Cheese-making Process Research Articles

Характеристика генома двух новых фагов Lactococcus lactis phage vL_296 и vL_20A

Fermented dairy products are produced using starter cultures. They ferment milk to create products with a certain texture, aroma, and taste. However, the lactic acid bacteria used in this production are prone to bacteriophage infection. We examined the genomes of two newly discovered bacteriophage species that were isolated from cheese whey during the cheesemaking process. We have determined the species and the lytic spectrum of these bacteriophages. Phages vL_20A and vL_296 were isolated using lactococcal indicator cultures. They have unique lytic spectra: of the 21 possible identified host bacteria, only four are shared amongst them. The vL_20A and vL_296 genomes comprise linear double-stranded DNA lengths with 21,909 and 22,667 nucleotide pairs, respectively. Lactococcus phage bIL67 (ANI 93.3 and 92.6, respectively) is the closest to the phages vL_20A and vL_296. The analysis of the CRISPR spacers in the genomes of starter cultures did not reveal any phage-specific vL_20A or vL_296 among them. This study highlights the biodiversity of L. lactis phages, their widespread presence in dairy products, and their virulence. However, the virulence of phages is balanced by the presence of a significant number of bacterial strains with different sensitivities to phages in the starter cultures due to the bacterial immune system.

Exploring cheese production enzymes from various plants as an alternative to Calf rennet

Milk coagulation, traditionally relied on Calf rennet, is a crucial enzymatic process in cheese production. Ethical and practical constraints in using Calf rennet have led to the exploration of alternative sources. This study aimed to identify plant-based substitutes for calf rennet by investigating the coagulating potential of extracts from three plants: Calotropis procera, lemon, and Solanum incanum. Each plant tested with three extract levels (15, 20, and 25 ml), and replicated three times. Juices were extracted from lemon and Solanum incanum fruits through incision and squeezing. Meanwhile, Calotropis procera aqueous filtrates were separated from its polymeric gum using centrifugation. Then after, all extracts were further purified through muslin cloth and Whatman filter paper. Extracts were added to a beaker containing 500 ml of milk heated at 50 °C, and allowed to coagulate, resulting in the separation of cheese, curds and whey. Then after whey production, fresh and dry weights of cheese, and cheese yield percentage were measured and recorded. Statistical analysis using SAS Studio showed that there is highly significant differences with P < 0.0001 among plant extracts in their effects on the cheese-making potential. For all extract levels, the highest cheese-dry weight and percentage of cheese yield were observed in Calotropis procera and the lowest cheese formation starting times observed from lemon juice. These findings offer insights into optimizing cheese-making processes using natural sources and suggest that Calotropis procera, along with lemon juice and Solanum incanum, could serve as alternative sources of rennet.

Mechanistic modeling of the dynamics of phage attack during milk acidification in the cheese-making process

Bacteriophage attacks represent a major threat in the dairy industry. Here, an unstructured mechanistic model predicting the dynamics of milk acidification in case of phage attack was developed and experimentally validated. Multiple acidification experiments were run with different combinations of initial phage titers and bacterial concentrations and the resulting pH dynamics were recorded. The model could successfully predict the success or failure of milk acidification. Using the model, important biological parameters were deduced from simple, low-cost acidification measurements. These parameters included bacteria’s maximum growth and lysis rates, phages’ burst size, etc. Sensitivity analysis helped identify biologically relevant aspects of phage-host interactions. Growth and lysis kinetics were shown to have the most important impacts. This knowledge can be used to develop easy routine strategies to fight phage attack in the dairy industry. The model can be used to raise awareness amongst cheese makers on the importance of cleaning to avoid food and material waste.

Interaction between a Lactococcus lactis autochthonous starter and a raw goat milk microbial community during long-term backslopping

Traditional cheesemaking processes often involve backslopping practice. However, over successive inoculations, acidification deficiencies may arise. In such cases, adding a starter is recommended to restore the ecosystem stability. This study examines the impact of an autochthonous starter composed of three Lactococcus lactis strains on a raw goat milk microbial community during their evolution. Bacterial composition and technological features (acidification and aroma) were analyzed during communities’ evolution over 800 generations. 16S rRNA gene metabarcoding showed that Lactococcus lactis strains predominated. The raw goat milk community acidification capacities varied early in the evolution and then remained stable. Adding the L. lactis starter to this community stabilized the ecosystem from the beginning of the evolution. The acetoin production was associated with the starter presence, consistent with the establishment of the diacetylatis biovar strain from the starter in the raw goat milk community throughout the evolution. Increased or decreased production of some volatile organic compounds when the starter was added revealed a specific aroma footprint due to interactions between the two communities. This study showed that adding a starter could help to achieve the maximum acidification rate from the early inoculation cycles and could significantly modify the aroma profile during long-term backslopping.

