974 resultados para Agriculture, Food Science and Technology|Health Sciences, Nutrition|Education, Health
Resumo:
Abstract In this work, a novel on-line process for production of food-grade emulsions containing oily extracts, i.e. oil-in-water (O/W) emulsions, in only one step is presented. This process has been called ESFE, Emulsions from Supercritical Fluid Extraction. With this process, emulsions containing supercritical fluid extracts can be obtained directly from plant materials. The aim in the conception of this process is to propose a new rapid way to obtain emulsions from supercritical fluid extracts. Nowadays the conventional emulsion formulation method is a two-step procedure, i.e. first supercritical fluid extraction for obtaining an extract; secondly emulsion formulation using another device. Other variation of the process was tested and successfully validated originating a new acronymed process: EPFE (Emulsions from Pressurized Fluid Extractions). Both processes exploit the supercritical CO2-essential oils miscibility, in addition, EPFE process exploits the emulsification properties of saponin-rich pressurized aqueous plant extracts. The feasibility of this latter process was demonstrated using Pfaffia glomerata roots as source of saponin-rich extract, water as extracting solvent and clove essential oil, directly extracted using supercritical CO2, as a model dispersed phase. In addition, examples of pressurized fluid-based coupled processes applied for adding value to food bioactive compounds developed in the past five years are reviewed.
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Abstract Millets are having superior nutritional qualities and health benefits; hence they can be used for supplementation of pasta. Pasta was prepared using composite flour (CF) of durum wheat semolina (96%) and carrot pomace (4%) supplemented with finger millet flour (FMF, 0-20g), pearl millet flour (PMF, 0-30g) and carboxy methyl cellulose (CMC, 2-4g). Second order polynomial described the effect of FMF, PMF and CMC on lightness, firmness, gruel loss and overall acceptability of extruded pasta products. Results indicate that an increasing proportion of finger and pearl millet flour had signed (p≤0.05) negative effect on lightness, firmness, gruel loss and overall acceptability. However, CMC addition showed significant (p≤0. 05) positive effect on firmness, overall acceptability and negative effect on gruel loss of cooked pasta samples. Numeric optimization results showed that optimum values for extruded pasta were 20g FMF, 12g PMF and 4g CMC per 100g of CF and 34ml water with 0.981 desirability. The pasta developed is nutritionally rich as it contains protein (10.16g), fat (6g), dietary fiber (16.71g), calcium (4.23mg), iron (3.99mg) and zinc (1.682mg) per 100g.
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Abstract In most industrialized countries, the sodium intake exceeds the nutritional recommendations. In this sense the search for healthier foods has led the food industry to review their formulations in relation to food components such as salt, which is associated with increased risk of chronic diseases. As a result, different strategies for reducing salt levels in processed foods have been investigated. Among the technological options available, the high-pressure processing has stood out by presenting intrinsic technological advantages that can contribute to optimization of food formulations with low / reduced sodium contents. This review provides a brief overview of the key strategies and use of high pressure in the development of reduced-salt products.
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Abstract The aim of this study was to evaluate the microbiological and sensory quality of the Jambu (Acmella oleracea L.) in natura and dried by cold air, and the determination of its drying curve. The microbiological analysis were performed to Salmonella spp, the coagulase-positive Staphylococcus, and coliforms in the both Jambu samples, at 45 °C. Tacacá, the typical food dish of Pará state, Brazil, has showed good consumer global acceptance in the sensory evaluation of Jambu in natura (score of 8.00 ± 1.46) and dried (score of 8.67 ± 0.66). Both samples, Jambu in natura and dried by cold air, were by the current legislation regarding the microbiological aspects, this is the absence of Salmonella spp, coagulase-positive Staphylococcus <1×101 CFU/g, and coliforms <3 MPN/g, at 45 °C. Thus, considering sensory and health aspects, the commercialization of dried Jambu becomes viable, facilitating its transportation and handling, as well as for reducing its vegetable mass.
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The objective of this study was to determine the effect of adding Amaranth leaf powder on the nutrient content and consumer acceptability of extruded provitamin A-biofortified (PVA) maize snacks. Flours of four varieties of PVA maize were composited with Amaranth leaf powder at 0, 1 and 3% (w/w) substitution of, respectively, and extruded into snacks. The ash content of the snacks increased from 0.53 g/100 g-0.58 g/100 g to 0.650 g/100g-89 g/100 g and protein content increased from 9.12 g/100 g-10.94 g/100 g when Amaranth was increased from 0% to 3%. Similarly, lysine content increased from 0.10 g/100 g to 0.17 g/100 g, whilst methionine increased from 0.14 g/100 g to 0.19 g/100 g. The provitamin A content of the snacks ranged from 1.29 µg/g to 1.40 µg/g at 0% Amaranth and 1.54 µg/g to 1.78 µg/g at 3% Amaranth. The acceptability of the snacks decreased with increasing Amaranth concentration, only a very small proportion (2-8%) of the panel liked the snacks extremely. PVA maize with added Amaranth leaf powder has a potential for use in nutritious and healthy extruded snacks, but the consumer acceptability of the snacks should be improved.
