30,474 research outputs found

    Characterization of Dutch-Cocoa produced using potash extract from cocoa pod husk as an alkalizing bioresource

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    Abstract Alkalizing agents in the processing of Dutch-Cocoa are often imported from developing countries. This occurs amidst humongous quantities of Cocoa Pod Husk (CPH) that are largely rotting away. This study therefore appraises the inherent alkalizing potentials of CPH, including its physicochemical and safety characteristics in the production of Dutch-Cocoa. CPH was calcined, potash extracted, characterized, and applied in formulation (1% to 5% conc.) in Dutch-production of Cocoa. Quality parameters of the resultant product were analyzed following AOAC procedures (p ≤ 0.05). In addition, rats(n=30) were fed it over a 21-day duration while nutritional and safety indicators were monitored. Sensory properties were also evaluated. The results showed some predominant properties of CPH potash extract [Potassium 35.7%, pH 12.3, alkalinity 15.6 g/100 g CO3] and Dutch-cocoa [protein (15.8% to 16.5%), colour (Hunter L,a,b) 36.9, 8.8, 11.7 light - dark red), dispersibility (1.5 to 2.3), wettability (143.7 s), sedimentation (20.7% to 49.3%)] which favourably compared with commercial variants. Apparent digestibility (AD%) was significant (Protein 86%, Fat 88%, Fiber 66% etc) (p ≤ .0.05). Safety indices exhibited no deleterious effect and the product was adjudged acceptable. Dutch-cocoa produced using CPH-derived-potash as an alternate alkalizing bioresource is feasible, while simultaneously providing an environmentally friendly outlet for CP

    Antioxidant Activity of Red Dragon Fruit Teabag (Hylocereus polyrhizus) Peels with the Addition of Ginger (Zingiber officinale var. amarum) and Cinnamon (Cinnamomum zeylanicum, BI)

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    Free radicals have very unstable and reactive molecules. Excessive free radicals can trigger oxidative stress and cause various diseases. The peel of red dragon fruit contains chemical compounds that shows potential as an antioxidants. This study aims to optimize the benefits of red dragon fruit peels as tea bags because its convenient and simple to use. Design of this study was a randomized block design (RBD) which consisted of two factors, the drying temperature of the red dragon fruit skin (T) and the teabag formulation (F). Ginger and cinnamon are added as flavoring ingredients to the formula. The result showed that the drying temperature of the peel red dragon fruit affects the antioxidant activity of the teabag, where T1 has the highest antioxidant activity. The formulation of teabags also affects the antioxidant activity of the teabag, where F1 has the highest antioxidant activity. T1F1 had the highest antioxidant activity, and the interaction between the two (T and F) had a significant effect on antioxidant activity (p < 0.05)

    Neuroanatomical and gene expression features of the rabbit accessory olfactory system. Implications of pheromone communication in reproductive behaviour and animal physiology

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    Mainly driven by the vomeronasal system (VNS), pheromone communication is involved in many species-specific fundamental innate socio-sexual behaviors such as mating and fighting, which are essential for animal reproduction and survival. Rabbits are a unique model for studying chemocommunication due to the discovery of the rabbit mammary pheromone, but paradoxically there has been a lack of knowledge regarding its VNS pathway. In this work, we aim at filling this gap by approaching the system from an integrative point of view, providing extensive anatomical and genomic data of the rabbit VNS, as well as pheromone-mediated reproductive and behavioural studies. Our results build strong foundation for further translational studies which aim at implementing the use of pheromones to improve animal production and welfare

    Metabolites changes of a low-temperature and low-salt fermented Chinese kohlrabi during fermentation based on non-targeted metabolomic analysis

