Cultivation of Goji berries (lycium barbarum and lycium ruthenicum) in the Maltese islands : an analysis of the main minerals and nutrients found in fresh berries

Abstract

Fruit of Goji berries (Lycium spp.) have high nutrients, minerals, and bioactive compounds, and because of this, its cultivation in China and nearby regions dates back to over 4000 years. The increased demand for Goji berries has incentivised many other regions across the globe to explore different methods for its cultivation. This study provides a detailed account on the origin of Goji berries, the main regions cultivating this plant and whether the Maltese Islands are suitable for growing this plant. Different trials on methods of propagation (seeds, root cuttings and hard wood cuttings) of Lycium were conducted during a two-year study (2018-2020). A total of 36 Lycium barbarum plants were planted in four different locations in Malta and were irrigated with three types of water (rainwater, tap water and saline water). All plants managed to grow well and produce berries during this 2-year experiment. During 2018 a total of 5,485 grams of goji berries was produced from the 36 Lycium barbarum plants and 6,234 grams during 2019. During both 2018 and 2019 the Lycium barbarum plants planted in the ground and irrigated with tap water produced the highest amount of berries. An important factor that affected the total goji berry production was the daily number of sunlight hours. The goji berry trees planted in the locations that received 8 hours of direct sunlight during the spring and summer produced more berries than those that received less hours of direct sunlight. This study also analysed the fresh and dried goji berries produced in the Maltese Islands for the beneficial metals, proximate analysis, polyphenols and carotenoids. The results show that the goji berries cultivated in the Maltese Islands have good levels of Potassium (3717 to 7113 ppm), Polyphenols (0.06 to 0.15%w/w) and Carotenoids (0.007 to 0.13 mg/100ml). The methodology of the tests used in this study and the results were compared with those of other studies.