Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “DAIRY PRODUCTS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

Major advances in extension education programs in dairy production.

The dairy industry has seen structural changes in the last 25 yr that have an impact on extension programming. The number of cows in the United States has decreased by 17%, whereas the number of dairy farms has decreased by 74%. The average milk production per cow has increased from 5,394 to 8,599 kg/lactation. Even though there are fewer farms, dairy farm managers are asking for more specific and targeted information. The extension resources available have also decreased during this period. Because of these changes, shifts have taken place in extension programming and staffing. A key change has been a shift to subject matter-targeted programs and workshops. Extension has also incorporated and expanded use of the Internet. Discussion groups, subject matter courses, and searchable databases are examples of Internet use. There will be continuing shifts in the demographics of the US dairy industry that will influence future extension efforts. It is also probable that fewer extension professionals will be available to provide programming due to changes in funding sources at national, state, and local levels. Future shifts in extension programming will be needed to provide the information needs of the industry with a smaller number of extension workers.

Animals↗

Plasma lipoprotein levels in vegetarians. The effect of ingestion of fats from dairy products.

The influence of dairy foods in the diet on plasma levels of total, low-density lipoprotein, and high-density lipoprotein cholesterol (TC, LDL-C, and HDL-C, respectively) was studied in 75 adult lactovegetarians living in the northeastern United States. Dairy products were the major sources of dietary saturated fat and cholesterol. The plasma TC level was positively correlated with dietary saturated fat and dietary cholesterol, and inversely correlated with the ratio of polyunsaturated to saturated fats in the diet. Correlations between the LDL-C level and the nutrients were similar to those of the TC level. The HDL-C level was not significantly related to any nutrients in the diet. The cholesterol levels of the lactovegetarians were compared with those of strict vegetarians. Lactovegetarians had 24% higher LDL-C levels and 7% higher HDL-C levels than strict vegetarians. Analysis within and among vegetarian populations suggests that ingestion of fatty dairy products raises the LDL-C level on a percentage basis about three times more than it raises the HDL-C level.

Adult↗

A novel dairy product fermented with Propionibacterium freudenreichii improves the riboflavin status of deficient rats.

OBJECTIVE: Riboflavin deficiency is common in many parts of the world, particularly in developing countries. The use of riboflavin-producing strains in the production of dairy products such as fermented milk, yogurt, and cheese is feasible and economically attractive because it would decrease the costs involved during conventional vitamin fortification and satisfy consumer demands for healthier foods. The present study in a rat bioassay assessed the response of administration of yogurt containing a riboflavin-producing strain of Propionibacterium freudenreichii on the riboflavin status of deficient rats. METHODS: Propionibacterium freudenreichii NIZO B2336 is a spontaneous roseoflavin-resistant mutant derived from P. freudenreichii B374 that produces larger amounts of riboflavin than the parental stain. Rats were fed a riboflavin-deficient diet for 21 d (depletion period), after which this same diet was supplemented with conventional yogurt, yogurt containing the riboflavin-producing strain (B2336), or the parental non-producing strain (B374) and fed to animals for 28 d (repletion period). As controls, rats were fed the same diet with different concentrations of commercial riboflavin. RESULTS: The novel fermented product containing P. freudenreichii B2336, with increased levels of riboflavin, eliminated most physiologic manifestations of ariboflavinosis such as stunted growth, high erythrocyte glutathione reductase activation coefficient values, and hepatomegaly that were observed when using a riboflavin depletion-repletion model, whereas the product fermented with the non-riboflavin-producing strain did not show this beneficial effect. CONCLUSIONS: Consumption of such products with increased levels of riboflavin on a regular basis may help prevent deficiencies of this essential vitamin.

Animals↗

Survey on mycoflora of cow and buffalo dairy products from Southern Italy.

Economic losses of dairy products due to spoilage by yeasts have been increasing in European companies because of the reduced use of preservatives, packaging in modified atmospheres, or new formulations that do not strictly control the growth of these organisms. This study reports the results of a survey of yeast species and populations in 145 samples of cow and buffalo dairy products collected in some regions of Southern Italy. Yeasts were isolated from 74% and 57% of cow and buffalo products, respectively. Candida inconspicua was the predominant species in unripened products from cow's milk, while C. famata was detected in medium and long-term ripened dairy products, mostly in association with other yeasts and with moulds belonging to the genus Penicillium. For dairy products produced from buffalo milk, C. inconspicua was the most important yeast frequently isolated from dairy products. Total yeast populations ranged from 5 x 10(2) to 5 x 10(5) cfu/g, indicating a good hygienic quality of the products. The isolation of C. albicans from one stracciatella sample is noteworthy, as this yeast represents a potential contamination by human. Even though yeasts are considered as environmental contaminants, the occurrence of some of them in dairy products at high levels could represent a risk for human health, in particular for immunocompromised patients.

