An innovative process for the production of spices through immediate thermal treatment of the plant material

Abstract

An innovative process for the production of spices was developed on pilot-plant scale. Immediately after harvest, fresh chili and green pepper (fruits), ginger (rhizomes), and coriander (whole plant) were blanched and subjected to coarse and fine grinding prior to lyophilization. Alternatively, thermal treatment was applied after processing the fresh plant material into a paste. Microbiological assays revealed low counts of aerobic germs, aerobic spore forming bacteria, Escherichia coli, coliforms, Staphylococcus aureus, Bacillus cereus, yeasts and moulds, and sulfite reducing clostridia. Salmonella as well as aflatoxins were not detected in any of the products. Because the spice powders obtained were generally characterized by improved color, in contrast to conventional spice processing, early inactivation of endogenous enzymes may have prevented degradation of plant pigments and browning. Industrial relevance Spices are common sources for microbial contaminations with special concern in minimally processed products. Sterilization of spices has been shown to adversely affect product quality criteria and ionizing or UV radiation have been met with consumer resistance. Pasteurization/sterilization or blanching as thermal processes effective in reducing microbial loads and inactivating enzymes. However, loss of volatiles could not be prevented in the process presented and needs to be tackled prior to industrial scale use.