Oxidative stability of olive oil via quantitative EPR analysis
The oxidative stability is a major problem in food related industries and is affected by a number of factors, such as oxygen, temperature, presence of metals and light. For example, extra virgin olive oil (EVOO) oxidation is of particular interest due to the complexity of its distribution channels around the world and the fact that it is an individually packaged product (its final quality reflects either positively or negatively on the producer). The resistance of EVOO to oxidation is related to the high levels of monounsaturated triacylglycerols and the presence of natural phenolic antioxidants. EPR is a useful tool to detect free radicals and to determine the level of free radical formation in olive oil during forced oxidation at different temperatures. Application of EPR to foods can reveal important information about radical reactions that may be responsible for food qualities and deterioration.
DPPH scavenging assay to measure antioxidant activity in beverages
Antioxidants play an important role as health protecting factor. Scientific evidence suggests that antioxidants reduce the risk for chronic diseases including cancer and heart disease. DPPH (2, 2-Diphenyl-1-picrylhydrazyl) is a free radical that is widely used to test the ability of compounds to act as free radical scavengers or hydrogen donors and to evaluate antioxidant activity. The DPPH assay method is based on the reduction of DPPH by antioxidants and is a rapid and simple method to measure antioxidant capacity of food and beverages.
Alanine radical detected by EPR corresponds to the irradiation dose
Alanine forms a very stable free radical when subjected to ionizing radiation. The alanine free radical yields an EPR signal that is dose dependent, yet is independent of the dose rate, energy type, and is relatively insensitive to temperature and humidity. Thus, alanine dosimetry is equally suited to gamma, e-beam, or x-ray irradiation facilities.
Lactose radicals in the tablet filler causes enhanced degradation of the active pharmaceutical ingrediants (APIs)
EPR spectroscopy has a wide variety of applications within the analysis of pharmaceutical compounds. These include photodegradation and oxidation of APIs, the effects of sterilization techniques such as irradiation, interactions between APIs and excipients, etc. Excipients can initiate, propagate or participate in radical chemistry interactions which may compromise the effectiveness of a medication and studied by EPR. Lactose radicals originating from lactose monohydrate, used as a filler in the tablets, react with the API causing an enhanced degradation.
Ionizing radiation of poultry and fruits creates very distinctive EPR spectra
Food irradiation is used to reduce the health risk associated with food-borne pathogens and to prolong shelf life. In fact, ionizing radiation inhibits the division of microorganisms and creates radiolytic products as well as free radicals. In a dry environment these radicals are very stable. For example, irradiated poultry bones or fruits may contain a substantial amount of stable radicals which can be easily detected by EPR.
Polyethylene radicals detected by EPR can predict premature failure of implants
Ultra-high molecular weight polyethylene (UHMWPE) has been used as standard lining material in orthopedic implant industry. Oxidative degradation of the polymer caused by free radical formation can lead to premature aging and wear of the material and implant, causing a painful inflammation. EMXnano is capable of detecting and quantifying polyethylene radicals providing reliable and accurate measurements.
EPR can detect the N3 and single substitution nitrogen centers in diamonds
It is an unambiguous technique for quantifying nitrogen centers and hence provide a tool for color grading. It can also be used to distinguish between synthetic and natural diamonds.