Nonfat Dairy Products Research Articles

Application of whey protein microparticulates in the production of ice cream and other dairy products

The aim of this paper is to systemize data on the use of whey protein microparticulates (WPMP) in production of ice cream and other dairy products. Information about the essence of the microparticulation process and methods for WPMP production is given. Data on the composition and physico-chemical properties of liquid and dry WPMP are presented. An effect of sizes of WPMP particles on quality characteristics of products made with their use is described. The majority of the analyzed studies indicate that the diameter of particles is 1.0–2.5 µm. However, contradictory data were obtained for this indicator — if the results of all studies are taken into consideration, a size of conglomerates can be 0.5 to 12 µm. These sizes are comparable with parameters of fat globules, which allow receptors of the human oral cavity to perceive them identically. Due to this, WPMP can be used as an imitator of milk fat. It is noted that the microparticulation process enables producing WPMP with targeted functional properties, namely, with particular characteristics by indicators “solubility”, “water holding capacity”, “gel formation”, “emulsifying and foam forming properties”. Information about the specific features of using and dosing WPMP in fermented milk products, such yogurt, kefir, curd cheese and cheese, is given. A special attention is paid to the results of the investigation of using WPMP in ice cream. It is noted that most often scientists used WPMP to make up for the sensation of fatness in defatted and nonfat dairy products. The ability of WPMP to increase the biological value of food products is highlighted. It has been concluded that WPMP enables formation of soft and elastic structure in low-fat dairy products, intensification of milky color and restriction of ice crystal growth in frozen desserts by binding and equally distributing moisture. The data were obtained about the clinical investigation of an effect of ice cream with WPMP on the health of children and adults. The negative effect of WPMP on the indicators of clinical analyses of humans and their health was not revealed.

Overview of Dairy-based Products with Probiotics: Fermented or Non-fermented Milk Drink.

Probiotic products have long been recognized for their health benefits. Additionally, milk has held a longstanding reputation as a dairy product that offers high-quality proteins and essential micronutrients. As awareness of the impact of food on health grows, interest in functional products such as probiotic dairy products is on the rise. Fermentation, a time-honored technique used to enhance nutritional value and food preservation, has been used for centuries to increase nutritional value and is one of the oldest food processing methods. Historically, fermented dairy products have been used as convenient vehicle for the consumption of probiotics. However, addressing the potential drawbacks of fermentation has recently led to increase in research on probiotic dairy drinks prepared without fermentation. These non-fermented dairy drinks have the advantage of maintaining the original flavors of milk drinks, containing potential health functional probiotics, and being an alternative dairy product that is helpful for probiotics intake. Currently, research on plant-based dairy products is rapidly increasing in the market. These developments might suggest the potential for novel forms of non-fermented dairy beverages with substantial prospects in the food market. This review aims to provide an overview of milk-based dairy beverages, both fermented and non-fermented, and discuss the potential of non-fermented dairy products. This exploration paves the way for innovative approaches to deliver probiotics and nutrition to consumers.

The relationship between fermented and nonfermented dairy products consumption and hypertension among premature coronary artery disease patients: Iran premature coronary artery disease study.

Dairy products may affect hypertension (HTN) risk. The aim of this study was to examine the association between fermented and nonfermented dairy foods and HTN in a sample of premature coronary artery disease (PCAD) subjects. This cross-sectional study was performed on 1854 PCAD patients. A 110-item food frequency questionnaire was used to assess dietary intakes. HTN was considered if systolic blood pressure was 140 mmHg and higher and/or diastolic blood pressure was 90 mmHg and higher. The odds ratio of HTN across the quartiles of different types of dairy products was evaluated by binary logistic regression. The mean (SD) of dairy products consumption was 339.8 (223.5) g/day, of which 285.4 g/day was fermented dairy products. In the crude model, participants in the fourth quartile of fermented dairy products had lesser risk of HTN compared to the bottom quartile (OR = 0.70, 95% CI: 0.52, 0.96; p for trend = .058). However, after considering the possible confounders, the significance disappeared. Subjects in the top quartile of high-fat fermented dairy products had 34% lower risk for HTN compared to the bottom quartile (95% CI: 0.49, 0.88; p for trend < .001). Adjustment for potential risk factors weakened the association but remained significant (OR = 0.73, 95% CI: 0.53, 1.01; p for trend = .001). Nonsignificant relation was detected between low-fat fermented, low-fat nonfermented, and high-fat nonfermented dairy products and HTN. Moderate consumption of high-fat fermented dairy products, in a population with low consumption of dairy foods, might relate to reduced likelihood of HTN.

