Drying of Acerola (Malpighia emarginata D. C.) by-Product: Evolution of Active Compounds in Function of Time

Abstract The objective of this study was to evaluate the behavior of active compounds concentration present in the industrial by-product of acerola during drying using convective dehydration at 40, 50 and 60 °C. For this, flavones and flavonols, total proanthocyanidins, vitamin C, total phenolic content and antioxidant capacity as function of drying time were determined. The drying data were adjusted using the models of Page, Lewis, Henderson & Pabis, Modified Page and Logarithmic. In relation to the applied models, Page model presented the best fit. Acerola by-products dried at 40 °C showed higher concentrations of active compounds and higher antioxidant capacity. Although the drying process provoked changes in concentration of the active compounds, in the studied temperature range, significant concentrations of those bioactive compounds were observed. Thus, acerola by-product may present potential for application in different foods.

Evaluation of Two Fitting Methods Applied for Thin-Layer Drying of Cape Gooseberry Fruits

ABSTRACT Drying data of cape gooseberry was used to compare two fitting methods: namely 2-step and 1-step methods. Literature data was also used to confirm the results. To demonstrate the applicability of these methods, two primary models (Page, Two-term-exponential) were selected. Linear equation was used as secondary model. As well-known from the previous modelling studies on drying, 2-step method required at least two regressions: One is primary model and one is secondary (if you have only one environmental condition such as temperature). On the other hand, one regression was enough for 1-step method. Although previous studies on kinetic modelling of drying of foods were based on 2-step method, this study indicated that 1-step method may also be a good alternative with some advantages such as drawing an informative figure and reducing time of calculations.