# Applications of Pulsed Light Decontamination Technology in Food Processing: An Overview
## 3 Pulsed Light Equipment  
Initially, PL treatments were used for aesthetic applications like cosmetic, skin, and hair treatment areas. Later on, after approval of FDA in 1996, there has been tremendous development in the field of PL-based disinfection that has further been spread to food industries, pharmaceuticals, and water treatment plants. During the 1970s, Hiramoto [29] patented a pulsed UV light system for microbial inactivation [4]. Later on, studies were performed by [PERSON] et al. [30], who patented systems for sterilization of food and packaging materials. Since then, a major organization pioneering the PL based research in the world for food and drinking water decontamination was the Purepulse Technologies Inc., San Diego, California, a subsidiary of Xenon Corporation [23]. They acquired [PERSON]'s patent and conducted further research to commercialize the PL equipment for food applications under the name PureBrightTM system [4]. Subsequently, after several advancements in this field, the major companies manufacturing PL based decontamination systems are SteriBeam Systems from Germany, Wek-tec Systems from Germany, Claranor from France, Xenon Corp. from USA, and Solaris Disinfection Inc. from Canada. Table 2 summarizes the available PL systems for food decontamination. A typical PL system works via the generation of light pulses using a pulse forming device. Pulses of light are produced by multiplying electrical power many folds by concentrating electrical energy in a capacitor over less than a second and releasing this energy in a relatively shorter duration (millionths or \(10^{-6}\) of a second) to flashlamps. The flashlamps, filled with inert gases give off light in the form of flashes [12]. The pulses per second or pulse frequency varies mostly as 1-3 Hz [20]. The pulsed light systems basically have of three main units [13] as given in schematic diagram (Figure 5):  
1. The power unit: Comprising electrical power supplier where high-voltage direct current (DC) power is obtained from low-voltage AC power. 2. Pulse configuration device: Comprising of high-voltage capacitors joined in parallel that concentrate energy from the power supplying unit in the charge cycle and release that during the discharge cycle, generating high electrical current. It is also connected to special high-power handling switches that perform on/off cycles of very short time converting the continuous low-electrical power into a pulsed high-electrical power. 3. The lamp unit: Comprising specially designed batteries of flashlamps containing gases that are excited due to pulsed high-electrical power from the pulsed configuration device. While transitioning to lower energy or ground states, they give off energy in the form of high intensity pulses. The high-intensity PL is delivered to the products by various lamp footprints and configurations. Figure 5: PL generation system. PL generation system consists of an electrical power source from where electric energy enters the capacitors, which accumulate the energy and get discharged into high-intensity light pulses. \begin{table}
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