Beyond Harmful: Exploring Biofilm Formation by Enterococci Isolated from Portuguese Traditional Cheeses.

This study investigated the biofilm-forming capabilities of Enterococcus isolates from Portuguese traditional cheeses with protected designation of origin (PDO) status, specifically Azeitão and Nisa. Given the absence of added starter cultures in the cheesemaking process, the characteristics of these cheeses are intrinsically linked to the autochthonous microbiota present in the raw materials and the production environment. Our findings demonstrate that all isolates possess biofilm production abilities, which are crucial for their colonization and persistence within cheese factories, thereby maintaining factory-specific microbial heritage. Through an integrated analysis utilizing principal component analysis (PCA), a direct correlation between biofilm formation and cell viability was established. Notably, these results underscore the adaptive capacity of enterococci to survive environmental fluctuations and their role in the unique characteristics of Portuguese traditional cheeses. Overall, this research enhances our understanding of the microbial dynamics in cheese production and highlights the importance of enterococci in preserving cheese quality and heritage.

Cheddar cheese production, structure and in-vitro semi-dynamic gastric digestion: The role of β-casein phenotype

The objective of this study was to establish the impact of β-casein A1/A1, A1/A2 and A2/A2 phenotypes on the cheese-making process, cheese structure and on the subsequent in vitro gastric digestion properties of the cheese samples. The time required for curd cutting in cheese milk containing β-casein A2/A2 was significantly delayed, compared to milks containing β-caseins A1/A1 and A1/A2. After 180 days of ripening no differences were observed in the level of soluble nitrogen at pH 4.6 between any of the cheese samples, with a decrease in the level of aggregated β-sheets and increase in the level of β-turns and random coils observed in all cheese over the ripening period. During simulated gastric digestion, cheese samples took between 15 and 20 min to form the initial digesta coagulum, which occurred between pH 4.3 and 4.0. The rate of protein breakdown was slower in A2/A2 cheese, with less cheese structure degradation occurring, compared to β-casein A1 containing cheeses. This study has shown that rennet coagulation takes significantly longer in cheese milk containing only β-casein A2/A2, and that there was less protein breakdown during its simulated gastric digestion.

Production of milk-coagulating protease by fungus Pleurotus djamor through solid state fermentation using wheat bran as the low-cost substrate

Proteases are enzymes that hydrolyze peptide bonds present in proteins and peptides. They are widely used for various industrial applications, such as in the detergent, food, and dairy industries. Cheese is one of the most important products of the dairy industry, and the coagulation stage is crucial during the cheese-making process. Enzymatic coagulation is the most common technique utilized for this purpose. Microbial enzymes are frequently used for coagulation due to their advantages in terms of availability, sustainability, quality control, product variety, and compliance with dietary and cultural/religious requirements. In the present study, we identified and subsequently characterized milk coagulant activity from the fungus Pleurotus djamor PLO13, obtained during a solid-state fermentation process, using the agro-industrial residue, wheat bran, as the fermentation medium. Maximum enzyme production and caseinolytic activity occurred 120 h after cultivation. When the enzyme activity against various protease-specific synthetic substrates and inhibitors was analyzed, the enzyme was found to be a serine protease, similar to elastase 2. This elastase-2-like serine protease was able to coagulate pasteurized whole and reconstituted skim milk highly efficiently in the presence and absence of calcium, even at room temperature. The coagulation process was influenced by factors such as temperature, time, and calcium concentration. We demonstrate here, for the first time, an elastase-2-like enzyme in a microorganism and its potential application in the food industry for cheese production.

Serial fermentation in milk generates functionally diverse community lineages with different degrees of structure stabilization.

Microbiome applications require approaches for shaping and propagating microbial communities. Shaping allows the selection of communities with desired taxonomic and functional properties, while propagation allows the production of the biomass required to inoculate the engineered communities in the target ecosystem. In top-down community engineering, where communities are obtained from a pool of mixed microorganisms by acting on environmental variables, a major challenge is to master the balance between shaping and propagation. However, the ecological factors that favor high dynamics of community structure and, conversely, those that favor stability during propagation are not well understood. In this work, short-term dairy backslopping was used to investigate the key role of the taxonomic composition and structure of bacterial communities on their dynamics. The results obtained open up interesting prospects for the biotechnological use of microbiomes, particularly in the field of dairy fermentation, to diversify approaches for injecting microbial biodiversity into cheesemaking processes.