Hybrid Cheeses—Supplementation of Cheese with Plant-Based Ingredients for a Tasty, Nutritious and Sustainable Food Transition

With increasing awareness of the impact of food on the climate, consumers are gradually changing their dietary habits towards a more plant-based diet. While acceptable products have been developed in meat analogues and non-fermented dairy products, alternative fermented dairy products such as yogurt and particularly ripened hard and semi-soft cheese products are not yet satisfactory. Since the cheese category has such a broad range of flavors and applications, it has proven complicated to find plant-based sources able to mimic them in terms of texture, meltability, ripening and flavor. Moreover, plant-based dairy alternatives do not provide the same nutritional supply. New technological approaches are needed to make cheese production more sustainable, which should be integrated in the already existing conventional cheese production to ensure a fast and cost-efficient transition. This can be tackled by incorporating plant-based components into the milk matrix, creating so-called “hybrid cheeses”. This review will discuss the challenges of both animal- and plant-based cheese products and highlight how the combination of both matrices can associate the best properties of these two worlds in a hybrid product, reviewing current knowledge and development on the matter. Emphasis will be drawn to the selection and pre-processing of raw materials. Furthermore, the key challenges of removing the off-flavors and creating a desirable cheese flavor through fermentation will be discussed.

Dairy product consumption and lung cancer risk: A prospective analysis

Current evidence on prospective associations between dairy product, dairy fat and lactose intakes and lung cancer risk is limited and inconsistent. We conducted a prospective analysis of associations of lung cancer risk with dairy product intakes in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) cohort. Pre-diagnostic dairy product intake was assessed through a validated Diet History Questionnaire. All incident lung cancer cases were pathologically verified. Multivariable Cox regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for associations of lung cancer risk with intakes of total, full-fat, low-fat dairy, fermented or non-fermented dairy products; milk fat content preference; and intakes of total and saturated fats and lactose from dairy products. Among 101,709 adults (mean age of 65.5 years), a total of 1583 lung cancer cases were identified during 1,167,239 person-years of follow up. Mean total dairy product intake was 156g/1000 kilocalories (kcal), including 20g/1000kcal from fermented dairy products. Total dairy intake was not associated with lung cancer risk (HR [95% CI]=1.03 [0.89-1.18]) comparing the highest quartile with the lowest. Fermented dairy intake was inversely associated with lung cancer risk (0.85 [0.72-0.99]). In contrast, there were no statistically significant associations with low-fat, full-fat or non-fermented dairy product intakes. The preference of whole milk when consuming milk as beverage was associated with a higher risk of lung cancer than the preference of <0.5% fat milk (1.24 [1.03-1.49]). Total fat, saturated fat and lactose intakes from dairy products each were not associated with lung cancer risk. Our results suggest an inverse association of lung cancer risk with fermented dairy intake and a positive association with the whole milk preference in a US population. Future studies exploring underlying molecular mechanisms are warranted.

Associations between total dairy, high-fat dairy and low-fat dairy intake, and depressive symptoms: findings from a population-based cross-sectional study

PurposeEvidence on the association between dairy intake and depression is conflicting. Given numerous dietary guidelines recommend the consumption of low-fat dairy products, this study examined associations between total dairy, high-fat dairy, and low-fat dairy intake and the prevalence of elevated depressive symptoms. Associations between dairy products, which differed in both fat content and fermentation status, and depressive symptoms were also explored.MethodsThis cross-sectional study included 1600 Finnish adults (mean age 63 ± 6 years; 51% female) recruited as part of the Kuopio Ischaemic Heart Disease Risk Factor Study. Dairy intake was assessed using 4-day food records. Elevated depressive symptoms were defined as having a score ≥ 5 on the Diagnostic and Statistical Manual of Mental Disorders-III Depression Scale, and/or regularly using one or more prescription drugs for depressive symptoms.ResultsIn total, 166 participants (10.4%) reported having elevated depressive symptoms. Using multivariate logistic regression models, intake in the highest tertile of high-fat dairy products (OR 0.64, 95% CI 0.41–0.998, p trend = 0.04) and high-fat non-fermented dairy products (OR 0.60, 95% CI 0.39–0.92, p trend = 0.02) were associated with reduced odds for having elevated depressive symptoms. Whereas no significant association was observed between intake of total dairy, low-fat dairy, or other dairy products, and depressive symptoms.ConclusionHigher intake of high-fat dairy and high-fat non-fermented dairy products were associated with reduced odds for having elevated depressive symptoms in middle-aged and older Finnish adults. Given the high global consumption of dairy products, and widespread burden of depression, longitudinal studies that seek to corroborate these findings are required.

