Milk Cheese Research Articles

Milk and Fresh Cheese Quality of Crossbred Cows Supplemented with Phytogenic Additives and Managed under Thermal Stress

This investigation aimed to assess the physiological parameters and quality of milk and fresh cheeses produced by cows that were housed in paddocks, either with or without shade, and supplemented with a phytogenic additive. Sixteen crossbred cows were allocated in a 4 × 4 Latin square design, dividing them into paddocks with or without shade, and providing or not providing a phytogenic additive in their feed. This resulted in a total of four treatment groups and sixteen experimental plots, each containing four animals, over four periods of 21 days. Various parameters were examined, including haematology, rectal and skin temperature, respiratory rate, milk yield and composition, serum parameters, and cheese yield and quality. It is worth noting that the temperature and humidity, as measured by a black globe thermometer, did not display significant variations between the different environments and exhibited minimal fluctuations throughout the day. Additionally, the supplementation of the phytogenic additive led to a reduction in haematocrit levels (p = 0.011). Furthermore, the analysis showed that whey obtained from cheese production had a higher fat content when cows were without access to shade (p = 0.005). Notably, there was an interaction between factors in relation to the total dry extract content, which was lower when cows had access to shade and received the additive (p = 0.010). In summary, the provision of a phytogenic additive and the presence or absence of shade did not bring about significant changes in milk production and quality or in the yield and quality of fresh cheese.

Sero-Prevalence, Epidemiology, and Public Health Significance of Small Ruminant Brucellosis

Brucellosis is a widespread zoonosis mainly transmitted from cattle, sheep, goats, pigs, and camels through direct contact with blood, placenta fetuses, or uterine secretion or through consumption of the contaminated raw animal product (especially unpasteurized milk and soft cheeses) in endemic areas. Therefore, the objective of this paper are to explain the Current Epidemiological Aspects of Brucellosis and the Importance of Small ruminant Brucellosis for Public Health and briefly illustrate the Economic Importance of Small ruminant Brucellosis. Sources of infection include aborted fetuses, fetal membranes, vaginal discharges and milk from infected sheep and goat. Brucellosis is caused by facultative, intracellular and Gram- negative bacteria called Brucella. Small ruminant brucellosis is caused by B. ovis (for sheep) and B. melitensis (mainly for goats), the latter one is the most virulent species of the Brucella genus. The disease in naturally infected sheep and goats is characterized by abortion in the last trimester of pregnancy, stillbirth and birth of weak offspring in females, and acute orchitis and epididymitis in males. Brucellosis occurs worldwide in domestic animals such as cattle, sheep, goats, camels and pigs and creates a high economic problem for both the intensive and extensive livestock production system in the tropics and a threat to public health. Diagnostic tests fall into two categories: those that demonstrate the presence of the organisms and those that detect an immune response to its antigens. As a general rule, treatment of infected livestock is not attempted because of the high treatment failure rate, cost, and potential problems related to maintaining infected animals in the face of ongoing eradication programs. To control the disease in human, prevention of the disease in reservoir host is important, so test and slaughter followed by proper disposal of seropositive animals to decrease the incidence of infection and effective vaccination and hygienic practices would reduce the disease spreading in/from endemic regions and to lessen the economic and zoonotic effects of brucellosis, the government, public health officials, and veterinarians must collaborate.

It is Possible to Work with Them and Develop such a Mutually Good Relationship…”

Abstract In this study, I examine the complex intertwining of the relationship between man and nature through the activities of a typical group of farmers dominated by urban-rural farmers, the artisan cheese makers of Hungary. I focus on a specific issue, raw milk cheese making, where humans and microbes work together on a daily basis to produce a sellable product. In this context, I will describe how the complex, hybrid nature of the knowledge required for this process of cheese making is produced, and then review the different narratives of Hungarian cheesemakers about the method. I will then show how this method and the particular perspective it entails affects the daily practice of farming, and how working with invisible microbes transforms the fundamental way these farmers think about the relationship between humans and non-human actors.

