Physico-chemical properties of 'Phoenix' jujube fruit (Ziziphus jujuba Mill.)

Nutritionists recommend fruits and vegetables containing large amounts of phytochemicals because of their health benefits. Epidemiological and nutritional studies suggested that the higher one’s fruit and vegetables’ consumption, the lower the incidence of chronic diseases. Jujube fruits contain high levels of vitamins, carotenoids, phenolic compounds and antioxidant activities so they are considered healthy foods. Nevertheless, jujube is considered as an underutilized species and is less known than other fruits so their varieties have not been investigated in depth in Spain. In this work, a traditional cultivar of jujube, ‘Phoenix’, cultivated in Spain, has been studied. It is called ‘Phoenix’ because they have an elongated and narrow shape, similar to a date fruit. The fruits of this cultivar have a weight of 9.17 g with an equatorial diameter of 23.90 mm and a height of 39.59 mm. Its stone has a weight of 0.36 g, a diameter of 6.81 mm and a height of 26.97 mm, which has a pulp yield of 95.12%. In commercial ripening it has a total chlorophyll content of 0.37 mg 100 g‑1 fresh weight and a total carotenoid content of 0.19 mg eq β-carotene 100 g(-1) fresh weight. External colour corresponds to the following reflection parameters: 72.10 (L*), -0.20 (a*) and 34.68 (b*), a Chroma index of 34.94 and a Hue angle of 90.29. The protein content is 0.615 mg g‑1 fresh weight, soluble solids are high with 24.07 °Brix, and the content of sucrose, glucose and fructose in percentage of 6.51, 3.02 and 4.84, respectively. Succinic acid is the major organic acid (0.82%), followed by ascorbic acid (0.36%), citric acid (0.33%), and malic acid (0.26%). Therefore, the commercial ‘Phoenix’ cultivar is of medium size, yellowish and has a slightly greenish colour, it is sweet and has low acidity. It is very suitable for fresh consumption.