Cheese Processing Research Articles

Small and large deformation rheology on pizza cheese as an example of application to study anisotropic properties of food soft materials

Various rheological techniques were applied to study pizza cheese, as a model anisotropic material. Small Amplitude Oscillatory Shear (SAOS) was combined with Large Amplitude Oscillatory Shear (LAOS) rheology, and the data compared to large deformation tests and confocal microscopy. Pizza cheese was analyzed at various stages of processing: before/during mixing, freshly stretched and after 1 and 2 weeks of storage. Directional sampling and testing were of critical importance for data interpretation. LAOS data were evaluated using a recently developed software that, with visual interactive analysis, including layover plots and similarity maps, allowed to provide a rheological fingerprint of the cheese's process and storage-induced structural changes. This work demonstrated that by using complementary rheological and microstructural techniques it is possible to improve our understanding of the anisotropy at different length scales, and to distinguish the differences in the networks among samples after various processing stages.

The use of milk Fourier-transform infrared spectra for predicting cheesemaking traits in Grana Padano Protected Designation of Origin cheese

The prediction of the cheese yield (%CY) traits for curd, solids, and retained water and the amount of fat, protein, solids, and energy recovered from the milk into the curd (%REC) by Bayesian models, using Fourier-transform infrared spectroscopy (FTIR), can be of significant economic interest to the dairy industry and can contribute to the improvement of the cheese process efficiency. The yields give a quantitative measure of the ratio between weights of the input and output of the process, whereas the nutrient recovery allows to assess the quantitative transfer of a component from milk to cheese (expressed in % of the initial weight). The aims of this study were: (1) to investigate the feasibility of using bulk milk spectra to predict %CY and %REC traits, and (2) to quantify the effect of the dairy industry and the contribution of single-spectrum wavelengths on the prediction accuracy of these traits using vat milk samples destined to the production of Grana Padano Protected Designation of Origin cheese. Information from 72 cheesemaking days (in total, 216 vats) from 3 dairy industries were collected. For each vat, the milk was weighed and analyzed for composition (total solids [TS], lactose, protein, and fat). After 48 h from cheesemaking, each cheese was weighed, and the resulting whey was sampled for composition as well (TS, lactose, protein, and fat). Two spectra from each milk sample were collected in the range between 5,011 and 925 cm-1 and averaged before the data analysis. The calibration models were developed via a Bayesian approach by using the BGLR (Bayesian Generalized Linear Regression) package of R software. The performance of the models was assessed by the coefficient of determination (R2VAL) and the root mean squared error (RMSEVAL) of validation. Random cross-validation (CVL) was applied [80% calibration and 20% validation set] with 10 replicates. Then, a stratified cross-validation (SCV) was performed to assess the effect of the dairy industry on prediction accuracy. The study was repeated using a selection of informative wavelengths to assess the necessity of using whole spectra to optimize prediction accuracy. Results showed the feasibility of using FTIR spectra and Bayesian models to predict cheesemaking traits. The R2VAL values obtained with the CVL procedure were promising in particular for the %CY and %REC for protein, ranging from 0.44 to 0.66 with very low RMSEVAL (from 0.16 to 0.53). Prediction accuracy obtained with the SCV was strongly influenced by the dairy factory industry. The general low values gained with the SCV do not permit a practical application of this approach, but they highlight the importance of building calibration models with a dataset covering the largest possible sample variability. This study also demonstrated that the use of the full FTIR spectra may be redundant for the prediction of the cheesemaking traits and that a specific selection of the most informative wavelengths led to improved prediction accuracy. This could lead to the development of dedicated spectrometers using selected wavelengths with built-in calibrations for the online prediction of these innovative traits.

