Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
3,097
result(s) for
"Cheese Microbiology."
Sort by:
Reinventing the wheel : milk, microbes, and the fight for real cheese
\"Reinventing the Wheel is equal parts popular science, history, and muckraking. Over the past hundred and fifty years, dairy farming and cheesemaking have been transformed, and this book explores what has been lost along the way. Today, using cutting-edge technologies like high-throughput DNA sequencing, scientists are beginning to understand the techniques of our great-grandparents. The authors describe how geneticists are helping conservationists rescue rare dairy cow breeds on the brink of extinction, microbiologists are teaching cheesemakers to nurture the naturally occurring microbes in their raw milk rather than destroying them, and communities of cheesemakers are producing \"real\" cheeses that reunite farming and flavor, rewarding diversity and sustainability at every level.\"--Provided by publisher.
Book
Hypocaloric diet supplemented with probiotic cheese improves body mass index and blood pressure indices of obese hypertensive patients - a randomized double-blind placebo-controlled pilot study
BACKGROUND: Gut lactobacilli can affect the metabolic functions of healthy humans. We tested whether a 1500 kcal/d diet supplemented with cheese containing the probiotic Lactobacillus plantarum TENSIA (Deutsche Sammlung für Mikroorganismen, DSM 21380) could reduce some symptoms of metabolic syndrome in Russian adults with obesity and hypertension. METHODS: In this 3-week, randomized, double-blind, placebo-controlled, parallel pilot study, 25 subjects ingested probiotic cheese and 15 ingested control cheese. Fifty grams of each cheese provided 175 kcal of energy. Blood pressure (BP), anthropometric characteristics, markers of liver and kidney function, metabolic indices (plasma glucose, lipids, and cholesterol), and urine polyamines were measured. Counts of fecal lactobacilli and L. plantarum TENSIA were evaluated using molecular methods. The data were analyzed by t-test for independent samples and Spearman’s partial correlation analysis. RESULTS: The probiotic L. plantarum TENSIA was present in variable amounts (529.6 ± 232.5 gene copies) in 16/25 (64%) study subjects. Body mass index (BMI) was significantly reduced (p = 0.031) in the probiotic cheese group versus the control cheese group. The changes in BMI were closely associated with the water content of the body (r = 0.570, p = 0.0007) when adjusted for sex and age. Higher values of intestinal lactobacilli after probiotic cheese consumption were associated with higher BMI (r = 0.383, p = 0.0305) and urinary putrescine content (r = 0.475, p = 0.006). In patients simultaneously treated with BP-lowering drugs, similar reductions of BP were observed in both groups. A positive association was detected between TENSIA colonization and the extent of change of morning diastolic BP (r = 0.617, p = 0.0248) and a trend toward lower values of morning systolic BP (r = −0.527, p = 0.0640) at the end of the study after adjusting for BMI, age, and sex. CONCLUSION: In a pilot study of obese hypertensive patients, a hypocaloric diet supplemented with a probiotic cheese helps to reduce BMI and arterial BP values, recognized symptoms of metabolic syndrome. TRIAL REGISTRATION: Current Controlled Trials ISRCTN76271778
Journal Article
Probiotics Reduce the Prevalence of Oral Candida in the Elderly : a Randomized Controlled Trial
Overgrowth of oral yeast is a common problem among the elderly. Probiotic bacteria are known to inhibit the growth of pathogenic microbes. We tested the hypothesis that cheese containing probiotic bacteria can reduce the prevalence of oral Candida. During this 16-week, randomized, double-blind, placebo-controlled study, 276 elderly people consumed daily 50 g of either probiotic (n = 136) or control cheese (n = 140). The primary outcome measure was the prevalence of a high salivary yeast count (≥ 104 cfu/mL) analyzed by the Dentocult® method. The prevalence decreased in the probiotic group from 30% to 21% (32% reduction), and increased in the control group from 28% to 34%. Probiotic intervention reduced the risk of high yeast counts by 75% (OR = 0.25, 95%CI 0.10–0.65, p = 0.004), and the risk of hyposalivation by 56% (OR = 0.44, 95%CI 0.19–1.01, p = 0.05). Thus, probiotic bacteria can be effective in controlling oral Candida and hyposalivation in the elderly.
