similar to 50%) and the energy consumption (42-62%). These pre-treatments also enhanced rehydration, whose initial rate and water retention were higher than the control. In addition, the carotenoid content was preserved after drying, for all the treatments. Any impact on shrinkage was observed. A mechanistic discussion, based on structura...

ABSTRACT Cassava, corn and potato starches were subjected to ozone processing under the same conditions, in order to allow comparisons. The molecular structure was evaluated using two chromatographic analyses: high-performance size-exclusion chromatography (HPSEC) coupled to multiangle laser light scattering (MALLS) and differential refractive index (RI) detectors, and gel permeation chromatography (GPC). Both proved the molecular depolymerization caused by ozonation, as well as illustrated the different behavior of each starch source – in special in relation to their molar mass dispersity. The granular morphology was not affected by ozone processing. On the other hand, the starch properties were affected by ozonation. In general, the apparent viscosity decreased during pasting, as well as the complex modulus (G*) of the immediately formed gels. After cooling and storage, however, the ...