Utilization of retentates for white brined cheese production: comparative evaluation of physico-chemical and sensory properties

The aim of the present study is (1) to enhance the protein fraction in cheese milk through membrane filtration and consequently (2) to separate the majority of whey as ‘ideal whey’ prior to the production of white brined cheese, and (3) to explore the potential utilization of retentates in the production of white brined cheese. The chemical, physical, textural and sensory properties of cheeses produced from microfiltration (MF) retentates were characterized to investigate the effects of cross-flow MF on white brined cheese. Polyether sulfone (MP005) membranes featuring a pore diameter of 0.05 μm and polyvinylidene fluoride (MV020) membranes with a pore diameter of 0.20 μm were utilized. The assessed quality parameters of cheeses derived from polyethersulfone membrane (MP005) retentates were similar to the control (p > 0.05), whereas the cheese obtained from polyvinylidene fluoride membrane (MV020) retentates exhibited notable differences (p < 0.05) from the control. The traditional whey generated after cheese-making, which typically requires substantial on-site processing and/or treatment, was reduced by 3.5–6.7 times using the MP005 retentates. Simultaneously, 58–70% of the cheese milk (w/w) was separated as ideal whey before the cheese-making process. MF shows potential as an eco-friendly technology suitable for use in cheese production processes. The potential utilization of MP005 for enriching the protein content in cheese milk holds promise for white cheese production.

Evaluation of In Vitro Antihypertensive and Anti-Inflammatory Properties of Dairy By-Products

Sweet whey (SW) and yogurt acid whey (YAW) are dairy by-products of the cheese-making process and Greek-style yogurt production, respectively. Both of them are considered pollutants with huge volumes of SW and YAW produced due to the growing demand for dairy products worldwide. Moreover, whey-derived peptides, resulting from fermentation as well as from further hydrolysis during digestion, have been associated with various biological activities. In the present study, the angiotensin-converting enzyme (ACE)-inhibitory activity of 48 SW samples and 33 YAW samples from bovine, ovine, caprine, and ovine/caprine milk obtained were evaluated. Additionally, the SW and YAW digestates and two of their fractions (smaller than 10 kDa, SW-D-P10 and YAW-D-P10, and smaller than 3 kDa, SW-D-P3 and YAW-D-P3), which were obtained after in vitro digestion and subsequent ultrafiltration, were also subjected to evaluation. Our data indicated that the D-P10 and D-P3 fractions exhibited higher ACE-inhibitory activity compared to the corresponding values before digestion. The ACE-inhibitory capacity after in vitro digestion was higher for the ovine SW samples compared to their bovine and caprine counterparts. The effect of the D-P3 fraction on the inhibition of nitric oxide (NO) production and the expression of a selected panel of immune-response-related genes in LPS-stimulated RAW 264.7 macrophages was also evaluated. Fractions from both dairy by-products inhibited NO production in LPS-stimulated RAW 264.7 cells. Especially, ovine SW-D-P3 showed a strong NO inhibitory activity and suppressed inducible nitric oxide synthase (Nos2) mRNA levels. However, YAW-D-P3 could not trigger neither the gene expression of inflammatory macrophage mediators Nos2 and cyclooxygenase-2 (Ptgs2) nor tumor necrosis factor-α (Tnf) and interleukin 6 (Il6) in LPS-stimulated murine macrophages regardless of animal origin. These findings suggest that in vitro digestion could enhance the production of ACE-inhibitory peptides in both dairy by-products, while SW from ovine origin displays higher potential as an anti-inflammatory agent, effectively preventing excessive NO production.

Occurrence of Enterococci in the Process of Artisanal Cheesemaking and Their Antimicrobial Resistance.

