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1.
Milk and fruit juices have paramount importance in human diet. Increasing demand of these liquid foods has made them vulnerable to economic adulteration during processing and in supply chain. Adulterants are difficult to detect by consumers and thus necessitating the requirement of rapid, accurate and sensitive detection. The potential adulterants in milk and fruit juices and their limits set by different regulatory bodies have been briefly described in this review. Potential advantages and limitations of various techniques such as physicochemical methods, chromatography, immunoassays, molecular, electrical, spectroscopy with chemometrics, electronic nose, and biosensors have been described. Spectroscopy in combination with chemometrics has shown potential for rapid, precise, and sensitive detection of potential adulterants in these liquid foods.  相似文献   

2.
Thermal imaging is a technique to convert the invisible radiation pattern of an object into visible images for feature extraction and analysis. Infrared thermal imaging was first developed for military purposes but later gained a wide application in various fields such as aerospace, agriculture, civil engineering, medicine, and veterinary. Infrared thermal imaging technology can be applied in all fields where temperature differences could be used to assist in evaluation, diagnosis, or analysis of a process or product. Potential use of thermal imaging in agriculture and food industry includes predicting water stress in crops, planning irrigation scheduling, disease and pathogen detection in plants, predicting fruit yield, evaluating the maturing of fruits, bruise detection in fruits and vegetables, detection of foreign bodies in food material, and temperature distribution during cooking. This paper reviews the application of thermal imaging in agriculture and food industry and elaborates on the potential of thermal imaging in various agricultural practices. The major advantage of infrared thermal imaging is the non-invasive, non-contact, and non-destructive nature of the technique to determine the temperature distribution of any object or process of interest in a short period of time.  相似文献   

3.
New food technologies, such as genetic modification, food fortification, and processing technologies, are of growing interest for future food security and safety. For ensuring successful implementation of such technologies, consumers and other food supply chain actors should embrace them. We present a systematic review to identify and compare key factors of supply chain actors’ evaluation of new food technologies. Evaluation encompasses indicators such as likelihood or intention to perform a behavior, perceived benefits/risks, willingness to pay, acceptance/adoption, and attitudes. Results from 183 studies showed several imbalances in research. Although studies mainly focused on (1) genetically modified foods, (2) by consumers, (3) in developed countries, only very few studies have targeted other food technologies, other supply chain actors such as farmers (13 studies) or processors (two studies), or developing countries (43 studies). With respect to consumers’ evaluation, key determinants were trust in institutions, information assessment, perceived risks and benefits, attitudes toward the product or technology, perceived behavioral control, quality perception of the product, and impact on health. Farmers’ evaluation of new food technologies was explained by the factors of perceived risk and benefits and of actual source of information. For the few processor evaluation studies, no convergence of factors could be reached. This systematic review contributes to a better understanding of consumers’ and farmers’ evaluation behavior and opens up avenues for future research on supply chain actors’ food technology evaluations. The differences in the conceptualization and measurement of extracted factors demonstrate the need for standardized approaches in future studies.  相似文献   

4.
There are four species of the genus Shigella: S. dysenteriae, S. flexneri, S. sonneii, and S. boydii. It is extremely difficult if not impossible to utilize the PCR for distinguishing between shigellae and the five diarrheagenic pathotypes of Escherichia coli—enterohemolytic (EHEC), enteropathogenic (EPEC), engteroinvasive (EIEC), enterotoxigenic (ETEC), and enteroaggresive (EAEC)—due to the extremely close genetic relationship between Shigella spp. and E. coli. This problem is magnified by the presence of common virulence plasmids in these two microbial groups with virulence genes of extremely high homology. Although gastrointestinal infections by shigellae and EICC occur most frequently in developing nations, the responsible E. coli strains are indistinguishable from shigellae by PCR. In addition, with the exception of S. boydii, the other three species of Shigella are completely indistinguishable from one another by the PCR. The most fruitful approach to date in attempting to use the PCR for distinguishing the four species of Shigella from one another has been to first use immuno-capture based on somatic O antigenicity immediately prior to the use of the PCR to impart species selectivity to a coupled ELISA-PCR assay system. Most PCR assays involving the detection of shigellae have been designed to detect shigellae plus the E. coli pathotype EIEC as a collective and indistinguishable group of enteroinvasive organisms or to distinguish Shigella from pathogenic members of other pathogenic genera.  相似文献   

