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The growing global demand for food has required innovations in the techniques of processing and conservation of food raw materials. An alternative to expand food availability is to apply technologies aimed at preserving and increasing the durability of materials, in addition to significantly reducing waste. Currently, the food industry has stood out with the application of drying techniques for better conservation and marketing. This review presents studies carried out in the last decade on developments in new drying technologies, the improvement of techniques and their advantages and disadvantages. Thus, the aim is to show the relevance of this food processing technique and its advances regarding the techniques applied in food, given the complexity of the composition of food raw materials.

The objective of this study was to evaluate the drying kinetics of the mass of jambu leaves and mass of jambu leaves in foam mat at different temperatures (50, 60 and 70 °C and thickness of 1.0 cm). The physicochemical characterization of the materials was performed before and after drying. Twelve different drying models were fitted to the drying kinetics data and the thermodynamic properties were calculated. The physicochemical parameters for the mass of leaves and foam after drying were moisture content from 2 to 7%, ash from 13 to 17%, protein content from 22 to 30%, lipids from 0.6 to 4% and total titratable acidity from 0.20 to 0.28% of tartaric acid. Wang & Singh and Midilli models were recommended for describing the drying kinetics. The use of foam mat promoted higher values of effective diffusion coefficient and activation energy and lower values of enthalpy and entropy, thus enhancing the reduction of drying time.

Among the bioactive compounds that are considered important for the food industry, anthocyanins, which are flavonoid compounds presenting antioxidant activity and are responsible for beneficial health effects, have received researchers' attention in the last decades. In addition, anthocyanins are highly reactive and can be used as indicators of foodstuff quality conditions, particularly as a packaging ingredient. Considering this line of work, the eco-friendly film is a novel packaging technology that arose from the concern to reduce non-renewable resources and their impact on the environment. These films can be vehicles for loading bioactive compounds such as anthocyanins. Among the contribution of films in the food industry, we can highlight several potential applications: i) smart film: assess food quality and safety, transmitting food information to consumers and increasing the reliability of their consumption without breaking the packaging; ii) active film: use to preserve food quality through the release of active agents; and iii) bioactive film: carry substances in desired concentrations until their controlled or rapid diffusion within the gastrointestinal tract so that they can promote its benefit to human health. Thus, this review presents anthocyanin extract's potential as a powerful tool to improve the development of eco-friendly films, directing its purpose to the application as smart, active, and bioactive films.

The aim of this paper was to analyze the drying kinetics, test the Akaike information criterion (AIC) and Schwarz’s Bayesian information criterion (BIC) in the selection of models, determine the effective diffusivity and activation energy of the crushed mass of ‘jambu’ leaves for different conditions of temperature and layer thicknesses. The experiment was carried out at the Food Laboratory of the Brazilian Agricultural Research Corporation (Embrapa) in Macapá-AP. Drying was carried out in air circulation oven with speed of 1.0 m s-1 at various temperatures (60, 70 and 80 ºC) and layer thicknesses (0.005 and 0.010 m). The experimental data were fitted to 11 mathematical models. Coefficient of determination (R2), mean relative error (P), mean estimated error (SE), Chi-square test (χ2), AIC and BIC were the selection criteria for the models. For the effective diffusivity, the Fick’s diffusion model was used considering the flat plate geometry. It was found that Midilli and Logarithmic models showed the best fit to the experimental data of drying kinetics. Effective diffusion coefficient increases with increment in the thickness of the material and with the temperature elevation. Activation energy of the material was of 16.61 kJ mol-1 for the thickness of 0.005 m, and 16.97 kJ mol-1 for the thickness of 0.010 m. AIC and BIC can be additionally included to select models of drying. RESUMO Objetivou-se com o presente trabalho analisar a cinética de secagem, testar os critérios da informação de Akaike (AIC) e informação Bayesiano de Schwarz (BIC) para seleção dos modelos, determinar a difusividade efetiva e a energia de ativação de massa triturada de folhas de jambu para diferentes condições de temperatura e espessuras de camada. O experimento foi desenvolvido no Laboratório de Alimentos da Empresa Brasileira de Pesquisa Agropecuária (Embrapa), em Macapá - AP. A secagem foi realizada em estufa de circulação de ar com velocidade de 1,0 m s-1 em diferentes temperaturas (60, 70 e 80 ºC) e espessuras da camada (0,005 e 0,010 m). Aos dados experimentais foram ajustados onze modelos matemáticos. O coeficiente de determinação (R2), erro médio relativo (P), erro médio estimado (SE), teste de Qui-quadrado (χ2), AIC e BIC, foram os critérios de seleção dos modelos. Para a difusividade efetiva utilizou-se o modelo difusivo de Fick para a forma geométrica de placa plana. Constatou-se que os modelos de Midilli e Logaritmo melhor se ajustam aos dados experimentais da cinética de secagem. O coeficiente de difusão efetivo aumentou com o incremento da espessura da camada de material e com a elevação da temperatura. A energia de ativação do material foi de 16,61 kJ mol-1 para a espessura de 0,005 m e de 16,97 kJ mol-1 para a espessura de 0,010 m. Os critérios de AIC e BIC podem ser incluídos adicionalmente para seleção de modelos de secagem.