The convective drying of apples from two different cultivars, Golden Delicious and Granny Smith, in a range of temperatures from 30 to 60°C is studied. Some chemical and physical properties were determined fresh after drying: moisture, acidity and sugar content, color, and textural attributes, in order to evaluate the effect of drying and drying temperature on these properties. Furthermore, the drying kinetics were studied in terms of thin layer models and also by means of the Fick’s equation of diffusion, and some mass transfer properties were evaluated, such as effective moisture diffusivity and convective mass transfer coefficient. It was concluded that drying decreased both acidity and sugar content for both apple cultivars. Color was significantly affected by drying, resulting in high values of the total color difference, between 19.43 and 25.04. Drying turned the products less hard and less cohesive. Furthermore, it was found that mass diffusivity increased with temperature following an Arrhenius type function, where D_e⁰ was 5.4621 × 10⁻⁴ and 1.8401 × 10⁻⁴ m²/s, and E was 35.3 and 32.8 kJ/mol, respectively, for cultivars Golden Delicious and Granny Smith.

Background: Beetroot is reported as an important source of polyphenols as well as betalains, which are compounds that possess high antioxidant effect and radical scavenging capacity. Objective: The present study aimed at identifying the most suitable extracting parameters to attempt maximizing the recovery of phenolic compounds with antioxidant activity in beetroot. Methods: Grounded beetroot was used to perform extractions with different aqueous solutions (ethanol at 50% and acetone at 60%), for different times (15 and 60 min), using different volumes of the extraction solution (25 and 50 ml). For each of the combinations three successive extraction steps were performed and in each extract were quantified the Total Phenolic Compounds (TPC), the anthocyanins (ANT) and the antioxidant activity (AOA), all by spectrophotometric techniques. Results: The results indicated the usefulness of using three successive extraction steps over the same sample besides clearly indicating clearly that an extraction time of 15 min was sufficient. It was further observed that 50 ml of extraction solvent were preferable than 25 ml and the best solution was acetone at 60%. The TPC in the fresh beetroot varied from 1.45 to 2.70 mg GAE/g, the ANT from 0.23 to 0.77 mg Mv3G/g and the AOA from 13.9 to 19.9 µmol TE/g. Conclusion: It was concluded that the method of using three successive extraction steps of 15 minutes each was appropriate to increase the recovery of phenolics with antioxidant activity from beetroot.

This paper presents an experimental method using computer-based image processing techniques of visual and infrared movies of a propagating fire front, taken from one or more cameras, to supply the time evolutions of the fire front shape and position, flame inclination angle, height, and base width. As secondary outputs, it also provides the fire front rate of spread and a 3D graphical model of the fire front that can be rendered from any virtual view. The method is automatic and non-intrusive, has space–time resolution close to continuum and can be run in real-time or deferred modes. It is demonstrated in simple laboratory experiments in beds of pine needles set upon an inclinable burn table, with point and linear ignitions, but can be extended to open field situations.