Oxidation Resistance of Flavonoids in Chinese Jujube Stone

[Objective] The aim was to study on the oxidation resistance of flavonoids in Chinese jujube stone. [Method] The extract of flavonoids from Chinese jujube stone was added to fresh rapeseed oil and lard to explore the oxidation resistance of flavonoids; the removal rates of it to O2-·,DPPH· and ·OH were also studied. [Result] The flavonoids from Chinese jujube stone had good oxidation resistance on rapeseed oil and lard,and the effects showed dose-dependent; citric acid and vitamin C appeared synergistic effects to the flavonoids; in free-radical reaction experiment,the flavonoids from Chinese Jujube stone also showed strong scavenging ability on O2-·,DPPH· and ·OH,in addition,the scavenging ability increased with concentration increasing. [Conclusion] The result of this study had provided theoretical basis for the further development and utilization of Chinese jujube resource.

Effects of IBA on the rooting of branch cuttings of Chinese jujube (Zizyphus jujuba Mill.) and changes to nutrients and endogenous hormones

‘Zhongqiusucui’ jujube secondary shoots were treated with 3-indolebutyric acid(IBA) at three concentrations, 500, 1000 and 1500 mg/L. Results show that IBA could significantly enhance rooting and root characteristics of cuttings and were best with IBA at 1500 mg/L. In the rooting process, the formation of adventitious roots was related to the consumption and accumulation of nutrients(soluble sugars and proteins) and the changes in endogenous hormones in phloem, leaf tips and leaf bases. The rooting of cuttings had a positive correlation with the consumption of soluble sugars during the period of callus formation and with the accumulation of soluble sugars during adventitious root formation and growth. Rooting was positively related to the breakdown of soluble proteins in the phloem when the callus formed, and had a positive correlation with its accumulation during adventitious root formation and growth. Leaf tips and leaf bases showed a reverse trend in changes of soluble protein. However, together with the phloem, leaf tips and leaf bases regulated and controlled the formation and development of adventitious roots. The main activities of soluble proteins exist in the leaf tips as this was the main source of soluble proteins. The relation between rooting and IAA(indole-3-acetic acid) content in phloem was positive and thus a high concentration of IAA could benefit the induction and formation of adventitious roots. However, rooting was negatively related with ABA(abscisic acid) and GA(gibberellic acid) and a high concentration of both could inhibit the induction and formation of adventitious roots. Rooting had a positive correlation with phloem IAA/ABA ratios, and higher ratios could improve rooting. Low concentrations of ZR(zeatin riboside) triggered the induction of adventitious roots, while higher concentrations promoted root growth.Endogenous hormones in leaf tips and bases had an impact on rooting. The activities of endogenous hormones mainly existed in leaf tips because they play a major role in the production and consumption of IAA and its ABA content increased during rooting. The ZR in leaf tips influenced the rooting of cuttings, especially in the callus formation and rooting stage. Leaf tips were the main source of GA.

Phenolic compounds and its antioxidant activities in ethanolic extracts from seven cultivars of Chinese jujube

Phenolic compounds and its antioxidant activity of extracts from seven cultivars of Chinese jujubes were investigated by high performance liquid chromatography(HPLC)with standards and different antioxidant evaluation methods,such as phosphomolybdenum assay,superoxide radical scavenging activity(SRSA),hydroxyl radical scavenging activity(HRSA),antihemolytic activity and inhibition of lipid peroxidation in rat liver homogenate,respectively.The results showed the components of the extracts are comprised of total phenols and flavonoids,and its content ranges from 454.3 to 1298.9(GAE mg/100 g dry weight).Phlorizin,catechin,gallic acid,chlorogenic acid,caffeic acid were the predominant phenolic compounds.All the extracts had significant antioxidant activities either in vitro or in vivo.Correlation analysis indicated that the antioxidant capacities of Chinese jujube extracts demonstrated a good positive relationship with some phenolic acids,which was higher in Xiao and Goutou.The results indicated that Xiao and Goutou could be attributed to a potential source of natural antioxidants for food applications.

Study on the Quality Control of Chinese Jujube Wine Fermentation

Fermentation processes were studied, with an aim of improving the quality of Chinesejujube wine. Results showed the quality of the wine made from fresh Chinese jujube anddried Chinese jujube were similar, but wine made from excessively dried Chinese jujubeshowed decreased quality. The reducing sugar content in Chinese jujube juice extractedby pectic enzymes was higher than the reducing sugar content extracted by hot water,however, methanol content in wine extracted by pectic enzymes also increased. Thereforethe hot water extraction method is recommended for fermentation of Chinese jujube wine.Fermentation using vacuum concentrated Chinese jujube juice was more effective than thatusing filtered juice readjusted to 20% soluble solid content (SSC) with sucrose orglucose. The inoculation of 0.3% Saccharomyces ellipsodieus Strain was suitable forfermentation of Chinese jujube wine. Fermentation was carried out at 21-25℃. Theconcentration of SO2 in wine affected fermentation time and the optimum additional amountwas 40 mg L-1. Post fermentation storage in oak barrel improved the quality of Chinesejujube wine, as did 4.5% diatomite filtration.

