Effects of processing conditions on the chemical distribution of mate tea leaves extracts obtained from CO_2 extraction at high pressures

摘要

This work reports the effects of industrial manufacturing steps on the distribution of chemical components of the extracts obtained from supercritical carbon dioxide (SCCO_2) of processed mate tea leaves. For this purpose, samples of mate tea leaves were collected from the actual industrial processing after the fast pre-heating, drying and storage (5 and 21 days) steps. To provide a consistent basis for comparisons, extractions were also conducted for the unprocessed leaves fed in the industrial environment. In order to select the appropriate extraction parameters at high pressure, it was evaluated the effects of temperature from 15 to 55℃ and pressure from 10 to 20MPa on the liquid yield of unprocessed mate tea leaves. The SCCO_2 extraction experiments regarding the effects of industrial processing conditions were then performed at 35℃ and 20MPa and the extract chemical analyses were carried out in a GC/MSD. Results show that the extraction yield and chemical composition of the extracts are strongly affected by the industrial processing steps. Chromatographic analyses permitted the identification of caffeine, theobromine, hexadecanoic acid, phy-tol, squalene, octacosanol, 2-heptacosanone, steroids and triterpenes as the main constituents in the extracts.