Sustainable Ice Cream Base: Harnessing Mango Seed Kernel (Mangifera indica L. var. Tommy Atkins) Waste and Cheese Whey

The agro-food industry plays a crucial role in enhancing living standards; however, inadequate losses and waste management persists as significant challenges within its processes. Particularly, mango and cheese processing generate substantial waste, leading to ecological disruptions, economic losses, and concerns related to food security and public health. To address these issues, this study was aimed at utilizing this waste to produce a high-quality ice cream base, thereby valorizing the discarded materials. This approach not only adds nutritional value but also contributes to food security and sovereignty. The raw materials (cheese whey, oil, and starch) were subjected to physicochemical characterization, leading to the development of three different ice cream base formulations. Subsequently, the ice cream bases were evaluated for their physicochemical, functional, and sensory properties. The findings of this study revealed that mango seed kernel and cheese whey waste contain valuable components that enable the creation of an ice cream base with excellent physicochemical, functional, and sensory properties. Moreover, this research showcases a promising solution for effectively valorizing food waste and generating value-added products such as ice cream, thus promoting sustainability and resource optimization within the agro-food industry.

Physicochemical evaluation of acid whey obtained from doble crema cheese produced in Belén, Boyacá, Colombia

The composition of acid whey makes it less usable, and it is an environmental and technical problem. This research aims to estimate the physicochemical characteristics of the doble crema cheese acid whey, from nine factories in the municipality of Belén in Boyacá. Laboratory methods were validated using the Lactoscan analyzer determinations and comparing them with reference methods. Accuracy was expressed in terms of relative error (% Edet) and f- and p-values; then, correlation curves were elaborated. To perform the physicochemical characterization of whey, fat, Solids-Not-Fat (SNF), protein, lactose, pH, total ash, calcium, density, and acidity were determined. The statistic of the comparison between analysis methods showed low percentages of relative error, there were no significant differences, and they had correlation coefficients greater than 0,8. The results of the physicochemical characterization showed differences in the content of protein, SNF, lactose, fat, ash, calcium, acidity, and pH. Each manufacturer has a manufacturing process for cheese and whey. There were no statistical differences for SNF, density, lactose, fat, ash, and pH within each company. However, there were differences between protein and acidity, even though companies work with the same quality of raw material and processing, there are deficiencies in the coagulation, drainage, and conservation of the whey. The analyzed acid whey is a good source of protein, calcium, lactose and has low fat content, which is attractive for manufacturing food products.

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.

Characterization of artisanal saffron ricotta cheese produced in Sicily: Physicochemical, microbiological, sensory, and antioxidant characteristics

The present study aims to characterize the artisanal saffron ricotta cheese produced from the whey of Piacentinu Ennese protected designation of origin (PDO) cheesemaking, including via technological parameters detected during the production process and by assessment of the main physicochemical, microbial, sensory, and antioxidant characteristics. A survey on the manufacture process of saffron and control ricotta cheese was conducted on 3 farms, located in the production area of the Piacentinu Ennese PDO cheese. pH and temperature followed a specific behavior, characterized by an inverse trend where pH decreased and temperature increased, playing an important role in the production process. All the analytical parameters were affected by the presence of saffron, also showing high between-farm variability, with significantly higher total solids and fat contents in saffron ricotta cheese compared with the control cheese (28.68% vs. 23.86%, and 19.83% vs. 14.22%, respectively). Microbial analysis showed significantly lower values in saffron compared with control ricotta cheese, for coliforms (1.51 vs. 1.91 log10 cfu/g, respectively), yeasts (1.55 vs. 2.06 log10 cfu/g, respectively), and molds (1.03 vs. 1.30 log10 cfu/g, respectively), denoting potential reduction of microbial growth asserted by saffron. Escherichia coli concentration (1.26 log10 cfu/g) in saffron ricotta cheese was in accordance with EU Regulation 2073/2005 and then safe for consumption. The presence of saffron influenced all sensory attributes, particularly color and aroma. Interestingly, high total antioxidant activity was found in saffron ricotta cheese (372 µC) compared with the control cheese. Thus, this artisanal dairy production could be considered a suitable option for functional foods with antimicrobial properties, due to the presence of saffron, which may contribute to extend the shelf life of the product. Further studies need to focus on the bioactive compounds that affect the antioxidant proprieties, characterization of the microbiota of saffron ricotta cheese, and evaluation of consumers' acceptance and perception as well as market demand.

