Effect of grinding methods on the retention of black pepper volatiles.

Black pepper (Piper nigrum L) was ground at four different feed temperatures viz., 40°C, ambient (24°C), 10°C
and -120°C, using hot or chilled water circulation through the grinder jacket or direct injection of liquid nitrogen
(LN2) into the mill along with the feed. The volatile oil content of the product indicated that chilled water and LN2
cooled conditions retained almost same quantity of volatiles (3.56 ml/100g and 3.60 m1/100g, respectively) and powder
fineness was greater In the case of the latter. The gas chromatographic analysis of the oil showed higher retention
of monoterpenes under cryogenic (LN2) and low temperature (chilled water) grinding conditions than under ambient
and high temperature grinding conditions.