Associations of Dairy Consumption and Cognitive Function in the Boston Puerto Rican Health Study

ObjectivesTo examine the cross-sectional and prospective associations between dairy consumption and cognitive function among Puerto Rican adults.MethodsData are from the Boston Puerto Rican Health Study (57 yrs, 71% female), an ongoing prospective cohort study. Diet was assessed using a validated food frequency questionnaire. Dairy products included milk, cheese, yogurt, cream, and butter. Our dairy exposures were total dairy (s/d), regular & reduced fat dairy (s/d), and nonfat dairy products (s/d). A battery of neurocognitive tests was administered by trained staff in the language of preference. Global cognitive function score (GCS) was calculated as the mean z-scores of the individual tests. A subset of BPRHS participants returned for neurocognitive testing at 13-yr follow-up. For the current study, we examined the baseline cross-sectional associations between dairy and GCS (n = 1067) and the prospective associations of dairy consumption (averaged of baseline and 2-yr FFQ data) with GCS at 13 years (n = 433). Multivariable linear regression models were adjusted for age, sex, education, smoking, physical activity, energy intake, and consumption of fruits and vegetables and added sugar. Baseline GCS was additionally included in prospective models. Dairy variables were skewed, and a log-transformation was applied.ResultsAverage dairy consumption for total, regular & reduced fat dairy, and nonfat dairy was 2.2 s/d, 1.9, s/d, and 0.3 s/d, respectively. In cross-sectional analyses, total [β = 0.078 (0.033, 0.124), P = 0.001] and reduced & regular fat dairy [0.066 (0.020, 0.112), P = 0.005] were positively associated with GCS. Nonfat dairy was not significantly associated [0.015 (−0.001, 0.033), P = 0.210]. In prospective analyses, we observed null associations between total [−0.0134 (−0.094, 0.067), P = 0.740], regular & reduced-fat [−0.039 (−0.123, 0.046), P = 0.370], and nonfat dairy [0.0027 (−0.020, 0.026), P = 0.820] and 13-yr GCS.ConclusionsIn this cohort of Puerto Rican adults, total and regular & reduced-fat dairy was associated with greater global cognitive function in cross-sectional analyses at baseline, but not after 13 years of follow-up. Additional prospective analyses are warranted to clarify these associations.Funding SourcesNational Institute on Aging.

Associations of fermented and non-fermented dairy consumption with serum C-reactive protein concentrations - A cross-sectional analysis.

The results of epidemiological studies on dairy products and low-grade inflammation are scarce and inconsistent. Some studies have suggested that the associations may vary depending on the type of dairy product consumed. The aim of this cross-sectional study was to investigate the associations between intake of fermented and non-fermented dairy products and separately butter and serum high-sensitivity C-reactive protein (hs-CRP), a common inflammation marker, among a population with high dairy intake. The study included 1338 generally healthy men aged 42-60 years and serum hs-CRP ≤10mg/L from the Kuopio Ischaemic Heart Disease Risk Factory Study, examined in 1984-1989. Dietary intakes were assessed using 4-day food records. ANCOVA and linear and logistic regression were used for analyses. The reported mean intakes of fermented and non-fermented dairy products and butter were 189 (SD 217), 522 (SD 330) and 33 (SD 27) g/d, respectively. In the model adjusted for age, year of examination and energy intake (Model 1), higher intake of total dairy, total non-fermented dairy, total milk and butter were associated with higher concentration of serum hs-CRP, whereas fermented dairy intake was not associated with serum hs-CRP. After further adjustment for potential confounders, only higher butter intake remained statistically significantly associated with increased serum hs-CRP (P-trend=0.049). The odds ratio for elevated hs-CRP (>3mg/L) in the highest vs. the lowest quartile was 2.50 (95% confidence interval 1.19-5.26, P-trend=0.02). These results suggest that high intake of butter, but not other dairy products may be associated with increased low-grade inflammation.