Animals↗

Alkylating activity in food products--especially sauerkraut and sour fermented dairy products--after incubation with nitrite under quasi-gastric conditions.

N-Nitroso compounds may well rank high among the genotoxic carcinogens present in our environment. Small amounts of such compounds may be formed in the human stomach after consumption of high-nitrate vegetables. Volatile nitrosamines can be conveniently determined but reliable methods of analysis for non-volatile N-nitroso compounds are still lacking. In this study we have used the 4-(4-nitrobenzyl)pyridine test to look for the formation of alkylating compounds such as N-nitroso-N-methylurea in a wide range of food products after incubation with nitrite under simulated gastric conditions. Our results indicate that many food products do not form alkylating compounds in appreciable amounts, even though the nitrite concentration used was five to ten times that found in saliva after a high-nitrate meal. Comparatively strong alkylating activity, however, was detected after incubation of samples of sauerkraut, certain dairy products (yoghurt, biogarde, quark, buttermilk and milk), wine and smoked mackerel. Samples of sauerkraut incubated with simulated gastric fluid, but without (added) nitrite, also displayed appreciable alkylating activity. The formation of alkylating substances in non-fat yoghurt was markedly inhibited by addition of ascorbic acid. The identity of the alkylating agents remains unknown. The isolation procedure was optimized for N-nitroso-N-methylurea, but will certainly result in the isolation of other compounds, such as C-nitroso-, C-nitro- or perhaps even C-nitroso-C'-nitro-compounds as well. Biogenic amines, glucosinolates, indole derivatives or other compounds may be involved as precursors. If alkylating agents are formed in vivo after ingestion of high-nitrate vegetables or drinking water, this is likely to occur only when the food products mentioned above are ingested simultaneously with or shortly after the nitrate load and not appreciably (except perhaps in the case of sauerkraut) when they are ingested alone, without a nitrate source. The health implications of these findings cannot yet be established. Many alkylating agents, however, have strong carcinogenic properties and continued investigation of food products (and their interaction products with nitrite) is indicated.

Alkylating Agents↗

Phenotypic relationships between the interval from calving to first luteal activity and fertility in a seasonal dairy production system.

In seasonal dairy production systems a high level of reproductive performance is required to maintain a 365-day calving interval. Compared with many countries New Zealand dairy cattle are fertile, with an average calving interval of 368 days and first service conception rates of around 55%. However, fertility has been demonstrated to have declined over the past 15-years. An extended interval from calving to first luteal activity (CLA) has previously been identified as a major cause of infertility in New Zealand dairy cows. This paper investigates the phenotypic relationship between CLA and reproductive performance in a population of second cross FriesianxJersey dairy cattle. The data consists of 1780 lactations, from 801 individuals that were managed in a seasonal, pasture-based dairy production system. Overall, reproductive performance in the herd was high, with first service conception rates of over 60% and more than 80% of the herd pregnant within 42-days of the start of the breeding period. Animals were divided into six groups of at least 270 animals per group based on CLA (</=16, 17-20, 21-26, 27-34, 35-50, >50 days). First service conception rates and the interval from the start of mating to conception were not statistically different between the CLA groups (p>0.05), despite the number of oestrous cycles prior to first mating being inversely proportional to CLA. However, only 47% of animals with a CLA of >70 days (n=88) were pregnant within 21-day of the start of mating, compared with 65% of animals with CLA of <70 days. Animals that had not ovulated by 1-week prior to the start of mating also had reduced reproductive performance (45% versus 67% pregnant within 21-days of the start of mating, p<0.001). The poor reproductive performance of animals with CLA>70 days is likely to be due to a lower proportion of animals having ovulated by the start of mating (0.28 versus 0.95, p<0.001). Contrary to previous findings in non-seasonal production systems the length of CLA was not related to fertility, except when CLA was greater than 70 days.

Aging↗

[Mineral nutrient content in cow milk and dairy products in Argentina].

