Smoking status, dietary intake, and physical activity in a sample of working adults.

The present study examined differences in dietary intake and physical activity by smoking status in a sample of 3,250 working adults. Cross-sectionally, current smokers consumed alcohol, dairy products, meat, eggs, and french fries more frequently, and engaged in leisure time physical activity less frequently, than former or never smokers. Over 2 years, current smokers increased their intake of meat, soft drinks, eggs, and total calories from high fat and high calorie foods compared to never or former smokers. Smokers who quit during the 2-year observation period increased their frequency of sweets consumption. Dietary and physical activity variables appear to be weak predictors of postcessation weight change. Implications for studies of chronic disease etiology and mechanisms of postcessation weight gain are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of a supercritical fluid extraction method for determination of lipid classes and total fat in meats and its comparison with conventional methods

A method has been developed for the determination of total fat and lipid classes in meat using supercritical fluid extraction (SFE). The results agreed well with results from the conventional Bligh and Dyer and Schmid, Bondzynski and Ratzlaff extraction methods. SFE has advantages compared to the latter methods of a low consumption of hazardous organic solvents and shorter extraction time. After investigation of several different conditions, the most rapid extraction was achieved by adding 1 ml of cyclohexane to a 0.5-g sample mixed with 1 g Hydromatrix in a 7-ml thimble. The optimized SFE parameters were: 370 bar, 50 degrees C, 8% ethanol modifier, 4 ml/min dynamic flow for 30 min and collection with a tube leading to a vial.     

Polymacron enzyme immunoassay system for detection of naturally contaminating Salmonella in foods, feeds, and environmental samples

A simple dot blot enzyme immunoassay was developed to screen enrichment broth cultures for the presence of Salmonella. This unique system utilizes macroporous polyester cloth (Polymacron) with an inexpensive hemoglobin coating to provide a high-affinity adsorbent for lipopolysaccharide (LPS) antigens in test samples. Bound LPS antigens are then detected using a monoclonal antibody conjugate recognizing a core oligosaccharide epitope common to all salmonellae frequently found in foods and related samples. The entire test (not including enrichment culture) could be completed in less than 1 h. The performance of this assay was evaluated in the analysis of enrichment broth cultures from a variety of egg and dairy products, chicken carcasses, animal feeds, and food-processing plant environmental samples for the presence of Salmonella.     

Levels of dioxins, dibenzofurans, PCB and DDE congeners in pooled food samples collected in 1995 at supermarkets across the United States

Food, particularly dairy products, meat, and fish, has been identified as the primary immediate source of intake of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) for the general population. We previously reported PCDD/Fs in individual analyses of food samples from a number of countries, including the U.S., the former Soviet Union, and Vietnam. We also previously estimated daily intake of dioxins and related chemicals in Americans at various ages in these reports. In this paper, the levels of dioxins, dibenzofurans, dioxin toxic equivalents (TEQs), selected dioxin-like PCBs, and DDE (a persistent metabolite of DDT) were measured in 12 pooled food samples from over 90 individual specimens collected from supermarkets throughout the United States during 1995. Samples were pooled by food groups and then analyzed. Food samples were collected in Binghamton, New York; Atlanta, Georgia; Chicago, Illinois; San Diego, California; and Louisville, Kentucky. In addition to the meat, dairy, and fish samples, a vegan (all vegetable, fruit and grain, no animal product) diet, was simulated; this showed the lowest level of dioxins.     

Predictive models of the effect of temperature, pH and acetic and lactic acids on the growth of Listeria monocytogenes

The combined effect of temperature (1-20 degrees C), pH (4.5-7.2) and acetic acid (0-10,000 mg/l; model 1) or lactic acid (0-20,000 mg/l; model 2) on growth of Listeria monocytogenes in laboratory media was studied. Growth curves at various combinations of temperature, pH and acid concentration were fitted by the model of Baranyi and Roberts (1994), and specific growth rates derived from the curve fit were modelled. Predictions of growth from the models were compared with data in the literature, and this showed the models to be suitable for use in predicting growth of L. monocytogenes in a range of foods including meat, poultry, fish, egg and milk and dairy products. The two models are compatible, i.e. they give similar predictions for cases when no acid is present.     

