Tracing the production area of citrus fruits using aroma-active compounds and their quality evaluation models.

BACKGROUND: Aroma is one of the most important aspects of fruit quality and can reflect the characteristics of different fruits. Aroma-active compounds can usefully be employed to trace the production areas of two citrus cultivars ('Eureka' lemon and 'Huapi' kumquat) and to evaluate their aroma quality. RESULTS: 'Huapi' kumquat peel displayed higher monoterpene and sesquiterpene compound content, whereas 'Eureka' lemon peel exhibited higher monoterpene and monoterpene aldehyde compound content. 'Eureka' lemon peel ('Wanzhou' cultivar) had higher nerol acetate and geraniol acetate compound content. Kumquat peel ('Suichuan' and 'Rongan' cultivars) had higher sesquiterpene content. In addition, 30 and 31 aroma-active compounds were observed in kumquat and lemon, respectively, based on their odor activity values. Principal component analysis (PCA) and hierarchical clustering analysis (HCA) results indicated that classification for production areas based on aroma-active compounds was useful. The selected aroma-active compounds have been checked as aroma quality parameters that could be used with multivariate analysis to establish a model of aroma quality evaluation. Higher aroma quality values from kumquat and lemon were collected from Rongan and Wanzhou cultivars, respectively. CONCLUSION: Aroma-active compounds can be used to discriminate production areas using multivariate statistics. An objective method was established to evaluate the aroma quality of citrus fruits. 'Huapi' kumquat and 'Eureka' lemon, which had the highest aroma quality, was harvested from the Rongan and Wanzhou production areas. This was the first time that the aroma quality of citrus fruits was evaluated using multivariate analysis. © 2019 Society of Chemical Industry.

Formulation of nanoemulsion from leaves essential oil of Ocimum basilicum L. and its antibacterial, antioxidant and larvicidal activities (Culex quinquefasciatus).

The present study, emphasis on the encapsulation of Ocimum basilicum L. leaf essential oil by utilizing Polysorbate 80 and its evaluation of antibacterial (MIC), antioxidants and larvicidal activity against C. quinquefasciatus. After the encapsulation, nanoemulsion characterized by using a Zeta potential analyzer and Scanning Electron Microscope (SEM). Nanoemulsion was exhibited significantly more antibacterial activity (MIC) against different enteric bacterial pathogens, Enterococcus faecalis (MTCC-2729), Staphylococcus aureus (MTCC-441), Salmonella paratyphi (MTCC-735), Klebsiella pneumoniae (MTCC-432) and antioxidant ability of the formulated nanoemulsion and essential oil was tested and results of DPPH, Hydroxyl radical scavenging activity, Superoxide scavenging activity and FRAP activities exhibits highest antioxidant activity. The larvicidal activities of C. quinquefasciatus larva was observed at 24 h exposure period and significant mortality were observed after the treatments of essential oil II instar larvae have the maximum mortality at 100 ppm (91.07 ±â€¯0.57) and nanoemulsion (96.87 ±â€¯0.55). The III instar larvae maximum mortality was observed at 24 h exposure period in essential oil at 100 ppm (88.95 ±â€¯0.80) and nanoemulsion (93.89 ±â€¯0.55). These results proposed for developed plant essential oil based nanoemulsion is thermodynamically stable and formulated nanoemulsion will be used for various biomedical applications, food industry and will be drug delivery against the mosquito vector control.

Comparative effects of five polymethoxyflavones purified from Citrus tangerina on inflammation and cancer.

Although the Citrus tangerina cultivar "Dahongpao" (CTD) has been established as a rich source of polymethoxyflavones (PMFs) with anti-inflammatory and anti-cancer properties, their individual effects on cellular signaling remain to be elucidated. In this study, five major PMFs from the peel of CTD were isolated, including sinensetin, tetramethyl-O-scutellarin (5,6,7,4'-tetramethoxyflavone), nobiletin (5,6,7,8,3', 4'-hexamethoxyflavone), tangeretin (5,6,7,8,4'-pentamethoxyflavone), and 5-demethylnobiletin (5-OH-6,7,8,3',4'-pentamethoxyflavone). These PMFs were found to significantly (p < 0.05) inhibit the production of NO and biomarkers of chronic inflammation (TNF-α and IL-6). Additionally, they effectively suppressed mRNA biomarkers of acute inflammation (Cox-2 and iNOS), and to varying degrees promoted the activation of anti-inflammatory cytokines (IL-4, IL-13, TNF-ß, and IL-10). Among the five PMFs, tangeretin was found to have a considerable anti-proliferative effect on tumor cell lines (PC-3 and DU145) and synergistically enhanced the cytotoxicity of mitoxantrone, partially via activation of the PTEN/AKT pathway. The findings of this study provide valuable insights into the activity of different PMF monomers and advance the understanding of the roles of PMFs in promoting apoptotic and anti-cancer effects.

Biosynthesized Gold Nanoparticles Integrated Ointment Base for Repellent Activity Against Aedes aegypti L.

The present study focused on preparing a nano-ointment base integrated with biogenic gold nanoparticles from Artemisia vulgaris L. leaf extract. As prepared, nano-ointment was characterized by using Fourier-transform infrared spectroscopy, and the morphology of the nano-ointment was confirmed through a scanning electron microscope. Initially, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide results showed nano-ointment cytocompatibility at different concentrations (20-200 µg/mL) against L929 cells. The in vitro hemolysis assay also revealed that the nano-ointment is biocompatible. Further studies confirmed that nano-ointment has repellent activity with various concentrations (12.5, 25, 50, 75, and 100 ppm). At 100 ppm concentration, the highest repellent activity was observed at 60-min protection time against the Aedes aegypti L. female mosquitoes. The results indicated that the increasing concentration of nano-ointment prolongs the protection time. Moreover, the outcome of this study provides an alternative nano-ointment to synthetic repellent and insecticides after successful clinical trials. It could be an eco-friendly, safer nano-bio repellent, which can protect from dengue fever mosquitoes.

Profiling of Flavonoid and Antioxidant Activity of Fruit Tissues from 27 Chinese Local Citrus Cultivars.

Flavonoid profile and antioxidant activity of citrus peels, pulps, and juices from 27 local citrus cultivars in China were investigated. Flavonoid composition and content were determined using UPLC-PDA. Total phenolic content (TPC) and total flavonoid content (TFC) were measured using a Folin-Ciocalteau reagent and Al(NO3)-NaNO2 complexometry, respectively. The antioxidant capacities of the extracts were evaluated by DPPH, ABTS and FRAP method, respectively. Citrus peel not only exhibited better antioxidant potential, but also presented more composition diversity and contained higher concentrations of flavonoids than pulp and juice. Different citrus species were characterized by their individual predominant flavonoids, contributing largely to the antioxidant activity, such as mandarin was characterized by hesperidin, nobiletin and tangeretin, while pummelo and papeda were characterized by naringin. The peel of Guihuadinanfeng (Citrus reticulata) had the highest TPC of 23.46 mg equivalent gallic acid/g DW (dry weight) and TFC of 21.37 mg equivalent rutin/g DW. Shiyueju (C. reticulata) peel showed the highest antioxidant capacity based on the antioxidant potency composite (APC) analysis. Overall, mandarin (C. reticulata) fruits peel contained more TPC and TFC, exhibiting higher antioxidant capacities than other species, and were good natural sources of flavonoids and antioxidants.