286 research outputs found

    A Homogenization Approach for the Roasting of an Array of Coffee Beans

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    While the processes underlying the roasting of a single coffee bean have been the focus of a number of recent studies, the more industrially relevant problem of roasting an array of coffee beans has not been well studied from a modeling standpoint. Starting with a microscale model for the heat and mass transfer processes within a single bean during roasting, we apply homogenization theory to upscale this model to an effective macroscale model for the roasting of an array of coffee beans. We then numerically simulate this effective model for two caricatures of roasting configurations which are of great importance to industrial scale coffee bean roasting: namely, drum roasters (where the beans are placed in a rotating drum) and fluidized bed roasters (where hot air is blown through the beans). The derivation of the homogenization problem has been carried out in a three-dimensional rectangular geometry. Simulations are presented both for simplified one-dimensional arrays of three-dimensional beans (as these are easier to visualize), as well as cross sections of full three-dimensional arrays of beans (for the sake of verification). We also verify our simulation results against experimental data from the literature. Among the findings is that increasing the air-to-bean volume fraction ratio decreases the drying time for the array of beans in a linear manner. We also find that, in the case of a fluidized bed, an increase in the hot air inflow velocity will decrease the drying time in a nonlinear manner, with diminishing returns observed beyond some point for large enough air inflow velocities

    Multi-frequency multimode modulated technology as a clean, fast, and sustainable process to recover antioxidants from a coffee by-product

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    Coffee chaff is a major coffee roasting by-product that could be valued as a source of antioxidants. In the present work, we compared classic, but optimized, solid-liquid extraction conditions with a new concept, namely, the Multi-frequency Multimode Modulated (MMM) vibration technique. The extracts obtained by both methods were analysed and compared in relation to several parameters, namely, phenolics profile (by HPLC/DAD), 5-caffeoylquinic acid content, total phenolics content, and Ferric Reducing Antioxidant Power. Compared to an optimized solid-liquid extraction (using a hydroethanolic solvent (1:1) at 40 °C for 60 min), the acoustic probe allowed a higher recovery of antioxidants in only 10 min and using only water as extraction solvent. Moreover, the effects that arise from the acoustic cavitation in the medium allowed the suppression of the sample preparation step (grinding). These results show that this type of technology can be of high interest to recover antioxidants from natural matrices, in a green, fast and very efficient way.info:eu-repo/semantics/publishedVersio

    Metal Oxide Sensors for Electronic Noses and Their Application to Food Analysis

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    Electronic noses (E-noses) use various types of electronic gas sensors that have partial specificity. This review focuses on commercial and experimental E-noses that use metal oxide semi-conductors. The review covers quality control applications to food and beverages, including determination of freshness and identification of contaminants or adulteration. Applications of E-noses to a wide range of foods and beverages are considered, including: meat, fish, grains, alcoholic drinks, non-alcoholic drinks, fruits, milk and dairy products, olive oils, nuts, fresh vegetables and eggs

    Determination of ochratoxin A in coffee and tea samples by coupling second-order multivariate calibration and fluorescence spectroscopy

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    A new method to quantify the mycotoxin ochratoxin A (OTA) in coffee and tea samples is proposed based on second-order multivariate calibration and excitation-emission fluorescence matrix (EEFM) data. Experimental conditions were optimized by studying the effect of pH and various organized media on the fluorescence signal of OTA. For each analysed matrix (coffee grains and tea leaves), several sample pretreatments and calibration methods (external or standard addition) and data processing by chemometric models (e.g., parallel factor analysis/PARAFAC and multivariate curve resolution-alternating least squares/MCR-ALS) were evaluated and discussed. The MCR-ALS algorithm provided an adequate fit to the data for both samples, while PARAFAC was satisfactory only for the tea samples. Regarding the figures of merit, the limits of detection were in the range of 0.2–0.3 ng mL−1; furthermore, low relative prediction errors, between 2% and 4%, were achieved in both the fortified and real samples. Accordingly, the proposed methodology was applied to analyse fortified roasted and green coffee and real tea leaf samples. Satisfactory recoveries were achieved (ranging from 92 to 110%), and the obtained concentrations were in agreement with the values obtained by the reference method (based on high-performance liquid chromatography with fluorescence detection/HPLC-FLD). In addition, all samples contained OTA levels lower than the maximum permissible levels. Finally, the proposed strategy allows the use of green analytical chemistry principles; for instance, the use of organic solvents and the generation of waste products were significantly lower than for similar analytical methods reported in the literature.Fil: Gonzalez, Albani L.. Pontificia Universidad CatĂłlica de ValparaĂ­so; ChileFil: Lozano, Valeria Antonella. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Rosario. Instituto de QuĂ­mica Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂ­micas y FarmacĂ©uticas. Instituto de QuĂ­mica Rosario; ArgentinaFil: Escandar, Graciela Monica. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Rosario. Instituto de QuĂ­mica Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂ­micas y FarmacĂ©uticas. Instituto de QuĂ­mica Rosario; ArgentinaFil: Bravo, Manuel A.. Pontificia Universidad CatĂłlica de ValparaĂ­so; Chil

    Frontier Research on the Processing Quality of Cereal and Oil Food

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    As everyone knows, cereal and oil are still the main part of our diet and provide essential nutrients and energy every day. With the progress of food processing technology, the quality of cereal and oil food is also improved significantly. Behind this, major nutrients of grain and oil, including protein, carbohydrate, lipid, and functional components, have experienced a variety of physical, chemical, and biological reactions during food processing. Moreover, research in this field also covers the multi-scale structural changes of characteristic components, such as component interaction and formation of key domains, which is essential for the quality enhancement of cereal and oil food. Based on the increasing consumer demand for nourishing, healthy, and delicious cereal and oil food, it might be interesting to report the latest research on the application of novel technology in food processing, multi-scale structural changes of characteristic components in food processing, structure-activity mechanism of food functional components. This book aimed to provide useful reference and guidance for the processing and utilization of cereal and oil food so as to provide technical support for the healthy development of cereal a oil food processing industry wordwide

