EFFECT OF GRINDING METHODS ON THE RETENTION OF BLACK PEPPER VOLATILES

Black pepper (Piper nigrum L) was ground at four different feed temper atures viz., 40 degrees C, ambient (24 degrees C), 10 degrees C and -1 20 degrees C, using hot or chilled water circulation through the grind er jacket or direct injection of liquid nitrogen (LN,) into the mill a long with the feed. The volatile oil content of the product indicated that chilled water and LN(2) cooled conditions retained almost same qu antity of volatiles (3.56 ml/100g and 3.60 ml/100g, respectively) and powder fineness was greater in the case of the latter. The gas chromat ographic analysis of the oil showed higher retention of monoterpenes u nder cryogenic (LN(2)) and low temperature (chilled water) grinding co nditions than under ambient and high temperature grinding conditions.