Whey draining of goat milk cheese: A model study using frontal filtration

Whey draining of goat milk cheese: A model study using frontal filtration

Influence of β-casein genotype on Cheddar cheese making and ripening

Milk characteristics and suitability for production of dairy products like cheese may be influenced by protein polymorphism; the possible influence of β-casein (β-CN) polymorphism on cheese manufacturing and cheese characteristics was examined using milk with three β-CN genotypes, A1A1, A1A2 and A2A2. The composition and rennet coagulation properties of raw and standardised cheese milk, cheese yield and their composition were examined, cheese meltability, texture and proteolysis were analysed at different ripening times. Milk with β-CN variant A2A2 was found to have poorer rennet coagulation properties following standardisation and pasteurisation. Cheese made from A1A1 milk had lower protein content, while that from A2A2 milk had lower fat content compared with the other two genotypes. There was no significant impact of genotype on proteolysis during cheese ripening. However, β-CN genotype was found to impact cheese texture; after 180-d ripening, the A1A1 cheese was the softest, and A2A2 cheese was the most fracturable.

Lacticaseibacillus Strains Isolated from Raw Milk: Screening Strategy for Their Qualification as Adjunct Culture in Cheesemaking.

The microbial ecology fundamentals of raw milk and long-ripened cheeses consist of a complex interaction between starter lactic acid bacteria (SLAB) and non-starter LAB (NSLAB). Although NSLAB aromatic properties are paramount, other phenotypic traits need to be considered for their use as adjunct cultures, such as the capability to endure technological parameters encountered during cheesemaking. The present study focused on the isolation and characterization of NSLAB from spontaneously fermented raw cow's milk coming from 20 dairies that produce Grana Padano PDO cheese. From 122 isolates, the screening process selected the 10 most diverse strains belonging to Lacticaseibacillus spp. to be phenotypically characterized. The strains were tested for their growth performance in milk in combination with the application of technological stresses, for their ability to produce volatile compounds after their growth in milk, and for their ability to use different nutrient sources and resist chemicals. The complex characterization qualified the strains 5959_Lbparacasei and 5296_Lbparacasei as the best candidates to be used as adjunct strains in the production of raw milk and long-ripened cheeses, provided that antibiotic resistance is measured before their employment. Other strains with interesting aromatic capabilities but lower heat resistance were 5293_Lbparacasei, 5649_Lbparacasei and 5780_Lbparacasei, which could be candidates as adjunct strains for uncooked cheese production.

Lactic acid bacteria from artisanal raw goat milk cheeses: technological properties and antimicrobial potential.

In cheese-making, a starter culture composed of adequately chosen lactic acid bacteria (LAB) may be suitable to ensure the rapid acidification of milk, improve textural and sensory characteristics, and avoid pathogen proliferation. In this work, 232 LAB isolates collected from artisanal goat's raw milk cheeses produced in Portugal were evaluated for their antimicrobial capacity (at 10 and 37°C), as well as their acidifying and proteolytic properties. Among the 232 isolates, at least 98% of those isolated in De Man- Rogosa-Sharpe (MRS) agar presented antagonism against Listeria monocytogenes, Salmonella Typhimurium, or Staphylococcus aureus, whereas less than 28.1% of M17-isolated LAB showed antagonism against these pathogens. M17-isolated LAB displayed better results than MRS ones in terms of acidifying capacity. As for the proteolytic assay, only 2 MRS isolates showed casein hydrolysis capacity. Principal component analyses and molecular characterization of a subset of selected isolates were conducted to identify those with promising capacities and to correlate the identified LAB genera and species with their antimicrobial, acidifying, and/or proteolytic properties. Lactococcus strains were associated with the highest acidifying capacity, whereas Leuconostoc and Lacticaseibacillus strains were more related to antimicrobial capacities. Leuconostoc mesenteroides, Lactococcus lactis, and Lacticaseibacillus paracasei were the predominant organisms found. The results of this work highlight various strains with pathogen inhibition capacity and suitable technological properties to be included in a customized starter culture. In future work, it is necessary to appropriately define the starter culture and implement it in the cheese-making process to evaluate if the in-vitro capacities are observable in a real food system.

