1,721,030 research outputs found
Application of analytical chemistry to foods and food technology
No full textFoods are a mixture of substances capable of supplying the human body with nutrients, which, once metabolized, are used mainly for the production of energy, heat, replenishment, and growth material for organs and tissues, ensuring the normal performance of vital functions necessary for growth of the human body. Therefore, the study of the chemical composition of foods and the properties of their constituents helps to define their nutritional and commodity values. Furthermore, it allows for evaluation of the chemical modifications that the constituents of the food undergo following the treatments (Food Technology) to which they are subjected. Analytical chemistry is the branch of chemistry based on the qualitative and quantitative determination of compounds present in a sample under examination. Therefore, through its application, it is possible to determine the quality of a product and/or its nutritional value, reveal adulterations, identify the presence of xenobiotic substances potentially harmful to human health (heavy metals, IPA, pharmaceuticals, etc.). Furthermore, some foods, in particular those of plant origin, contain numerous substances, secondary metabolites, with huge beneficial effects for human health. These functional components can be taken both through a correct diet, but also obtained from different food matrices by technological or biotechnological processes for the formulation of both functional foods and/or nutraceutical products. This Special Issue brings together 10 original studies and two comprehensive reviews on the above topics, in particular: (i) processes of extraction, identification, and characterization of biologically active compounds from different food matrices, (ii) overview of the main techniques applied for the determination of food colors, (iii) newer and greener solid-liquid extraction techniques
Quality control of butter by means of capillary column RTX 65-TG
No full textIn this paper a new analytical method for the detection of extraneous fats fraudulently added to butter is proposed. Such determination is carried out by gas chromatographic analysis of butter triglycerides, using a capillary column for triglycerides having 65% phenyl methyl silicone as stationary phase. During the last twenty years, different methods for evaluation of butter genuineness were proposed. The presence of vegetable oils mixed with butter is based on sterol analysis; the revelation of vegetable sterols in butter represents a clear evidence of fraud. The Official EU method for detection of animal fats in butter, as lard and tallow, is time consuming, it often brings to not easily reproducible results and it is not of great accuracy especially in the cases of small additions of extraneous fats. The method proposed in this paper allows to detect the presence of extraneous vegetable and animal fats in a simple, rapid, and precise way, even if the quantities added to butter are minimum. The analysis is based on the best resolution, actually achievable, of single triglyceride components and their comparison with those present in certainly genuine butters, taken as reference
Effects of different cryo-macerating temperature on the quality of chardonney wine
No full textUsing a new plant set up for this aim, quick cooling processes at different
final temperature of 12.0; 10.0; 8.0; 6.0 and, 4.0 °C, for the considered
Chardonney grape, have been performed, obtaining different batches of
mashed grapes. Subsequently the wine-making process for each of the
obtained batches has been performed, producing five different type of wine.
Chemical and organoleptic analysis of the obtained wines have been
performed and it has been possible to notice that for the Chardonney
cultivar grapes, lowering the temperature from 12 up to 6 °C quality
improvements were observed (extracted polyphenols), while lowering the
temperature below 6 °C quality improvements were negligible. Then for the
treated grapes varieties, overcoming such values of temperature (6°C), only
notable increases of consumption of CO2 have been obtained, with increases
negligible of wine quality. This has allowed the determination, for the
considered grapes, of the best value of the cryo macerating temperature, at
parity of initial conditions of the considered grape and the productive
processes used. Moreover, for a better understanding of the studied phenomena’s, a numerical simulation has been performed aimed to evaluate the temperature distribution during the considered process along the pipeline in which mashed grapes flow
Assessment of copper and heavy metals in family-run vineyard soils and wines of campania region, south italy
