EFFECT OF ULTRAVIOLET (UV-C) LIGHT AND GASEOUS OZONE ON MICROBIAL AND COLOR QUALITIES OF WHOLE BLACK PEPPER SEEDS (PIPER NIGRUM L.)
Esra Doğu-Baykut, Gürbüz Güneş, M Akbas, M Ozdemir, M Akbas, M Ozdemir, H Cheon, J Shin, K Park, M Chung, D Kang, B Dhillon, D Wiesenborn, H Dhillon, C Wolf-Hall, E Dogu-Baykut, G Gunes, E Decker, E Dogu-Baykut, G Gunes, L Eliasson, P Libander, M Lvenklev, S Isaksson, L Ahrn, Z Emer, M Akbas, M Ozdemir, S Erdodu, H Ekiz, S Erdodu, H Ekiz, J Farkas, C Mohcsi-Farkas, J Fowles, J Mitchell, H Mcgrath, E Gayn, S Condn, I lvarez, V Gmez-Lpez, T Koutchma, K Linden, J Guerrero-Beltrn, G Barbosa-Cnovas, M Hemmati, N Asefi, S Hanifian, C Hertwig, K Reineke, J Ehlbeck, D Knorr, O Schlter, Y Hidaka, K Kubota, Icmsf, W Keith, L Harris, L Hudson, M Griffiths, M Khadre, A Yousef, J Kim, C Kim, Y Hung, J Kim, D Lee, S Min, M Ngadi, X Jun, J Smith, G Raghavan, I Nicorescu, B Nguyen, M Moreau-Ferret, A Agoulon, S Chevalier, N Orange, S Patil, P Cullen, P Bourke, J Sadecka, U Schweiggert, R Carle, A Schieber, R Sharma, A Demirci, S Srey, I Jahid, S Ha, N Staack, L Ahrne, E Borch, D Knorr, E Torlak, D Sert, P Ulca, H Virtanen, K Vehmas, T Erho
Abstract
Microbial contamination of spices, especially black pepper, may sometimes reach as high as 8 log cfu/g, which can cause a major problem in the quality and safety of foods they are added. This study aimed to explore the potential of ultraviolet C (UV-C) light and ozone for decontamination of black pepper seeds. Ozone (15 ppm for 1 h) and UV-C (28.8 J/cm 2 ) treatments were applied alone, in succession, or simultaneously to whole black pepper seed with a laboratory scale fluidized bed UV-C system. Total aerobic mesophilic bacteria (TAMB) count (in uninoculated seeds), Escherichia coli (E. coli) count (in inoculated seeds) and color (L*, a* and b*) of black pepper were evaluated. Ozone and UV-C treatments alone caused 0.41-and 0.77-log reduction in the initial TAMB count (6.97 log cfu/g), respectively. TAMB decreased by 0.74-and 0.66-log upon successive and simultaneous treatments, respectively. Thus, the combined treatments did not have any additive or synergistic effects on TAMB. Both ozone and UV-C treatments alone resulted a 0.8-log reduction in the initial E. coli count of 6.3-log. The combined treatments caused an additive effect on inactivation of E. coli in black pepper seeds. The successive and simultaneous treatments caused 1.7and 1.4-log reductions in the E. coli, respectively. None of the treatments affected the color (L*, a* and b* values) significantly. In conclusion, the individual treatment has potential for reducing the natural contamination level on the seeds, and the combined treatments may have further potential towards reducing specific microbial contaminations.