Different compounds are extracted with different time courses from fruits during microwave hydrodiffusion: Examples and possible causes

We set out to determine how nutrients diffuse during extraction, using fractional collection. The highest concentrations of sugars (195.5, 64.8 and 60.8 g/L, respectively for grape, ‘Najbolia’ plum and apricot) were found for the earliest stages of extraction, with a decrease in concentration (to 41.4 g/L, 48.2 g/L and 1.7 g/L, respectively) at the end of extraction process. Total polyphenols showed the same trends for plum and apricot (from 4.1 g/L to 2.9 g/L for ‘Najbolia’ plum, from 2.2 to 0.2 g/L for apricot) but highest concentrations of total polyphenols (for grape and cherry) were obtained at fraction 5 or 6 (out of 7). Carotenoids from cherry tomato also had highest concentrations (at circa 25 mg/L) almost at the end of extraction. For volatile molecules from sweet cherry, hexanal, 2-hexenal and linalool had their highest concentrations at fractions 3–4 (out of 7). ion of nutrients depended on fruit destructuring, molecule solubility and localization of the compounds. Fruit size seemed unimportant.