5.
The present review is based mainly on papers published between 2000 and 2011 and gives information about the properties of the carotenoid lycopene in chemical and biological systems and its possible role in preventing cardiovascular diseases (CVD). The main aim of this report is to highlight its role as an antioxidant, also reported are bioactive properties that may influence the development of foam cells and protection against endothelial cell damage. The paper will also examine recent observations that lycopene may improve blood flow and reduce inflammatory responses. Lycopene possesses antioxidant properties in vitro, and some epidemiological studies have reported protective effects against the progression of CVD. The oxidation of human low density lipoproteins (LDL) is a fundamental mechanism in the initiation of atherosclerosis. A beneficial role of lycopene as antioxidant in the prevention of CVD is suggested but the data are still controversial. Lycopene is believed to be the most potent carotenoid antioxidant in vitro. Tissue culture experiments and animal studies support potential cardioprotective effects for lycopene and other carotenoids in the blood. Most studies showed beneficial effects of lycopene to individuals who are antioxidant-deficient like elderly patients, or humans exposed to higher levels of oxidative stress like smokers, diabetics, hemodialysis patients and acute myocardial infarction patients. By defining the right population and combining antioxidant potentials of lycopene with vitamins and other bioactive plant compounds, the beneficial role of lycopene in CVD can be clarified in future studies.  相似文献   

6.
Although the use of superheated steam has been known for quite a long time, only in the recent past has it emerged as a viable technology for food processing. Superheated steam, having higher enthalpy, can quickly transfer heat to the material being processed, resulting in its rapid heating. The major advantages of using superheated steam for food processing are better product quality (color, shrinkage, and rehydration characteristics), reduced oxidation losses, and higher energy efficiency. This review provides a comprehensive overview of recent studies on the application of superheated steam for food-processing operations such as drying, decontamination and microbial load reduction, parboiling, and enzyme inactivation. The review encompasses aspects such as the effect of superheated steam processing on product quality, mathematical models reported for superheated steam drying, and the future scope of application in food processing. Recent studies on process improvisation, wherein superheated steam is used at low pressure, in fluidized bed mode, sequential processing with hot air/infrared, and in combination with micro droplets of water have also been discussed.  相似文献   

7.
8.
Food forgery is one of the most articulated socio-economic concerns which contributed to increase people’s awareness on what they eat and how and where it is produced. Consumers are anxious about the consequences of food falsification on their choices, religious rituals, health, and hard-earned fortunes. The recent scandals of horse and rat meats in Europe and China have given us a brainstorming apprehension on the detection, differentiation, and identification of meat products. To restore consumers’ trust and protect wildlife in natural habitats, researchers and policy-making and policy-implementing authorities have massively monitored all steps in the production of foods and food materials. Analytical approaches based on lipids, proteins, and DNA have been proposed for the authentication of meat species under pure and complex matrices. However, protein and lipid-based methods are less effective since the target biomarkers could be modified throughout the processing treatments. On the other hand, DNA-based species identification schemes have gained wider acceptance and reliability because of the superior stability and universality of DNA in all tissues and cells. We systematically presented here major species detection schemes with special emphasis on multiplex polymerase chain reaction (PCR) of both end-point and real-time platforms. We believe this short but comprehensive review would serve as a reference guide for the developers and users of multiplex PCR and others DNA-based techniques.  相似文献   

9.
《Food chemistry》1998,62(1):73-97
This work reviews the literature on the compositional data of vegetable fats used or proposed as alternatives to cocoa butter in chocolate and confectionery products. Cocoa butter is the only continuous phase in chocolate, thus responsible for the dispersion of all other constituents and for the physical behaviour of chocolate. Unique to cocoa butter is its brittleness at room temperature and its quick and complete melting at body temperature. There were, and are, strong efforts to replace cocoa butter in part for chocolate production for technological and economic reasons. Such cocoa butter alternatives are the so-called cocoa butter equivalents (CBEs), cocoa butter substitutes (CBSs) and cocoa butter replacers (CBRs). These are mostly mixtures of various vegetable fats (often modified) and can consist of palm and palm kernel oil, illipé fat, shea butter, sal fat and kokum butter. In addition, a large variety of other vegetable oils can be used. Their composition according to triglycerides, fatty acids, sterols and other unsaponifiable components is discussed in this report.  相似文献   