Associations of Calcium Intake and Calcium from Various Sources with Blood Lipids in a Population of Older Women and Men with High Calcium Intake.

Promoting calcium intake is a cornerstone for osteoporosis management. Some individuals limit dairy product consumption, a major calcium source, due to their high content in saturated fats and their perceived negative impact on lipid profiles. This study explored the associations of calcium from various sources with blood lipids in community-dwelling elderly (n = 717) from the GERICO cohort. Dietary calcium intake was assessed at several timepoints using a validated food frequency questionnaire (FFQ) and calcium supplement use was recorded. Blood lipids were treated as categorical variables to distinguish those with normal and abnormal levels. Increasing total calcium intake was associated with lower risks for high total cholesterol (p = 0.038) and triglycerides (p = 0.007), and low HDL-cholesterol (p = 0.010). Dairy calcium (p = 0.031), especially calcium from milk (p = 0.044) and milk-based desserts (p = 0.039), i.e., low-fat (p = 0.022) and non-fermented (p = 0.005) dairy products, were associated with a lower risk of high total cholesterol. Greater calcium intakes from total dairies (p = 0.020), milk (p = 0.020) and non-fermented dairies (p = 0.027) were associated with a lower risk of hypertriglyceridemia. No association was observed between calcium from non-dairy sources, cheese or high-fat dairies and blood lipids. Increasing calcium through supplements was associated with lower risks for hypertriglyceridemia (p = 0.022) and low HDL-cholesterol (p = 0.001), but not after adjustments. Our results suggest that higher calcium intakes from dietary sources or supplements are not adversely associated with blood lipids in the elderly, whilst total, and particularly low-fat, dairy products are valuable calcium sources potentially related to favorable lipid profiles.

The relationship between dairy products intake and breast cancer incidence: a meta-analysis of observational studies

BackgroundThe effect of dairy products intake on breast cancer (BC) is highly controversial. This study aims to investigate the relationship between dairy intake and BC incidence.MethodsA search was carried out in PubMed, EBSCO, Web of Science, and Cochrane Library databases before January 2021. The primary objective was the risk of BC and intake of dairy products were exposure variables.ResultsThe meta-analysis comprised 36 articles with 1,019,232 participants. Total dairy products have a protective effect on female population (hazard ratio (HR) =0.95, 95% confidence interval (CI) =0.91–0.99, p = 0.019), especially for estrogen receptor-positive (ER+) (HR = 0.79, p = 0.002) and progesterone receptor-positive (PR+) BC (HR = 0.75, p = 0.027). For ER+/PR+ BC, there is a trend of protection, but it has not reached statistical significance (HR = 0.92, p = 0.075). Fermented dairy products can reduce BC risk in postmenopausal population (HR = 0.96, 95%CI = 0.93–0.99, p = 0.021), but have no protective effect on premenopausal population (HR = 0.98, 95%CI = 0.94–1.03, p = 0.52). Non-fermented dairy products have no significant effect on BC occurrence (p > 0.05). High-fat dairy products are harmful to women, without statistical difference (HR = 1.06, 95%CI = 1.00–1.13, p = 0.066). On the contrary, low-fat dairy products can protect the premenopausal population (HR = 0.94, 95%CI = 0.89–1.00, p = 0.048).ConclusionThe intake of dairy products can overall reduce BC risk in the female population, but different dairy products have varying effects on different BC subtypes and menopausal status.

