The objective of this study was to evaluate the effect of pasteurization, lyophilization and spray-drying on the lipid profile of donated human milk (DHM) at different lactation stages. Nine frozen samples of colostrum, transitional and raw mature human milk (HM) were collected from the Human Milk Bank (HMB) of the Hospital Universitário de Maringá (HUM). Samples were thawed and pooled according to lactation stage. Thereafter, it was submitted to pasteurization, lyophilization and spray-drying processes and later the fatty acid (FA) composition and the lipid profile analyses were performed. Gas chromatograph (GC) with flame ionization detector (FID) and electrospray ionization (ESI) mass spectrometer (MS) were used, respectively. In the FA composition analysis, it was observed that the same classes of saturated FA (SFA), monounsaturated FA (MUFA) and polyunsaturated FA (PUFA) were preserved throughout the process and in all lactation stages. The lipid profiles were also preserved after processing. Therefore, the lyophilization and spray-drying processes are promising techniques to preserve the DHM in the HMB, once the components evaluated were preserved, and both techniques facilitate the transport and storage, as the techniques reduce the sample volume.

ABSTRACT The aim of this study was to determine the composition and antioxidant potential of leaves of a new variety of Stevia rebaudiana (Stevia UEM-13). Stevia leaves of UEM-13 contain rebaudioside A as the main glycoside, while most wild Stevia plants contain stevioside. Furthermore can be multiplied by seed, which reduces the cost of plant culture techniques as other clonal varieties are multiplied by buds, requiring sophisticated and expensive seedling production systems. Ethanol and methanol were used in the extraction to determine the bioactive compounds. The methanolic extract was fractionated sequentially with hexane, chloroform, ethyl acetate and isobutanol, and the highest concentration of phenolic compounds and flavonoids was obtained in the ethyl acetate fraction (524.20 mg galic acid equivalent/g; 380.62 µg quercetin equivalent/g). The glycoside content varied greatly among the fractions (0.5% - 65.3%). Higher antioxidant potential was found in the methanol extract and the ethyl acetate fraction with 93.5% and 97.32%, respectively. In addition to being an excellent source for obtaining of extracts rich in glycoside, this new variety can also be used as raw material for the production of extracts or fractions with a significant amount of antioxidant activity and potential to be used as additives in food.