Development and application of rice starch based edible coating to improve the postharvest storage potential and quality of plum fruit (<i>Prunus salicina</i>)

The study investigated the possibility of enhancing the shelf life of plum fruit coated with rice starch-ι-carrageenan (RS-ι-car) composite coating blended with sucrose fatty acid esters (FAEs). Film solution (starch 3%, carrageenan 1.5% and FAEs 2%) was prepared by mixing the ingredients and properties of stand-alone films (physical, mechanical, barrier and surface morphology) were studied before applying the coating on fruit surface. Fruit were stored at 20 °C for 3 weeks and analyzed for weight loss, ethylene production, respiration rate, color change, firmness, and titratable acidity (TA) and soluble solid content (SSC). Surface morphology of stand-alone film and fruit surface (after applying on the plum fruit) was studied using scanning electron microscopy (SEM). Phytochemical analysis was performed during the storage period and total phenolic content (TPC), total antioxidant capacity (TAC), flavonoid content (FC) and free radical scavenging activity were determined. The rice starch composite coating was shown to be effective in reducing both weight loss (WL) and respiration rate and inhibiting the endogenous ethylene production when compared to the uncoated control fruit stored at room temperature (p &lt; 0.05). TPC, TAC, FC and free radical scavenging activity was unaffected in the coated fruit throughout the storage period (p &lt; 0.05). The findings reported in this study indicate that the RS-ι-car-FAEs coating prolongs the shelf life and maintains the overall quality of plum fruit during storage and could potentially be commercialized as a new edible coating for the plum fruit industry

Comparison stripmap COSMOS SkyMed X-band and tops Sentinel-1 C-band in estimating ground subsidence using irstea TOMOSAR platform: Ho Chi Minh City case study

International audienceThe objective of this paper is to provide a better understanding of Persistent Scatterers Interferometry (PSI) capabilities in subsidence estimations of TOPSAR Sentinel-1 data. This work has presented an advanced PSI analysis, to provide unprecedented spatial extent and continuous temporal coverage of the subsidence in Ho Chi Minh City by using 49 stripmap Cosmos SkyMED (CSK) X-band and TOPS Sentinel-1 Cband 23 images acquired from 2014 to 2016. The analysis was carried out by using the Irstea TomoSAR platform, which supports the entire processing from SAR, Interferometry, Polarimetry, to Tomography (so called TomoSAR). The study shows that the performance of stripmap CSK and TOPS Sentinel-1 is quite similar and effective to detect the subsidence phenomena. Subsidence is most severe in the Holocene silt loam areas along Sai Gon river and in the Southwest of the city, with the maximum value up to-30 mm/yr, similar with the previous study using ALOS PALSAR. Index Terms-Synthetic Aperture Radar, TOPS Sentinel-1, Comos SkyMED, TomoSAR platform, service as demand, subsidence, Ho Chi Minh City, Vietnam

Phytochemical, antibacterial and antifungal properties of an aqueous extract of Eucalyptus microcorys leaves

Australia is home to over 800 different species of <i>Eucalyptus</i> and traditionally, many <i>Eucalyptus</i> species have been utilised to heal wounds and treat fungal infections by the Indigenous people of Australia. In view of this, our study was designed to investigate the phytochemical, antibacterial and antifungal properties of crude aqueous extract of <i>E. microcorys</i> leaves. The freeze-dried powdered extract was prepared and the phytochemical profile was studied by analysing the total phenolic content (TPC), total flavonoid content (TFC), proanthocyanidins, antioxidants and saponins. The TPC, TFC and proanthocyanidin values found were: 501.76 ± 14.47 mg of gallic acid equivalents per g, 61.53 ± 0.83 mg of rutin equivalents per g and 10.76 ± 0.89 mg of catechin equivalents per g, respectively. The antioxidant values expressed in mg trolox equivalents per g of extract (mg TE/g) were: ABTS = 1073.13 ± 10.73 mg TE/g, DPPH = 1035.44 ± 65.54 mg TE/g and CUPRAC = 1524.30 ± 66.43 mg TE/g. The powdered extract was also evaluated for activity against three pathogenic bacterial strains (<i>Escherichia coli, Enterobacter aerogenes, Staphylococcus lugdunensis</i>); and three fungal strains (<i>Geotrichum candidum, Aspergillus brasiliensis and Candida albicans</i>) using the disc diffusion method and 96 well plate-based method with resazurin dye. The extract exhibited clear zones of inhibition against the tested bacteria and fungi. Minimum inhibitory concentration (MIC) values were demonstrated to be: <i>A. brasiliensis </i>= 2.44 μg/mL, <i>G. candidum</i> = 4.88 μg/mL, <i>S. lugdunensis</i> = 78 μg/mL, <i>E. coli</i> = 156.25 μg/mL, <i>E. aerogenes</i> = 312.5 μg/mL and <i>C. albicans</i> = 1250 μg/mL. These results reveal the significant potential of <i>E. microcorys</i> as a source of phenolics, antioxidants and antimicrobial agents and also highlight the necessity of further purification and characterisation of solitary bioactive compounds for their prospective applications in food, nutraceutical and pharmaceutical industries