Improving the quality and the technology of processed cheeses

This article investigates processed cheese's nutritional value and safety by adding vegetable additives (dry Spirulina powder). Processed cheese for lunch is taken as a basis for the formulation. As a control, we took cheese made according to classical technology. We used cheeses from cow's milk. We used combined raw materials in the developed technology: cow's and goat's milk cheeses. Spirulina was added to the formulation as an enrichment agent in the 1%, 2%, and 3% ratio, respectively. The sample with a 1% addition was found to be rational according to the results of the organoleptic evaluation. The formulation was optimised in further study by selecting 0.5%, 1.5% and 2%. A centre composite plot was used to add points around the pre-lagged optimum. A regression formula was obtained, and the melting salts and the dosage of the added enrichment agent were determined. Also, the share of cheese from goat's milk in the recipe of processed cheese was determined. The recipe was calculated on the principle of material balance. Experimental samples were examined for fatty acid and amino acid composition. The tables compare the best sample on organoleptic evaluation with the control. It was found that when 3% is added, the cheese acquires a dark green tinge. The colour is deep green when 2% is added; when 1% or less is added, the colour is salad. The dose of melting salts in the recipe was reduced to 2%; in the classic recipe, it was 3.9%. The protein of the experimental sample turned out to be closer to the ideal protein. PDCAAS is equal to 96.9, while in the control sample, PDCAAS is equal to 39.9. Also, when comparing the fatty acid composition, the thrombogenicity coefficient was lower in the experimental sample than in the control.

Nanomolar detection of essential amino acid in dairy products using a novel electrochemical sensor based on zinc cobaltite nanoflowers embedded porous 3D reduced graphene oxide

L-tryptophan (L-Trp) is a vital amino acid that sways neuronal function, immunity, and gut homeostasis, and its accurate detection in food samples is crucial. The aim of this study is to integrate zinc cobaltite (ZCO) nanoparticles and 3D porous reduced graphene oxide (rGO) on a screen-printed carbon electrode (SPCE) surface for building a novel electrochemical sensor to sensitively detect L-Trp in food products. A low-temperature aqueous solution method was employed in ZCO nanoflower synthesis and a hydrothermal approach was utilized to prepare 3D rGO. SEM, elemental mapping, XRD, Raman spectroscopy, XPS, and EIS characterizations were performed on the prepared nanocomposite, ZCO/3DrGO. Electrochemical experiments conducted with the cyclic and differential pulse voltammetric techniques were used for effectively assessing the catalytic power of ZCO/3DrGO/SPCE. With a low detection limit of 3 nM, high sensitivity of 19.53 μAμM−1cm−2, and a broad linear range of 0.08–5.93; 5.93–87.18 μM, the sensor demonstrated promising electrocatalytic activity towards L-Trp. Further, the reliability of the sensor was proved by analyzing its stability, repeatability, reproducibility, and selectivity towards L-Trp. The successful detection of L-Trp in dairy products (yogurt, milk, and cottage cheese) using the proposed sensor evinced its practical feasibility with high recovery of 98.16%–101.16% and low RSD of 2.8%.

Effect of Lactiplantibacillus plantarum on the Conversion of Linoleic Acid of Vegetable Oil to Conjugated Linoleic Acid, Lipolysis, and Sensory Properties of Cheddar Cheese.

Conjugated linoleic acid (CLA) is perceived to protect the body from metabolic diseases. This study was conducted to determine the effect of Lactiplantibacillus plantarum (Lp. plantarum) on CLA production and sensory characteristics of cheddar cheese. Lp. plantarum can convert linoleic acid (LA) to CLA. To increase CLA in cheddar cheese and monitor the conversion of LA to CLA by Lp. plantarum, the LA content of cheese milk (3.4% fat) was increased by partially replacing fat with safflower oil (85% LA of oil) at 0, 3, 6, and 9% concentrations (T1, T2, T3, and T4). Furthermore, Lp. plantarum 108 colony-forming units (CFU)/mL (8 log CFU mL-1) was added in all treatments along with traditional cheddar cheese culture (Lactococcus lactis ssp. lactis and L. lactis ssp. cremoris). After 30 days of ripening, Lp. plantarum in T1, T2, T3, and T4 was 6.75, 6.72, 6.65, and 6.55 log CFU g-1. After 60 days of ripening, Lp. plantarum in T1, T2, T3, and T4 was 6.35, 6.27, 6.19, and 6.32 log CFU g-1. After 60 days of ripening, Lp. plantarum in T1, T2, T3, and T4 was 6.41, 6.25, 6.69, and 6.65 log CFU g-1. GC-MS analysis showed that concentrations of CLA in the 90 days' control, T1, T2, T3, and T4 were 1.18, 2.73, 4.44, 6.24, and 9.57 mg/100 g, respectively. HPLC analysis revealed that treatments containing Lp. plantarum and LA presented higher concentrations of organic acids than the control sample. The addition of safflower oil at all concentrations did not affect cheese composition, free fatty acids (FFA), and the peroxide value (POV) of cheddar cheese. Color flavor and texture scores of experimental cheeses were not different from the control cheese. It was concluded that Lp. plantarum and safflower oil can be used to increase CLA production in cheddar cheese.

