Exploitation and valorisation of the PDO Citron ‘Santa Maria del Cedro’ in the fresh-cut market

One of the five species of citrus progenitors is the citron (Citrus medica L.). Similar to other citrus species, the citron originated in areas in northeastern India, northern Myanmar, and northwest Yunnan. There are several citron cultivars that grow wild or are grown for use as food or in traditional remedies in southern Asia, India, and the Middle East. The citron was introduced to the Mediterranean region during Alexander the Great's reign, and it spread there because of the Greeks and the Jewish diaspora, who utilised it for religious and ornamental purposes, respectively. Its cultivation is now restricted to a small area of the Tyrrhenian-northern Calabrian coast in Italy. Two types of citron have been produced here for years, sheltered from frosts: Liscia-diamante, which is used to make candied fruit and in pastry making, and Etrog, which is highly sought after by Jews worldwide for the Sukkot festivals. In Calabria, citrons are currently grown in small orchards on a limited area, but they are highly productive and yield about 13 million euros annually. With the name Cedro di Santa Maria del Cedro, Citron Liscia-diamante has been granted a protected indication of origin label by the European Union since 2023. This citron cultivar is distinguished by its enormous weight and shape, as well as its small pulp and low juice content. By contrast, the albedo is a very large part cross section of fruit, it’s white, thick with a firm and crunchy texture and pleasant fresh scent. The amount of pectin and its claims are significant among the many nutritional and health-related factors. In two R&S projects (“CEDROTRACK”, C.U.P. J52C22000600005, Contract n. 188616, PSR 2014–2020 Calabria Region, Program 16.02.01.; “INNOCEDRO”, C.U.P. J57F22000000002, PSR 2014–2020 Calabria Region, Program 16.01.01) on the valorisation of the processed products from citron, our research team (CNR-ISPA Foggia and Bari, IT joint with CNR-ISA, Avellino - IT) is collaborating with other research departments and local producers. Despite being used fresh in many traditional Italian culinary recipes, citron deteriorates quickly after harvest, primarily because of senescence and fungal decays. While pastry preparations use the green flavedo of young fruits, salads are notable for utilising the albedo of ripe citrons. Therefore, to determine the best storage conditions for whole fresh citrons, we conceived and built a suitable experimental trial using three level approaches. Secondarily, we removed the green outer part of peel (rich in coumarins) of sanitised citrons, and we produced slices of albedo before placing them in plastic trays. The citron albedo slices were stored at 5°C in air and controlled atmosphere (CA, 20 % CO2 and 10 % O2) first arranged freely on the shelves of the incubation chambers (mod. Milano2; Fruit Control equipment s.r.l., Locate di Triulzi, Milan, Italy) and subsequently packed in polypropylene (PP) and polylactate (PP) films. When compared to control samples and air treatment, CA produced the greatest outcomes for the unpacked fresh cut citrons in terms of improved visual quality and decreased weight loss, respiration rate, and total microbial counts. While the elevated marketability values (VQ and Whitness index) were comparable between samples packed with PP and PLA films but significantly higher than those of control in air, PP film was chosen for packaging citron slices primarily due to its high control respiration air and weight loss during cold storage. These findings will be used to enhance postharvest citron storage conditions and create fresh-cut citrons that are naturally high in chemicals that promote health.