Vol.:(0123456789) 1 3 Journal of Food Measurement and Characterization https://doi.org/10.1007/s11694-020-00713-9 ORIGINAL PAPER Determination of phenolics, organic acids, minerals and volatile compounds of jujube (Ziziphus jujuba miller) jam produced by under vacuum evaporation compared with open pan method Alper Kuşçu 1  · Özcan Bulantekin 1 Received: 22 June 2020 / Accepted: 17 October 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract The jujube fruit (Ziziphus jujuba Miller) is used in alternative medicine due to its important bioactive components and is well-suited for jam processing due to its high sugar content. In this study, changes in the chemical and aroma compounds of jujube jams produced using the open-pan (OPJ) and vacuum evaporation (VEJ) methods were determined immediately after production and after a storage period of 4 months. Concentrations of 5-hydroxymethylfurfural (HMF) in the OPJ and VEJ were 13.94 and 1.53 mg/kg initially and 22.63 and 1.66 mg/kg after storage, respectively. Epicatechin was identifed as the major phenolic component in jujube fruit and jams. Concentrations of phenolic compounds were higher in the VEJ both before and after storage. It was determined that jujube jam is a good source of the minerals Fe, Ca, Zn, Se, and Cu. Ascorbic acid loss was 86.47% in the OPJ versus 73.32% in the VEJ after production and continued during storage in both jams. Numerous novel aroma compounds that are not found in fresh jujube fruit were produced as a result of the diferent jam production methods. Signifcant advantages of the vacuum evaporation process have been determined in the production of jujube jam compared to the open pan process. Keywords Jujube jam · Vacuum evaporation · HMF · Organic acids · Phenolic compounds · Aroma compounds Introduction The jujube (Ziziphus jujuba Miller) is a unique fruit of the Rhamnaceae family that has been used by people for over 4000 years. Its natural distribution extends from Asia (Afghanistan, China, India, Iran, Pakistan, Turkey, South Korea, etc.) to Europe (Greece, Italy, Russia, Spain, etc.) and the Australian continent [1, 2]. The jujube fruit is a good source of minerals, proteins, sugars, organic acids, vitamin C, phenolics, and polysac- charides. It also contains various bioactive compounds that imbue the fruit with high nutritional value, functional prop- erties, and health benefts [3, 4]. In traditional Chinese medi- cine, the pharmaceutical efects of jujube fruit are utilized in the treatment of diabetes, jaundice, diarrhea, urinary prob- lems, ulcers, constipation, chronic bronchitis, liver disease, wounds, depression, and insomnia. Previous studies have shown that the bioactive components in jujube have anti- proliferative, anti-infammatory, antioxidant, antiobesity and antitumor efects and were protective against cardiovascular diseases and type 2 diabetes [1, 5, 6]. Jujube fruit is pro- cessed via numerous methods for consumption in various forms, as a dried snack, sweetened tea syrup or teabags, paste, soup, compote, pickle, jam, and wine. Fruits and vegetables are preserved through various methods. One of these methods is processing fruits and vegetables into jam by concentrating and adding sugar. Jams are popular food products due to their low cost, year- round accessibility, and organoleptic properties. The con- sumption of commercial jams has become increasingly popular due to consumers’ modern lifestyles. Although modern technologies are used today in commercial jam production, they are still produced using home-cooking methods [7]. In homemade jam production, fruit and sugar are mixed at a certain ratio and the mixture is concentrated at high temperatures to reach the fnal total soluble solid * Alper Kuşçu alperkuscu@sdu.edu.tr Özcan Bulantekin obulantekin@gmail.com 1 Engineering Faculty Department of Food Engineering, Süleyman Demirel University, Isparta, Turkey