Journal Article
Effect of pH and Water Activity on the Growth Limits of Listeria monocytogenes in a Cheese Matrix at Two Contamination Levels
Listeria monocytogenes can proliferate at the beginning of cheesemaking as the conditions favor growth. The objective of this study was to establish the growth limits of L. monocytogenes in a cheese matrix, in case of potential contamination of the milk prior to cheese manufacture. A semisoft laboratory scale model cheese system was made at different initial pH and water activity (a(w)) levels with a mix of two strains of L. monocytogenes. A factorial design of five pH values (5.6 to 6.5), four a(w) values (0.938 to 0.96), and two L. monocytogenes inoculation levels (1 to 20 CFU/ml and 500 to 1,000 CFU/ml) was carried out. Each combination was evaluated in six independent replicates. In order to determine if there was a dominant strain, isolated colonies from the cheeses were analyzed by pulsed-field gel electrophoresis. The data relating to growth initiation were fitted to a logistic regression model. The a(w) of milk influenced the probability of growth initiation of L. monocytogenes at both low and high contamination levels. The pH, at the concentrations tested, had a lower effect on the probability of growth initiation. At pH 6.5 and a(w) of 0.99 for low contamination levels and pH 6.5 and a(w) of 0.97 for high contamination levels, increases in population of up to 4 and 2 log were observed at low and high contamination levels, respectively. This shows that if conditions are favorable for growth initiation at the early stages of the cheesemaking process, contamination of milk, even with low numbers, could lead to L. monocytogenes populations that exceed the European Union's microbiological limit of 100 CFU/g of cheese.
Journal Article
Fermentation of plant‐based dairy alternatives by lactic acid bacteria
Summary Ethical, environmental and health concerns around dairy products are driving a fast‐growing industry for plant‐based dairy alternatives, but undesirable flavours and textures in available products are limiting their uptake into the mainstream. The molecular processes initiated during fermentation by lactic acid bacteria in dairy products is well understood, such as proteolysis of caseins into peptides and amino acids, and the utilisation of carbohydrates to form lactic acid and exopolysaccharides. These processes are fundamental to developing the flavour and texture of fermented dairy products like cheese and yoghurt, yet how these processes work in plant‐based alternatives is poorly understood. With this knowledge, bespoke fermentative processes could be engineered for specific food qualities in plant‐based foods. This review will provide an overview of recent research that reveals how fermentation occurs in plant‐based milk, with a focus on how differences in plant proteins and carbohydrate structure affect how they undergo the fermentation process. The practical aspects of how this knowledge has been used to develop plant‐based cheeses and yoghurts is also discussed. The mechanisms of fermentation by lactic acid bacteria are reviewed in relation to plant‐based dairy alternatives. Particular attention is paid to proteolytic and carbohydrate metabolism systems, and how these have been studied in plant‐based dairy alternative products is discussed.
Journal Article
Beneficial bile acid metabolism from Lactobacillus plantarum of food origin
Bile acid (BA) signatures are altered in many disease states. BA metabolism is an important microbial function to assist gut colonization and persistence, as well as microbial survival during gastro intestinal (GI) transit and it is an important criteria for potential probiotic bacteria. Microbes that express bile salt hydrolase (BSH), gateway BA modifying enzymes, are considered to have an advantage in the gut. This property is reported as selectively limited to gut-associated microbes. Food-associated microbes have the potential to confer health benefits to the human consumer. Here, we report that food associated
Lactobacillus plantarum
strains are capable of BA metabolism, they can withstand BA associated stress and propagate, a recognised important characteristic for GIT survival. Furthermore, we report that these food associated
Lactobacillus plantarum
strains have the selective ability to alter BA signatures in favour of receptor activation that would be beneficial to humans. Indeed, all of the strains examined showed a clear preference to alter human glycol-conjugated BAs, although clear strain-dependent modifications were also evident. This study demonstrates that BA metabolism by food-borne non-pathogenic bacteria is beneficial to both microbe and man and it identifies an evolutionary-conserved characteristic, previously considered unique to gut residents, among food-associated non-pathogenic isolates.
Journal Article
Outcome of oral provocation test in egg-sensitive children receiving semi-fat hard cheese Grana Padano PDO (protected designation of origin) containing, or not, lysozyme
Purpose
Lysozyme, obtained from egg white, is a potential food allergen used in the dairy industry to prevent late blowing of the loaf caused by the outgrowth of clostridial spores (
Cl. butyricum
and
Cl. tyrobutyricum
) during cheese aging. The aim of this study was to evaluate the possible correlation between egg protein allergy in pediatric age and sensitization to egg lysozyme, used for the preparation of Grana Padano cheese.
Methods
The tolerability of Grana Padano cheese has been evaluated in pediatric patients allergic to egg proteins through an oral provocation test with increasing amounts of cheese containing, or not, lysozyme at 12 and 24 months of aging.
Results
When lysozyme-sensitized children received 12-months aged and lysozyme-containing cheese, several immediate and late adverse reactions such as itching, abdominal pain, vomiting, nausea, dermatitis, rhinitis, bronchial asthma, urticaria, and angioedema were seen in 5 out of 21 subjects; only 1 out of 21 children showed an adverse reaction after challenge with 24-months-ripened lysozyme-containing cheese.
Conclusions
There is a possible relationship between the severity of allergic reactions and the lysozyme-specific IgE level in blood. In particular vomiting, hypotension, and abdominal pain were present when IgE level was higher than 7 kU/L. A ripening time of 24 months may reduce allergy problems when lysozyme-containing cheese is given to sensitized subjects, probably due to the hydrolysis of antigenic epitopes during aging.