Broadening the antimicrobial spectrum of nisin-producing Lactococcus lactis subsp. Lactis to Gram-negative bacteria by means of active packaging

Cast films obtained from polyvinyl alcohol (PVOH) blended with casein hydrolysates (HCas) in a weight ratio of 1:1 were employed to carry nisin-producing L. lactis and phytic acid in order to broaden the antimicrobial spectrum of L. lactis to Gram-positive and Gram-negative spoilage and pathogen bacteria. For this purpose, the effect of the antimicrobial activity of various film formulations and combinations of films on the growth of E. coli at 37 °C for 24 h was studied. The film system that showed antimicrobial activity against Gram-negative bacteria consisted of phytic acid and L. lactis incorporated in separate films. When the active agents were in the same film the viability of L. lactis decreased considerably and it did not exert antimicrobial activity against the bacterium. Therefore, the combination of L. lactis and phytic acid in separate films was chosen as the reliable system, and the effect of its activity on the growth of Gram-negative bacteria (E. coli, Salmonella enterica, and Pseudomonas fluorescens) and Gram-positive bacteria (Listeria monocytogenes) in liquid culture medium was tested at refrigeration temperature (4 °C), and with simulated breaks in the cold chain (14 °C and 24 °C). The survival of L. lactis in coexistence with these bacteria was also studied. The film system exerted an antimicrobial effect against the Gram-negative bacteria tested, and the activity depended on the bacteria and the temperature assayed. With regard to the antimicrobial activity against L. monocytogenes, phytic acid improved the antimicrobial capacity of L.lactis. The survival of L. lactis was maintained at 7–8 log (CFU/mL) culture in liquid medium throughout the storage period.The films developed were intended to be used as coatings in the design of a double-sided active bag for a non-fermented dairy product. The bags were filled with homemade preservative-free pastry cream, and the microbiological shelf life and evolution of pH of the packaged ready-to-eat food stored at 4 °C was studied for 20 days. The results showed a reduction in the growth of spoilage bacteria and therefore an increase in the shelf life of the packaged product. The films developed could be applied in the design of packages for perishable dairy foods in order to increase their microbiological shelf life.

Incorporation of omega-3 fatty acid-rich grape seed oil in yoghurt: Response surface optimization of physicochemical, textural, and sensory attributes during refrigerated storage.

The demand for consuming low‐fat or nonfat dairy products, especially fat‐free yoghurt, has increased considerably because of the effects of high‐fat diet on human health during the two past decades. Generally, consumers prefer low‐fat products to the same high‐fat products. For this reason, manufacturers are looking for an ideal source for replacing fat substitute. In this research, the effect of grape seed oil (GSO) as a fat replacement on different quality attributes of the produced set yoghurt was determined. The effect of diverse ratios (3:0, 1.5:1.5, and 0.5:3%) of milk fat and GSO on the change in the quality attributes of the set yoghurt for up to 22 days of refrigeration period (4 ± 1°C) was investigated. Statistical analysis revealed that increase in GSO concentration leads to a significant increase (p < .05) in viscosity, acidity, and water‐holding capacity (WHC), whereas syneresis and pH value decreased during the storage time. Furthermore, increasing the proportion of fat replacement to 3% (w/w) in set yoghurt increased the samples hardness while in case of cohesiveness; negative effect was observed because of the action of fat globules within the protein system. Result of fatty acid analysis revealed that the yoghurt samples containing GSO have higher unsaturated fatty acid content than the control yoghurt sample. In conclusion, the best fat replacement concentration of GSO in producing low‐fat yoghurt was found in 1.5%, which also had the highest overall acceptance score between different yoghurt samples containing different levels of GSO.

Intake of Fermented Dairy Products Induces a Less Pro-Inflammatory Postprandial Peripheral Blood Mononuclear Cell Gene Expression Response than Non-Fermented Dairy Products: A Randomized Controlled Cross-Over Trial.

It is aimed to investigate how intake of high-fat meals composed of different dairy products with a similar fat content affects postprandial peripheral blood mononuclear cell (PBMC) expression of inflammation-related genes, as well as circulating inflammatory markers and metabolites. Healthy subjects (n = 47) consume four different high-fat meals composed of either butter, cheese, whipped cream, or sour cream in a randomized controlled cross-over study. Fasting and postprandial PBMC gene expression, plasma metabolites, and circulating inflammatory markers are measured. Using a linear mixed model, it is found that expression of genes related to lymphocyte activation, cytokine signaling, chemokine signaling, and cell adhesion is differentially altered between the four meals. In general, intake of the fermented products cheese and sour cream reduces, while intake of the non-fermented products butter and whipped cream increases, expression of these genes. Plasma amino acid concentrations increase after intake of cheese compared to the other meals, and the amino acid changes correlate with several of the differentially altered genes. Intake of fermented dairy products, especially cheese, induces a less inflammatory postprandial PBMC gene expression response than non-fermented dairy products. These findings may partly explain inconsistent findings in studies on health effects of dairy products.

