Characterization of Pistachio lipids and polyphenols
- Pistacia is part of the Anacardiaceae family. Pistacia vera is the only genus within the 11 Pistacia geniuses that produces nuts large enough to be used commercially. Pistachios were originally cultivated in Iran and much later, were introduced to California. The nutrients contained in pistachio are responsible for their potentially beneficial influences on human health. Numerous studies reveal that nut intake is accompanied by a wide range of health benefits, including the modulation of antioxidant, anti-inflammatory activities, due to the presence of bioactive compounds including lipids (unsaturated fatty acids, sphingolipids, phytosterols), dietary fiber, plant protein, carbohydrates, antioxidants, vitamin E, arginine, as well as minerals (potassium, calcium, and magnesium). The pistachios have long been used for health and medicinal purposes, and have unique properties, for example improving cardiovascular health, due to pistachios’ ability to decrease cholesterol levels, and reduction of glucose in diabetes. The lipid fraction of Pistachio nuts of various origins were characterized by high resolution and tandem mass spectrometry coupled to high performance liquid chromatography. Total lipid content was determined as a sum parameter gravimetrically. Based on mass spectrometrical data more than 100 triacylglycerides (TAGs) could be identified, the majority of them for the first time from this source. Complementary measurements using the FAME method based on gas chromatography revealed the presence of 26 fatty acids as building blocks for the TAGs. Selected pistachio lipid samples showed the presence of oxygenated TAG bearing epoxy, hydroxy and peroxy moieties. HPLC-MS measurements based on high resolution and tandem mass spectrometry allowed structure elucidation. These compounds are unique to pistachio. The unusual complexity of the pistachio lipidome prompted the development of novel bioinformatic strategies for compound assignment.