Enterococci are a group of microorganisms that have a controversial position from some scientific points of view. The species of the greatest clinical importance are E. faecalis and E. faecium, which are common agents of nosocomial infections. However, enterococci also have important applications in the dairy industry, as they are used as non-starter lactic acid bacteria (NSLAB) in a variety of cheeses, especially artisanal cheeses. The aim of this study was to determine the presence of representatives from the Enterococcus genus using PCR and MALDI-TOF MS methods on samples of raw milk, processing environment swabs, and cheese from four different artisanal dairy plants in Slovakia. Among the 136 isolates of enterococci, 9 species of genus Enterococci (E. faecalis, E. faecium, E. durans, E. devriesi, E. hirae, E. italicus, E. casseliflavus, E. malodoratus, and E. gallinarum) were identified and were tested for their antimicrobial resistance (AMR) to 8 antibiotics (amoxicillin, penicillin, ampicillin, erythromycin, levofloxacin, vancomycin, rifampicin, and tetracycline); most of them were resistant to rifampicin (35.3%), ampicillin (22.8%), and tetracycline (19.9%). A PCR analysis of vanA (4.41%) and tetM (14.71%) revealed that antimicrobial resistance genes were present in not only phenotypic resistant isolates of enterococci but also susceptible isolates. The investigation of antimicrobial resistance in enterococci during the cheesemaking process can be a source of valuable information for public health in the concept of "One Health".

Valorization of cheese-making residues in biorefineries using different combinations of dark fermentation, hydrothermal carbonization and anaerobic digestion

Dark fermentation (DF), hydrothermal carbonization (HTC) and anaerobic digestion (AD) are applied, in different combinations, to cheese whey (CW), which is the liquid effluent from the precipitation and removal of milk casein during the cheese-making process. The aim and novelty of this research is to investigate the production of various biofuels (H2-rich gas, hydrochar and biogas) in cascade, according to the waste biorefinery concept. The simplest case is the direct AD of CW. The second investigated possibility is the preliminary HTC of CW, producing hydrochar, followed by the AD of the process water from which hydrochar is separated by filtration. The third possibility is based on DF of CW, followed by the AD of the fermentate (F) from DF. The final possibility is based on DF of CW, followed by HTC of the F, and then AD of the process water. Accordingly, the physical and chemical properties of CW, F, resulting hydrochar and process water (PW), and biomethane potentials of CW, F, and process waters are studied to determine the energy and carbon balances of all variants. In brief, the first variant, direct AD of CW, is believed to be the most energy efficient method.

Investigation of Freezing and Freeze-Drying for Preserving and Re-Using a Whole Microbial Cheese Community.

Preserving microbial ecosystems obtained from traditional cheese-making processes is crucial to safeguarding the biodiversity of microbial cheese communities and thus ensuring that the high flavor quality of traditional cheeses is maintained. Few protocols have been proposed for the long-term storage of microbial consortia. This work aimed to develop preservation methods to stabilize the entire microbial community in smear-ripened cheese without multiplication or isolation. A simplified microbial community, capable of reproducing the metabolic pattern of cheese maturation, was used in three independent cheese productions. Cheese samples were taken before and after the ripening step, mixed with maltodextrin or saline solution, and subjected to different stabilization conditions including freezing and freeze-drying, followed by 1 month of storage. Microbial survival was quantified using the colony-forming unit assay. Differential scanning calorimetry was used to relate the physical events occurring within the samples to the microbial storage stability. Freezing at -80 °C resulted in the lowest loss of culturability (<0.8 log unit), followed by freezing at -20 °C and freeze-drying. The ripening bacteria appeared as the most sensitive microorganisms within the community. Moreover, a successful cheese production using the best-stabilized community showed the possibility of preserving and re-using an entire microbial community of interest.

Assessment of protein and phospholipid bioaccessibility in ultrafiltered buttermilk cheese using TIM-1 in vitro gastrointestinal methods

To meet the high consumer demand, butter production has increased over the last few years. As a result, the buttermilk (BM) co-produced volumes require new ways of adding value, such as in cheese manufacturing. However, BM use in cheese milk negatively influences the cheesemaking process (e.g., altered coagulation properties) and the product’s final quality (e.g., high moisture content). The concentration of BM by ultrafiltration (UF) could potentially facilitate its use in cheese manufacturing through an increased protein content while maintaining the milk salt balance. Simultaneously, little is known about the digestion of UF BM cheese. Therefore, this study aimed to characterize the impact of UF BM on cheese manufacture, its structure, and its behavior during in vitro digestion. A 2-fold UF concentrated BM was used for cheese manufacture (skim milk [SM] – control). Compositional, textural, and microstructural analyses of cheeses were first conducted. In a second step, the cheeses were fed into an in vitro TNO gastrointestinal digestion model (TIM-1) of the stomach and small intestine and protein and phospholipid (PL) bioaccessibility was studied. The results showed that UF BM cheese significantly differed from SM cheese regarding its composition, hardness (p < 0.05) and microstructure. However, in TIM-1, UF BM and SM cheeses showed similar digestion behavior as a percentage of protein and PL intake. Despite relatively more non-digested and non-absorbed PL in the ileum efflux of UF BM cheese, the initially higher PL concentration contributes to an enhanced nutritional value compared to SM cheese. To our knowledge, this study is the first to compare the bioaccessibility of proteins and PL from UF BM and SM cheeses.