Effect of Commercial and Autochthonous Bioprotective Cultures for Controlling Listeria monocytogenes Contamination of Pecorino Sardo Dolce PDO Cheese.

The composition and physicochemical characteristics of short-aged Pecorino Sardo PDO (Protected Designation of Origin) cheese makes it permissive to Listeria monocytogenes growth. The PDO product specification stipulates that this cheese is produced with whole sheep's milk inoculated with cultures from the area of origin. Therefore, the use of bioprotective cultures for the inhibition of pathogens in PDO cheeses is allowed only if autochthonous microorganisms are used. Furthermore, bioprotective cultures are generally used on the cheese surface to prevent the outgrowth of L. monocytogenes, the application of which can be time-consuming and require specialist technical knowledge. In this study, we examine the direct addition of bioprotective cultures to the cheese vat and compare the activity of a commercial bioprotective culture (Lactiplantibacillus plantarum) and an autochthonous lactic acid bacterium with bioprotective properties (Lactobacillus delbruekii sups. sunkii), for the inhibition of L. monocytogenes in Pecorino Sardo PDO cheese. Three types of Pecorino Sardo PDO cheese were made with bioprotective cultures added directly to the cheese milk along with the starter inoculum: PSA, with the commercial bioprotective culture; PSB, with the autochthonous bioprotective culture; and a CTRL cheese with no bioprotective culture. A challenge test was performed on each of these cheeses by artificially contaminating the cheese surface with L. monocytogenes (2 Log10 CFU/g). Three batches of each cheese type were analyzed to enumerate mesophilic and thermophilic lactic acid bacteria and to investigate the growth potential of L. monocytogenes during manufacturing, at the end of ripening, at the end of shelf-life, and after 180 days from cheese production. Both bioprotective cultures tested in this study showed inhibitory action against the pathogen with 0.3-1.8 Log10 CFU/g (colony-forming unit per gram) reduction levels. The autochthonous organism, L. sunkii, was as effective as the commercially supplied culture, and the addition of the bioprotective cultures to the cheese-making procedure offered protection against L. monocytogenes. The direct addition of bioprotective cultures to the making procedure of Pecorino Sardo PDO cheese is a potentially innovative strategy to improve the safety of this product.

Genetic Characterization of Multi Drug Resistant Staphylococcus Spp. in Raw Milk and Karish cheese

Genetic Characterization of Multi Drug Resistant Staphylococcus Spp. in Raw Milk and Karish cheese

Utilization of lactoferrin to inhibit E. coli and S. aureus isolates from milk and kariesh cheese

Utilization of lactoferrin to inhibit E. coli and S. aureus isolates from milk and kariesh cheese

Prevalence and Antimicrobial Susceptibility of Ceftiofur-Resistant Enterobacteriaceae in Raw Cow’s Milk and Kareish Cheese: Implications for Public Health

Prevalence and Antimicrobial Susceptibility of Ceftiofur-Resistant Enterobacteriaceae in Raw Cow’s Milk and Kareish Cheese: Implications for Public Health

English

English

Survey on husbandry and cheese manufacturing practices in small ruminants' farmhouse dairies in Central Italy.