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Pesticides in “PERA” orange samples (N = 57) from São Paulo City, Brazil were assessed and the pesticide intake contribution was estimated for chronic risk assessment. Seventy-six pesticides were evaluated by the gas chromatography multi-residue method, including isomers and metabolites (4.332 determinations). The mean recoveries at the limit of quantification level were in the range of 72-115% and the relative standard deviation for five replicate samples was 1-11%. The limits of detection and quantification ranged from 0.005 to 0.4 mg.kg−1 and from 0.01 to 0.8 mg.kg−1, respectively. Pesticides were found in 42.1% of the samples at levels ranging from 0.06 to 2.9 mg.kg−1. Of the contaminated samples, 3.5% contained residues (bifenthrin and clofentezine) above the maximum residue level and 12.3% contained unauthorized pesticides (azinphos-ethyl, parathion, myclobutanil, profenofos, and fenitrothion). The estimated risk characterization for orange intake by adults and children, respectively, ranged from 0.04 to 6.6% and from 0.1 to 26.5% of the acceptable daily intake. The detection of irregular residues emphasizes the need for better implementation of Good Agriculture Practices and greater control of formulated products. Other pesticides surveyed did not pose a health risk due to consumption.
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Abstract The marolo (Annona crassiflora Mart.) and jerivá (Syagrus romanzoffiana Cham Glassm) fruits grow in the Cerrado biome, and have important sensory and nutritional characteristics. These fruits are eaten fresh or processed and embedded in ice cream, candy, juices, and liquors. However, their use is very limited and is localized exclusively to their native region. The aim of this study was to evaluate the use of these fruits in food consumer products to improve the nutritional patterns of consumers and extend knowledge thereof. To do this, different levels (0%, 5%, 10%, 15%, and 20%) of flour derived from the marolo and jerivá fruits were incorporated into food bars, which were then characterized in terms of their physical of the texture (TPA), porosity, color and sensorial properties. The food bars enriched with marolo and jerivá flours had an intense yellow color and increased hardness relative to the control bars; the porosity of the bars progressively decreased as the amount of flour added increased. The sensorial analysis in the snack bars developed added with the fruits flour no was influence by incorporation this component, showed good averages for the scores evaluated.
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Abstract Germinated grains have been known as sources of Gamma-aminobutyric acid (GABA) that provide beneficial effects for human health. This study was aimed to investigate GABA production, dietary fiber, antioxidant activity, and the effect of cooking on GABA loss in germinated legumes and sesame. The highest GABA content was found in germinated mung bean, (0.8068 g kg-1, 24 h incubation) followed by germinated soybean, germinated black bean and soaked sesame. Beside GABA, dietary fiber content also increased in all grains during germination where the insoluble dietary fiber fractions were always found in higher proportions to soluble dietary fiber fractions. Our results also confirmed that germinated mung bean is a rich source of GABA and dietary fibers. Microwave cooking resulted in the smallest loss of GABA in mung bean and sesame, while steaming led to the least GABA content loss in soybean and black bean. Therefore microwave cooking and steaming are the most recommended cooking processes to preserve GABA in germinated legumes and sesame.
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Abstract In Turkey and several Middle East countries' people consume “leblebi” which is a traditional snack food made from chickpeas (Cicer arietinum L.). Chickpea products are highly nutritive and a cheap food for human consumption and have become an essential part of daily diets in the world. The present study aims to determine the chemical, nutritional and dietary composition of fifty leblebi samples marketed in Turkey. Protein values of the leblebi ranged from 19.4 to 23.9% dehulled and 20.3 to 20.8% for nondehulled leblebi while a value of 19.1% was recorded for chickpeas. Mineral results showed that Potassium (K) was the most abundant element in leblebi ranging from 6514 to 14431 mg/kg. The amount of dietary components neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) and cellulose did not vary much between the samples analyzed.
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There is an enormous demand for chemical sensors in many areas and disciplines including chemistry, biology, clinical analysis, environmental science. Chemical sensing refers to the continuous monitoring of the presence of chemical species and is a rapidly developing field of science and technology. They are analytical devices which transform chemical information generating from a reaction of the analyte into an measurable signal. Due to their high selectivity, sensitivity, fast response and low cost, electrochemical and fluorescent sensors have attracted great interest among the researchers in various fields. Development of four electrochemical sensors and three fluorescent sensors for food additives and neurotransmitters are presented in the thesis. Based on the excellent properties of multi walled carbon nanotube (MWCNT), poly (L-cysteine) and gold nanoparticles (AuNP) four voltammetric sensors were developed for various food additives like propyl gallate, allura red and sunset yellow. Nanosized fluorescent probes including gold nanoclusters (AuNCs) and CdS quantum dots (QDs) were used for the fluorescent sensing of butylated hydroxyanisole, dopamine and norepinephrine. A total of seven sensors including four electrochemical sensors and three fluorescence sensors have been developed for food additives and neurotransmitters.