Mozzarella Cheese Processing Training for Farmers in Tonjong Village, Tajurhalang District, Bogor Regency

One of the main problems faced by farmers in Tonjong Village, Tajur Halang Regency, Bogor is that the selling price of pure milk in 1 liter is quite low. Public knowledge regarding processing technology to increase product added value is still low, which is the reason farmers sell pure milk directly. This community service training aims to determine the effect of processing pure milk into mozzarella cheese on increasing community knowledge and skills. This increase in knowledge was measured using a one group pretest posttest design which was carried out in a prametric analysis using a paired sample t-test to see the difference in the mean scores. This training activity was given to 10 people in the community around the cattle farm in Tonjong Village who had an age range of 26-70 years and had the last education from elementary to high school. The results of this training community service indicate that there is a significant effect of giving on increasing community knowledge as evidenced by the significantly different pretest (68%) and posttest (87%) values (p <0.05). The expected results of community service can be implemented independently by breeders to increase the added value of dairy products through the processing of mozzarella cheese.

Focus on histamine production during cheese manufacture and processing: A review.

Histamine (HIS) intoxication is a poisoning caused by histamine in food. Cheese is one of the most common dairy products associated with histamine levels which vary depending on the processing methods. The final content of histamine in cheese is influenced by intrinsic and extrinsic factors, their interactions, and contamination stemming from food processing. The application of control measures may be useful to inhibit/reduce production during cheese manufacture and processing but have a limited effect. To reduce histamine intoxication outbreaks from cheese consumption the introduction of quality control programs and appropriate risk mitigation options should be applied along the dairy chain from an overall perspective of food safety based on individual susceptibility and consumer sensitivity. As key food safety, this topic should be considered in future regulations in dairy products because the lack of a clear law on HIS limits in cheese may result in a significant potential deviation from the EU food safety strategy.

The Impact of White Mulberry, Green Barley, Chia Seeds, and Spirulina on Physicochemical Characteristics, Texture, and Sensory Quality of Processed Cheeses.

Processed cheeses (PC) are products resulting from the mixing and melting of rennet cheese, emulsifying salts, water, and possibly various additional ingredients. They are considered good vehicles for new ingredients, including plant-based ones. In addition to the health-promoting effects of plant-based ingredients, some of them can also affect positively the quality characteristics of PC (e.g., texture, taste, and consistency) and their addition may reduce the amount of emulsifying salts used. The aim of the study was to determine the possibility of the addition of 0.5, 1.0, 2.0, and 3.0% white mulberry (M), chia (Ch), green barley (GB), or spirulina (S) to PC and the effects on selected characteristics of these products (chemical composition, pH, water activity, color parameters, texture, and sensory properties). In all PC variants, a significance decrease in the dry matter content was observed with an increase in the additive level. The use of plant-based additives allowed us to reduce the addition of emulsifying salts by 50% compared to their typical amounts and the share of rennet cheese in the PC recipe by approximately 18%, which had a beneficial effect on the nutritional value of these products. The use of 3% GB, Ch, or M as additives to PC enabled a reduction in its sodium content by 27, 27, and 42%, respectively, compared to the control cheese. Among the tested additives, GB caused the greatest increase in the hardness of PC (even at the amount of 0.5%), indicating that is beneficial and can be used in the production of sliced PC. All the additives either significantly reduced the adhesiveness of PC or had no effect on this parameter. In terms of sensory characteristics, the highest acceptable addition of GB was 0.5%, and that for S and Ch was 1%, while the addition of M, even at 3%, was assessed very positively. The results of this research may be helpful in the development of new recipes for processed cheeses obtained in industrial conditions.

Effect of Palmito cheese processing on sensory characteristics and degree of liking