Educational and nutritional status of the adult population of the Russian Federation. The results of an epidemiological study ESSE-RF

Educational status affects the nature of nutrition. Aim. To study the differences in the nutrition pattern of the adult population of the Russian Federation, depending on the educational qualification. Material and methods . The analysis includes the results of a survey of representative samples of male and female population aged 25-64 years (19,520 people, of which 7,329 men and 12,191 women) from 13 regions of the Russian Federation. The nature of the diet was evaluated by the frequency of consumption of the main groups of products and individual eating habits (supplementation, the use of animal fats in cooking). Results. Men of high literacy have higher consumption of raw vegetables and fruits — by 20%, dairy products — by 14%, including cheese — by 15%. There is also a lower consumption of meat and sausage products — by 17%, pickles — by 12% and poultry — by 11%. Less commonly, there is an adding more salt habit — by 18% and the use of animal fats in cooking — by 10%, more often — the consumption of low-fat and non-fat dairy products — by 22%, as well as raw sugar in an amount not exceeding 5% of the daily calorie content — by 21% The level of consumption of red meat, cereals and pasta, legumes, sweets, cottage cheese, sour cream and cream showed no significant differences with men of a different educational status. Women of high educational status more often include vegetables and fruits in their daily diet — by 14%, dairy products — by 18%, including cheese — by 15%. Less often they consume butter — by 12%, as well as foods with a high salt content: meat and sausage products — by 22% and pickles, marinades — by 15%. Russians with “above average” education are less likely to add more salt — by 14% and use animal fats in cooking — by 14%, more often they choose low-fat and nonfat dairy products — by 21%. In the level of consumption of red meat, cereals and pasta, legumes, sour cream and cream, there were no differences. Conclusion. People with a high literacy in the Russian population regardless of gender differences have a more protective diet compared to people with a low educational status. ESSE-RF study participants and article co-authors: Moscow: Zhernakova Yu. V., Boytsov S. A., St. Petersburg: Rotar O. P., Vladivostok: Kulakova N. V., Nevzorova V. A., Vladikavkaz: Astakhova Z. T., Vologda: Shabunova A. A., Volgograd: Nedogoda S. V., Voronezh: Chernykh T. M., Ivanovo: Belova O. A., Kemerovo: Artamonova G. V., Indukaeva E. V., Krasnoyarsk: Grinshtein Yu. I., Petrova M. M., Orenburg: Libis R. A., Samara: Duplyakov D. V., Tomsk: Trubacheva I. A., Kaveshnikov V. S., Serebryakova V. N., Tyumen: Efanov A. Yu., Medvedeva I. V., Shalaev S. V.

Physical, chemical, and microstructural properties of nonfat yogurts fortified with the addition of tara gum alone or in combination with buttermilk powder

Finding proper milk fat substitutes for manufacturing of nonfat dairy products is a major challenge for dairy industry in order to respond the consumer' demands. Three different concentrations of tara gum (TG) and three combinations of TG with buttermilk powder (BP) were used as fat replacers for manufacturing of nonfat yogurt. Use of TG (0.25 and 0.50/gl) and a combination of TG (0.25/gl) and BP (10/gl) decreased whey separation while improved the gel firmness and viscosity of nonfat yogurt (p < .05). Denser microstructure observed in nonfat yogurts fortified with TG (0.25 and 0.50/gl) and combination of TG and BP (0.25 + 10/gl). Significant changes were observed in pH and viscosity of yogurts (p < .05) during storage. In conclusion, fortification of nonfat yogurt with specific concentrations of TG or combination of TG and BP had positive effect on quality properties of the product. Practical applications Low-fat or nonfat yogurts have been preferred by consumers in recent years because of health concerns. However, nonfat products have quality defects due to the lack of milk fat. For this purpose, TG and BP as fat replacers at different rates for the production of nonfat yogurt were used in this research. Use of TG and BP changed yogurt's physicochemical characteristics and caused relatively denser microstructures. With this study, combined use of TG and BP provided the improvement of nonfat yogurt product.

New Term to Quantify the Effect of Temperature on pH min -Values Used in Cardinal Parameter Growth Models for Listeria monocytogenes.

