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1.
Introduction Milk is a raw material used in the fabrication of a very large range of products. The modalities of payment are designed to orientate milk production according to technological needs and hygiene and food security requirements. The processors seek milk witch is adapted for all types of processing ( Beguin, 1994 ).  相似文献   

2.
Protein–polysaccharide interactions are of great importance in the design of dairy formulations, as they play a key role in the formation of structure and texture in dairy products. With a detailed understanding of the factors affecting the interactions, the ability of charged polysaccharides to associate with the milk proteins is continuously exploited to create functional complexes, novel ingredients and delivery systems. In addition, formulations containing non-interacting polysaccharides also need to be carefully controlled, as these biopolymers may give rise to segregative phase separation, with important consequences to the stability and quality of the final matrix. As casein micelles play a major role in imparting structure to dairy products, emphasis in this review will be given to the molecular details of the interactions between polysaccharides with these protein particles. Some of the most researched polysaccharides will be highlighted in this context, and the progress made in understanding their role during structure formation of dairy matrices will be discussed. The opportunity of creating novel microstructures provided by association or/and incompatibility of milk proteins and different polysaccharides will be assessed.  相似文献   

3.
《Food microbiology》1996,13(3):243-256
Hazard analyses of black pudding (`boudin noir') preparation practices were conducted in four operations at an abattoir in Trinidad. The analyses consisted of watching all steps of preparation of the product on three occasions by each of the four processors, taking samples of ingredients and mixtures used during the steps to culture for common food pathogens, taking swab samples of chopping boards used for celery, pepper, onions and garlic, recording the sequential temperatures of water used for heating the stuffed intestine and the internal temperature of the stuffed intestine. A general build up of aerobic mesophilic bacteria was observed on addition of various ingredients like spices, celery, pepper, onions, garlic, fat, bread and blood before stuffing the intestine with a semi-solid mixture. The mean total aerobic plate count was 8.8×108±2.7×109and 8.5×105±1.3×106g−1for pre-heated and post-heated stuffed intestine, respectively. Preheated samples yieldedEscherichia coli(89.0%),Staphylococcus aureus(99.0%) andSalmonella(14.6%). The mean temperatures of water used in heat processing ranged from 81.0±3.5 to 87.0±8.0°C, the mean internal temperature of stuffed intestine during processing ranged from 63.2±2.8 to 72.6±2.5°C and the mean processing time ranged from 17.3±10.2 to 26.7±4.2min between processors. The temperature treatments employed by the processors were lower than the 85°C for 10–15min recommended for the product. Consequently, the temperature exposure achieved between a 1–4log decrease in the counts aerobic mesophilic bacteria per gram. Of the 22 ready-to-consume black pudding samples tested, 15 (68.2%), 19 (86.4%) and 3 (13.6%) were positive forE. coli,S. aureusandSalmonella, respectively. Hazards were primarily associated with the keeping of blood at ambient temperature for several hours before use, insanitary practices and keeping processed black pudding at ambient temperature. Critical control points were cooking or heat processing, handling of the product after cooking and holding processed black pudding.  相似文献   

4.
Inadequate regulation of food intake plays an important role in the development of overweight and obesity, and is under the influence of both the internal appetite control system and external environmental cues. Especially in environments where food is overly available, external cues seem to override and/or undermine internal signals, which put severe challenges on the accurate regulation of food intake. By structuring these external cues around five different phases in the food consumption process this paper aims to provide an overview of the wide range of external cues that potentially facilitate or hamper internal signals and with that influence food intake. For each of the five phases of the food consumption process, meal initiation, meal planning, consumption phase, end of eating episode and time till next meal, the most relevant internal signals are discussed and it is explained how specific external cues exert their influence.  相似文献   

5.
This work describes an improved, simple high performance liquid chromatography (HPLC) method for the simultaneous determination of furfuraldeydes (2-furfural (2-F), 5-methylfurfural (5-MF) and 5-hydroxymethylfurfural (5-HMF)) and patulin in food products. The compounds were simultaneously determined by reversed-phase HPLC using a C18 column and photodiode array (DAD) detection. The method, simple and accurate, showed recoveries of furfuraldeydes from 6% to 100% and the recovery of patulin is about 90%. The method was applied to different commercial food matrices: honey, white and demerara table sugars, white and red balsamic vinegars, caramel, nutritional supplement, sugar substitute, apple juices (clear and cloudy) and also to a mould infected apple. The one-step, sensitive (the limits of detection (LODs) for patulin, 5-HMF, 5-MF and 2-F were 0.09, 0.06, 0.23 and 0.73 ppb, respectively), no time consuming methodology will contribute to characterize and quantify the presence of these compounds in human diet and to determine the quality of foods.  相似文献   

