| 摘要 |
Plant matter is treated with saturated steam to strip aroma and flavor substances while pressure and temperature are raised continuously. Plant matter (especially ground coffee beans) is treated with saturated steam to strip aroma and flavor substances while pressure and temperature are raised continuously. The steam is cooled to 2-5 deg C, recovering condensed concentrate. Residual beans are extracted at low temperatures (LT) of 60-120 deg C and 20-40 bar. The extract is let-down and the vapor condensed and cooled. This concentrate is sent to a centrifugal column where it is stripped with saturated steam which is cooled and condensed together with flavoring substances. Residual beans from LT extraction are further extracted at high temperatures (HT) of 160-220 deg C, followed by extract expansion, cooling and condensation, and recovering the liquid portion of HT extraction. The condensate is disposed of. The extract from respective stages is concentrated. Following HT extraction (P8-P11) the residual beans undergo an ultra high temperature (UHT) extraction (P12) at 180-230 deg C, the extract being cooled and condensed. Condensate is discarded and the liquid portion is recovered as UHT extract. Preferred features: Roasting precedes extraction. The roasted coffee beans have a moisture content of about 10 wt.%. Comminuted matter is ground down from a mean grading of 1.8 mm. Initial treatment takes place in a percolator, the grading increasing from about 2 mm to about 3 mm over its height.
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