8 research outputs found

    Shelf life extension of walnut kernels using rice starch-based edible coating formulations

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    The shelf life of raw walnut kernel is limited due to the influenced of various factors such as its chemical composition, storage condition and environments etc. The effects of five different rice starch-based edible coating formulations on the chemical, physicochemical and textural properties of coated walnut kernels were studied. The peroxide value, anisidine value, totox value, free fatty acid content, hexanal content, color, moisture content, and textural properties were monitored in coated walnuts stored at accelerated temperature (60°C). Results indicated that the coated walnuts had a better quality in terms oxidative stability based on all the chemical indicators of rancidity, and a firmer texture when compared to the uncoated ones, even after 20 days of storage at high temperature. The walnut kernels that were coated with the basic rice starch formulation can be stored longer than the uncoated control samples i.e. with additional of 6 to7 days at 60°C. However, the color of the coated sample was significantly (P≤0.05) lighter than the control group with L values of 49.86 and 46.88, respectively. The predicted shelf life based on calculation showed that the shelf life of the walnut kernels can be extended to 1024 days from 160 days at storage temperature of 20 ± 2°C.It can be concluded that the physicochemical and storage qualities of walnut kernels can be improved by addition of palm oil or chitosan to the rice starch-based edible coating formulations

    Optimization of leavening agents in extruded gluten-free brewer's rice hard pretzel using response surface methodology

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    Celiac is the second most important issue in food sensitivities. The only treatment for celiac is a lifetime avoidance of consuming gluten. As pretzels are one of the most popular snacks in the world, making gluten-free pretzels is a market need. To produce gluten-free products, it is important to optimize the ingredients of the formulation. This research focused on optimization of the leavening agents of the most popular commercial hard pretzel formulation in which wheat flour is replaced with brewer's rice flour. This research also attempts to explain the effect of leavening agents in products containing no matrix molecules such as gluten. Response surface methodology via the central composite design was used to optimize the effects of yeast and bicarbonate of soda on the hardness (cutting strength), fracturability (brittleness), surface color, lateral expansion, expansion ratio, specific length, density (bulk, particle, material), porosity (open, close, total), water absorption index, water solubility index, water holding capacity, oil absorption index and oil holding capacity of gluten-free hard pretzel. The optimized results indicated that the gluten-free pretzel requires 8.05g yeast and 2.59g bicarbonate of soda for every 500g of brewer's rice flour

    Comparison of starch films and effect of different rice starch-based coating formulations on physical properties of walnut during storage time at accelerated temperature

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    Effects of different rice starch-based coating formulations on physical properties of walnut were studied during 20 days storage at accelerated temperature. Results from different starch films indicated there were nonsignificant differences in water and oxygen barrier properties of the starch films. However, significant (p ≤ .05) differences were present in the elongation at break characteristics between the corn and rice films. Tensile strength varied significantly between edible films made from rice starch with that of wheat and corn. Melting temperature (Tm) of wheat and corn starch films was higher than rice starch films (152.77 °C). Thus, rice starch in combination with different additives such as chitosan, emulsifier, and red palm oil, which improve the properties of rice starches have been chosen to coat dried walnut kernels. The coated walnuts were significantly (p ≤ .05) lighter than the control group. Results on different functional ingredients also showed significant variations, for example; yellowness of walnut in the presence of chitosan was lower among the coating formulas (p ≥ .05). However, the variations in textural characteristics of walnuts with different coating formulas remained nonsignificant (p > .05)

    Evaluation of cell adhesion molecules (LFA-1 and L-selectin) in ankylosing spondylitis patients after treatment with β-D-mannuronic acid (M2000)

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    Background & objectives: To examine β-D-mannuronic acid (M2000) effects on L-selectin shedding and leucocyte function-associated antigen-1 (LFA-1) expression as mechanisms of action of this drug in patients with ankylosing spondylitis (AS). Methods: To investigate the molecular consequences of β-D-mannuronic acid on L-selectin shedding, flow cytometry method was used. Furthermore, the effect of it on LFA-1 gene expression was analyzed by using quantitative real time (qRT)-PCR technique. Results: The LFA-1 expression in patients with AS was higher than controls (P=0.046). The LFA-1 expression after 12 wk therapy with β-D-mannuronic acid was meaningfully decreased (P=0.01). After 12 wk treatment with β-D-mannuronic acid, the frequency of CD62L-expressing CD4+ T cells in patients with AS, was not considerably altered, compared to the patients before therapy (P=0.5). Furthermore, after 12 wk therapy with β-D-mannuronic acid, L-selectin expression levels on CD4+ T-cells in patients with AS, were not remarkably changed, compared to the expression levels of these in patients before treatment (P=0.2). Interpretation & conclusions: The results of this study for the first time showed that β-D-mannuronic acid can affect events of adhesion cascade in patients with AS. Moreover, β-D-mannuronic acid presented as an acceptable benefit to AS patients and could aid in the process of disease management

    Exploring curing potential of epoxy nanocomposites containing nitrate anion intercalated Mg–Al–LDH with Cure Index

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    This paper focuses to provide information about the structure-property relationship in epoxy/LDH system by studying the curing characteristic of nanocomposite containing 0.1 wt.% of Mg–Al–NO3–LDH. For this purpose, Mg–Al–LDH intercalated with nitrate anion was synthesized using hydrothermal method. The formation of lamellar structure of LDH was confirmed by Fourier-transform infrared spectrophotometry (FTIR), X-ray diffractometry (XRD), and thermogravimetric analysis (TGA/DTG) analyses. Then, the role of synthesized LDH in curing reaction of epoxy was qualitatively evaluated by nonisothermal differential scanning calorimetry (DSC) performed at different heating rates via Cure Index (CI). From this point of view, the cure state of epoxy nanocomposite at heating rate of 2 °C/min was Poor, due to the vitrification of epoxy system before complete cure taking place in the system. By increasing the heating rates up to 5, 7 and then 10 °C/min, the mobility reactants was increased in the system, so that curing reaction was facilitated. Besides, nitrate anion taking part in epoxide ring opening reaction caused progress in crosslinking network formation, as evidenced by Excellent cure state
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