    Detecció i Quantificació d’Adulteracions en la Prevenció de Fraus en Cafù mitjançant empremtes HPLC-UV i HPLC-FLD

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    Treballs Finals de Grau de QuĂ­mica, Facultat de QuĂ­mica, Universitat de Barcelona, Any: 2021, Tutors: Oscar NĂșñez Burcio, Javier Saurina PurroyGlobalization has produced a total change of scenario in food industry producing a tough competence to occupy the market share, instigating the reduction of costs by usage of fraudulent practices derived from food adulteration. These practices are performed by substitution of most valuable components for other with less commercial value and/or lower health beneficial properties supposing an economic fraud and a potential health problem. Coffees are sometimes the target of this kind of fraudulent practices due to the high demand of the product where manufacturers adulterate coffee with wheat, corn, and other grains, seeds and plants. In this work, simultaneous non-targeted HPLC-UV and HPLC-FLD fingerprinting methods were developed to achieve the classification and authentication of different instant coffee, and chicory samples using multivariate chemometric methodologies such as principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA) and partial least squares (PLS). Both HPLC-UV and HPLC-FLD fingerprints, proved to be excellent chemical descriptors for the discrimination of chicory samples against instant coffee and decaffeinate coffee by PLS-DA. However, better results were obtained with HPLC-UV fingerprints when coffee was discriminated from decaffeinated coffee (94.4% classification rate respect to 83.3% for HPLC-FLD fingerprints). Besides, both methodologies were able to detect and quantify adulterant levels in coffee and decaffeinated samples adulterated with chicory exhibiting good regression linearity (R2≄0.996), and low calibration (0.7-2.1%) and prediction (2.4-3.5%) errors. Overall, both non-targeted HPLC-UV and HPLC-FLD showed to be effective, simple, and trustable to accomplish the characterization, classification and authentication of instant coffee and chicory samples being potential methodologies to prevent food fraud

    A Coffee-Scented Space: Historical, Cultural, and Social Impacts of the Japanese Kissaten

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    A 2016-2017 William Prize for best essay in East Asian Studies was awarded to Claire Williamson (Jonathan Edwards College \u2717) for her essay submitted to the East Asian Studies Program, “A Coffee-Scented Space: Historical, Cultural, and Social Impacts of the Japanese Kissaten.” (William Kelly, Professor of Anthropology and Sumitomo Professor of Japanese Studies, advisor.) Japan has a long and well-documented history as a tea culture, from everyday practices to the refined aesthetics of the tea ceremony and its associated arts. Yet modern Japan is also a highly developed culture of coffee, and this is the topic that Claire Williamson addresses in A Coffee-Scented Space: Historical, Cultural, and Social Impacts of the Japanese Kissaten. The notion of coffee shops, especially in urban settings, providing not only nourishment but also places for social engagement was the starting point for Williamson’s analysis. However, the Japanese landscape of coffee shops is quite variegated, and it is a strength of the essay that she explores some of these differences and their significance. Williamson does this historically by using a framework of First, Second, and Third Waves of coffee, and structurally by comparing several types of coffee shops, especially kissaten, chain shops, cafĂ©s, and coffee stands. The essay is excellent—it is an effective combination of using analytical and descriptive literatures and conducting thorough field research in Tokyo, Kanazawa, and other parts of Japan. The essay itself is a pleasure to read, well-structured and nicely phrased. It offers a grounded and persuasive account of Japan’s modern coffee culture, especially the enduring kissaten at its core

    Natural Antioxidants: Innovative Extraction and Application in Foods

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    Natural Antioxidants: Innovative Extraction and Application in Foods compiles comprehensive information and recent findings on the extraction of antioxidants from different natural resources and investigates their application in food. The book focuses on different sources of natural antioxidants such as the Hypochaeris and Hyoseris species, pomegranate seed oil, thyme, hemp, coriander, olive mill wastewaters, the edible mushroom Hericium erinaceus, Brewer’s spent grain, broccoli byproducts, cardoon, and Norway spruce bark. Moreover, the effect of different treatments such as blanching, microwave exposure, roasting, and enzymatic browning on the phytochemical content and bioactivity of the extracts is also addressed. Readers will find valuable insights into the impact of extraction methodologies on the bioactivity of the extracts, along with an understanding of the vast potential of natural extracts for the quality of food products. Readership Food and nutrition researchers, health professionals, nutritionists, and food science and chemistry student

    Methodologies for processing plant material into acceptable food on a small scale

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    Based on the Controlled Environment Life Support System (CELSS) production of only four crops, wheat, white potatoes, soybeans, and sweet potatoes; a crew size of twelve; a daily planting/harvesting regimen; and zero-gravity conditions, estimates were made on the quantity of food that would need to be grown to provide adequate nutrition; and the corresponding amount of biomass that would result. Projections were made of the various types of products that could be made from these crops, the unit operations that would be involved, and what menu capability these products could provide. Equipment requirements to perform these unit operations were screened to identify commercially available units capable of operating (or being modified to operate) under CELSS/zero-gravity conditions. Concept designs were developed for those equipment needs for which no suitable units were commercially available. Prototypes of selected concept designs were constructed and tested on a laboratory scale, as were selected commercially available units. This report discusses the practical considerations taken into account in the various design alternatives, some of the many product/process factors that relate to equipment development, and automation alternatives. Recommendations are made on both general and specific areas in which it was felt additional investigation would benefit CELSS missions
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