Description of “Ovino Belmontese”, a new semisoft sheep's milk cheese processed using “Italico” cheese technology

The objective of this study was to create a new semisoft sheep's milk cheese called “Ovino Belmontese” cheese (OBCh) by applying the “Italico” cheese-making technology. The cheese production took place under industrial conditions, with the addition of a commercial starter formulation containing Streptococcus thermophilus. The microbiological, physicochemical, and sensory characteristics of OBCh were assessed and compared to those of a commercially available cow's Italico cheese (CICh). Streptococcus thermophilus dominated the microbial community during the cheese-making process, reaching levels of approximately 9.0 Log CFU/g in both OBCh and CICh. Among physical characteristics, no statistically significant difference (p ≥ 0.05) was registered in terms of lightness, redness, yellowness, and hardness between the two cheeses. OBCh exhibited a twofold higher short-chain fatty acid content compared to CICh. Both cheeses displayed similar classes of volatile organic compounds, although their relative percentages differed. The application of Italico cheese technology to process sheep's milk did not negatively affect sensory attributes. This study highlighted that utilizing a cheese-making technology not commonly used for processing sheep's milk represents a promising strategy to diversify Sicilian dairy productions.

Sensorial Attributes of Fermented Whey Drinks with Either Natural or Artificial Flavoring Agents

Abstract A clear-yellowish liquid, resulting from the separation and pressing of curds in the cheese-making process, is obtained, and it is commonly known as whey. Despite being commonly regarded as waste, whey still contains some nutrients such as protein, lactose, and minerals. These compounds endow whey with the potential to be processed into a food product. However, an unwanted sensory aspect can be caused by the presence of these organic compounds. This is a consequence of chemical changes in organic compounds within whey during production and storage, which can impact flavor and lead to the formation of off flavors. One alternative that can be employed to reduce off-flavors is the conversion of whey into probiotic drinks through a fermentation process involving lactic acid bacteria (LAB). Although a fermentation process could impart a more favorable sensory aspect to whey, it is still deemed necessary to incorporate natural or artificial flavorings. Orange (citrus) is a common flavor used in food products. Consequently, this study was conducted to enhance the sensory aspect of whey by fermenting it and adding natural and artificial citrus flavorings, with subsequent evaluation through consumer acceptance. According to the study results, significant findings were observed in flavored fermented whey, exhibiting higher consumer acceptance compared to fermented whey without flavor. In conclusion, the addition of both natural and artificial citrus flavorings to fermented whey served to enhance its sensory aspect and elevate consumer acceptance.

Utilization of Whey for Eco-Friendly Bio-Preservation of Mexican-Style Fresh Cheeses: Antimicrobial Activity of Lactobacillus casei 21/1 Cell-Free Supernatants (CFS).

Using whey, a by-product of the cheese-making process, is important for maximizing resource efficiency and promoting sustainable practices in the food industry. Reusing whey can help minimize environmental impact and produce bio-preservatives for foods with high bacterial loads, such as Mexican-style fresh cheeses. This research aims to evaluate the antimicrobial and physicochemical effect of CFS from Lactobacillus casei 21/1 produced in a conventional culture medium (MRS broth) and another medium using whey (WB medium) when applied in Mexican-style fresh cheese inoculated with several indicator bacteria (Escherichia coli, Salmonella enterica serovar Typhimurium, Staphylococcus aureus, and Listeria monocytogenes). The CFSs (MRS or WB) were characterized for organic acids concentration, pH, and titratable acidity. By surface spreading, CFSs were tested on indicator bacteria inoculated in fresh cheese. Microbial counts were performed on inoculated cheeses during and after seven days of storage at 4 ± 1.0 °C. Moreover, pH and color were determined in cheeses with CFS treatment. Lactic and acetic acid were identified as the primary antimicrobial metabolites produced by the Lb. casei 21/1 fermentation in the food application. A longer storage time (7 days) led to significant reductions (p < 0.05) in the microbial population of the indicator bacteria inoculated in the cheese when it was treated with the CFSs (MRS or WB). S. enterica serovar Typhimurium was the most sensitive bacteria, decreasing 1.60 ± 0.04 log10 CFU/g with MRS-CFS, whereas WB-CFS reduced the microbial population of L. monocytogenes to 1.67 log10 CFU/g. E. coli and S. aureus were the most resistant at the end of storage. The cheese's pH with CFSs (MRS or WB) showed a significant reduction (p < 0.05) after CFS treatment, while the application of WB-CFS did not show greater differences in color (ΔE) compared with MRS-CFS. This study highlights the potential of CFS from Lb. casei 21/1 in the WB medium as an ecological bio-preservative for Mexican-style fresh cheese, aligning with the objectives of sustainable food production and guaranteeing food safety.

