Inactivation of porcine reproductive and respiratory syndrome (PRRS) virus

Abstract

We review the principles of ultraviolet (UV) irradiation, the inactivation of infectious agents by UV, and current applications for the control of microorganisms. In particular, wavelengths between 200nm and 280nm (germicidal UV) affect the double-bond stability of adjacent carbon atoms, including pyrimidines, purines, and flavin. Thus, the UV inactivation of microorganisms results from the formation of dimers in RNA (uracil and cytosine) and DNA (thymine and cytosine). The classic application of UV is the inactivation of microorganisms in biological safety cabinets. In the food-processing industry, germicidal UV has shown potential for the surface disinfection of fresh-cut fruit and vegetables. UV treatment of water (potable and wastewater) is increasingly common because the process is effective against a wide range of microorganisms, overdose is not possible, chemical residues or by-products are avoided, and water quality is unaffected. UV has been used to reduce the concentration of airborne microorganisms in limited studies, but the technology will require further development if it is to gain wider application. For bioaerosols, the primary technical challenge is delivery of sufficient UV to large volumes of air, but the absence of UV inactivation constants for airborne pathogens under a range of environmental conditions (temperature, relative humidity) further compound the problem.

Physical and Mechanical Characteristics of Gelatin-Based Films as a Potential Food Packaging Material: A Review

“…Conjugated bonds hold two electron pairs in which each electron possesses an independent and opposite spin of equal energy. When a photon of ultraviolet radiation energy strikes an electron, it is induced to rise to an excited (higher energy) level and is able to travel the entire organic structure without breaking the bonds [ 117 ]. Composite films of bovine gelatin/carboxymethyl cellulose (CMC) have also been reported to exhibit low UV light absorption within the range of 0.15–4.00 [ 63 , 66 ].…”