The aim of this study was to quantify the influence of temperature on pHmin-values of Listeria monocytogenes as used in cardinal parameter growth models and thereby improve the prediction of growth for this pathogen in food with low pH. Experimental data for L. monocytogenes growth in broth at different pH-values and at different constant temperatures were generated and used to determined pHmin-values. Additionally, pHmin-values for L. monocytogenes available from literature were collected. A new pHmin-function was developed to describe the effect of temperatures on pHmin-values obtained experimentally and from literature data. A growth and growth boundary model was developed by substituting the constant pHmin-value present in the Mejlholm and Dalgaard (2009) model (J. Food. Prot. 72, 2132–2143) by the new pHmin-function. To obtain data for low pH food, challenge tests were performed with L. monocytogenes in commercial and laboratory-produced chemically acidified cheese including glucono-delta-lactone (GDL) and in commercial cream cheese. Furthermore, literature data for growth of L. monocytogenes in products with or without GDL were collected. Evaluation of the new and expanded model by comparison of observed and predicted μmax-values resulted in a bias factor of 1.01 and an accuracy factor of 1.48 for a total of 1,129 growth responses from challenge tests and literature data. Growth and no-growth responses of L. monocytogenes in seafood, meat, non-fermented dairy products, and fermented cream cheese were 90.3% correctly predicted with incorrect predictions being 5.3% fail-safe and 4.4% fail-dangerous. The new pHmin-function markedly extended the range of applicability of the Mejlholm and Dalgaard (2009) model from pH 5.4 to pH 4.6 and therefore the model can now support product development, reformulation or risk assessment of food with low pH including chemically acidified cheese and cream cheese.

Effects of full-fat dairy products on subclinical vascular function in adults with elevated blood pressure: a randomized clinical trial.

High consumption of low- and non-fat dairy products improves vascular dysfunction associated with elevated arterial blood pressure (BP). Currently, it is unknown if conventional full-fat dairy products improve vascular functions. To determine if adding whole milk and full-fat dairy products to the normal routine diet improves vascular function in adults with elevated BP. Sixty adults (age ± SEM; 58 ± 2 years) with elevated BP (systolic/diastolic; 120-159/ < 99 mmHg) were randomized into a controlled crossover intervention trial consisting of two 4-week dietary periods. The high dairy condition consisted of adding four daily servings of whole milk or full-fat dairy products to the normal diet and eliminated all dairy intake during the control (no dairy) condition. A 2-week washout period separated the dietary conditions. Carotid-femoral pulse wave velocity (cfPWV) did not differ significantly between high dairy (11.3 ± 0.3 versus 10.9 ± 0.3 m/sec) and no dairy conditions (11.2 ± 0.3 versus 11.0 ± 0.3 m/sec). The results were consistent when ultrasound-derived vascular distension measures (arterial compliance, beta-stiffness index, and elastic modulus) were evaluated. Cardiovagal baroreceptor sensitivity (via Valsalva maneuver) demonstrated no significant difference for either dietary condition. Brachial arterial flow-mediated dilation (FMD) did not differ significantly during the high dairy (5.7 ± 0.5 versus 5.4 ± 0.6%) and no dairy conditions (6.5 ± 0.5 versus 5.6 ± 0.6%). The solitary addition of whole milk and full-fat dairy products has no effect on subclinical vascular function in adults with elevated BP.

High dietary intake of whole milk and full-fat dairy products does not exert hypotensive effects in adults with elevated blood pressure

Regular consumption of low- and nonfat dairy products reduces blood pressure (BP) in adults with elevated BP. Currently, it is unknown if conventional full-fat dairy products exert similar hypotensive effects. We hypothesized that adding full-fat dairy products to the normal routine diet would reduce seated office and ambulatory BP (primary outcome) in adults with elevated BP when compared with a no dairy control. Using a randomized controlled crossover design, 60 adults with elevated systolic BP (systolic/diastolic BP: 120-159/<99 mm Hg) participated in a 4-week high-dairy (4 servings a day of full-fat dairy products + regular diet) and a 4-week no-dairy condition (plant-based food items + regular diet) separated by a 2-week washout period. Data were analyzed based on time, condition, and sex. Seated office systolic BP did not change significantly in either condition. There were no changes in systolic BP in male or female participants across either dietary period. Ambulatory (24-hour) systolic BP did not change significantly in the high-dairy (133 ± 2 vs 131 ± 1 mm Hg) or no-dairy conditions (132 ± 2 vs 131 ± 1 mm Hg). No significant changes were observed for diastolic BP or pulse pressure during condition for office or ambulatory measures. The solitary addition of full-fat dairy products to the normal routine diet does not exert hypotensive effects in adults with elevated BP when compared to the no-dairy control.