GST family genes in jujube actively respond to phytoplasma infection

Jujube witches’broom(JWB)caused by phytoplasma has a severely negative effect on multiple metabolisms in jujube.The GST gene family in plants participates in the regulation of a variety of biotic and abiotic stresses.This study aims to identify and reveal the changes in the jujube GST gene family in response to phytoplasma infection.Here,70 ZjGSTs were identified in the jujube genome and divided into 8 classes.Among them,the Tau-class,including 44 genes,was the largest.Phylogenetic analysis indicated that Tau-class genes were highly conserved among species,such as Arabidopsis,cotton,chickpea,and rice.Through chromosome location analysis,37.1%of genes were clustered,and 8 of 9 gene clusters were composed of Tau class members.Through RT-PCR,qRT-PCR and enzyme activity detection,the results showed that the expression of half(20/40)of the tested ZjGSTs was inhibited by phytoplasma infection in field and tissue culture conditions,and GST activity was also significantly reduced.In the resistant and susceptible varieties under phytoplasma infection,ZjGSTU49-ZjGSTU54 in the cluster IV showed opposite expression patterns,which may be due to functional divergence during evolution.Some upregulated genes(ZjGSTU45,ZjGSTU49,ZjGSTU59,and ZjGSTU70)might be involved in the process of jujube against JWB.The yeast two-hybrid results showed that all 6 Tauclass proteins tested could form homodimers or heterodimers.Overall,the comprehensive analysis of the jujube GST gene family revealed that ZjGSTs responded actively to phytoplasma infection.Furthermore,some screened genes(ZjGSTU24,ZjGSTU49-52,ZjGSTU70,and ZjDHAR10)will contribute to further functional studies of jujube-phytoplasma interactions.

Immunomodulatory effect of a formula developed from American ginseng and Chinese jujube extracts in mice

Background： American ginseng（Panax quinquefolius L.） and Chinese jujube（Zizyphus jujuba Mill.） are commonly used in traditional Chinese medicine to enhance immune function. Objective： The present study aimed to develop one Chinese prescription, Shenzao Cha（SZC）, consisting of American ginseng and Chinese jujube, and systematically investigate its immunomodulation in healthy ICR mice. Methods： Normal ICR mice received intragastric administration of SZC（1.3, 2.6, and 5.2 g raw material/kg body weight） once daily for four weeks, while a control group received the same amount of sterile water. Results： SZC significantly increased the spleen and thymus indices and T-lymphocyte proliferation, while the T-lymphocyte proliferation in the 5.2 g/kg group was 1.4-fold higher than that in the control. Further, 1.3 g/kg SZC could markedly improve hemolytic activity by 25.2%, and 2.6 g/kg SZC increased the NK cell activity by 78.6% relative to the control. In addition, the activities of antioxidant enzymes（superoxide dismutase, catalase, and glutathione peroxidase）, that participated in modulating oxidative stress, were significantly increased in the liver, spleen, thymus, and serum, while the contents of malondialdehyde were dramatically decreased. Conclusions： SZC exhibited potent immunomodulatory effects on innate and adaptive immunity in healthy ICR mice, as well as potential antioxidant activity for prevention of oxidative stress, which was suggested to partly contribute to the immune enhancement.

Effect of pre-treatments on drying characteristics of Chinese jujube (Zizyphus jujuba Miller)

Chinese jujube is delicious and nourishing fruit.However,fresh Chinese jujube is liable to rot and drying is a necessary process.Traditional drying is a time-consuming task due to the thick cuticle of Chinese jujube.To improve its drying efficiency,fresh Chinese jujube was pretreated with nine different methods prior to hot-air drying.Among these methods,dipping in 2%ethyl oleate plus 5%K_(2)CO_(3) for 10 min(alkaline emulsion of ethyl oleate,AEEO)was recommended for its time-saving effect,which was found more significant at lower drying temperatures.The beneficial effect was considered based on its cuticle destruction by AEEO pre-treatment.In the meantime,the drying process was divided into three stages;each of them obeyed the first order reaction kinetics.Activation energies for the first,second and third stages of control over jujube drying were 41.45 kJ/mol,35.24 kJ/mol and 49.52 kJ/mol,and reduced by 20.9%,22.1%and 29.0%,respectively,after AEEO pre-treatment,and the drying process was well predicted by Midilli et al.model.In view of browning during drying at higher temperatures,AEEO pretreated jujube was suggested to be dried at 60°C.This finding was considered to be helpful to the industrial drying of Chinese jujube.