6.
As Mycoplasma bovis spreads to new countries and becomes increasingly recognized as a disease with major welfare and economic effects, control measures on dairy farms are needed. To minimize the risk of infection spread to naive herds, all possible risk factors for M. bovis infection should be identified and controlled. Mycoplasma bovis was first diagnosed in dairy cattle in Finland in 2012, and by January 2020, 86 Finnish dairy farms (<1.5%) supporting M. bovis infections were identified. We evaluated risk factors for M. bovis infection using a questionnaire provided to 40 infected and 30 control dairy farms. Control measures were advised for 19 of the infected dairy farms during visits by a veterinarian. The course of the infection on those farms was followed by analyzing calf nasal swabs with PCR for presence of M. bovis 4 times at 6-mo intervals. Control measures included culling of M. bovis mastitic cows, isolation of new calves from older animals after initial M. bovis mastitic cows had been culled, prevention of nose-to-nose contact with infected animals, early detection of mastitis cases using M. bovis PCR, and hygiene measures mainly related to milking, calf pens, feeding buckets, and teats. Farms implemented the control measures related to the isolation of calves or avoidance of nose-to-nose contact in various ways, according to farm structures and financial circumstances. In our study, the control measures recommended to the dairy farms appeared effective, such that 13 of 19 farms reached a low risk level during at least 3 consecutive negative samplings from calves, with no M. bovis mastitis detected subsequently. Among risk factors, insemination with an M. bovis-positive bull indicated a trend of increasing the odds of M. bovis infection on the farm in a multivariable logistic model. In contrast, higher herd average milk yield had an association with lower odds for M. bovis infection. Occurrence of other infectious diseases affecting several animals on the dairy farm in the previous 6 mo before M. bovis infection were more frequent on M. bovis-infected farms.  相似文献   

7.
New options to process dairy products by means of new single unit operations or combinations thereof are presented. The innovative possibilities discussed in this paper mainly refer to novel ways of influencing product microstructures or textures as perceived during consumption, by means of contributions of single molecule fractions of complex systems derived from membrane fractionation techniques. In addition, options to integrate physiologically active components which also have a structure forming effect in fermented or other dairy products are highlighted. Alternatives derived from thermal, mechanical and enzymatic processing and from fractionation techniques by means of membranes are presented which can be exploited for fractionation and compositional matrix design of dairy products.  相似文献   

8.
In the wake of recent outbreaks associated with Listeria monocytogenes in ready-to-eat foods and an increasing desire for minimally processed foods, there has been a burgeoning interest in the use of natural antimicrobials by the food industry to control this pathogen. The minimum inhibitory concentrations (MICs) of nisin and salts of organic acids (sodium lactate (SL), sodium diacetate (SD), sodium benzoate (SB), and potassium sorbate (PS)) against twelve strains of L. monocytogenes in a TSBYE broth medium at 35 degrees C were determined. The MICs were strain-dependent and fell in the range of 0.00048-0.00190% for nisin, 4.60-5.60% for SL, 0.11-0.22% for SD, 0.25-0.50% for SB and 0.38-0.75% for PS, respectively. The two most antimicrobial-resistant strains were used as a cocktail in the following experiments to represent a worst case scenario. The five antimicrobials alone and in binary combinations were screened for their efficacy against the two-strain cocktail in TSBYE at sub-MIC and sub-legal levels at 35 degrees C. Seven effective antimicrobial treatments were then selected and evaluated for their long-term antilisterial effectiveness in cold-smoked salmon paté and fillets during refrigerated storage (4 degrees C) of 3 and 6 weeks, respectively. The two most effective antimicrobial formulations for smoked salmon paté, 0.25% SD and 2.4% SL/0.125% SD, were able to inhibit the growth of L. monocytogenes during the 3 weeks of storage. Surface application of 2.4% SL/0.125% SD was the most effective treatment for smoked salmon fillets which inhibited the growth of L. monocytogenes for 4 weeks. These antimicrobial treatments could be used by the smoked salmon industry in the U.S. and Europe in their efforts to control L. monocytogenes as they are effective against even the most antimicrobial-resistant strains tested in this study.  相似文献   