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Set readings 1. Sismondo S. (2009). The Kuhnian revolution. In An introduction to science and technology studies. p12-22 2. Ben-David J, Sullivan T. (1975) Sociology of science. Annual Review of Sociology p203-21 3. Clarke A, Star SL. (2008) The social worlds framework: a theory/methods package. In Hackett EJ et al. The handbook of science and technology studies. Cambridge MA: MIT Press p113-137 Bonus paper (read if you have time) 4. Mitroff I. (1974). Norms and Counternorms in a Select Group of Apollo Moon Scientists. American Sociological Review 39:79-95 • Aim to ensure that you understand the core arguments of each paper • Look up/note any new terminology (and questions you want to ask) • Think about your critical appraisal of the paper (what are the merits/demerits of the argument, evidence etc) In the seminar we will spend about 5 minutes talking about each paper, and then - building on the two lectures - discuss how these ideas might be used to think about the Web and Web Science. At the end there will be some time for questions and a chance to note your key learning points.
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Cardiovascular disease (CVD), which includes coronary heart disease and stroke, remains the major killer in the EU, being responsible for 42% of total mortality. The amount and composition of dietary fat is arguably the most important dietary factor contributing to disease risk. A significant body of consistent evidence indicates that a decrease in dietary saturated fat:unsaturated (polyunsaturated + monounsaturated) ratio and an increased intake of long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) found in fish, is cardioprotective. Furthermore, although the evidence is currently less convincing, such a strategy is also likely to improve insulin sensitivity, the central metabolic defect in diabetes. Currently in the UK only 12% of men, 17% of women and 8% of children have an SFA intakes <10% of energy. The average intake of LC n-3 PUFA is <0.2 g/day, which is less than half the current conservative recommendation of a minimum of 0.45 g/day. Public health strategies to reverse these dietary fatty acid imbalances, aimed at educating and motivating the consumer and making affordable and acceptable food products with an ‘enhanced’ fatty acid profile more widely available, must remain a public health priority in the ‘fight’ against CVD.
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The human gut microbiota is increasingly recognized as playing a central role in human health and disease. This dichotomous relationship with the host forms a central theme in this review, which addresses how we may divert the gut microbiota away from some of its more harmful activities towards beneficial interactions with the human host. We describe the concept of prebiotics, which use specific dietary carbohydrates to increase the numbers of what are seen as beneficial bacteria within the colon, in a selective manner. Specifically, the use of β(2-1) fructans or inulin in general, and certain of its fractions in particular as prebiotics, will be described. Prebiotic fructans constitute efficacious functional foods and there is strong evidence supporting the selectivity of their fermentation within the human gut microbiota, resulting in an increase in the relative numbers of Bifidobacterium spp. There is also considerable evidence, mainly from animal studies but also in humans, that dietary supplementation with prebiotic fructans, through modulation of the microbiota, plays a protective role in colon cancer, heart disease and bone health. However, the mechanisms by which this prebiotic microbiota modulation mediates such diverse health outcomes remain unclear. The future challenge facing the field of prebiotic functional foods will be the elucidation of these mechanisms of action. Recent high resolution bioomics technologies, especially metabonomics, provide the tools necessary to define the metabolic consequences of prebiotic microbiota modulation.
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In November 2008, a group of scientists met at the 6th Meeting of the International Scientific Association of Probiotics and Prebiotics (ISAPP) in London, Ontario, Canada, to discuss the functionality of prebiotics. As a result of this, it was concluded that the prebiotic field is currently dominated by gastrointestinal events. However, in the future, it may be the case that other mixed microbial ecosystems may be modulated by a prebiotic approach, such as the oral cavity, skin and the urogenital tract. Therefore, a decision was taken to build upon the current prebiotic status and define a niche for ‘dietary prebiotics’. This review is co-authored by the working group of ISAPP scientists and sets the background for defining a dietary prebiotic as ‘‘a selectively fermented ingredient that results in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon host health’’.
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Oligosaccharides are attracting increasing interest as prebiotic functional food ingredients. They can be extracted or obtained by enzymatic hydrolysis from a variety of biomass sources or synthesized from simple oligosaccharides by enzymatic transfer reactions. The major prebiotic oligosaccharides on the market are inulin, fructo-oligosaccharides, and galacto-oligosaccharides. They have been evaluated using a range of in vitro and in vivo methods, although there is a need for more large-scale human trials using modern microbiological methods. Prebiotics are being studied for their effects on gut health and well being and specific clinical conditions, including colon cancer, inflammatory bowel disease (IBD), acute infections, and mineral absorption. Developing understanding of the functional ecology of the human gut is influencing current thinking on what a prebiotic might achieve and is providing new targets for prebiotic intervention.