Browsing by Subject "Grape"

Now showing 1 - 4 of 4
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    Amelioration of hypercholesterolemiainduced hepatic changes with red grape juice: A histopathological study
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2014) Al-Ahmadi, Ahlam Abdulaziz; Ali, Soad Shaker; Ayuob, Nasra Naeim; Al Ansary, Abeer Khaled
    Objectives: Hypercholesterolemia was confirmed as a risk factor for hepatic fibrosis, as well atherosclerosis and coronary heart disease. This biochemical and histoplathological study was conducted to investigate the possible protective effect of red grape against hepatic injury induced by a high-cholesterol diet (HCD). Material and methods: Thirty male Wister rats were randomly divided into three groups (n=10): the control received saline, the induction group was fed HCD, and the treated group was fed a HCD and 0.4 ml of 100% red grape juice (RGJ) for 13 weeks. After the animals were sacrificed, liver tissue samples were taken to be processed for light and electron microscopy examination. Results: The administration of the RGJ and HCD significantly decreased the animals’ blood glucose, insulin, cholesterol, triglycerides, Low Density Lipoprotein levels and increased their High Density Lipoprotein level compared to the rats fed the HCD alone. It also decreased the periportal (macro- and microvesicular) steatosis, fibrosis, lymphocytic infiltration and blood sinusoidal congestion that were observed in HCD-fed rats alone. The RGJ reduced the number of activated myofibrobasts. This was confirmed by a reduction in the expression of alpha smooth muscle actin and desmin. The RGJ increased, although not significantly, the expression of endothelial Nitric Oxide Synthetase. Conclusion: The administration of RGJ succeeded in alleviating the biochemical and, to some extent, the histopathological changes induced by the high cholesterol diet. Consumption of fresh RGJ or its pharmaceutical preparations is advised especially for those who are used to eat a high fat diet.
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    Cinética de hidroxilación y oxidación de compuestos fenólicos por Polifenol Oxidasa de uva Monastrell (Vitis Vinifera)
    (Murcia: Universidad de Murcia, Servicio de Publicaciones, 1987) Sánchez Ferrer, Álvaro; Cabanes Cos, Juana; Bru Martínez, Roque; Facultad de Biología
    La enzima polifenol oxidasa ha sido purificada a partir de uva Monastrell mostrando actividad tanto en la oxidación de monofenoles (cresolasa) como en la de o-difenoles (catecolasa). Los parámetros cinéticos, Km y temperatura óptima, han sido evaluados en ambas actividades. La actividad cresolasa presenta un período de retardo característico, que puede ser modificado por la temperatura, la concentración de enzima, la presencia de o-difenoles y la concentración de sustrato.
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    Combining high-power ultrasound and enological enzymes during winemaking to improve the chromatic characteristics of red wine
    (Elsevier, 2021-12-28) Pérez Porras, Paula; Bautista Ortín, Ana Belén; Jurado, Ricardo; Gómez Plaza, Encarna; Tecnología de Alimentos, Nutrición y Bromatología; Facultad de Veterinaria
    Several techniques have been used by the winemaking industry to facilitate the extraction of grape phenolic compounds during the maceration process. Interest in innovative techniques such as high-power ultrasound (US) has increased in recent years, replacing more traditional techniques such as the addition of pectolytic enzymes (E). This study evaluates the combined effect of ultrasound and enological enzymes, used at semi-industrial scale at the time of crushing, on the chromatic characteristics of red wine. Variables such as the timing of enzyme addition and the ripening state of the grapes were considered. The results showed that ultrasound had a greater effect than enological enzymes when used alone, especially when the ripest grapes were used. The results also indicate that, when added after sonication, the enzymes favored the US effect, enabling the contact time necessary to achieve a wine with chromatic characteristics similar to those resulting from a traditional maceration process to be reduced by 4 days. Carried out on a semi-industrial scale, the study demonstrates that the adequate combination of these two techniques can optimize the maceration process both in terms of time and the wine organoleptic characteristics, making the technique of special interest for industrial application.
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    The generation of suspended cell wall material may limit the effect of ultrasound technology in some varietal wines
    (MDPI, 2024-04-24) Pérez Porras, Paula; Bautista Ortín, Ana Belén; Martínez-Lapuente, Leticia; Guadalupe, Zenaida; Ayestarán, Belén; Gómez Plaza, Encarna; Tecnología de Alimentos, Nutrición y Bromatología; Facultad de Veterinaria
    The disruptive effect exerted by high-power ultrasound on grape cell walls enhances phenolic extraction, improving chromatic characteristics during red wine maceration. However, short maceration times may, sometimes, hinder this enhancement, and this effect could be attributed to the suspended cell wall material formation facilitated by sonication. This suspended material, having a strong affinity for phenolic compounds, can lead to their precipitation and elimination during subsequent vinification stages and, consequently, a significant portion of extracted phenolic compounds may not contribute to the final phenolic composition of the wine, impacting its chromatic features. To demonstrate this effect, sonicated grapes of two different varieties were vinified with No modified process that eliminated part of this suspended material. Results confirm our hypothesis; that is, the lack of positive outcomes in some cases is due to phenolic compound adsorption on suspended material.