Journal Article
Bacterial community assembly from cow teat skin to ripened cheeses is influenced by grazing systems
The objectives of this study were to explore bacterial community assembly from cow teat skin to raw milk cheeses and to evaluate the role of farming systems on this assembly using 16S rRNA gene high-throughput sequencing. The two grazing systems studied (extensive vs. semi-extensive) had a greater effect on the microbiota of cow teat skin than on that of raw milks and cheeses. On teat skin, the relative abundance of several taxa at different taxonomic levels (Coriobacteriia, Bifidobacteriales, Corynebacteriales, Lachnospiraceae, Atopobium, and Clostridium) varied depending on the grazing system and the period (early or late summer). In cheese, the abundance of sub-dominant lactic acid bacteria (LAB) varied depending on the grazing system. Overall, 85% of OTUs detected in raw milks and 27% of OTUs detected in ripened cheeses were also found on cow teat skin. Several shared OTUs were assigned to taxa known to be involved in the development of cheese sensory characteristics, such as Micrococcales, Staphylococcaceae, and LAB. Our results highlight the key role of cow teat skin as a reservoir of microbial diversity for raw milk, and for the first time, that cow teat skin serves as a potential source of microorganisms found in raw-milk cheeses.
Journal Article
Enhancing methane production using anaerobic co-digestion of waste activated sludge with combined fruit waste and cheese whey
Background
Recently, it has been indicated that anaerobic co-digestion of waste activated sludge with other waste streams at wastewater treatment plants is a promising strategy for enhancing methane production and materials recovery. The enhanced methane production can be used as a renewable source of energy in wastewater treatment plants. It can also reduce the amount of greenhouse gas emission in landfilling of the waste streams.
Results
According to the results obtained in this study, anaerobic co-digestion of waste activated sludge with mixed fruit waste and cheese whey improves methane production and the quality of digested sludge in comparison to the anaerobic digestion of waste activated sludge individually. It was indicated that carbon/nitrogen ratio (C/N) in the mixture of waste activated sludge, fruit waste and cheese whey improved considerably, leading to better anaerobic organisms’ activity during digestion. With assessing the activity of protease and cellulase, as the main enzymes hydrolyzing organic matter in anaerobic digestion, it was indicated that co-digestion of waste activated sludge with mixed fruit waste and cheese whey enhances the activity of these enzymes by 22 and 9% respectively. At the end of digestion, the amount of cumulative methane production significantly increased by 31% in the reactor with 85% waste activated sludge and 15% mixed fruit waste and cheese whey, compared to the reactor with 100% waste activated sludge. In addition, chemical oxygen demand (COD) and volatile solid (VS) in digested sludge was improved respectively by 9 and 7% when mixed fruit waste and cheese whey was used.
Conclusions
This study revealed that mixed fruit waste and cheese whey is potentially applicable to anaerobic digestion of waste activated sludge, as fruit waste and cheese whey have high C/N ratio that enhance low C/N in waste activated sludge and provide a better diet for anaerobic organisms. This is of significant importance because not only could higher amount of renewable energy be generated from the enhanced methane production in wastewater treatment plants, but also capital costs of the companies whose waste streams are being transported to wastewater treatments plants could be reduced considerably.
Journal Article
Metagenomics of pasteurized and unpasteurized gouda cheese using targeted 16S rDNA sequencing
Background
The microbiome of cheese is diverse, even within a variety. The metagenomics of cheese is dependent on a vast array of biotic and abiotic factors. Biotic factors include the population of microbiota and their resulting cellular metabolism. Abiotic factors, including the pH, water activity, fat, salt, and moisture content of the cheese matrix, as well as environmental conditions (temperature, humidity, and location of aging), influence the biotic factors. This study assessed the metagenomics of commercial Gouda cheese prepared using pasteurized or unpasteurized cow milk or pasteurized goat milk via 16S rDNA sequencing.
Results
Results were analyzed and compared based on milk pasteurization and source, spatial variability (core, outer, and under the rind), and length of aging (2–4 up to 12–18 months). The dominant organisms in the Gouda cheeses, based on percentage of sequence reads identified at the family or genus levels, were
Bacillaceae
,
Lactococcus
,
Lactobacillus
,
Streptococcus
, and
Staphylococcus
. More genus- or family-level (e.g.
Bacillaceae
) identifications were observed in the Gouda cheeses prepared with unpasteurized cow milk (120) compared with those prepared with pasteurized cow milk (92). When assessing influence of spatial variability on the metagenomics of the cheese, more pronounced differences in bacterial genera were observed in the samples taken under the rind;
Brachybacterium
,
Pseudoalteromonas
,
Yersinia
,
Klebsiella
, and
Weissella
were only detected in these samples. Lastly, the aging length of the cheese greatly influenced the number of organisms observed. Twenty-seven additional genus-level identifications were observed in Gouda cheese aged for 12–18 months compared with cheese only aged 2–4 months.
Conclusions
Collectively, the results of this study are important in determining the typical microbiota associated with Gouda cheese and how the microbiome plays a role in safety and quality.
Journal Article