569 research outputs found

    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

    A starch edible surface coating delays banana fruit ripening

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    A rice starch edible coating blended with sucrose esters was developed for controlling the postharvest physiological activity of Cavendish banana to extend postharvest quality during ripening at 20 ± 2 °C. Coating effectiveness was assessed against changes in fruit physiochemical parameters such as weight loss, titratable acidity, total soluble solids, flesh fruit firmness, ion leakage, colour change, respiration, ethylene production, chlorophyll degradation and starch conversion were determined. The topography of coating material on the fruit surface was evaluated by scanning electron microscope (SEM). Surface morphology studies highlighted the binding compatibility of the coating matrix with the fruit peel character and formed a continuous uniform layer over the fruit surface. The results showed that the coating was effective in delaying ethylene biosynthesis and reducing respiration rate. Other factors impacting included delayed chlorophyll degradation, reduced weight loss and retention of fruit firmness for the first six days, all of which improved the commercial value of the fruit. The shelf life of coated fruit was prolonged for 12 days in comparison with the untreated control which ripened within seven days and lost marketability after Day 6. The pilot study demonstrates the effectiveness of a starch-based edible coating formulation for improving the ambient storage capacity of banana fruit

    Effect of starch physiology, gelatinization, and retrogradation on the attributes of rice starch-ι-carrageenan film

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    Edible films and coatings have been applied as the potential substitutes for conventional plastics in food packaging. However, their physical and mechanical properties still have limitations and thus require further improvement. In this study, we compared the physico–chemical properties of starches extracted from eight rice varieties and attempted to predict their promising effects on the physical (thickness and solubility), mechanical (tensile strength and elongation break), barrier (water vapor permeability), and optical properties (color and transparency) of rice starch-ι-carrageenan films. The results showed that starch amylose content and amylose–amylopectin associations during retrogradation play a significant role in determining various properties of the films. The film containing starch from “Reiziq” variety showed minimum thickness (0.08 mm), water vapor permeability (WVP) (2.7 gs−1 m−1 Pa−1), solubility (43.12%) opacity (0.44%), and better mechanical properties, demonstrating the importance of selection of the source of the starch. The results also indicated that rice starch had compatibility with ι-carrageenan, and the blend of these two polysaccharides can be potentially used for coating fruit and vegetables

    Amylose-lipid complex as a measure of variations in physical, mechanical and barrier attributes of rice starch- ι -carrageenan biodegradable edible film

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    Improvements in the hygroscopic properties of starch based films are important to strengthen their mechanical properties. The effects of different hydrophobic components-butyric acid (BA, C4:0), lauric acid (LA, C12:0), palmitic acid (PA, C16:0), oleic acid (OA, C18:1), stearic acid (SA, C18:0) and sucrose fatty acid ester (FAEs) on the rice starch (RS)-ι-carrageenan (ι-car) composite films were investigated. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) in combination with amylose-lipid complexing index (CI) were used to characterise the changes in structure and properties of edible films. The SEM results showed that the surface of films became smoother after the incorporation of fatty acids. Carbon-chain length was a major determinant of CI formation which further influenced the attributes of RS-ι-car films. The addition of FAEs to RS-ι-car improved film thickness, permeability, transparency, tensile properties (TS) and could be used to tailor biodegradable edible films with enhanced properties and future fruit coating applications

    Evaluating land use and management Natural Flood Management potential

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    Soil use and management as a form of Natural Flood Management (NFM) has potential to increase infiltration and soil water storage above and below ground. As a result, it can slow the flow of water and reduce flooding caused by surface run-off, rivers and groundwater. Here, we report findings from the LANDWISE project, which examined the potential of land use and management in lowland groundwater-fed catchments in the River Thames Basin, England. We focused on five soil classes within two geology types: shallow permeable soils on carbonate geology (Limestone and Chalk) and deep clay soils on mudstone geology; across agricultural land, grassland and woodland. We compared different farming systems, including conventional, innovative and organic agriculture. We gathered empirical evidence of within and between field variation for different soil use and management strategies, through a broad survey of 164 fields and an in-depth survey of 7 sites. We show that both land use and soil type are significant in affecting bulk density. We also show correlation between organic matter and bulk density, which is important for NFM as organic matter content can be controlled by land use and management practices. We adopted a co-production research approach, to deliver usable impacts for farmers who will ultimately deliver NFM through land use change and management. This work will inform policy and design and delivery of agri-environment schemes; such as the soil survey scheme, a key part of the DEFRA soil action plan. It will help co-deliver NFM alongside other ecosystem services

    Flavor decomposition of the sea quark helicity distributions in the nucleon from semi-inclusive deep-inelastic scattering

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    Double-spin asymmetries of semi-inclusive cross sections for the production of identified pions and kaons have been measured in deep-inelastic scattering of polarized positrons on a polarized deuterium target. Five helicity distributions including those for three sea quark flavors were extracted from these data together with re-analyzed previous data for identified pions from a hydrogen target. These distributions are consistent with zero for all three sea flavors. A recently predicted flavor asymmetry in the polarization of the light quark sea appears to be disfavored by the data.Comment: 5 pages, 3 figure

    Observation of a Single-Spin Azimuthal Asymmetry in Semi-Inclusive Pion Electro-Production

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    Single-spin asymmetries for semi-inclusive pion production in deep-inelastic scattering have been measured for the first time. A significant target-spin asymmetry of the distribution in the azimuthal angle phi of the pion relative to the lepton scattering plane was observed for pi+ electro-production on a longitudinally polarized hydrogen target. The corresponding analyzing power in the sin(phi) moment of the cross section is 0.022 +/- 0.005 +/- 0.003. This result can be interpreted as the effect of terms in the cross section involving chiral-odd spin distribution functions in combination with a time-reversal-odd fragmentation function that is sensitive to the transverse polarization of the fragmenting quark.Comment: 5 pages of RevTex, 3 ps figures, 2 table

    Evidence for Quark-Hadron Duality in the Proton Spin Asymmetry A1A_1

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    Spin-dependent lepton-nucleon scattering data have been used to investigate the validity of the concept of quark-hadron duality for the spin asymmetry A1A_1. Longitudinally polarised positrons were scattered off a longitudinally polarised hydrogen target for values of Q2Q^2 between 1.2 and 12 GeV2^2 and values of W2W^2 between 1 and 4 GeV2^2. The average double-spin asymmetry in the nucleon resonance region is found to agree with that measured in deep-inelastic scattering at the same values of the Bjorken scaling variable xx. This finding implies that the description of A1A_1 in terms of quark degrees of freedom is valid also in the nucleon resonance region for values of Q2Q^2 above 1.6 GeV2^2.Comment: 5 pages, 1 eps figure, table added, new references added, in print in Phys. Rev. Let
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