Strategies to reduce microbial contaminations and increase the shelf life of pistachio fruit: a review

Pistachios are good sources of some functional compounds that are essential for human health. In addition to consuming dried pistachios (salted/roasted) or used as ingredients in a variety of confectionery and cookery products, consuming fresh pistachios is also gaining a foothold in the market. This review presents pre- and postharvest operations to prevent microbial contamination and to preserve physicochemical properties of fresh and processed pistachios for extending their shelf life. There is a potential in pistachios to be contaminated with some undesirable microbes, especially aflatoxin-producing fungi, during pre- and postharvest operations. In this regard, strategies to the prevention of aflatoxin production and the decontamination of produced aflatoxin in pistachios have been of interest to researchers. Different practices including sorting, thermal processing, biological control, ozone treatment, gamma irradiation, ultraviolet irradiation, and cold plasma have been proposed for aflatoxin decontamination. Sorting out damaged pistachios is one of the most important postharvest strategies to reduce aflatoxin levels (up to 98%) that can be done manually or electronically. The majority of pistachios (~85%) are consumed as roasted form that combining roasting with lemon juice improves the elimination of aflatoxin (up to 93%). Drying and packaging are the most important methods to maintain quality and improve the shelf life of pistachios. Laminated and metallized films with vacuum or modified atmosphere are the proper packaging for pistachios.