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Improving microbial inactivation effect for black pepper using intense pulsed light combined with TiO2 photocatalyst
- 언어ENG
- URLhttps://db.koreascholar.com/Article/Detail/352959
Black pepper (piper nigrium L.) is a spice commonly used but has a problem with microbial control, so it needs non-thermal decontamination method for product quality of dried foods. Intense pulsed light (IPL) technology is a non-thermal method for superficial decontamination of foods to inactivate pathogenic microorganisms by using high peak power and short duration pulses of a broad-spectrum (170-2600 nm) using a xenon lamp. The objective of this study was to reduce total number of bacteria in ground black pepper effectively by combined treatments of IPL and immobilized TiO2 photocatalyst. Self-designed cyclone type of pilot-scaled IPL device (> 5 kg/h) was used, which makes samples to flow cyclonically in a vacuum space longer time rather than moving vertically. Using this device alone, without TiO2 coated, 0.3-0.6 log reductions were achieved under a total energy fluence of 14.85 J/cm2 (DC voltage; 1200, 1800, and 2400 V, pulse duty; 0.5, 2.1, and 3.0 ms, treatment time; 60, 120, 180, 240, and 300 s, frequency; 2 Hz). Subsequently, TiO2-coated quartz plates with different layers between light source and samples were installed to observe the effect of photocatalyst and the efficiency of decontamination was improved slightly. However to increase the effect of the photocatalyst, several factors (TiO2 particle size, TiO2 film thickness and transparency, adhesiveness between quartz and photocatalyst, etc.) need to be concerned additionally. Nevertheless, the application of IPL treatment combined with TiO2 photocatalyst offers a potential of effective non-thermal decontamination method for dealing with powder foods in food industry.