Estimates of food and macronutrient intake in a random sample of Northern Ireland adolescents

Estimates of food consumption and macronutrient intake were obtained from a randomly selected population sample (2%) of 1015 adolescents aged 12 and 15 years in Northern Ireland during the 1990/1991 school year. Dietary intake was assessed by diet history with photographic album to estimate portion size. Reported median energy intakes were 11.0 and 13.1 MJ/d for boys aged 12 and 15 years respectively and 9.2 and 9.1 MJ/d for girls of these ages. Protein, carbohydrate and total sugars intakes as a percentage of total energy varied little between the age and sex groups and were approximately 11, 49 and 20% respectively of daily total energy intakes. Median dietary fibre intakes were approximately 20 and 24 g/d for boys aged 12 and 15 years respectively and 18 and 19 g/d for girls of these ages. Major food sources of energy (as a percentage of total energy intakes) were bread and cereals (15-18%), cakes and biscuits (12-14%), chips and crisps (13-14%), dairy products (9-11%), meat and meat products (9-11%) and confectionery (9%). Fruit and vegetable intakes were low at about 2.5% and 1.5% respectively of total energy intakes. Median fat intakes were high at 39% of total daily energy intakes. Major food sources of fat as a percentage of total fat intakes were from the food groupings: chips and crisps (16-19%), meat and meat products (14-17%), fats and oils (14-16%), cakes and biscuits (13-16%) and dairy products (12-15%). Median intakes of saturated fatty acids were also high at approximately 15% of daily total energy intake while intakes of monounsaturated fatty acids averaged 12% of daily total energy intake. Median polyunsaturated fatty acid (PUFA) intakes were low, comprising 5.2 and 5.5% of daily total energy intake for boys aged 12 and 15 years respectively and were lower than the PUFA intakes (5.9 and 6.3% of daily total energy intake) for girls of these ages. About 1.3% for boys and 1.4% for girls of daily total energy intake was in the form of n-3 PUFA. Ca and Mg intakes were adequate for both sexes. Based on these results, some concern about the dietary habits and related health consequences in Northern Ireland adolescents appears justified.     

Congener-specific levels of dioxins and dibenzofurans in U.S. food and estimated daily dioxin toxic equivalent intake

Food, especially meat, milk, and fish, is the immediate source of almost all polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and dioxinlike compounds in the general population. To estimate intake of these highly toxic compounds, we performed congener-specific dioxin analyses for the first time on U.S. food for 18 dairy meat, and fish samples from a supermarket in upstate New York. 2,3,7,8 Tetrachlorodibenzo-p-dioxin (TCDD, "dioxin") toxic equivalents (TEqs) on a wet weight basis for the dairy products ranged for 0.04 to 0.7 ppt, meat TEqs ranged from 0.03 to 1.5 ppt, and fish TEqs ranged from 0.02 to 0.13 ppt. Previous human breast milk and infant formula analyses were used with the current preliminary food data to estimate a range of dioxin intake for Americans. Average daily food intake of TEqs for an adult weighing 65 kg was estimated to be between 0.3 and 3.0 pg/kg body weight, for a total of 18-192 pg TEq, using 1986 American consumption rates. Due to the relatively high level of PCDDs and PCDFs commonly found in human breast milk from American women and from women in other industrial countries, a nursing infant may consume an average of 35-53 pg TEq/kg body weight/day in its first year of life. This may be compared with the current U.S. EPA virtually safe dose of 0.006 pg TCDD/kg body weight per day over a 70-year lifetime based on an upper limit cancer risk of 10(-6), or the 10 pg/kg/day used by some European government agencies.     