9.
α-Dicarbonyl compounds (α-DCs) are readily produced during the heating and storage of foods, mainly through the Maillard reaction, caramelization, lipid-peroxidation, and enzymatic reaction. They contribute to both the organoleptic properties (i.e., aroma, taste, and color) and deterioration of foods and are potential indicators of food quality. α-DCs are also important precursors to hazardous substances, such as acrylamide, furan, advanced lipoxidation end products, and advanced glycation end products, which are genotoxic, neurotoxic, and linked to several diseases. Recent studies have indicated that dietary α-DCs can elevate plasma α-DC levels and lead to “dicarbonyl stress.” To accurately assess their health risks, quantifying α-DCs in food products is crucial. Considering their low volatility, inability to absorb ultraviolet light, and high reactivity, the analysis of α-DCs in complex food systems is a challenge. In this review, we comprehensively cover the development of scientific approaches, from extraction, enrichment, and derivatization, to sophisticated detection techniques, which are necessary for quantifying α-DCs in different foods. Exposure to α-DCs is inevitable because they exist in most foods. Recently, novel strategies for reducing α-DC levels in foods have become a hot research topic. These strategies include the use of new processing technologies, formula modification, and supplementation with α-DC scavengers (e.g., phenolic compounds). For each strategy, it is important to consider the potential mechanisms underlying the formation and removal of process contaminants. Future studies are needed to develop techniques to control α-DC formation during food processing, and standardized approaches are needed to quantify and compare α-DCs in different foods.  相似文献   

10.
Although research is shedding new light on the phenomenon, it is proving difficult to manage.  相似文献   

11.
12.
The biological control capability of strain 34-9 of Kloeckera apiculata against Penicillium italium (Wehmer), postharvest rot of citrus fruits and Botrytis cinerea, postharvest rot of grape fruits was studied in vitro and in vivo. Strain 34-9 of K. apiculata at 3×108 CFU (colony-forming unit)/ml of washed cells provided complete control of 3×105 spores/ml of P. italium and B. cinerea during storage at 25 °C for 6 d. Antagonist population increased 40, 195 times in citrus fruit wound site and grape fruit wound site at 25 °C for 3 d, respectively, then the population stabilized for the remaining storage period. Cell-free culture filtrate, supernatant fluid and sterilized solution of strain 34-9 of K. apiculata had no antagonist against P. italium of citrus and B. cinerea of grape. These results showed that competition for nutrient, not antibiotic production, played a major role in the biological control capability of strain 34-9 of K. apiculata against P. italium of citrus and B. cinerea of grape.  相似文献   

13.
The Alberta Johne's Disease Initiative (AJDI) is a Johne's disease (JD) control program with the goal of reducing the spread of Mycobacterium avium ssp. paratuberculosis (MAP) through implementation of best management practices. The objective was to estimate the economic benefit of participation in the AJDI. A decision tree was constructed in which disease prevalence, test characteristics, and probabilities for implementation of best management practices suggested by herd veterinarians were implemented. Analysis was performed using a Markov analysis, and input data were assigned using estimates from the AJDI and published data. A cost-effectiveness analysis was performed and the net benefit of participation (from the perspective of a dairy farmer) in the AJDI compared with no participation was calculated. A series of 1-way sensitivity analyses were used to control for uncertainty. Farms participating in the AJDI were estimated to have a net benefit of Can$74 per cow over the course of 10 yr. If project costs were covered by the participating farm, the net benefit was Can$27. In addition to the effects on MAP infection, a reduction in calf diarrhea was modeled for farms that improved their calf management through the use of pasteurizers. In that case, the additional costs outweighed additional revenues compared with the baseline analysis, resulting in a reduced net benefit of Can$19. Participation would not be cost effective if cows in early stages of MAP infection did not have decreased production and if prevalence of MAP infection did not increase on farms with poor management. A limitation of the study, despite high uncertainty in some input parameters, was the lack of knowledge regarding changes in prevalence on farms with various management strategies. In conclusion, participation in the AJDI was cost effective for the average Alberta dairy farm.  相似文献   

