884 research outputs found

    Effect of biocomposite edible coatings based on pea starch and guar gum on nutritional quality of ‘Valencia’ orange during storage

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    Application of environmentally friendly components is an approach for substitution of synthetic substances in commercial waxes applied to citrus. In this study, the effect of biocomposite edible coatings based on pea starch and guar gum (PSGG) on total vitamin C, phenolic, flavonoid, anthocyanins, and carotenoid content, and antioxidant capacity of ‘Valencia’ orange stored at 5 °C and 20 °C for four weeks were evaluated. The fruits were coated by a single layer PSGG coating, blended composite PSGG coating containing shellac (Sh) and oleic acid as hydrophobic compounds (PSGG-Sh), and a layer-by-layer (LBL) coating (PSGG as an internal layer and Sh as an external layer). The results showed no significant differences in changes of bioactive compounds between coating treatments after first week storage at both temperatures. The PSGG coatings incorporated with hydrophobic compounds (PSGG-Sh) better preserved the nutritional value and the antioxidant potential of oranges during storage compared with other treatments. The single layer PSGG coating was almost similar to bilayer coating in preserving nutritional value of fruit during storage and less effective than the blended composite PSGG-Sh coating

    Characterization of pea starch-guar gum biocomposite edible films enriched by natural antimicrobial agents for active food packaging

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    Antimicrobial activity of epigallocatechin-3-gallate (EGCG) and two native Australian plants blueberry ash (BBA) fruit and macadamia (MAC) skin extracts against nine pathogenic and spoilage bacteria and seven strains of fungi, using an agar well diffusion assay were investigated. The minimum inhibitory concentrations (MIC) of these compounds were calculated using 96-well microtiter plates method. Finally, active antimicrobial packaging films were prepared by incorporation of EGCG, BBA and MAC extracts at 1-, 2-, 3-, and 4-fold of their correspondence MIC values into edible films based on pea starch and guar gum (PSGG). The antimicrobial activity of films was investigated against target microorganisms by agar disc diffusion technique and quantified using the viable cell count assay. Among the test microorganisms, Salmonella typhimurium and Rhizopus sp. were the most resistance to active films. Films containing EGCG showed the highest activity against all test strains. As the concentration of compounds increased higher than 2 × MIC, the mechanical characteristics of the films were affected considerably. The results indicated that EGCG-PSGG, BBA-PSGG and MAC-PSGG films can be used as active food packaging systems for preserving food safety and prolonging the shelf-life of the packaged food

    Effect of low-pressure storage on the quality of green capsicums (<i>Capsicum annum L.</i>)

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    Green capsicums (Capsicum annum L.) were stored under low pressure (4 kPa) at 10°C for 5 and 11 days with 100% RH. The results showed that the incidence of stem decay under low pressure storage for 5 and 11 days and storage at ambient atmosphere at 20°C for three days lower compared to fruits that were stored at regular atmosphere at 10°C. Fruit that had been stored at low pressure at 10°C had no symptoms of flesh rots for up to 11 days, whilst fruit which had been stored at regular atmosphere at 10°C had 6% flesh rots after 11 days storage at 10°C.There was no difference in flesh firmness and colour retention between fruits stored at low pressure and regular pressure at 10°C. Capsicums stored at low pressure had higher overall acceptability compared to fruit that were stored at regular atmosphere at 10°C. These results demonstrate the potential of low pressure storage as an effective technique to manage capsicum fruit quality, however there was no additional benefit when fruits were stored at low pressure for more than 5 days

    Encapsulation of citrus by-product extracts by spray-drying and freeze-drying using combinations of maltodextrin with soybean protein and ι-carrageenan

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    The effect of different combinations of maltodextrin (MD) coating agents (MD, MD + soybean protein, and MD + ι-carrageenan) on the encapsulation of lemon by-product aqueous extracts using freeze-drying and spray-drying were investigated. The total phenolic content (TPC), total flavonoid content (TFC), and ferric ion reducing antioxidant power (FRAP) of the microparticles were evaluated. Freeze-drying with the mixture of MD + soybean protein resulted in the highest retention of TPC, TFC, and FRAP (1.66 ± 0.02 mg GAE/g d.b., 0.43 ± 0.02 mg CE/g d.b., and 3.70 ± 0.05 mM TE/g, respectively). Freeze-drying resulted in microparticles with lower moisture content (MC) and water activity (aw) than those produced by spray-drying. Specifically, the MC and aw of the microparticles produced by freeze-drying ranged from 1.15 to 2.15% and 0.13 to 0.14, respectively, while the MC and aw of the microparticles produced by spray-drying ranged from 6.06% to 6.60% and 0.33 to 0.40, respectively. Scanning electron microscopy revealed that spray-drying resulted in the formation of spherical particles of different sizes regardless of the type of coating agent. Although freeze-drying resulted in microparticles with amorphous glassy shapes, the mixture of MD + soybean protein resulted in the formation of spherical porous particles. X-ray diffraction revealed a low degree of crystallinity for the samples produced by both techniques.</p

