正交法优选中药材苏木水提取工艺

以苏木中总酚含量为考察指标，采用索氏和超声两种提取工艺，利用正交实验法考察加水量、提取时间和提取次数三个因素的影响，并对苏木提取工艺进行优选，为苏木的进一步开发利用提供参考。结果表明，索氏提取法提取次数对提取工艺有显著性影响，最佳提取工艺条件为加10倍量水，索氏提取2次，每次4．5h；超声提取法提取时间和提取次数对提取工艺均有显著性影响，最佳提取工艺为加10倍量水，超声提取3次，每次1．5h。因此，两种工艺均可应用于水作溶剂的苏木提取，且索氏提取法效果较好。     

柚皮提取物不同级分的抗氧化活性研究

为柚皮资源的精细化利用提供参考依据，采用弱极性的DM130大孔吸附树脂为吸附剂、以不同浓度的乙醇溶液对柚皮提取物进行梯度洗脱，得到5种洗脱级分。采用二苯代苦肼自由基法和硫氰酸铁盐比色法对该5种级分的抗氧化活性进行了测定。结果显示：5种洗脱级分表现出不同程度的清除DPPH自由基和抗亚油酸过氧化活性，其作用大小依次为：水级分、20％乙醇级分、40％乙醇级分、60％乙醇级分和80％乙醇级分，5种洗脱级分的抗氢化活性均高干柚皮苷，但均低于二丁基羟基甲苯。柚皮提取物不同洗脱级分具有不同的抗氧化活性。     

Release characteristics of paracetamol and oleuropein from Mech-Degla date fruit tablets enriched and non-enriched with freeze-dried olive leaf extract

Release characteristics of paracetamol from date (Phoenix dactylifera L., var. Mech-Degla) fruit tablets enriched and non-enriched with freeze-dried olive leaf extract (OLE) were studied. For this, two types of tablets (T) were obtained by direct compression: (1) T1 from P1-powder blend, containing 60% date powder (DP) and 40% paracetamol, and (2) T2 from P2-powder blend, containing 57% DP, 40% paracetamol, and 3% OLE. The release of paracetamol was studied in phosphate buffer (pH?6.8) and HCl solution (0.1N). Additionally, the oleuropein released was investigated in the case of T2-tablets. Based on obtained results, P1- and P2-powder blends showed acceptable flow properties in terms of Hausner’s ratio (1.30, in the case of P2) and angle of repose for both P1 (31 degrees) and P2 (33 degrees). Dissolution study showed that the released paracetamol achieved 80% after 70?min, whereas the oleuropein release was almost complete after 30?min. On the other hand, the Peppas model described correctly dissolution kinetics of both paracetamol (R²=?0.99) and oleuropein (R²=?0.89) whatever the applied dissolution medium. Furthermore, the presence of OLE in T2-tablets enhanced their microbiological shelf-life.     

Applications of an oak extract on Petit Verdot grapevines. Influence on grape and wine volatile compounds

Petit Verdot vineyards were treated at veraison with a commercial aqueous French oak extract in order to determine if the extract’s volatile components can be transferred to grapes and then to wines. Three different formulations (25% (one application), 25% (four applications) and 100%) were tested, together with an eugenol and guaiacol standard solution to better follow their behaviour. The volatile compounds of treated grapes and their wines after alcoholic and malolactic fermentation and after 8 months were analysed by stir bar sorptive extraction and gas chromatography mass spectrometry (SBSE-GC–MS). The results showed that the grapes stored the volatile compounds mainly as non-volatile precursors, and some of these were released after winemaking. In the case of wines, it was possible to distinguish the control versus the ones from vineyard treatments. The different oak extract applications were evident only after alcoholic fermentation sampling, making it very interesting for young wines.     

Influences of vanillin and licorice root extract supplementations on the decimal reduction times of Escherichia coli O157:H7 in mildly heated young coconut liquid endosperm

This study determined the influences of supplementing different combinations of vanillin (0–500 ppm) and licorice root extract (LRE, 0–420 ppm) on the mild heat (55 °C) decimal reduction times (D₅₅-values) of a cocktail of Escherichia coli O157:H7 in young coconut liquid endosperm. The maximum level of supplementation per additive tested was previously established not to result in the lowering of general consumer acceptability of the liquid endosperm. The D₅₅-values ranged from 15.08 to 31.40 min. The influences of both additives on the D₅₅-value fitted significantly into a 2-factor, interaction model with only the joint effect of the additives having significant effect on D₅₅. The combined efficacies of the additives were most significant at concentrations above 250 ppm vanillin and 210 ppm LRE. The results obtained may be used in the establishment of mild heat pasteurization processes for supplemented young coconut liquid endosperm, for better control of quality and safety.     

Green synthesis and characterization of RGO/Cu nanocomposites as photocatalytic degradation of organic pollutants in waste-water

Recently, nanocomposite photocatalysts based on semiconductors have attracted much attention due to their suitable bandgap. Combination of tow of several semiconductors can slow down the electron-hole recombination. In this regard, we have depicted an eco-friendly and green fabrication technique to synthesize RGO/Cu nanocomposite by the reduction of graphene oxide and Cu²⁺ ion utilizing spearmint extract as a reductant and capping agent. The sample was identified by FTIR, XRD, FESEM, EDS, HRTEM, and CV. The results of photocatalytic performance revealed that RGO/Cu is an efficient catalyst for degrading organic pollutants. This compound can eliminate Rhodamine B (RhB) and Methylene blue (MB) 91.0% and 72.0%, respectively.     

Maintenance of postharvest quality and bioactive compounds of fresh‐cut sweet leaf bush (Sauropus androgynus L. Merr.) through hot CaCl2 dips

The effects of hot CaCl₂ dips on postharvest quality and bioactive compounds of fresh‐cut sweet leaf bush were investigated. The vegetable was dipped in 0.5% or 1.0% (w/v) of CaCl₂ solutions at 40 °C for 30 s and the control was the untreated sample. Hot CaCl₂ dips significantly delayed the weight loss, maintained the overall quality and inhibited the wiltness (P < 0.05). Both hot CaCl₂ dips had no effect on the changes in lightness (L*) and delayed the decrease in greenness (‐a*) and total chlorophyll content and the increase in both yellowness (b*) and carotenoid content. Hot CaCl₂ dips enhanced total antioxidants, total phenolics content and both AsA‐POD and G‐POD activities from 38.6, 0.44, 15.2 and 22.4 at day 0 to 55.3, 0.55, 50.5 and 362.4 at day 8, respectively. Moreover, hot CaCl₂ dips also delayed the loss of DPPH free radical scavenging activity, total flavonoid, ascorbic acid and CAT activity when compared to other treatments during storage. This study showed that hot CaCl₂ dip maintains postharvest quality and enhanced bioactive compounds of fresh‐cut sweet leaf bush during storage.