Mate tea ( Ilex paraguariensis) has been used for centuries and is widely consumed in Brazil, Argentina, Paraguay, and Uruguay. The aim of the present study was to determine how growing and drying conditions affect the phenolic concentration and antioxidant capacity of 15 Mate teas from forest or plantation cultivations, dried either with hot air or wood smoke. The total polyphenol concentration determined with Folin-Ciocalteu ranged from 100.3 +/- 5.5 to 179.7 +/- 3.6 mg equiv chlorogenic acid/g dry leaves. The antioxidant capacity according to the oxygen radical absorbance capacity assay ranged from 1.5 +/- 0.3 to 4.1 +/- 0.1 mmol Trolox equiv/g dry leaves. Ten phenolic compounds were identified and correlated with antioxidant capacity ( R (2) = 0.80). Principle component analysis and multivariate linear regression were conducted to assess the effect of growing and drying conditions. Sun-exposed (plantation grown) Mate teas exhibited higher levels of all polyphenols as compared to shaded (forest grown) Mate teas ( P < 0.05). Lower rainfall, temperature, and drying conditions had varying effects on the phenolics. On average, plantation grown Mate teas had a greater concentration of phenolics than forest grown teas. Thus, plantation grown Mate teas represent better potential sources for their commercial extraction.

The objective of this research was the determination of color (L, a and b values, hue, chroma and ÁE), chlorophylls, caffeine and water content variation during industrial processing of yerba mate´(Ilex paraguariensis Saint Hillarie). For leaves, the greatest variation in color, total chlorophyll concentration (>80%) and water content (approximately 70%) was found during blanching, operation performed with hot gases at temperatures above 500 C. On the contrary, caffeine loss (about 20%) in leaves mainly occurred during hot air drying, carried out in two stages, with inlet air temperatures about 110 C. Moisture content variation in twigs were more 599 important in the drying steps, the values being strongly dependent on twig diameter.

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PRACTICAL APPLICATIONSThis work evaluates the pretreatment and drying conditions of pumpkin. Five parameters of the optimal product are considered: pretreatment time, drying time, temperature, color and rehydration rate of the product. With these results, drying of pumpkin can be carried out in industrial convective dryers and the dried product may be used in the preparation of soups, premixed foods, snacks, etc.