| 摘要 |
<p>Dark coloured freeze dried coffee is prepd. by (a) rapidly chilling an aqeuous coffee extract to -2 to -5 deg.C to form a slush; (b) heating the slush to just below 0 deg.C to cause some melting; (c) chilling the slush once more to -2 to -5 dev.C, (d) repeating steps (b) and (c) one or more times, (e) rapidly chilling the extract below the eutectic point and (f) freeze drying the extract. - The prod. has a dark appearance more closely resembling roast and ground fresh coffee. It is prepd. without the need for relatively slow, time consuming, chilling of the extract, which is otherwise necessary in order to obtain large ice crystals in the solid before freeze-drying. (A frozen mass contg. relatively large crystals yields a dark-coloured prod.).</p> |