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    A low-temperature and low-salt industrially fermented Chinese kohlrabi (LSCK) was developed in this study, with the salt usage decreased by approximately 70% compared to the traditional high-salt fermented Chinese kohlrabi (HSCK). The differences in physicochemical properties, metabolites and overall flavors during LSCK fermented for 0, 45 and 90 days (d) were analyzed by gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS), electronic nose (E-nose) and other techniques. The results showed that the total acid content increased significantly from 3.68 to 8.59 g/kg. However, the protein content significantly decreased from 2.52/100 to 0.66 g/100 g. The number of lactic acid bacteria cells increased significantly from 3.69 to 4.46 log10CFU/g. Based on multivariate statistical analysis, 21, 14, and 15 differential metabolites were identified in the three treatment groups A1 (0 and 45 days), A2 (45 and 90 days), and A3 (0 and 90 days) respectively (VIP > 1, p < 0.05, |log2FC| ≥ 1.1). Carbohydrates, sugar alcohols, amino acids and their derivatives were the main differential metabolites in the LSCKs fermented for different periods. Aminoacyl−tRNA biosynthesis and glycine, serine and threonine metabolism pathways significantly correlated with the differential metabolites based on Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis (p < 0.05). Furthermore, the overall odors were significantly different among the LSCKs with different fermentation periods, as detected by E-nose. The present study describes the change trend of metabolites during LSCK fermentation and elucidates important metabolic pathways in LSCK, providing a theoretical basis for the target regulation of functional metabolites in kohlrabi and the optimization of LSCK processing

    Refrigerated storage of blackberry cultivar ‘BRS Cainguá’ harvested at different ripeness stages

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    ABSTRACT Blackberries have a short post-harvest conservation period, making it necessary to optimize harvest and storage conditions. The objective of this study was to evaluate the impact of refrigerated storage and maturation stage on the physicochemical quality of ‘BRS Cainguá’ blackberries, produced in an organic system. Blackberries from an experimental orchard, were harvested at three ripeness stages (RS), with RS1 being fruits with 100% red skin; RS2 skin 50% red and 50% black; and EM3 100% black skin. The samples were stored in a cold chamber at 4±0.5ºC and 90-95% RH for 12 days. The evaluations were carried out after 0, 3, 6, 9 and 12 days of storage, for: weight loss (WL), soluble solids (SS), pH, titratable acidity (TA), ratio (SS/TA) and color parameters. Blackberries harvested in RS3 had the highest SS content, lowest TA and the highest SS/TA ratio and pH. During storage, TA and WL showed decreasing and increasing linear responses, respectively, regardless of the RS of the fruits. Harvesting based on the skin color of ‘BRS Cainguá’ blackberries influences the physicochemical quality and postharvest conservation. Fruits harvested with 100% black skin, have the best quality and are the most suitable for subsequent refrigerated storage

    Desarrollo de papeles biocativos por injerto de moléculas específicas en celulosa

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    Tesis (DCI)--FCEFN-UNC, 2019En la presente tesis se presenta el desarrollo de papeles bioactivos con potencial aplicación en el envasado activo de alimentos. Para tal fin, se propuso el injerto de eugenol, un compuesto de origen natural con propiedades antimicrobiana, antioxidante y repelente de insectos, en celulosa, utilizando ácido policarboxílico como agente ligante. Con el objetivo de evaluar la escalabilidad del proceso propuesto, se estudiaron distintas tecnologías de curado, tales como calentamiento por convección, infrarrojo, microondas y conducción. En todos los casos, se analizaron la influencia de las variables operativas sobre el avance de la reacción y propiedades finales del papel preparado, utilizando un diseño de experimentos Doehlert para elegir las experiencias a realizar, y analizando los resultados mediante metodología de superficie de respuesta y análisis estadístico ANOVA. Se pudo comprobar que la reacción de injerto de eugenol en papel comercial se produjo con éxito en todas las tecnologías estudiadas. Asimismo, se encontraron las condiciones óptimas de reacción para cada una de las tecnologías, para lo cual se buscó un compromiso entre el avance de la reacción y las propiedades finales del material (mecánicas y color). A partir de estas condiciones, se prepararon papeles y se realizó una caracterización más específica para su aplicación como envase de alimentos comparando los papeles modificados con el papel virgen. Se analizaron las propiedades mecánicas por ensayo de tracción, rasgado y punzonado y se midió la absorción de agua y la capacidad de degradación. Por otro lado, las propiedades bioactivas analizadas fueron la actividad antioxidante, antimicrobiana, repelente e insecticida de gorgojos (T. castaneum y R. dominica). Una vez probado que el papel modificado presenta buenas características físicas y bioactivas para su posible aplicación en el envasado de alimentos, se realizaron prototipos de envasado para harina, como alimento representativo de alimentos derivados de cereales, susceptibles al ataque de plagas. En este estudio se analizó la migración de reactivos, propiedades organolépticas y conservación del alimento, arrojando resultados promisorios para la industria de envases de alimentos. Finalmente, se realizó una comparación de las tecnologías de curado ensayadas, analizando diferentes aspectos como avance de reacción, propiedades finales, apariencia, tiempo de reacción, consumo de energía, entre otros, como así también disponibilidad y uso de estas tecnologías a escala industrial, seleccionando la tecnología de conducción como la más adecuada para una propuesta de escalado industrial.Fil: Muratore, Florencia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Muratore, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada; Argentina