Milk protein polymorphisms of Aosta Valley cattle breeds

Abstract Cow’s milk proteins are encoded by highly polymorphic genes characterized by several mutations which result in different allelic variants. Each allelic variant has different possible effects on cheese-making properties and on human health. β-casein A1-A3-I-B, k-casein B and β-lactoglobulin B are supposed to influence milk cheese-making properties by increasing cheese or milk yield, by varying chemical parameters, by having small casein micelle size, and by influencing rennet coagulation time (RCT) and curd-firming rate (CFR). In addition, β-casein A1-B are also considered to be a risk factor for different health diseases such as ischemic heart disease (IHD), type 1 diabetes (T1D), decreased glutathione (GSH) concentration, and milk intolerance. An LC-MS method was applied to profile, for the first time, the main milk proteins genetic variants from Aosta Valley autochtonous cattle breeds. Analyses performed on milk collected from bovines of three cattle breeds (Red Pied – VRP, Black Pied – VNP and Chestnut – CAS), either from IAR experimental farm or from herds of dairy-producers in Aosta Valley region, showed quite high frequencies of β-casein A2 and A3/I, and low frequencies of β-casein A1. Moreover, low frequencies of β-casein B in VRP breed and high frequencies of the same variant in CAS, and VNP breeds have been found. As far as k-casein is concerned allelic variant B is the most diffused in VRP while allelic variant A in VNP and CAS breeds. Finally, β-lactoglobulin most diffused allelic variant for all breeds is B. Results suggest that Aosta Valley milk has good cheese-making properties and good frequencies of β-casein A2 which may be related to beneficial effects on human health. In light of these results, it is important to develop breeding programs which take into consideration milk proteins polymorphisms to further increase the milk suitability for cheese-making process and to decrease the presence of β-casein A1 and B in drinking milk which can be a risk factor for human health.

Microbiological, chemical, and artificial sensory assessment of Sicilian cheeses made using different milk-clotting enzymes

In the present study, cheeses coagulated with different milk-clotting enzymes were investigated. In detail, calf rennet, microbial coagulant, and a kiwifruit enzymatic extract were used in three independent cheesemaking processes. Microbiological, chemical, and sensory profiles, by using E-Eye, E-Nose, and E-Tongue platforms, were evaluated. Based on microbiological data, mesophilic bacteria, Lactobacilli, and Lactococci showed similar viable count in cheeses clotted with animal rennet and with vegetable coagulant. Differently, higher value of mesophilic bacteria and lower count of both Lactobacilli and Lactococci were detected in samples obtained using microbial coagulant. Additionally, as revealed by the fatty acid composition, the kiwifruit enzymatic extract allowed to obtain a final product with improved health properties. Concerning the artificial senses, E-Eye, E-Nose, and E-Tongue, a similar sensory profile was revealed among cheeses clotted using the kiwifruit enzymatic extract and the calf rennet whereas a different sensory profile was observed in microbial clotted cheeses. This work demonstrated that the kiwifruit extract is a valid coagulant alternative to calf rennet and microbial coagulant.

Factors affecting the coagulation of milk protein during quark cheese processing in Vietnam

In recent years, cheese consumption in Vietnam is markedly rising, leading to the attention of local milk processors on cheese making. Quark-type cheese, a traditional food in Central Europe, is a type of well-known acid-coagulated cheese product. Milk coagulation properties (MCPs) play an important role to the success of the cheese-making process and are influenced by different parameters. In this study, the quality of raw milk for cheese making and the coagulation conditions in quark-type cheese processing were investigated. Raw milk collected from Phu Dong dairy farm met the requirement of Vietnamese standard for cheese making. The appropriate conditions for coagulation were identified: the heat treatment of milk at 60°C for 15 minutes, coagulation temperature at 40oC and pH 5.5, CaCl2 concentration at 0.04g/l. Under these conditions, a short coagulation time (72.33 seconds) and high curd yields (50.70%) were obtained. These results suggested that quark-type cheese using raw milk in Vietnam could be successfully developed at larger scale.