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

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    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

    The application of low pressure storage to maintain the quality of zucchinis

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    Zucchini (Cucurbita pepo var. cylindrica) were stored at low pressure (4 kPa) at 10°C at 100% relative humidity for 11 days. Fruit quality was examined upon removal and after being transferred to normal atmosphere (101 kPa) at 20°C for three days. Zucchinis stored at low pressure exhibited a 50% reduction in stem-end browning compared with fruit stored at atmospheric pressure (101 kPa) at 10°C. The benefit of low pressure treatment was maintained after the additional three days storage at normal atmospheric pressure at 20°C. Indeed, low pressure treated fruit transferred to regular atmosphere 20°C for three days possessed a significantly lower incidence of postharvest rot compared to fruit stored at regular atmospheric pressure at 10°C. Zucchinis stored at low pressure showed higher levels of acceptability (28% and 36%, respectively) compared to fruit stored at regular atmospheres at 10°C for both assessment times.<br/

    Application of biocomposite edible coatings based on pea starch and guar gum on quality, storability and shelf life of ‘Valencia’ oranges

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    Novel edible composite coatings based on pea starch and guar gum (PSGG), PSGG blended with lipid mixture containing the hydrophobic compounds shellac and oleic acid (PSGG-Sh), and a layer-by-layer (LBL) approach (PSGG as an internal layer and shellac as an external layer), were investigated and compared with a commercial wax (CW) and uncoated fruit on postharvest quality of ‘Valencia’ oranges held for up to four weeks at 20 °C and 5 °C with an additional storage for 7 d at 20 °C. The incorporation of lipid compounds into the PSGG coatings (PSGG-Sh) generally resulted in the best performance in reducing fruit respiration rate, ethylene production, weight and firmness loss, peel pitting, and fruit decay rate of the coated oranges. Fruit coated with PSGG-Sh and a single layer PSGG coatings generally resulted in higher scores for overall flavor and freshness after four weeks at 5 °C followed by one week at 20 °C than uncoated fruit, as assessed by a sensory panel. Although the LBL coating reduced weight loss and respiration rate with improved firmness retention to a greater extent than the single layer PSGG coating, the bilayer coating also resulted in higher levels of ethanol causing increased perception of off-flavors. Overall results suggested that PSGG-based edible coatings could be a beneficial substitute to common commercial waxes for maintaining quality and storability, as well as extending shelf life of citrus fruit and potentially other fresh horticultural produce

    Successful treatment of ciliary body medulloepithelioma with intraocular melphalan chemotherapy: a case report.

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    Intraocular medulloepithelioma is commonly treated with primary enucleation. Conservative treatment options include brachytherapy, local resection and/or cryotherapy in selected cases. We report for the first time the use of targeted chemotherapy to treat a ciliary body medulloepithelioma with aqueous and vitreous seeding. A 17-month-old boy with a diagnosis of ciliary body medulloepithelioma with concomitant seeding and neovascular glaucoma in the right eye was seen for a second opinion after parental refusal of enucleation. Examination under anesthesia showed multiple free-floating cysts in the pupillary area associated with iris neovascularization and a subluxated and notched lens. Ultrasound biomicroscopy revealed a partially cystic mass adjacent to the ciliary body between the 5 and 9 o'clock meridians as well as multiple nodules in the posterior chamber invading the anterior vitreous inferiorly. Fluorescein angiography demonstrated peripheral retinal ischemia. Left eye was unremarkable. Diagnosis of intraocular medulloepithelioma with no extraocular invasion was confirmed and conservative treatment initiated with combined intracameral and intravitreal melphalan injections given according to the previously described safety-enhanced technique. Ciliary tumor and seeding totally regressed after a total of 3 combined intracameral (total dose 8.1 μg) and intravitreal (total dose 70 μg) melphalan injections given every 7-10 days. Ischemic retina was treated with cryoablation as necessary. Three years later, ab interno trabeculotomy followed by 360° gonioscopy-assisted transluminal trabeculotomy 6 months later was performed for uncontrolled intraocular pressure despite antihypertensive drugs combined to cyclophotocoagulation and 7 intravitreal anti-VEGF injections for recurrent iris neovascularization. Cataract was removed at the same operative time. The child has remained disease- and metastasis-free at a 5-year follow-up since the last melphalan injection (25-month follow-up after the combined lensectomy-trabeculotomy) with a controlled intraocular pressure under topical quadritherapy and a best corrected Snellen visual acuity of 0.08. We report for the first time complete regression of a non-infiltrating ciliary body medulloepithelioma with seeding achieved with only a small number of intracameral and intravitreal melphalan injections. Concomitant secondary neovascular glaucoma and cataract needed appropriate management to allow long-term eye and vision preservation
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