    Aflatoxins

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    The aflatoxin producing fungi Aspergillus flavus, A. parasiticus, and A. nomius, although they are also produced by other species of Aspergillus as well as by Emericella spp.(Telemorph). There are many types of aflatoxins, but the four main ones are aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), and aflatoxin G2 (AFG2, while aflatoxin M1 (AFM1) and M2 (AFM2) are the hydroxylated metabolites of AFB1 and AFB2. Aflatoxin B1, which is a genotoxic hepatocarcinogen, which presumptively causes cancer by inducing DNA, adducts leading to genetic changes in target liver cells. Cytochrome-P450 enzymes to the reactive intermediate AFB1–8, 9 epoxide (AFBO) which binds to liver cell DNA, resulting in DNA adducts, metabolize AFB1 Ingestion of contaminated food is the main source of exposure to aflatoxins, which adversely affect the health of both humans and animals. The compounds can cause acute or chronic toxic effects of a teratogenic, mutagenic, carcinogenic, immunotoxic or hepatotoxic character. You can reduce your aflatoxin exposure by buying only major commercial brands of food and by discarding that look moldy, discolored, or shriveled

    Interview with Wolfgang Knauss

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    An oral history in four sessions (September 2019–January 2020) with Wolfgang Knauss, von Kármán Professor of Aeronautics and Applied Mechanics, Emeritus. Born in Germany in 1933, he speaks about his early life and experiences under the Nazi regime, his teenage years in Siegen and Heidelberg during the Allied occupation, and his move to Pasadena, California, in 1954 under the sponsorship of a local minister and his family. He enrolled in Caltech as an undergraduate in 1957, commencing a more than half-century affiliation with the Institute and GALCIT (today the Graduate Aerospace Laboratories of Caltech). He recalls the roots of his interest in aeronautics, his PhD solid mechanics studies with his advisor, M. Williams, and the GALCIT environment in the late 1950s and 1960s at the dawn of the Space Age, including the impact of Sputnik and classes with NASA astronauts. He discusses his experimental and theoretical work on materials deformation, dynamic fracture, and crack propagation, including his solid-propellant fuels research for NASA and the US Army, wide-ranging programs with the US Navy, and his pioneering micromechanics investigations and work on the time-dependent fracture of polymers in the 1990s. He offers his perspective on GALCIT’s academic culture, its solid mechanics and fluid mechanics programs, and its evolving administrative directions over the course of five decades, as well as its impact and reputation both within and beyond Caltech. He describes his work with Caltech’s undergraduate admissions committee and his scientific collaborations with numerous graduate students and postdocs and shares his recollections of GALCIT and other Caltech colleagues, including C. Babcock, D. Coles, R.P. Feynman, Y.C. Fung, G. Neugebauer, G. Housner, D. Hudson, H. Liepmann, A. Klein, G. Ravichandran, A. Rosakis, A. Roshko, and E. Sechler. Six appendices contributed by Dr. Knauss, offering further insight into his life and career, also form part of this oral history and are cross-referenced in the main text
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