24 research outputs found

    Influencia del calentamiento en microonda sobre la estabilidad de elaborado de "samn"

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    Butter was converted to samn by microwave and conventional heating. The quality of the processed samn by the two methods was followed by determining the acid, peroxide and TBA values over a period of six weeks at 60°C. The fatty acid composition of samn samples was determined by gas-liquid chromatographic technique. The data show that butter conversion to samn by microwave heating was accomplished in about one half of the time that conventional heating requires. Microwave heating obviously increased the development of samn rancidity compared with the conventional heating. The parameters used for measuring lipid rancidity indicated that the main cause of samn rancidity under the present conditions is an oxidation mechanism.Mantequilla fue transformada en samn por calentamiento en microonda y convencional. La calidad del elaborado de samn por los dos métodos fue seguida mediante determinación de los índices de acidez, peróxido y TBA durante un período de seis semanas a 60°C. La composición en ácidos grasos de muestras de samn fue determinada por técnica cromatográfica gas-líquido. Los datos mostraron que la conversión de mantequilla a samn por calentamiento en microonda fue realizada en aproximadamente una vez y media el tiempo que exige el calentamiento convencional. El calentamiento en microonda, evidentemente, aumentó el desarrollo de la rancidez del samn comparado con el calentamiento convencional. Los parámetros usados para la medida de la rancidez lipídica indicaron que la causa principal de la rancidez del samn bajo las condiciones presentes es un mecanismo de oxidación

    Influence of microwave heating on the stability of processed samn

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    Butter was converted to samn by microwave and conventional heating. The quality of the processed samn by the two methods was followed by determining the acid, peroxide and TBA values over a period of six weeks at 60°C. The fatty acid composition of samn samples was determined by gas-liquid chromatographic technique. The data show that butter conversion to samn by microwave heating was accomplished in about one half of the time that conventional heating requires. Microwave heating obviously increased the development of samn rancidity compared with the conventional heating. The parameters used for measuring lipid rancidity indicated that the main cause of samn rancidity under the present conditions is an oxidation mechanism.Mantequilla fue transformada en samn por calentamiento en microonda y convencional. La calidad del elaborado de samn por los dos métodos fue seguida mediante determinación de los índices de acidez, peróxido y TBA durante un período de seis semanas a 60°C. La composición en ácidos grasos de muestras de samn fue determinada por técnica cromatográfica gas-líquido. Los datos mostraron que la conversión de mantequilla a samn por calentamiento en microonda fue realizada en aproximadamente una vez y media el tiempo que exige el calentamiento convencional. El calentamiento en microonda, evidentemente, aumentó el desarrollo de la rancidez del samn comparado con el calentamiento convencional. Los parámetros usados para la medida de la rancidez lipídica indicaron que la causa principal de la rancidez del samn bajo las condiciones presentes es un mecanismo de oxidación

    Effectiveness of esterified whey proteins fractions against Egyptian Lethal Avian Influenza A (H5N1)

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    <p>Abstract</p> <p>Background</p> <p>Avian influenza A (H5N1) virus is one of the most important public health concerns worldwide. The antiviral activity of native and esterified whey proteins fractions (α- lactalbumin, β- lactoglobulin, and lactoferrin) was evaluated against A/chicken/Egypt/086Q-NLQP/2008 HPAI (H5N1) strain of clade 2.2.1 (for multiplicity of infection (1 MOI) after 72 h of incubation at 37°C in the presence of 5% CO<sub>2</sub>) using MDCK cell lines.</p> <p>Result</p> <p>Both the native and esterified lactoferrin seem to be the most active antiviral protein among the tested samples, followed by β- lactoglobulin. α-Lactalbumin had less antiviral activity even after esterification.</p> <p>Conclusion</p> <p>Esterification of whey proteins fractions especially lactoferrin and β-lactoglobulin enhanced their antiviral activity against H5N1 in a concentration dependent manner.</p

    Quality attributes and antioxidant activity of stirred yoghurt fortified with some nano-fruit waste powders

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    Abstract Agro-industrial wastes have emerged as a significant source of bioactive compounds. Therefore, this study was conducted to evaluate the feasibility of using nano-powders of some fruit wastes, namely; apricot (Prunus sp.) and peach (Prunus persica L. Batsch) kernels, watermelon (Citrullus lanatus) rind and banana (Musa spp.) peel as functional ingredients (0.5%) in stirred yoghurt, as well as their effect on the antioxidant activity, quality characteristics, viability of yoghurt starter culture and sensory attributes. Results revealed that the fortification process significantly (P < 0.05) elevated the total solids, fat, protein and ash contents, especially with apricot and peach kernels (AK and PK), which distinctly increased fat by average values of 3.46 and 3.40%, and protein by 3.70 and 3.68% during storage compared to control (3.12 and 3.57%), respectively. The addition of watermelon rind (WMR) increased the titratable acidity (0.97%) and viscosity (463.59 cP) with a significant reduction of syneresis (16.38%), increased the total viable count of starter culture, acetaldehyde and diacetyl contents (167.10 and 18.82 mg/100 g) in yoghurt, followed by banana peel (BP). Stirred yoghurt fortified with BP nano-powder had the highest total phenolic content (20.96 mg gallic acid/g) and DPPH scavenging activity (31.93%) as average values during storage compared to the other nano-fruit wastes. Sensory attributes of stirred yoghurt were improved with the addition of WMR and BP during storage periods, compared to those fortified with AK and PK. All the nano-powders of the studied fruit wastes constitute excellent raw materials for the development of novel functional stirred yoghurt
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