Anthocyanins can be incorporated into vegetables as a strategy of fortification and/or colour change. Some technologies, such as pulsed electric fields (PEF) can modify the vegetable structure, also changing the incorporation kinetics. This work evaluated the different colours (red and blue) anthocyanin incorporation into potato slices PEF pre-treated. PEF processing was performed using an electric field strength of 600 V/cm. The samples were distributed inside the treatment chamber containing tap water and with a gap between electrodes of 8 cm. Treatments consisted of the application of 75 pulses of 25 μs with a frequency of 10 Hz (total energy of 762.75 J/kg). After PEF treatment, the anthocyanins incorporation were conducted using solutions of 2 g/L of commercial anthocyanin from red cabbage with colour red (pH 2) and blue (pH 8.7). The samples slices (thermally bleached: > 98 °C for 60 s) were immersed into the solutions (1:4.3) up to 50 min, with agitation to 150 rpm at room temperature. After treatment, the samples were washed with water (5 s) and then dried with paper. Anthocyanins quantification was conducted using differential pH method and the colour evolution was measured with a colorimeter. The Peleg and Weibull Models were chosen to describe the impregnation kinetics. Higher anthocyanin contents were obtained with red colour anthocyanin extract. The anthocyanin content and the samples colour stabilized after 30 min using the red extract and at 35 min using the blue extract. In fact, the lower value of the kinetic model parameters of red colour extract (k1 ~31.05 min -1; β ~ 11.52 min) indicated higher initial rate of incorporation than blue colour ones (k1 ~ 50.61 min -1; β ~14.62 min). Therefore, it was possible to evaluate the kinetics of anthocyanin incorporation in potato slices treated with PEF, which could help to the process efficiency.

Thermal processing is still the most important method to ensure food safety, however, there is a need for further improvements, from basic data to advanced optimization methods. Due to the competitive market, customer demands and environmental concerns, several challenges have been raised. In this review, some important topics are discussed, including inactivation kinetics, engineering properties, process design and control, packaging systems and regulatory, environmental, and economic aspects. This position paper describes our opinion about the main challenges associated with thermal processing (conventional and alternative technologies, as microwave and ohmic heating), as well as some possibilities to deal with them.

This study evaluated the effects of ethanol pre‐treatment on convective drying and its impacts on the bioactive compounds of uvaia. The treatments consisting of control and samples pre‐treated by immersion in ethanol (99.8% v/v) for 10 and 20 min, followed by convective drying (1 m/s) at 40 and 60°C. The sample temperatures were traced over processing and the products were evaluated in relation to their content of phenolic compounds and antioxidant capacity. Pre‐treatment times in combination with temperatures influenced drying time and were associated with ethanol penetration and volatility in the sample. Furthermore, the high vapor pressure of ethanol reduced the initial temperature of the samples. Drying temperatures and pre‐treatments reduced by 16%–34% phenolics compounds and 13%–45% antioxidant capacity, which was associated with degradation and possible extraction by ethanol. The advantages of using ethanol were discussed, but also some limitations, especially on bioactive compounds. Uvaia is a native fruit rich in sensory and healthy aspects. However, its high perishability and seasonality make it unfeasible for post‐harvest commercialization. This work demonstrated that drying and application of ethanol proved to be effective for preserving this fruit, resulting in a shorter processing time. Although ethanol partially extracted the bioactive compounds, significant levels are still found in the final product—which can be used as convenient products with a positive impact on consumers' health. Furthermore, the proposed approach is simple, relatively cheap, and viable techniques to obtain stable products for both industry and small producers.