Identification of bitter compounds from dried fruit of Ziziphus jujuba cv. Junzao

Abstract

Bitterness in dried jujube fruit can adversely influence its palatability and consumer acceptability. In the present investigation, sensory-guided fractionation with techniques of liquid-liquid extraction, macroporous resin separation, and LC-MS/QTof was applied to identify the bitter compounds in dried jujube fruit (Z. jujuba cv. junzao). The results showed that bitter substances can be successfully extracted from dried jujube fruit using ethanol followed by n-butanol solution. The extract could then be further separated into five fractions by utilizing the macroporous resin separation technique. From this, three bitter fractions were obtained where 35 compounds, including 7 nitrogen compounds, 14 flavonoids, 12 saponins, and 2 fatty acid oxides，were tentatively identified. Based on the structures of these compounds, bitterness generation is likely to result from endogenous phytochemicals of jujube fruit and Maillard reactions during drying processing and also storage. ARTICLE HISTORY

Comparative Analysis of Pigments, Phenolics, and Antioxidant Activity of Chinese Jujube (Ziziphus jujuba Mill.) during Fruit Development

“…Nineteen phenolic compounds, including five flavanols (procyanidin B1, procyanidin B2, procyanidin B3, (−)-epicatechin and (+)-catechin), six phenolic acids (gallic acid, chlorogenic acid, caffeic acid, ferulic acid and cinnamic acid) and five flavonols (quercetin-3-galactoside, quercitrin-3-glucoside, quercetin-3-rutinose, quercetin-3-rhamnoside and quercetin) were well separated and quantified by HPLC. Similar types of phenolic compounds have been described previously in jujubes [ 11 , 18 , 26 , 27 ].…”

Phytochemical characterization of the Ziziphus joazeiro Mart. metabolites by UPLC-QTOF and antifungal activity evaluation

“…Previous studies have performed Ultra-High-Performance Liquid Chromatography (UPLC) analyses with species from the Ziziphus genus of the Rhamnaceae family, where some of these corroborate with the chemical composition found in the extracts herein, such as Ziziphus mauritiana (26,27), Ziziphus jujuba (28) and Ziziphus jujuba (29,30).…”

Effect of harvest, drying and storage on the bitterness, moisture, sugars, free amino acids and phenolic compounds of jujube fruit (Zizyphus jujuba cv. Junzao)

“…8 In our previous study, bitterness was also perceived in dried jujube fruit stored for 3 months at ambient temperature, and a series of phytochemicals and nitrogen compounds were tentatively identified from bitter fractions of the dried jujube fruit by LC-MS/MS. 9 Although there is little knowledge on bitterness formation during harvest, drying and storage of jujube fruit, a number of studies have indicated that bitterness could be perceived in jujube fruit and its products.…”