Cow milk and dairy products supply essential inorganic elements for humans, and constitute the most important source of bioavailable calcium in our diet. In order to obtain data about mineral nutrient composition of dairy products that are produced and sold in Argentina, the contents of Ca, P, Mg, Na, K, Fe, Zn and Cu in whole and low fat fluid milk, dried milk and yogurt were analyzed. P was assessed by a colorimetric method, and the other elements by atomic absorption spectroscopy. In raw milk, the mineral content shows a certain degree of variability, in addition to the variability introduced by the different processing conditions, in order to meet the requirements prescribed by trade regulations and to produce dairy products. In all cases, skimming increases the concentration of mineral nutrients, which is especially remarkable in Ca contained in skimmed milk powder. In yogurt, added milk solids like dried milk or evaporated milk appreciably increase the mineral content, even more so if ultrafiltrates are used. These ultrafiltrates increase the Ca/P ratio, which probably improves Ca bioavailability. The results obtained in these analyses provide data that are not yet available from the National Table of Food Composition, and which prove necessary and fundamental for nutritional and dietary evaluation.

Animals↗

Incidence and characterization of Bacillus cereus isolates contaminating dairy products.

A total of 293 dairy products purchased from local markets were examined to determine the incidence of and characterize Bacillus cereus. Isolations were made on mannitol-egg yolk-polymyxin B agar medium and confirmed by several staining and biochemical tests. B. cereus occurred in 17% of fermented milks, 52% of ice creams, 35% of soft ice creams, 2% of pasteurized milks and pasteurized fruit- or nut-flavored reconstituted milks, and 29% of milk powders, mostly in fruit- or nut-flavored milk mixes. The average population of B. cereus in these dairy products was 15 to 280 CFU/ml or CFU/g (range, 5 to 800). The characteristics of these B. cereus isolates in terms of heat resistance, biochemical reactions, and antibiotic susceptibility were similar to previously reported data except for a higher utilization of sucrose. Some isolates were especially resistant to carbenicillin, nalidixic acid, streptomycin, and tetracycline. The MICs for the isolates were also determined. All of the tested isolates lysed rabbit erythrocytes; 98% showed verotoxicity, 68% showed cytotonic toxicity for CHO cells, and 3 of 11 selected isolates that showed strong hemolysin activity killed adult mice.

Animals↗

[The effect of pesticides on dairy product quality].

Coming into the milk and dairy products from animals, pesticides exert a high effect on human health. Depending on the fatness of dairy products and a process, the levels of pesticide residues vary greatly. Toxic agents and their metabolic products are most completely removed by vacuum deodorization. Monitoring the levels of pesticides in the milk and dairy products requires introduction of new methods for determining toxic agents and use of well-studied and less toxic compounds.

Animals↗

Do dairy products induce bronchoconstriction in adults with asthma?

BACKGROUND: Dairy products have often been implicated as a cause of exacerbation of asthma, but there is little scientific evidence to support this hypothesis. OBJECTIVE: We sought to determine whether dairy products induce bronchoconstriction in a group of adults with asthma. METHODS: Twenty subjects with asthma (13 women and 7 men) were recruited from respondents who had previously completed a food and asthma questionnaire. Ten subjects perceived that their asthma became worse with ingestion of dairy products (positive perceivers), whereas ten were negative perceivers. None of the subjects had positive skin prick test results with cow's milk. The study was a randomized, cross-over, double-blind, placebo-controlled trial. Subjects complied with a dairy-free diet throughout the study. The active challenge was a single-dose drink equivalent to 300 ml of cow's milk. A positive reaction was defined as a 15% reduction in both FEV1 and peak expiratory flow (PEF) on the active challenge day compared with results obtained at the same time on the placebo day. RESULTS: For both FEV1 and PEF there were no statistically significantly differences in group means between active challenge and placebo challenge, between sequence of administration, or between perceptions. Nine subjects showed FEV1 or PEF changes that were greater than 15% of baseline values: four patients showed changes after both active and placebo treatment; two after treatment with placebo only; and three after active treatment alone. Of the latter group, two subjects showed changes only in PEF, and when one of these subjects underwent a further detailed study, no asthmatic reaction could be demonstrated. CONCLUSION: It is unlikely that dairy products have a specific bronchoconstrictor effect in most patients with asthma, regardless of their perception.

Adolescent↗

Consumption of dairy products and the risk of breast cancer: a review of the literature.

