Impact of Pulsed Light on Food Constituents

Abstract

As one of the emerging non-thermal food treatment technologies, pulsed light (PL) has been intensively studied since the twenty first century. PL technology uses intermittent light pulses to treat food products without leaving any residues. The current use of PL technology is for decontamination purposes. The decontamination effects of PL treatment rely on primarily light with the different wavelength and the pulsed energy. Therefore, this chapter starts by explaining the disinfection mechanism of PL technology, where analysis of the UV disinfection mechanism would be helpful. Unlike electron beam, X-rays, and gamma rays, UV light is non-ionizing irradiation and does not break molecular bonds. The UV light can be emitted either as a continuous wave (continuous light) or in short duration pulses of 1–20 per second as in the case of pulsed light. Continuous UV light may be categorized into three types according to the emission spectrum: (1) short-wave UV (UV-C) with wavelengths from 200 to 280 nm, (2) medium-wave UV (UV-B) with wavelengths from 280 to 320 nm, and (3) long-wave UV (UV-A) with wavelengths from 320 to 400 nm. UV-C has been used for disinfection of air, surface, water, and liquid foods. The mechanisms responsible for microbial inactivation by UV light are believed to be due to the photochemical, photothermal and photophysical effects on microbes exposed to UV light.