Farmhouse cheeses made from raw ovine or caprine milk are very popular among the consumers not only in Italy but also overseas because of their unique organoleptic properties. These cheeses are usually manufactured, according to traditional methods, in small rudimental facilities adjacent to the farm where the achievement of satisfactory hygienic standards can be challenging. However, the lack of systematic data about farm management and the cheese manufacturing processes hampers the conduction of specific risk assessment studies. In order to fill the knowledge gaps, we collected relevant data, through a questionnaire - based survey, from 125 small ruminants' farmhouse dairies spread in Lazio. Results showed that 1.1% of registered farms process their own milk for the production of raw milk cheeses. Hand milking is still applied in almost half of them and most products are subject to a short ‑ to ‑ medium ripening period which might not be sufficient to reduce eventual pathogen load. Products are mainly sold directly to consumers on the farm premises. Our results suggest the need to support these artisan cheese producers in order to improve the production standards without altering the traditional cheesemaking practices. The reported data are also useful for specific risk assessment studies.

Growth patterns of Pseudomonas aeruginosa in milk fortified with chitosan and selenium nanoparticles during refrigerated storage

Pseudomonas spp are considered a common milk-associated psychotropic bacteria, leading to milk deterioration during storage; therefore, our study aimed to study the distribution of Pseudomonas aeruginosa in raw milk and its associated products then studying the growth behavior of P. aeruginosa in milk after employing chitosan nanoparticles (CsNPs 50, 25, and 15 mg/100ml) and selenium nanoparticles (SeNPs 0.5, 0.3 and 0.1 mg/100ml) as a trial to control the bacterial growth in milk during five days of cooling storage. Our study relies on the ion gelation method and green synthesis for the conversion of chitosan and selenium to nanosized particles respectively, we subsequently confirmed their shape using SEM and TEM. We employing Pseudomonas selective agar medium for monitoring the bacterial growth along the cooling storage. Our findings reported that high prevalence of Pseudomonas spp count in raw milk and kareish cheese and high incidence percent of P. aeruginosa in ice cream and yogurt respectively. Both synthesized nanoparticles exhibited antibacterial activity in a dose-dependent manner. Moreover, CsNPs50 could inhibit the P. aeruginosa survival growth to a mean average of 2.62 ± 1.18 log10cfu/ml in the fifth day of milk cooling storage; also, it was noted that the hexagonal particles SeNPs0.5 could inhibit 2.49 ± 11 log10cfu/ml in comparison to the control P. aeruginosa milk group exhibited growth survival rate 7.24 ± 2.57 log10cfu/ml under the same conditions. In conclusion, we suggest employing chitosan and selenium nanoparticles to improve milk safety and recommend future studies for the fate of nanoparticles in milk.

Food allergy - New risks through vegan diet? Overview of new allergen sources and current data on the potential risk of anaphylaxis.

A vegan diet is increasingly en vogue, i.e., a diet based on plants, in which animal products are completely avoided, often for health and environmental reasons. The menu is supplemented with pulses (e.g., soy, lentils, peas), nuts (e.g., cashew, macadamia, almond, pecan, para, walnut) and seeds (e.g., chia, flaxseed) or pseudo-grains (quinoa, buckwheat). Indeed, the product range is expanding to include vegan foods such as milk alternatives (e.g., oat, almond, soy drinks) and cheese or meat substitutes (e.g., soy-based). Food allergies are also on the rise, with an increasing prevalence worldwide. It is worthy of note that the main allergens of anaphylactic reactions to food in adults are predominantly of plant origin, mainly pulses and nuts - the very foods that form the main source of protein in the vegan diet. In this context, allergies to storage proteins (e.g., Gly m 5 and Gly m 6 from soya beans) can lead to severe anaphylactic reactions, while highly processed substitute products containing plant protein isolates (e.g., pea flour) in concentrated form continue to be of particular concern and may therefore be allergologically problematic. In this article, we aim to provide an overview of allergens and emerging allergen sources in vegan foods and highlight the anaphylaxis risk of the vegan diet.