No full textCopper-based phytosanitary treatments are widely employed in viticulture for combating the fungal diseases of European grape (Vitis vinifera L.). Herein we evaluated copper accumulation in the soil of a 50-year-old still productive vineyard in South Italy in comparison with samples taken from a ‘control’ area in which grapevines had never been cultivated, as well from an abandoned vineyard, now planted with cereals and forage crops, both close to the main area under investigation. Even though the heavy metal contents detected were not of concern for soils nor for wine, Cu accumulates in the soil in amounts significantly higher than the (grapevine free) control and remains at detectable concentrations also in abandoned vineyards where spraying activities had ceased about 20 years before this study. Despite the long Cu residence times in soil, the wine produced with grapes of the same vineyard showed Cu levels low enough to be safely used for human consumption, probably due to mechanisms of metal precipitation occurring during wine maturation, which are typically accompanied by sedimentation processes in artisanal production. However, this should not diminish the urgency of decreasing the copper usage as antifungal remedy in viticulture to prevent copper contamination of the agricultural soils
Surface Characterization of Composite Catalysts Prepared by Sol-Gel Route
Full text linkThe aim of this work is to synthesize Nb-V oxide catalysts by sol gel route starting from metal alkoxides using different H2O/V ratios. Dried samples are characterized by X-ray diffraction (XRD), atomic absorption, and Brunauer-Emmett-Teller (BET) analysis. Calcination of dried materials up to 600°C in flowing air has been followed with Thermogravimetry-Fourier-transform infrared spectroscopy (TG-FTIR) spectroscopic analysis. The catalytic properties of calcined materials are tested in the oxidative dehydrogenation of ethane at 600°C. An improvement of the catalytic performances of vanadium for the gel prepared with the higher H2O/V ratio is found with respect to those of the supported catalyst due to the better interaction between vanadium and niobium
Hybrid grapes for a sustainable viticulture in south italy: Parentage diagram analysis and metal assessment in a homemade wine of chambourcin cultivar
No full textThe aim of this work was to explore a more sustainable approach in the viticulture of Mediterranean countries that could derive from growing hybrid grape varieties inheriting toler-ance/resistance characters from the wild vines utilized for their selection. Among the plethora of hybrid grapes developed in the last decades, some are able to produce high-quality wines whose flavor resembles European varieties, thus overcoming a typical limit of several old hybrids based on V. labrusca whose wine was characterized by a distinctive wild flavor. In this context, we examined some characteristics of Chambourcin, one of the most promising hybrid cultivars producing quality red wine and requiring much less phytosanitary interventions than European grapevine. In detail, the scope of this study included the investigation of the parentage diagram for this hybrid grape variety and the chemical analysis of a Chambourcin wine produced in South Italy. We filled the gaps corresponding to some of the Vitis ancestors participating in its complex pedigree by means of a literature analysis and a mathematical approach. We found high ancestry of V. vinifera (about 41%), followed by V. berlandieri (about 28%), V. rupestris (about 19%) and to a lesser extent other American wild vines. The significant content of V. berlandieri and V. rupestris genome in Chambourcin explains the considerable resistance of this variety to the two main pathogens affecting grapevines, i.e., downy mildew and powdery mildew. We then analyzed an organic Chambourcin wine produced in South Italy from grapes obtained without any phytosanitary treatment by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) in order to assess heavy metal content and found it comparable to other (red and rosè) V. vinifera wines obtained from family-run vineyards. Heavy metals contents detected were not of concern for any of the wines analyzed, however, copper accumulation in V. vinifera vineyard soils, and pollution deriving from other phytosanitary chemicals remain issues that in the case of Chambourcin vineyards could be solved at least in large part
Laboratory Production of Lemon Liqueur (Limoncello) by Conventional Maceration and a Two-Syringe System To Illustrate Rapid Solid–Liquid Dynamic Extraction
No full textTwo experimental techniques of solid–liquid extraction are compared relating to the lab-scale production of lemon liqueur, most commonly named “limoncello”; the first is the official method of maceration for the solid–liquid extraction of analytes and is widely used to extract active ingredients from a great variety of natural products; the second is a two-syringe system based on a Naviglio extractor, which represents a new solid–liquid extractive technology called rapid solid–liquid dynamic extraction (RSLDE) that changes the philosophy of the process of solid–liquid extraction. Maceration is based on the principle of diffusion (Fick’s law) that depends mainly on temperature; in fact, to increase the speed of maceration, heating of the system is required. In the case of RSLDE, the principle is based on the generation, in the presence of an appropriate solvent, of a negative pressure gradient between the outside and the inside of the solid matrix, followed by a sudden restoration of the initial conditions of equilibrium, which induces the forced extraction of compounds not chemically bonded to the matrix; consequently, the extraction can be performed at room temperature. In the experiment described, students evaluate the efficiency of extraction by the two methods. This laboratory experiment can be used in a food science laboratory course for secondary schools and for university students