10.
11.
Food composite samples from the Canadian Total Diet Study which was conducted each year from 2008 to 2012 rotating between different cities were analysed for bisphenol A (BPA). The overall levels of BPA in the composite food samples from each of the five years from 2008 to 2012 were similar in general with averages (range) of 7.7 ng/g (0.20–106 ng/g), 7.8 ng/g (0.26–110 ng/g), 6.9 ng/g (0.20–84 ng/g), 7.7 ng/g (0.20–105 ng/g) and 9.0 ng/g (0.15–90 ng/g) for 2008, 2009, 2010, 2011 and 2012, respectively. Levels of BPA in most of the non-canned food composite samples were low and no particular trends were observed. In contrast, the trend of BPA levels in canned food composite samples over the five years (2008–2012) varies. BPA levels in most of the canned food composite samples from 2008 to 2012 were consistent in general (e.g. canned luncheon meat: 10–18 ng/g, canned baked beans: 18–25 ng/g). While BPA levels over the five years were found to decrease for some canned food composite samples (e.g., canned fish: 109 ng/g in 2009 vs. 51 ng/g in 2012), they were also found to increase for some other canned food composite samples (e.g. canned meat soups: 90–104 ng/g in 2011–2012 vs. 29 ng/g in 2008). Thus, recent changes in can coating for food packaging to BPA-free alternatives may have not been fully reflected in all canned food products over the period from 2008 to 2012. Continued monitoring is necessary to more fully assess the potential impact on dietary exposure by the use of BPA alternatives in food contact materials.  相似文献   

12.
The search on pyridalyl residues, the novel insecticide, in strawberries and spring onions was evaluated. The QuEChERS technique was used for sample preparation. A fast gas chromatography–mass spectrometry (GC–MS) method was developed and validated for the analysis of pyridalyl in both matrices. Fast GC–MS was performed with a narrow-bore capillary column and a quadrupole mass detector with electron ionization and negative chemical ionization, both operating in selected ion monitoring mode. Fortification studies at 1, 5, 10, and 250 μg/kg for fruit and vegetable matrices were performed. Recoveries for all fortification levels, two ionization modes ranged from 72 to 114 %. Matrix effects were discussed. Limits of quantification were established at 1 μg/kg. Field experiments to investigate the pre-harvest interval were carried out. The proposed method was applied successfully to the determination of pyridalyl residues in samples available on Slovak market, and none of the samples contained detectable amounts of pesticides. The developed method is simple, efficient, and easy to adopt in laboratories engaged in pesticide residue analysis method.  相似文献   

13.
Huang  Xiaojun  Nie  Shaoping  Yang  Meiyan  Xie  Jianhua  Li  Chang  Xie  Mingyong 《Food science and biotechnology》2016,25(2):631-636
Food Science and Biotechnology - Nine different edible oil types from 7 cities in China were analyzed. Trans fatty acid (TFA) contents in edible oils were determined, TFA distribution...  相似文献   

14.
Although laboratory studies have revealed that many different neutral degradates of chloroacetamide herbicides can form during thermochemical, biological, and photochemical transformations, relatively few have been sought in the environment, despite their likely generation in appreciable amounts, relative persistence, and known or potential toxicity. The present paper describes a GC/ MS method for the analysis of 20 neutral chloroacetamide degradates, along with the four parent compounds, three triazine herbicides, and two neutral triazine degradates. Using large volume injections and 300:1 concentration via solid phase extraction, detection limits for most neutral chloroacetamide degradates were in the hundreds of pg/L range (low ng/L range for degradates possessing a hydroxy group). In a depth profile taken in midsummer from the upper Chesapeake Bay, 19 of the 20 neutral chloroacetamide degradates of interest were detected, along with three ionic oxanilic acid derivatives. Of those degradates encountered, eight do not appear to have been previously reported in natural or affected environmental samples. Concentrations of most neutral chloroacetamide degradates exceeded those of the parent compounds, while the total concentration of the neutral chloroacetamide degradates was 20-30 times that of the parents. These micropollutants therefore merit more detailed attention as contaminants of potential environmental concern.  相似文献   

15.
BACKGROUND: Dietary fibre lowers the risk of coronary heart disease and colorectal cancer. This survey quantifies mixed link β‐glucan (MBG) and arabinoxylan (AX) in wheat and investigates relationships between the grain carbohydrates. MBG and AX contents were measured in 500 and 200 wheat accessions respectively, including diploid, tetraploid and hexaploid genotypes comprising primitive, synthetic and elite lines. RESULTS: Overall, MBG contents ranged between 1.8 and 18.0 g kg?1 grain dry weight. In wheat–barley addition lines and triticale hexaploids the levels were 9.0–11.3 and 3.5–9.6 g kg?1 respectively. The amounts in synthetic wheats were nearer their tetraploid parents than their diploid parents. AX and total non‐starch polysaccharide (NSP) contents ranged from 23.7 to 107.5 g kg?1 and from 31.7 to 136.7 g kg?1 respectively. Linear regressions showed that the relationships of starch and grain weight with NSP glucose were stronger than those with AX. CONCLUSION: The results indicated insufficient genetic diversity in the germplasm surveyed to initiate a breeding programme to increase the amount of MBG in wheat grain to 20 g kg?1, a level considered high enough to confer a 10–15% reduction in blood cholesterol. Copyright © 2011 Society of Chemical Industry  相似文献   