Fluorometric determination of acid phosphatase in cooked, boneless, nonbreaded broiler breast and thigh meat

This method is applicable for determining activity of acid phosphatase (ACP), a heat-labile enzyme, in cooked, boneless, nonbreaded broiler marinated (83.65% meat) and nonmarinated (100% meat) breast and thigh and in a 50:50 blend of breast and thigh meat. The assay uses a self-indicating substrate that, when acted upon by ACP, loses a phosphate radical and becomes a highly fluorescent compound. Cooked meat is added to deionized distilled water in a 1:3 ratio, blended with a hand-held homogenizer, and then centrifuged at 2500 relative centrifugal force for 5 min. ACP activity in the filtrate is measured after shaking on a Vortex mixer 75 microL of the extract with a pH 5.00 acetate buffer containing a nonfluorescent aromatic monophosphoric ester substrate. The rate of fluorophore formation is monitored during a 3 min incubation period (38 degrees C) in a fluorometer, and ACP enzyme activity (mU/kg sample) is calculated. Three laboratories analyzed 6 cooked poultry products (marinated and nonmarinated breast, thigh, and 50:50 breast/thigh blend). Five cooking temperatures were used to generate different ACP activity levels, which were replicated twice with duplicate samples and duplicate sample tests representing 720 data points. Log10 ACP activity (mU/kg sample) performance repeatability and reproducibility standard deviations (sr and sR) and relative standard deviations (RSDr and RSDR) over 5 cooking treatments for 6 products were as follows: marinated breast: sr = 0.02, sR = 0.08, RSDr = 0.60%, RSDR = 2.12%; nonmarinated breast: sr = 0.02, sR = 0.04, RSDr = 0.66%, RSDR = 1.29%; marinated thigh: sr = 0.01, = 0.01, RSDr = 0.37%, RSDR = 0.37%; nonmarinated thigh: sr = 0.02, sR = 0.05, RSDr = 0.53%, RSDR = 1.43%; marinated 50:50 breast/thigh blend: sr = 0.01, sR = 0.05, RSDr = 0.36%, RSDR = 1.31%; nonmarinated 50:50 breast/thigh blend: sr = 0.01, sR = 0.04, RSDr = 0.32%, RSDR = 1.12%.     

Outbreaks of trypanosomosis due to Trypanosoma vivax in cattle in Bolivia

Some new commercial methods for the extraction of viral RNA have been introduced recently. In addition to the study published previously (Verhofstede, C., Reniers, S., Van Wanzeele. F., Plum J., 1996. AIDS 8, 1421-1427), seven different methods (four newly developed and three reference methods) for extraction of HIV-1 RNA from plasma have been evaluated. The RNA preparation method that gave the best results (acceptable reproducibility, highest sensitivity, reasonable price, fast and easy to perform), was the QIAamp Viral RNA kit from QIAgen. The High Pure Viral RNA Kit (Boehringer Mannheim) as well as the non-commercialised extraction kits were also very sensitive. The non-commercial tests seem less suitable for routine use and for the processing of large number of samples. Two methods, RNA Insta-Pure LS (Eurogentec) and PANext RNA extraction kit 1 (NTL, PANsystems GmbH) are not adapted for HIV plasma extraction. The single step methods using glass fibre or silica column are rapid (from 60 to 75 min depending on the number of wash steps) and although the price is high they are cheaper than the Boom extraction methods: High Pure Viral RNA Kit (Boehringer Mannheim) ($3.3/sample), QIAamp Viral RNA Kit (Qiagen) ($3.6/sample), Boom extraction ($5/sample). The Qiagen kit is the only kit that combines sensitivity with reproducibility, it is commercialised, rapid and affordable in price and can be automated. For most of the methods evaluated the inter-test variability was acceptable (mean variation coefficient between duplicate extractions varied between 26.4 and 48.6%).     

Structural changes in the poultry production industry and in the tasks of veterinarians

The rapid expansion and improvement in poultry production began during the mid-1930s. These enhanced by innovation in technology, science and management on different levels such as on artificial incubation, genetics, breeding, rearing, nutrition, disease control and processing technology. During the past 30 years the total egg production as well as poultry meat production has increased tremendously. The modern poultry industry oriented for high production and better quality at low cost, together with increasing claim of consumers for poultry meat and products, demand continuous efficient and goal oriented veterinary care. For this purpose, in many countries poultry health services supervised by veterinarians in co-operation with a central veterinary diagnostic laboratory, are established. Today the main duties of the poultry veterinarians have changed from therapeutic to prevention objectives. The tasks of the modern veterinary poultry specialists are described.     