Combining bioactive compounds and antioxidant activity profiling provide insights into assessment of geographical features of Chinese jujube

As the largest jujube cultivating areas of the world,the market price and quality of Chinese jujube are obviously affected by its producing regions in China.Therefore,traceability of Chinese jujube has become an important issue.To search the suitable geographical labels of Chinese jujube,26 major cultivars from five geographical regions of China were investigated by evaluating their bioactive compounds and antioxidant activity profiling.Multivariate statistical techniques(e,g.,PCA,PLS,VIP value)applied to the above-obtained data were further used to identify geographical origin in different areas of Chinese jujube.The results indicated that the highest median contents of total phenols(TP)and flavonoids(TF)of Chinese jujube were originated from Ningxia and Henan provinces,both of which also exhibited the stronger bioactivity.p-Hydroxybenzoic acid and rutin exhibited the highest contents among the all detected individual phenolic compounds.The highest median contents of cyclic adenosine monophosphate(cAMP),cyclic guanosine monophosphate(cGMP)and polysaccharides were all found in Chinese jujube samples of Xinjiang province.In particular,p-hydroxybenzoic acid,rutin,cAMP,cGMP and polysaccharides can be regarded as the potential biomarkers in distinguishing the geographical origin of Chinese jujube.Additionally,the high altitude and latitude might be benefit for the accumulation of cAMP,cGMP and polysaccharides(primary metabolites),and high longitude and annual precipitation maybe improve the contents of TP and TF(secondary metabolites).These information could provide an effective methods in distinguishing the geographical features of Chinese jujube,and also be benefit for the products development.

Effect of Nitric Oxide on Alcoholic Fermentation and Qualities of Chinese Winter Jujube During Storage

This article investigates the effects of nitric oxide （NO） on alcoholic fermentation and the qualities of Chinese Winter Jujube during storage, and explores the action mechanisms of browning and softening of fruits to provide theoretical proofs for using NO in the storage of Chinese Winter Jujube. Chinese Winter Jujube fruits were fumigated with different concentrations of NO gas （0, 10, 20, 30 μL L^-1） under anaerobic conditions and stored at 22±1℃ and 4± 1℃. The changes in appearance qualities, the contents of pyruvate, ethanol, acetaldehyde, and the activities of alcohol dehydrogenase （ADH） and lactate dehydrogenase （LDH） were investigated. The contents of pyruvate, ethanol, and acetaldehyde were significantly reduced, and the peak of pyruvate content was delayed by 20 μL L^-1 NO. The activities of ADH and LDH in 20 μL L^-1 NO treated fruits were also significantly inhibited. However, the alcoholic fermentation and softening of Chinese Winter Jujube fruits were promoted by 30 μL L^-1 NO during storage. The results indicated that 20 μL L^-1 NO could mitigate the injury of ethanol on Chinese Winter Jujube and effectively delay the browning and softening of fruits during storage.

Comprehensive analysis of antibacterial and anti-hepatoma activity of metabolites from jujube fruit

Jujube is one of the most produced dried fruits in China,and it is also a traditional Chinese medicine that enhances immunity and has anti-cancer activity.Jujube fruit is rich in phenolic compounds,but few reports are available on its biological activities.To evaluate the biological activities of the phenolic compounds in dried jujube fruit,the composition and content of metabolites in dried jujube fruit were determined by metabolomics,and the antibacterial and anticancer activities of the phenolic compounds were analyzed in dried jujube fruit.The results showed that 463 compounds were identified in dried‘Junzao’fruit,including 102 phenolic compounds.The in vitro activity test showed that the jujube phenolic metabolites had extensive antibacterial effects and caused disruption and nuclear sclerosis of hepatocellular carcinoma(HepG2)cells.Canonical correlation analysis showed that total phenolic content,quercetin-3-rutinose,and procyanidin B1 were the main active antibacterial and anticancer components.The study provides data supporting the application of dried jujube fruit in the development of functional foods,pharmaceuticals and cosmetics.

Expression profiles of genes and enzymes related to ascorbic acid metabolism in fruits of Ziziphus jujuba Mill.‘Jinsixiaozao’

The fruit of Chinese jujube(Ziziphus jujuba)possesses extremely high concentrations of ascorbic acid(As A).The accumulation of As A,the expression patterns of the nine genes related to As A metabolism as well as the activities of five enzymes involved in As A synthesis,oxidation and recycling were investigated during fruit development in Z.jujuba Mill.‘Jinsixiaozao'.The results showed that the high level of As A accumulation in jujube fruit is due to a contribution from both As A biosynthesis and As A recycling.It is suggested that L-galactono-1,4-lactone dehydrogenase,ascorbate peroxidase and monodehydro-ascorbate reductase are the crucial genes/enzymes of jujube As A synthesis,oxidization and recycling,respectively.These results provide useful new insights into the regulatory mechanisms of As A accumulation in Chinese jujube.