Inactivation of Aspergillus sp. spores on whole black peppers by nonthermal plasma and quality evaluation of the treated peppers

In this study, a rotating nonthermal plasma (NTP) reactor was designed and its practical use for the inactivation of microorganisms on dried granular agricultural products such as black pepper was investigated. As the target microorganism to inactivate in the rotating NTP reactor, Aspergillus spores were artificially inoculated on whole black peppers. Inactivation treatments were carried out under several conditions. Rotating the NTP reactor facilitated the inactivation of the Aspergillus spores on the whole black peppers, and a decrease in the survival ratio of three orders (3 Log) was achieved after 4 min treatment. Using humidified gases for inactivation treatment in the rotating NTP reactor also facilitated the inactivation of the Aspergillus spores on the whole black peppers, and no viable spores of Aspergillus sp. were detected after 4 min treatment. The quality of the NTP- and dry-heat-treated whole black peppers was compared with that of untreated peppers in terms of the piperine content and antioxidative activity. The piperine contents of the NTP- and dry-heat-treated black peppers showed no significant difference, but the antioxidative activity in the NTP-treated peppers was higher than that in the dry-heat-treated peppers.
Source: Food Control - Category: Food Science Source Type: research