地质样品中贵金属分析方法现状及展望

贵金属是具有战略地位的稀有关键矿产资源,地质样品中贵金属元素的准确分析对于保障国家贵金属资源安全具有重要的现实意义。文章阐述并归纳了近年来贵金属地质样品的采集、制备、分解、分离富集及测试的现状和应用进展,对样品分解过程中常用的火试金法和湿分解法,分离富集过程中常用的共沉淀法、吸附法、萃取法、离子交换树脂法、蒸馏法及测试中常用的分光光度法、原子吸收光谱法、原子发射光谱法、中子活化法和电感耦合等离子体质谱法等进行了介绍和总结,并对贵金属分析前景进行了展望。超高温高压溶样技术具有高效、易挥发元素不易损失、试剂本底值容易控制等优点,如果将来其能够在取样量和复杂矿种消解难点上取得进一步突破,再联合具有多元素同时测定、高灵敏度、高稳定性的电感耦合等离子体质谱技术,将为地质样品中贵金属元素分析方法带来突破性进展。     

Consumption of meat, animal products, protein, and fat and risk of breast cancer: a prospective cohort study in New York

Epidemiologic studies have focused on the association between diet and breast cancer with conflicting results. Whereas a majority of case-control studies indicate a role for the intake of total fat and saturated fat, most prospective cohort studies either are negative or indicate very modest associations. Only a few authors have examined the role of meat intake in relation to breast cancer risk. The aim of this study was to examine the relation between risk of breast cancer and dietary intake of meat, animal products, fat, and protein. Between 1985 and 1991, we recruited 14,291 New York City women in a prospective cohort study of endogenous hormones, diet, and cancer in which they reported on their recent diet using a food frequency questionnaire self-administered at enrollment. From the cohort, 180 invasive breast cancer cases diagnosed before December 1990 and five times as many controls, individually matched by age, calendar time at enrollment, menopausal status, and, if premenopausal, phase of menstrual cycle, were included in a nested case-control study. There was an evident increase in the relative risk (RR) of breast cancer for increasing consumption of meat. Women in the upper quintile of meat consumption, as compared with the lowest quintile, had an energy-adjusted RR of 1.87 (95% confidence interval = 1.09-3.21). There was a modest RR increase in the upper quintile of total and saturated fat and no apparent association for other types of fat, protein, dairy products, poultry, or fish.(ABSTRACT TRUNCATED AT 250 WORDS)     

The unique endometrial expression and genomic organization of the porcine IGFBP-2 gene

Nisin was first introduced commercially as a food preservative in the UK approximately 30 years ago. First established use was as a preservative in processed cheese products and since then numerous other applications in foods and beverages have been identified. It is currently recognised as a safe food preservative in approximately 50 countries. The established uses of nisin as a preservative in processed cheese, various pasteurised dairy products, and canned vegetables will be briefly reviewed. More recent applications of nisin include its use as a preservative in high moisture, hot baked flour products (crumpets) and pasteurised liquid egg. Renewed interest is evident in the use of nisin in natural cheese production. Considerable research has been carried out on the antilisterial properties of nisin in foods and a number of applications have been proposed. Uses of nisin to control spoilage lactic acid bacteria have been identified in beer, wine, alcohol production and low pH foods such as salad dressings. Further developments of nisin are likely to include synergistic action of nisin with chelators and other bacteriocins, and its use as an adjunct in novel food processing technology such as higher pressure sterilisation and electroporation. Production of highly purified nisin preparations and enhancement by chelators has led to interest in the use of nisin for human ulcer therapy, and mastitis control in cattle.     