16.
Pasta products enriched with ingredients to improve their nutritional value or functionality have become increasingly popular, and substantial research efforts have been directed towards the development of new enriched pasta products. In this work, a meta‐analysis was conducted to quantify the impact of enrichment and process specifications on the quality attributes of pasta. A literature search revealed 66 studies on enriched pasta. Process specifications and quality attributes, namely proximate composition, dough, drying, cooking, and mechanical properties, color, and sensory attributes, were extracted from the studies and compiled in a data set. Analysis of the data set revealed significant differences between pasta enriched with high‐fiber ingredients and pasta enriched with pulse flour. High‐fiber ingredients generally preserved the quality attributes of pasta more effectively than pulse flour. Comparisons based on the drying temperature showed that high drying temperatures generally improve the cooking properties of enriched pasta. Sensory evaluations indicated that enrichment levels below 10% generally do not affect consumer acceptance, but higher enrichment levels significantly decrease it. Pearson correlation coefficients showed that the gelatinization temperature and Farinograph properties are useful indicators of the mechanical properties and sensory attributes of pasta. The meta‐analysis revealed the need to better understand the impact of the processing history of the enrichment ingredient on the quality attributes and the health benefits of enriched pasta.  相似文献   

17.
There is no scientific consensus regarding the safety of the Yellow Knight mushroom Tricholoma equestre (L.) P.Kumm. Following reports of cases of intoxication involving effects such as rhabdomyolysis, and supportive observations from in vivo experimental models, T. equestre is considered as a poisonous mushroom in some countries while in others it is still widely collected from the wild and consumed every year. In this paper, we review all the available information on T. equestre including its morphological and molecular characterization, nutritional value, levels of contaminants observed in fruiting bodies, the possibility of mistake with species that are morphologically similar, and the in vivo data on safety and cases of human intoxication. Based on available data, it is suggested that T. equestre cannot be considered as a toxic species and does not appear to exhibit any greater health threat than other mushroom species currently considered as edible. More care should be taken when reporting cases of human poisoning to fully identify T. equestre as the causative agent and to exclude a number of interfering factors. Specific guidelines for reporting future cases of poisoning with T. equestre are outlined in this paper. Any future research involving T. equestre should present the results of molecular phylogenetic analyses.  相似文献   

18.
There is little agreement among governments, institutions, scientists and food activists as to how to best tackle the challenging issues of health and sustainability in the food sector. This essay discusses the potential of school meals as a platform to promote healthy and sustainable food behavior. School meal programs are of particular interest for improving public diet because they reach children at a population scale across socio-economic classes and for over a decade of their lives, and because food habits of children are more malleable than those of adults. Current research on the history and health implications of school meal programs is reviewed in a cross-national comparative framework, and arguments explored that speak for the need of a new developmental phase of school meals as an integrative learning platform for healthy and sustainable food behavior. Nutritional, social, practical, educational, economical, political, and cultural perspectives and challenges linked to the implementation of healthy and sustainable school meals are discussed. Finally, the need for long-term interventions and evaluations is highlighted and new research directions are proposed.  相似文献   

19.
A mean stress failure criterion is applied to the Volkersen-model used for analysis of lag screws and glued-in rods subjected to withdrawal. Expressions are derived for pull-pull as well as pull-push loading conditions. The solutions for glued-in rods appear as special cases of the theory for lag screws, and the usual solutions for a maximum stress failure criterion appear as special cases of the solutions for a mean stress failure criterion. The theoretical solutions for lag screws are compared with test results, and a suggestion is made for taking into account initial shear stresses caused by the thread of the screw when driving the screw into the wood. The main advantage of considering initial shear stresses is that the number of necessary fitting parameters is limited to one, and that the usual values of shear strength and mode II fracture energy of wood can be applied.  相似文献   

20.
Marine lipids have long been documented to be the major source of polyunsaturated fatty acids (PUFAs), especially n-3 fatty acids such as eicosapentaenoic acid (EPA; 20:5 n-3) and docosahexaenoic acid (DHA; 22:6 n-3). Both EPA and DHA have been documented to have significant influence on biochemical and physiological changes in the body. Although these long chain PUFA exert positive influences on human nutrition and health, there are also some controversies pertaining to the functioning of these n-3 PUFAs including the extent of their requirement by the body. As marine lipids have been thoroughly reviewed often, the present review mainly focuses on works related to physiological effects of EPA and DHA.  相似文献   

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