Quantitative Detection of Extra Virgin Olive Oil Adulteration, as Opposed to Peanut and Soybean Oil, Employing LED-Induced Fluorescence Spectroscopy.

As it is high in value, extra virgin olive oil (EVOO) is frequently blended with inferior vegetable oils. This study presents an optical method for determining the adulteration level of EVOO with soybean oil as well as peanut oil using LED-induced fluorescence spectroscopy. Eight LEDs with central wavelengths from ultra-violet (UV) to blue are tested to induce the fluorescence spectra of EVOO, peanut oil, and soybean oil, and the UV LED of 372 nm is selected for further detection. Samples are prepared by mixing olive oil with different volume fractions of peanut or soybean oil, and their fluorescence spectra are collected. Different pre-processing and regression methods are utilized to build the prediction model, and good linearity is obtained between the predicted and actual adulteration concentration. This result, accompanied by the non-destruction and no pre-treatment characteristics, proves that it is feasible to use LED-induced fluorescence spectroscopy as a way to investigate the EVOO adulteration level, and paves the way for building a hand-hold device that can be applied to real market conditions in the future.

Sex specific effects of capsaicin on longevity regulation.

The consumption of spicy food in daily diets have been found to be inversely associated with human mortality. However, whether intake of spices is the reason for reduced mortality, and whether capsaicin, the main bioactive component of spices, plays a major role, remain elusive. Here, we report that low concentration of capsaicin can indeed extend life span. Capsaicin had no effect on food consumption, reproductive fitness, or stress tolerance. However, it did appear to decrease the daytime activity of females. We hypothesize that this decrease in activity may be a contributing factor in the life span extending property of capsaicin.