14.
Bhutan: the world's most advanced tobacco control nation?   总被引:1,自引:1,他引:0       下载免费PDF全文
Ugen S 《Tobacco control》2003,12(4):431-433
Significant achievements in the area of tobacco control have been made in the kingdom of Bhutan in the Eastern Himalayas, following the initiation of several tobacco control activities  相似文献   

15.
Electronic warp delivering control system based on Programmable Logic Controller (PLC) has been applied into the textile machine and sizing machines and other machines, using PLC as the control core and the man-machine interface (HMI) for interactive platform. The system can control the warp tension, continuously along with the unwinding diameter becoming smaller and smaller and the winding diameter becoming larger and larger, and use a proportional integral derivative controller (PID) to adjust technology in order to ensure the web tension within the desired range and keep the warp tension constant. The thesis describes the action process of control systems, introduces the system hardware structure composition, the system control principle and system software design.  相似文献   

16.
17.
ABSTRACT

The determination of acrylamide in potato products, bakery products and coffee, and the human dietary exposure is reported. The method reported is based on a single extraction step with water, followed by the clean-up of the extract using solid phase extraction columns and finally, the determination of acrylamide using UPLC–MS/MS. The MS/MS detection was carried out using an ESI interface in positive ion mode. Internal calibration was used for the quantification of acrylamide, because of the suppression/enhancement matrix effects due to the complex nature of the samples. The method performance characteristics were determined after spiking blank samples. The mean recoveries in spiked coffee samples, potato chips, breakfast cereals and crispbread ranged from 93% to 99%, with RSDs lower than 5% for both repeatability and reproducibility conditions. The estimated limits of detection and quantification of the method were 10 and 32 μg kg?1, respectively. The method was used for monitoring acrylamide in 406 samples. Acrylamide amounts ranged from <32 to 2450 μg kg?1. A total of 360 samples (89%) were contaminated with acrylamide, but only 14% of the samples exceeded the benchmark levels of the EU legislation. Foods with the highest mean acrylamide amounts were potato crisps (642 μg kg?1), French fries (383 μg kg?1) and biscuits (353 μg kg?1). The mean and 95th percentile acrylamide exposures of adolescents in Cyprus were 0.8 and 1.8 μg kg?1 body weight per day, respectively. The estimated levels of dietary exposure to acrylamide are not of concern with respect to neurotoxicity. However, the margins of exposure (MOEs) indicate a concern for carcinogenicity. Potato fried products (45%), fine bakery ware (21%) and potato chips (14%) contributed the most to overall acrylamide exposure.  相似文献   

18.
19.
A better understanding of the social context of smoking may help to enhance tobacco control research and practice  相似文献   

20.
The frequencies of coliform bacteria (CB), thermotolerant coliforms (TC), Escherichia coli, and Salmonella were determined for jalape?o and serrano peppers. In addition, the behavior of four serotypes of Salmonella and three E. coli strains on whole and sliced jalape?o and serrano peppers as well as in blended sauce at 25 ± 2°C and 3 to 5°C was investigated. Chili peppers were collected from markets in the city of Pachuca, Hidalgo, Mexico. CB, TC, E. coli, and Salmonella were detected on serrano peppers in 100, 90, 50, and 10 % of the samples, and on jalape?o peppers in 100, 86, 32, and 12 % of the samples. Concentrations of CB ranged from 3.8 to 7.9 log CFU per serrano sample and from 5.3 to 8.2 log CFU per jalape?o sample, whereas concentrations of TC and E. coli were between < 3 and 1,100 most probable number per serrano and jalape?o samples. On whole serrano and jalape?o peppers stored at 25 ± 2°C or 3 to 5°C, no growth was observed for rifampin-resistant strains of Salmonella and E. coli. After 6 days at 25 ± 2°C, the tested Salmonella serotypes and E. coli strains had decreased from an initial inoculum level of 5 log CFU to 1 and 2.5 log on serrano and jalape?o peppers, respectively, and at 3 to 5°C they decreased to approximately 1.8 and 1.2 log, respectively, on serrano and jalape?o. Both the Salmonella serotypes and E. coli grew on sliced chili peppers and in blended sauce; after 24 h at 25 ± 2°C, both bacteria types had grown to approximately 4 and 5 log CFU on pepper slices and in sauce, respectively. At 3 to 5°C the bacterial growth was inhibited.  相似文献   

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