Proceedings of the 21st International Conference on Near Infrared Spectroscopy

Recently there has been a renewed interest in hempseed oil (Cannabis sativa L.) in the food industry due to the beneficial properties provided by hemp seeds and oil. Hemp oil is extremely rich in linoleic (18:2 w6) and α-linolenic (18:3 w3) acids. Moreover, it is rich in antioxidants, such as tocopherols and phenolic compounds. The presence of high concentrations of unsaturated fatty acids in hemp oil determines its high sensitivity to oxidative and photo-oxidative degradation. These processes generate peroxides, dienes, and trienes that are at the basis of the phenomenon of rancidity. A batch of hemp oil was obtained by cold pressing Futura 75 seeds. The oil was then transferred and packed into 20ml vials made of polypropylene, clear glass, amber glass, and amber glass coated with aluminum foil. The samples were stored for 150 days at ambient temperature (T 25 °C) under diffused light and refrigerated temperature (T 10 °C) in dark conditions in order to simulate the common storage conditions. To monitor the stability of hemp seed oil, peroxide value determination and conjugated dienes and trienes were evaluated. The peroxide number (expressed as meq O2/kg) was determined using the iodometric technique, while spectrophotometer analysis was used to measure the conjugated dienes and trienes of fatty acids. NIR spectra were measured in transmission. The sample dataset of spectra was analyzed using ASCA in order to test the spectral significance of the experimental factors. Analysis of the ASCA model showed a significance with a confidence of 5% of all factors and of all the simple interactions.