Analytical methods for the determination of 3-chloro-1,2-propandiol and 2-chloro-1,3-propandiol in hydrolysed vegetable protein, seasonings and food products using gas chromatography/ion trap tandem mass spectrometry

The EC Scientific Committee for Foods and more recently the Food Advisory Committee in the UK have proposed that levels of 3-chloro-1,2-propanediol (3-MCPD) in foods and ingredients should be reduced to the lowest possible. This paper reports on the development of methods for the determination of parts-per-billion (microgram/kg) levels of 3-MCPD in hydrolysed vegetable protein (HVP), flour, bread, meat and starch products using gas chromatography/ion-trap tandem mass spectrometry (GC/ITMS/MS). Mass spectrometer conditions for detecting 3-MCPD and the stable isotope internal standard (3-chloro-1,2-propandiol-d7) were established. Candidate extraction methods were initially evaluated for recovery and repeatability by spiking selected commodities at a level of 100 micrograms/kg. Extracts of ingredients and foods prepared by the candidate extraction methods were examined by GC/ITMS/MS using samples spiked at a level of 25 micrograms/kg. The results showed that detection limits of between 3 and 5 micrograms/kg could be achieved for all commodities.     

Comparison of supercritical CHF3 and CO2 for extraction of sulfonamides from various food matrices

Supercritical CHF3 and methanol-modified CHF3 were compared with supercritical CO2 and methanol-modified CO2 for the extraction of sulfonamides from a spiked sand sample. In addition, a fortified nonfat milk powder, fortified egg yolk, and fortified beef liver were studied. The results showed CHF3 has higher solvating power and selectivity for extraction of two of the three sulfonamides than CO2. Extraction efficiencies of sulfamethazine and sulfadimethoxine using pure CHF3 were more than 45% higher from spiked sand samples and over 200% higher from fortified beef liver samples than pure CO2.     

Gender differences in food-related concerns, beliefs and behaviours of north Queensland adolescents

OBJECTIVE: To describe the beliefs, attitudes, behaviours and knowledge of North Queensland adolescents about food and nutrition. METHODOLOGY: A questionnaire surveyed 791 Year 8 students from private schools. RESULTS: More girls than boys felt guilt about food, sometimes ate from boredom, reported trying to select foods that were good for them and were concerned about the fat content of food; 30% of boys and 17% of girls thought they should be concerned about their food intake only when overweight. Low daily dietary intakes were reported for bread, fruit, vegetables and dairy products with only 24% eating at least one fruit, one vegetable, one dairy product and one core cereal food daily. Fat and sugar intake was high: 41% students ate high fat savoury foods and 53% ate high sugar foods at least seven times during the week. Parents, television and school provided information about food and nutrition to 70-80% of these students, followed by friends and magazines with doctors and teachers providing information on weight and weight loss to 10% of students. CONCLUSIONS: Doctors should be aware of the low intake of recommended foods as well as the high intakes of fat and sugar among adolescents and the gender differences in food related beliefs and behaviours when treating nutrition related diseases and providing guidance for their prevention.     

The effects of frying and grilling on the fat content of common foods (salmon, hake and beefsteak)

The effects of pan frying and deep frying in olive oil on the fat content in very lean meat (fat = 4.0%), salmon (fat = 26.0%) and hake (fat = 1.8%) have been studied. Both techniques produced fat loss in the meat: pan fried 0.5% (p = 0.07), deep fried 1.3% (p = 0.00036); and salmon: pan fried 11.7% (p = 0.0000026), deep fried 7.9% (p = 0.00012). Hake increased fat content with pan fried 2.4% (p = 0.002) and with deep fried 5% (p = 0.00001). Deep frying or pan frying of meat induce fat loss without dietetic relevance. Fat loss in salmon is nutritionally important specially when pan fried. Fat gain in hake is too small to be considered biologically relevant. This results can not be applied to frying with others fats than olive oil or to frying others food with the same oil.     