Effect of metabolic activity of lactic acid bacteria and propionibacteria on cheese protein digestibility and fatty acid profile

This study aimed at investigating the influence of different variants of bacterial starter cultures on the metabolism of the bacteria used, cheese protein digestibility, and fatty acid profile. The results revealed that lactic acid bacteria had a significant effect on the proportions of fatty acids in cheeses, with saturated fatty acids being predominant in in all cheese variants. Fatty acid proportions are complex and depend on the type of cheese culture and monoculture used. Additionally, the analysis of fatty acid composition showed variations in the proportion of saturated and unsaturated fatty acids, impacting the values of atherogenic and thrombogenic indices. Notably, the atherogenic index was highest in samples of mature cheeses obtained from a typical mesophilic cheese culture, whereas it was lowest in samples of fresh milk and mature cheeses obtained from a mesophilic cheese culture and monocultures of Lacticaseibacillus casei and Propionibacterium. The study also highlighted the influence of lactobacilli on the content of available free lysine, glycine, and methionine in cheese proteins. Mature cheeses obtained with Propionibacterium and L. casei starter cultures exhibited higher free lysine and glycine content compared with fresh cheeses and those obtained solely with the cheese culture. Additionally, mature cheeses obtained with starter cultures of mesophilic cheese culture, Propionibacterium, and L. casei had the highest free methionine content. Based on these findings, it is evident that the choice of cheese making cultures and monocultures can significantly affect the fatty acid composition and amino acid content of cheese and fresh milk, potentially bearing important health implications.

Functionality of process cheese made from Cheddar cheese with various rennet levels and high-pressure processing treatments

Due to its versatility and shelf stability, process cheese is gaining interest in many developing countries. The main structural component (base) of most processed cheese formulations is young Cheddar cheese that has high levels of intact casein. Exporting natural Cheddar cheese base from the United States to distant overseas markets would require the aging process to be slowed or reduced. As Cheddar cheese ripens, the original structure is broken down by proteolysis and solubilization of insoluble calcium phosphate. We explored the effect of varying rennet levels (we also used a less proteolytic rennet) and application of high-pressure processing (HPP) to Cheddar cheese, as we hoped these treatments might limit proteolysis and concomitant loss of intact casein. To try to retain high levels of insoluble Ca, all experimental cheeses were made with a high-draining pH and from concentrated milk. To compare our intact casein results with current practices, we manufactured a Cheddar cheese that was prepared according to typical industry methods (i.e., use of unconcentrated milk, calf chymosin [higher levels], and low draining pH value [∼6.2]). All experimental cheeses were made from ultrafiltered milk with protein and casein contents of ∼5.15% and 4.30%, respectively. Three (low) rennet levels were used: control (38 international milk clotting units/mL of rennet per 250 kg of milk), and 25% and 50% reduced from this level. All experimental cheeses had similar moisture contents (∼37%) and total Ca levels. Four days after cheese was made, half of the experimental samples from each vat underwent HPP at 600 MPa for 3 min. Cheddar cheese functionality was monitored during aging for 240 d at 4°C. Cheddar cheese base was used to prepare process cheese after aging for 14, 60, 120, 180, and 240 d. Loss tangent (LT) values of cheese during heating were measured by small strain oscillatory rheology. Intact casein levels were measured using the Kjeldahl method. Acid or base titrations were used to determine the buffering capacity and insoluble Ca levels as a percentage of total Ca. The LTmax values (an index of meltability) in process cheese increased with aging for all the cheese bases; the HPP treatment significantly decreased LTmax values of both base (natural) and process cheeses. All experimental cheeses had much higher levels of intact casein compared with typical industry-make samples. Process cheese made from the experimental treatments had visually higher stretching properties than process cheese made from Cheddar with the typical industry-make procedure. Residual rennet activity was not affected by rennet level, but the rate of proteolysis was slightly slower with lower rennet levels. The HPP treatment of Cheddar cheese reduced residual rennet activity and decreased the reduction of intact casein levels. The HPP treatment of Cheddar cheese resulted in process cheeses that had slightly higher hardness values, lower LTmax values, and retained higher storage modulus values at 70°C. We also observed that the other make procedures we used in all experimental treatments (i.e., using a less proteolytic chymosin, using a concentrated cheese milk, and maintaining a high draining pH value) had a major effect on retaining high levels of intact casein.