Effects of two different drying methods (freeze-drying and hot air-drying) on the phenolic and carotenoid profile of 'Ataulfo' mango by-products

The agro-industrial processing of mango generates high amounts of by-products, like peels and paste, that are commonly discarded. These are potential sources of bioactive ingredients, such as phenolic compounds and carotenoids, that can be used to supplement other edible products to increase their nutritional value. In order to be successful in this regard, the processing methods used must avoid losses of the compounds of interest. The objective of this study was to identify the effects of freeze-drying (frozen 24 h at - 80 A degrees C, freeze dried 48 h at - 50 A degrees C, 4.00 Pa) and hot air-drying (convective hot air at 60 A degrees C) on the profile and concentration of phenolic compounds and carotenoids, using sensitive chromatographic analyses. Our data showed that the total phenolic concentration, and that of the most abundant compounds (mangiferin and valoneic acid dilactone), were unaffected by drying method. Conversely, freeze-dried paste had greater carotenoid concentration than peel, while hot air-dried peel had greater carotenoid concentration than paste (main carotenoids: all-trans-beta-carotene, 9-cis-beta-carotene, all-trans-lutein, and 13-cis-beta-cryptoxanthin). We concluded that carotenoids from mango peel and paste were more sensitive to drying method than phenolic compounds, and the effects on each by-product were in function of the food matrix and method used. By choosing the most adequate drying method, mango by-products can be sources of bioactive compounds to produce functional foods or beverages.