Antimicrobial drug residues in milk and meat: causes, concerns, prevalence, regulations, tests, and test performance

This paper presents a historical review of antimicrobial use in food animals, the causes of residues in meat and milk, the types of residues found, their regulation in Canada, tests used for their detection, and test performance parameters, with an emphasis on immunoassay techniques. The development of residue detection methods began shortly after the introduction of antimicrobials to food animal production in the late 1940s. From initial technical concerns expressed by the dairy industry to the present public health and international trade implications, there has been an ongoing need for reliable, sensitive, and economical methods for the detection of antimicrobial residues in food animal products such as milk and meat. Initially there were microbial growth inhibition tests, followed by more sensitive and specific methods based on receptor binding, immunochemical, and chromatographic principle. An understanding of basic test performance parameters and their implications is essential when choosing an analytical strategy for residue testing. While each test format has its own attributes, none test will meet all the required analytical needs. Therefore the use of a tiered or integrated system employing assays designated for screening and confirmation is necessary to ensure that foods containing violative residues are not introduced into the food chain.     

Dioxins, dibenzofurans, dioxin-like PCBs, and DDE in U.S. fast food, 1995

Food, especially dairy products, meat, and fish, is the primary source of environmental exposure to dioxins in the general population. Little data exists on dioxin levels in the popular and widely consumed "fast foods". Data presented in a previously published pilot study was limited to measuring only the levels of dioxins and dibenzofurans in three types of U.S. fast food. This study adds to the previous paper by presenting data, in addition to dioxins and dibenzofurans, on the closely related dioxin-like polychlorinated biphenyls (PCBs), and the persistent metabolite of DDT, 1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene (DDE), in four types of popular U.S. fast food. These include McDonald's Big Mac Hamburger, Pizza Hut's Personal Pan Pizza Supreme, Kentucky Fried Chicken (KFC) three piece original recipe mixed dark and white meat luncheon package, and H?agen-Daz chocolate-chocolate chip ice cream. Dioxin plus dibenzofuran dioxin toxic equivalents (TEQ) ranged from 0.03 to 0.28 TEQ pg/g wet or whole weight for the Big Mac, from 0.03 to 0.29 for the Pizza, from 0.01 to 0.31 for the KFC, and from 0.03 to 0.49 TEQ pg/g for the ice cream. Daily TEQ consumption per kilogram body weight (kg/BW), assuming an average 65 kg adult and a 20 kg child, from one serving of each of these fast food ranged between 0.046 and 1.556 pg/kg in adults whereas in children the values were between 0.15 and 5.05 pg/kg. Total measured PCDD/Fs in the Big Mac, Personal Pan Pizza, KFC, and the H?agen-Daz ice cream varied from 0.58 to 9.31 pg/g. Measured DDE levels in the fast foods ranged from 180 to 3170 pg/g. Total mono-ortho PCB levels ranged up to 500 pg/g or 1.28 TEQ pg/g for the KFC and for di-ortho PCBs up to 740 pg/g or 0.014 TEQ pg/g for the pizza sample. Total PCB values in the four samples ranged up to 1170 pg/g or 1.29 TEQ pg/g for the chicken sample.     

熔融制样-X射线荧光光谱法测定磷铁中磷硅锰钛

使用熔融制样-X射线荧光光谱法(XRF)测定磷铁合金样品,关键是要解决样品前处理中合金样品侵蚀铂-黄坩埚的难题。采用陶瓷坩埚石墨垫底低温预氧化后,高温熔融制样,建立了X射线荧光光谱测定磷铁中磷、硅、锰和钛的方法。选用磷铁标准样品,按照一定的比例合成及在磷铁标准样品中加入标准溶液的方式,配制成一定梯度的磷铁校准样品,拓宽了校准曲线的含量范围。以碳酸锂和过氧化钡复合氧化剂,从400℃缓慢升温至800℃,对磷铁样品进行预氧化,避免了熔融过程中对铂-黄坩埚的腐蚀。实验结果表明,以四硼酸锂为熔剂,溴化铵溶液为脱模剂,稀释比40∶1,于1100℃下熔融20min,制得的玻璃熔片均匀稳定。各元素的检出限为32.47~57.49μg/g。在最佳实验条件下对磷铁标准样品进行测定,各元素测定结果的相对标准偏差(RSD,n=10)为0.28%~1.1%。实验方法应用于磷铁实际样品的测定,与其他方法的测量结果无显著性差异。