Relationships between food and diseases: What to know to ensure food safety
No full textIn recent years, the concept of food has undergone a radical transformation to the point of attributing to foods, in addition to their nutritional and sensorial properties, an important role in maintaining health and psycho-physical well-being and in the prevention of certain diseases. However, foods can hide many pitfalls for human health. There are many critical points in food production processes and they can represent real risks of contamination or of unsafe food production for consumers. Proper conservation, physico-chemical and microbiological stability, cooking methods are fundamental control parameters to ensure the safety of food products. Generally, the development of a food-borne disease is due to specific conditions, such as the virulence of the microorganism present, the microbial load present in the food and the conditions of the host's immune system. Furthermore, the possible presence of other types of contaminants, in addition to microbial ones, can have implications for the health of consumers. Consequently, the rigorous compliance of personnel who work in contact with food during the phases of production, processing, transport and storage with hygienic rules is essential to guarantee food safety and prevent foodborne disease. So, in this review, major issues are addressed such as reviewing the major food-related causes of disease. From this point of view, the relevant microorganisms involved in food contamination (bacteria, viruses, parasites, fungi and mycotoxins), are taken into account. In addition, potentially allergenic foods or foods most commonly associated with food intolerance, are also considered. Many adverse reactions of the body towards foods are caused by the treatments to which they are subjected in order to maintain unchanged organoleptic characteristics as long as possible over time. This is also a critical point for food contamination that is considered in this review. A section is reserved to food additives potentially capable of causing disorders to the human body. In addition to biological contamination, the important issues represented by chemical contamination caused by pesticides, heavy metals, contaminants produced involuntarily are also considered. In conclusion, this review highlights that to protect consumers from food-borne diseases, an integrated approach to food safety must be adopted which affects the entire food chain, from farm to fork
Sol–gel synthesis and thermal behavior of bioactive ferrous citrate–silica hybrid materials
Full text linkImbalance of the iron level in the body causes several diseases. In particular, the low level of iron, during pregnancy, is
responsible for the iron deficiency anemia, and even of neurodegenerative diseases. Although the treatment of iron
deficiency anemia with oral iron supplements has been known, this problem still afflicts many people. The aim of this work
was the development of a system able to release ferrous ions in a controlled manner. Controlled drug release for medical
applications, indeed, appears to be a very interesting alternative to a systemic therapy because it is assurance of treatment
continuity and drug stability and optimizes drug absorption. For this purpose, ferrous citrate (Fe(II)C) was synthesized by a
redox reaction between iron powder and citric acid. Fourier transform infrared spectroscopy (FTIR), 1,10-phenanthroline
and sodium thiocyanate colorimetric assays confirmed that only Fe(II)C was obtained by redox reaction. Afterward,
obtained Fe(II)C was embedded within a SiO2 matrix in different mass percentage, by means of a sol–gel route. FTIR
spectroscopy and simultaneous thermogravimetry/first-order derivative of thermogravimetry were used to confirm the
Fe(II)C presence in the silica matrix and to investigate the thermal behavior of the sol–gel materials, respectively. The
bioactivity test carried out by soaking the synthesized drug delivery systems in a simulated body fluid showed that the
biological properties of the silica matrix are not modified by the presence of Fe(II)C
Determination of nicotine in the soil mixed with tobacco powder as fertilizer
No full textThe nicotine content of the tobacco powder completely degrades in one week when it is added to a non manured soil. If some organic manure is added to the soil so as to sensibly increase the microbial flora, then nicotine degrades in less than twenty-four hours. In sterilized soil nicotine content is constant over the time because of the total absence of microorganism. In the determination of the nicotine in the soil, accurate analytical results can be obtained by adding methanol to the soil sample at the moment of the sampling. Methanol degrades the enzymatic systems causing a soil sterilization and avoids, therefore, the degradation of the alkaloid. The extracted nicotine is analyzed by means of high performance liquid chromatography in a rapid and accurate manner
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