Bio-active compounds and functional properties of pistachio hull: A review

Background: Pistachio (Pistacia vera L.) hull is the major part of pistachio by-product that has a high content of bioactive compounds (such as polyphenols, tocopherols, dietary fibers, essential oils, and unsaturated fatty acid) with antioxidant properties and health-promoting effects. However, it is considered as a waste and can lead to environmental problems. Scope and approach: This review presents the chemical composition, traditional and modern extraction methods and the reported functional effects of pistachio green hull, aiming to find potential uses for this valuable natural resource. Key findings and conclusions: Both in vivo and in vitro studies have demonstrated how pistachio extract acts as antioxidant, cytoprotective, and photopmtective and shows antibacterial, anti-inflammatory, anti-melanogenic, and anti-mutagenicity activities. Several studies evaluated the use of pistachio hull as a source of healthy and technological compounds that could be used in food and pharmaceutical industries to improve their products stability and nutritional characteristics. Further studies are needed to develop the application of this natural by-product.