Quantitative Assessment of Phenolic Acids, Flavonoids and Antioxidant Activities of Sixteen Jujube Cultivars from China.

Increasing attention has been paid to the nutritional values and pharmacological effects of Ziziphus jujuba. Therefore, in this study, four phenolic and flavonoid fractions of 16 jujube cultivars from different geographic regions of China were separated and quantified. In addition, the antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH·) scavenging method and the ferric reducing antioxidant power (FRAP) assay. The total phenols and flavonoids contents ranged from 253.4 to 494.9 mg GAE/100 g and 125.3 to 425.4 mg rutin/100 g, respectively. Subsquently, a total of 10 phenolic acids and two flavonoids were identified, and most quantified phenolic acids with antioxidant activity were mainly present in the glycosided and insoluble-bound phenolic fractions. The results of this study indicate that some jujube cultivars, especially Zanghuang Z. jujuba, Leling Z. jujuba, and Jiaxian Z. jujuba could be selected to promote a healthy diet due to their more plentiful nutritional and phytochemical beneficial effects.

Optimized Extraction of Phenolics from Jujube Peel and Their Anti-inflammatory Effects in LPS-Stimulated Murine Macrophages.

The extraction of phenolics from jujube peel (PJP) was optimized using response surface methodology (RSM). A Box-Behnken design was utilized to analyze the effects of NaOH concentration, temperature, and extraction time on the total phenolic content (TPC). The results showed that RSM could be an adequate approach for modeling the extraction of PJP. The optimal extraction condition for the highest TPC was obtained with 3.4 M NaOH concentration for 67 min at 50 °C. Not only PJP but also phenolics from the jujube seed (PJS) contain considerable amounts of phenolics, particularly flavonoids. Quercetin and galangin were found to be the predominant phenolics. PJP markedly down-regulated the levels iNOS and COX-2 proteins in macrophages by inhibiting the activation of NF-κB through interfering with the MAPK signaling pathways. Compared to PJS, PJP presented higher anti-inflammatory activities, reflecting increased amounts of TPC and total flavonoid content (TFC). These findings suggest that PJP could be a potential source of anti-inflammatory agents.

Protective effects of theasinensin A against carbon tetrachloride-induced liver injury in mice.

Theasinensins have been identified as a major group of unique catechin dimers mainly found in oolong tea and black tea. Among several types of theasinensins, theasinensin A (TSA), an epigallocatechin gallate (EGCG) dimer with an R-biphenyl bond, is the most abundant theasinensin prevalent in oolong tea. Previous studies have reported that TSA exhibits antioxidative, anti-inflammatory and anti-cancer activities in vitro and in vivo. However, little is known about the hepatoprotective effect of TSA. Thus, the aim of this study was to investigate the inhibitory effect of TSA on carbon tetrachloride (CCl4)-induced hepatic fibrosis in mice. After intraperitoneal injection of CCl4 for eight weeks, histological lesions in the liver tissue and elevated serum levels of alanine aminotransferase and alkaline phosphatase were found in mice. Conversely, oral administration of TSA relieved CCl4-induced liver injury as well as ameliorated liver functions. Our immunohistochemical staining results revealed that collagen deposition was profoundly reduced due to supplementation with TSA. In addition, we also found that hepatic α-smooth muscle actin (α-SMA) and matrix metallopeptidase 9 (MMP-9) expression was suppressed through the inhibition of transforming growth factor ß (TGF-ß). Taken together, our current findings suggest that TSA may serve as a potent bioactive constituent from oolong tea that acts against liver fibrosis through the inhibition of hepatic stellate cell (HSC) activation.

Drying and decontamination of raw pistachios with sequential infrared drying, tempering and hot air drying.

Pistachio nuts have been associated with outbreaks of foodborne disease and the industry has been impacted by numerous product recalls due to contamination with Salmonella enterica. The current hot air drying of pistachios has low energy efficiency and drying rates, and also does not guarantee the microbial safety of products. In the study described herein, dehulled and water-sorted pistachios with a moisture content (MC) of 38.14% (wet basis) were dried in a sequential infrared and hot air (SIRHA) drier to <9% MC. The decontamination efficacy was assessed by inoculating pistachios with Enterococcus faecium, a surrogate of Salmonella enterica used for quality control in the almond industry. Drying with IR alone saved 105min (34.4%) of drying time compared with hot air drying. SIRHA drying of pistachios for 2h with infrared (IR) heat followed by tempering at a product temperature of 70°C for 2h and then by hot air drying shortened the drying time by 40min (9.1%) compared with drying by hot air only. This SIRHA method also reduced the E. faecium cell population by 6.1-logCFU/g kernel and 5.41-logCFU/g shell of pistachios. The free fatty acid contents of SIRHA dried pistachios were on par with that of hot air dried samples. Despite significant differences in peroxide values (PV) of pistachio kernels dried with the SIRHA method compared with hot air drying at 70°C, the PV were within the permissible limit of 5Meq/kg for edible oils. Our findings demonstrate the efficacy of SIRHA drying in achieving simultaneous drying and decontamination of pistachios.

Protective effects of buckwheat honey on DNA damage induced by hydroxyl radicals.

To understand the antioxidant properties of buckwheat honeys, we investigated their antioxidant effects on hydroxyl radical-induced DNA breaks in the non-site-specific and site-specific systems, the physicochemical properties, antioxidant activities (1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical scavenging activity, chelating, and reducing power assays), total phenolic content and individual phenolic acids were also determined. Total phenolic content of buckwheat honeys ranged from 774 to 1694 mg PA/kg, and p-hydroxybenzoic and p-coumaric acids proved to be the main components in buckwheat honeys. All the buckwheat honey samples possess stronger capability to protect DNA in the non-site-specific systems than in the site-specific systems from being damaged by hydroxyl radicals. In the non-site-specific and site-specific system, buckwheat honeys samples prevented ()OH-induced DNA breaks by 21-78% and 5-31% over control value, respectively.