Intake of fermented and non-fermented dairy products and risk of incident CHD: the Kuopio Ischaemic Heart Disease Risk Factor Study.

Recent dairy product studies have suggested that fermented rather than non-fermented dairy products might provide benefits on cardiovascular health, but the evidence is inconclusive. Therefore, we investigated whether fermented and non-fermented dairy products have distinct associations with the risk of incident CHD in a population with high dairy product intake. The present study included a total of 1981 men, aged 42-60 years, from the Kuopio Ischaemic Heart Disease Risk Factor Study, with no CHD at baseline. Dietary intakes were assessed with instructed 4-d food records. We used Cox's proportional hazards regression model to estimate the associations with the risk of CHD. Fatal and non-fatal CHD events were ascertained from national registries. During a mean follow-up of 20·1 years, 472 CHD events were recorded. Median intakes were 105 g/d for fermented (87 % low-fat products) and 466 g/d for non-fermented dairy products (60 % low-fat products). After adjusting for potential confounders, those in the highest (v. lowest) intake quartile of fermented dairy products had 27 % (95 % CI 5, 44; P-trend=0·02) lower risk of CHD. In contrast, those in the highest intake quartile of non-fermented dairy products had 52 % (95 % CI 13, 104; P-trend=0·003) higher risk of CHD. When analysed based on fat content, low-fat (<3·5 % fat) fermented dairy product intake was associated with lower risk (hazard ratio in the highest quartile=0·74; 95 % CI 0·57, 0·97; P-trend=0·03), but high-fat fermented dairy and low-fat or high-fat non-fermented dairy products had no association. These results suggest that fermented and non-fermented dairy products can have opposite associations with the risk of CHD.

Dairy product consumption is associated with pre-diabetes and newly diagnosed type 2 diabetes in the Lifelines Cohort Study.

Previous studies show associations between dairy product consumption and type 2 diabetes, but only a few studies conducted detailed analyses for a variety of dairy subgroups. Therefore, we examined cross-sectional associations of a broad variety of dairy subgroups with pre-diabetes and newly diagnosed type 2 diabetes (ND-T2DM) among Dutch adults. In total, 112 086 adults without diabetes completed a semi-quantitative FFQ and donated blood. Pre-diabetes was defined as fasting plasma glucose (FPG) between 5·6 and 6·9 mmol/l or HbA1c% of 5·7-6·4 %. ND-T2DM was defined as FPG ≥7·0 mmol/l or HbA1c ≥6·5 %. Logistic regression analyses were conducted by 100 g or serving increase and dairy tertiles (T1ref), while adjusting for demographic, lifestyle and dietary covariates. Median dairy product intake was 324 (interquartile range 227) g/d; 25 549 (23 %) participants had pre-diabetes; and 1305 (1 %) had ND-T2DM. After full adjustment, inverse associations were observed of skimmed dairy (OR100 g 0·98; 95 % CI 0·97, 1·00), fermented dairy (OR100 g 0·98; 95 % CI 0·97, 0·99) and buttermilk (OR150 g 0·97; 95 % CI 0·94, 1·00) with pre-diabetes. Positive associations were observed for full-fat dairy (OR100 g 1·003; 95 % CI 1·01, 1·06), non-fermented dairy products (OR100 g 1·01; 95 % CI 1·00, 1·02) and custard (ORserving/150 g 1·13; 95 % CI 1·03, 1·24) with pre-diabetes. Moreover, full-fat dairy products (ORT3 1·16; 95 % CI 0·99, 1·35), non-fermented dairy products (OR100 g 1·05; 95 % CI 1·01, 1·09) and milk (ORserving/150 g 1·08; 95 % CI 1·02, 1·15) were positively associated with ND-T2DM. In conclusion, our data showed inverse associations of skimmed and fermented dairy products with pre-diabetes. Positive associations were observed for full-fat and non-fermented dairy products with pre-diabetes and ND-T2DM.