Differences in eating patterns and breast cancer rates across countries suggest that several dietary components, including dairy products, could affect breast cancer risk. However, dairy products are a diverse food group in terms of the factors that could potentially influence risk. Some dairy products, such as whole milk and many types of cheese, have a relatively high saturated fat content, which may increase risk. Moreover, milk products may contain contaminants such as pesticides, which have carcinogenic potential, and growth factors such as insulin-like growth factor I, which have been shown to promote breast cancer cell growth. In contrast, the calcium and vitamin D contents of dairy products have been hypothesized to reduce breast cancer risk. We reviewed the current epidemiologic literature on the relation between dairy product intakes and breast cancer risk, focusing primarily on the results of cohort and case-control studies. Most of the studies reviewed showed no consistent pattern of increased or decreased breast cancer risk with a high consumption of dairy products as a whole or when broken down into high-fat and low-fat dairy products, milk, cheese, or butter. Measurement error may have attenuated any modest association with dairy products. The available epidemiologic evidence does not support a strong association between the consumption of milk or other dairy products and breast cancer risk.

Adult↗

Evaluation of the stable reaction products of histidine with formaldehyde or with other carbonyl compounds in dairy products.

Combined formaldehyde (FA) can be evaluated in cheese and other dairy products by determining spinacine (6-carboxy-1,2,3,4-tetrahydroimidazopyridine), an imino acid arising from the reaction of FA with the alpha-amino group of histidine. Other carbonyl compounds usually produced by fermentations can react themselves with histidine, forming molecules which interfere with the determination of spinacine. A sensitive (minimum detectable amount, 5 fmol spinacine) and interference-free HPLC method, with precolumn derivatization with o-phtalaldehyde (OPA) and 9-fluorenylmethylchloroformate (FMOC), to evaluate these histidine reaction-compounds in dairy products is described. The clean-up of the FMOC-derivatized sample has been performed for the first time with solid-phase extraction (SPE) on an amino cartridge. The method was applied to samples of casein and differently ripened cheese, the origins of which were either known or commercial, in order to quantify the natural level of spinacine (0.7-2.7 ppm) probably deriving from biogenic FA, and to detect whether FA was used in processing.

Aldehydes↗

Freeze-substitution and low-temperature embedding of dairy products for transmission electron microscopy.

Dairy products are comprised largely of fat, air and water, which makes it difficult to preserve their ultrastructure for electron microscopy. Keeping the samples frozen throughout fixation and embedding protects the structure and distribution of the components of emulsions and foams. Therefore, dairy products were freeze-substituted and embedded at low temperature (-20 degrees C) to prepare them for transmission electron microscopy. Whipped cream, ice cream mix and dairy/non-dairy mixed systems were frozen by plunging in propane, at its boiling point (-187 degrees C). Ice cream, because it is already frozen, was fractured into 1-mm3 pieces in liquid nitrogen and then added to frozen fixative (-196 degrees C). Fixative solution consisted of glutaraldehyde, osmium tetroxide and uranyl acetate dissolved in either methanol or acetone. When material was to be stained after sectioning the fixative was limited to glutaraldehyde in methanol. The temperature was increased step-wise from -80 to -20 degrees C. Solvent was replaced with resin; the polar resin Lowicryl HM4, the non-polar resin Lowicryl HM20, LR White and LR Gold were tested. Samples were embedded and polymerized at -20 degrees C using ultraviolet light to cross-link the resin. Methanol proved to be the most effective solvent for substituting the ice; the hydrophobic resin Lowicryl HM20 was the most effective resin for retaining fat structure following osmium fixation.

Journal Article↗

Prospective studies of dairy product and calcium intakes and prostate cancer risk: a meta-analysis.

BACKGROUND: The Dietary Guidelines for Americans 2005 recommends that Americans increase their intake of dairy products. However, some studies have reported that increasing dairy product intake is associated with an increased risk of prostate cancer. We conducted a meta-analysis to examine associations between intakes of calcium and dairy products and the risk of prostate cancer. METHODS: We searched Medline for prospective studies published in English-language journals from 1966 through May 2005. We identified 12 publications that used total, advanced, or fatal prostate cancer as end points and reported associations as relative risks (RRs) with 95% confidence intervals (CIs) by category of dairy product or calcium intake. Data were extracted using standardized data forms. Random-effects models were used to pool study results and to assess dose-response relationships between dairy product or calcium intakes and the risk of prostate cancer. We conducted sensitivity analyses by changing criteria for inclusion of studies or by using fixed-effects models. All statistical tests were two-sided. RESULTS: Men with the highest intake of dairy products (RR =1.11 [95% CI = 1.00 to 1.22], P = .047) and calcium (RR = 1.39 [95% CI = 1.09 to 1.77], P = .018) were more likely to develop prostate cancer than men with the lowest intake. Dose-response analyses suggested that dairy product and calcium intakes were each positively associated with the risk of prostate cancer (Ptrend = .029 and .014, respectively). Sensitivity analyses generally supported these associations, although the statistical significance was attenuated. The pooled relative risks of advanced prostate cancer were 1.33 (95% CI = 1.00 to 1.78; P = .055) for the highest versus lowest intake categories of dairy products and 1.46 (95% CI = 0.65 to 3.25; P > .2) for the highest versus lowest intake categories of calcium. CONCLUSIONS: High intake of dairy products and calcium may be associated with an increased risk of prostate cancer, although the increase appears to be small.

Calcium, Dietary↗

Lymphatic fat absorption varies among rats administered dairy products differing in physiochemical properties.

We examined in rats the intestinal absorption of fat from dairy products differing in physiochemical properties. Five dairy products (cream cheese, cream, sour cream, butter, and mixed butter) with minor differences in fatty acid composition were administered by gavage to rats, and lymphatic fat absorption was examined. Absorption was followed for 8 h after administration of 300 mg fat from the dairy products. Administration of cream and sour cream resulted in faster lymphatic fat absorption than cream cheese, butter, and mixed butter, and at 8 h the accumulated absorption of fat was significantly higher. The lymphatic absorption of fat after cream cheese administration was similar to the absorption after butter and mixed butter administration up to the 4-h time point; then it increased to a level between that of rats administered cream or sour cream and butter or mixed butter. Overall, these results demonstrated different lymphatic absorption patterns of fat from dairy products differing in physiochemical properties. Because the fatty acid composition of the dairy products differed only slightly, other factors such as viscosity, type of emulsion, particle size, and likely also protein content may have contributed to the differences in absorption.

Absorption↗

Increased intake of dairy products is related to lower periodontitis prevalence.

BACKGROUND: An inverse association between calcium intake and periodontitis prevalence was recently reported. Dairy products are rich sources of calcium and other important nutrients. To date, it appears that the relationship between the intake of dairy products and periodontitis has not been investigated. The purpose of the present study was to examine whether or not there is an association between the intake of dairy products and periodontitis prevalence. METHODS: A total of 12,764 individuals who participated in the Third National Health and Nutrition Examination Survey were included in this study. Individuals who had at least one site with an attachment loss>or=3 mm and a probing depth>or=4 mm were considered to have periodontitis. The intake of dairy products was categorized into quintiles. Descriptive statistics and logistic regression models were used for data analyses. RESULTS: Prevalence of periodontitis was 41% lower for individuals in the highest quintile of intake of dairy products than those in the lowest quintile (P<0.001 for trend). After adjusting for known and suspected periodontitis risk factors (age, gender, race\ethnicity, cigarette smoking, education, diabetes, poverty index, vitamin use, body mass index, physical activity, time since the last dental visit, dental calculus, and gingival bleeding), individuals in the highest quintile of intake of dairy products were 20% less likely to have periodontitis than those in the lowest quintile (P=0.024 for trend). CONCLUSIONS: The results of this study showed an inverse association between the intake of dairy products and prevalence of periodontitis. Longitudinal and/or intervention studies are required to confirm these findings and to further examine the impact of a higher intake of dairy products on the prevention and treatment of periodontitis.

Adult↗

Migration of mineral hydrocarbons into foods. 2. Polystyrene, ABS, and waxed paperboard containers for dairy products.

Migration of mineral hydrocarbons into dairy products and sunflower oil (fatty food simulant) has been studied using a gas chromatographic procedure. The food contact materials examined were polystyrene and ABS pots and tubs, and waxed paperboard. Levels of mineral oil in the polystyrene and ABS articles ranged from 0.3 to 5.5% w/w (13 to 366 mg/dm2) and as a coating on the paperboard ranged from 1.0 to 7.7% (55 to 565 mg/dm2). Exposure conditions were 7 days at 4 degrees C for the dairy products and 10 days at 40 degrees C for the oil. However, individual serving milk and creams (UHT) were retail samples which were stored at ambient temperature before analysis. Migration into the milk products was less than 3 mg/kg. Transfer to sunflower oil simulant and into individual serving milk products was much higher at levels up to 150 mg/kg (2 mg/dm2) and 90 mg/kg (4 mg/dm2) for the oil and milk respectively.

Acrylic Resins↗