Introduction. The production of regional food with local and cultural identity has become an attractive business for small-scale producers because it allows them to market their products highlighting local ingredients and traditional processing that reflects the know-how of each region. One example is Pasta filata cheese. Objective. To identify sensory characteristics and level of liking for Costa Rican Pasta filata cheeses (Palmito cheese). Materials and methods. The project was carried out at the facilities of the University of Costa Rica, during 2015. Nineteen samples of Costa Rican Palmito cheese were used, with fourteen of them being produced by artisanal producers and five by industrial producers. The methodology of Generic Quantitative Descriptive Analysis (QDA) was followed, with ten trained judges defining twenty-one attributes. Agglomerative Hierarchical Clustering (AHC) and Principal Component Analysis (PCA) were conducted to relate the samples to their attributes. Acceptance testing was performed with one hundred consumers. Consumer AHC and external preference mapping were applied to correlate the results of the liking with those of the QDA. Results. Significant differences (p<0,05) among samples were obtained in the QDA for all attributes. The samples were grouped into three clusters based on similarity attributes. The PCA showed one group, primarily consisting of traditional cheeses, clustered by attributes such as acid and salty flavor, firmness, moisture, and stringy appearance. Another group, corresponding to refrigerated, pasteurized, and unpasteurized cheeses, had a higher intensity of yellow color, greasy texture, softness, and less stringy appearance. A final group, composed of one sample, had a lettuce flavor. Conclusion. Through the external preference mapping, it was concluded that consumers like the majority of industrial Palmito cheeses, but they prefer traditional ones with characteristics such as stringy and creamy flavor.

ANALYTICAL REVIEW OF BIOTECHNOLOGICAL PROBLEM OF UKRAINIAN HARD CHEESES

An analytical review of the biotechnological process of production of various hard and semi-hard cheeses in the EU and Ukraine, as well as domestic recipes of fermented cheeses for production at craft cheese factories and at home, was conducted. An analysis of the conditions of the key stages of production, including fermentation, coagulation and ripening, was carried out. The composition and type of lactic acid bacteria in sourdough for fermented cheeses, as well as enzymes for fermentolysis and coagulation of milk casein, were studied. As a result of a complex study, a total of 73 types of hard and semi-hard cheeses were analyzed: 35 recipes of the New England Cheesemaking Supply Company by Jim Wallace; 30 production processes of hard and semi-hard cheeses from the EU; 8 technical conditions of hard cheeses of Ukrainian producers. It is shown that the prospects for optimizing the development of new types of hard and semi-hard cheeses in Ukraine are mainly related to the regulation of the time and temperature of fermentation, cooking and ripening of cheeses, as well as the expansion of the biodiversity of the primary and secondary microbiome of starter cultures to improve the taste and aroma of the ready-to-use product. Purpose: to analyze the fermentation process and recipes for the production of hard cheeses in Ukraine with the main world samples, to compare the composition and type of lactic acid bacteria in industrial and craft starters, as well as the types of enzymes for fermentolysis and casein coagulation of milk, in order to optimize production to improve the taste and aroma of ready-to-use product. Materials and methods. Methodical analysis and abstract-logical method for summarizing the evaluation criteria of the biotechnological process of various hard and semi-hard domestic cheeses with world samples according to recommendations, requirements and standards with the development of patents, technical conditions of their production in the EU and Ukraine; DSTU 6003 (Solid cheeses); New England Cheesemaking Supply Company cheese recipes by Jim Wallace. The obtained data were processed by methods of statistical analysis, systematization, comparison and generalization of information. Results. In this study, the documentation was examined and the data of standards, regulations, requirements and recommendations regarding the biotechnology of hard and semi-hard cheeses were analyzed, an analysis of the market of hard cheeses and the peculiarities of the fermentation process of their production was carried out with the determination of critical points and key stages of production using industrial deposited fermentation producers and protein enzymes coagulation and biodiversity of lactic acid bacteria in sourdoughs for fermented cheeses at world productions, with an assessment of the prospects for developing new and improving the biotechnology of Ukrainian benign and safe hard cheeses for healthy nutrition.

Anti-Listerial Activity Control of Postbiotic in Cow Milk Lump Cheese Processing

Anti-Listerial Activity Control of Postbiotic in Cow Milk Lump Cheese Processing

Cheese value chain in the highlands of Southern Peru: critical success factors

PurposeThis article examines the dairy value chain in Southern Peru and identifies four critical success factors that can enhance the local situation.Design/methodology/approachThe study employed descriptive research using semi-structured interviews with entrepreneurs from 17 cheese factories across eight districts, namely Azángaro, Ayaviri, Pucara, Lampa, Cabana, Acora, Pomata and Puno. Quantitative market data were also gathered and analyzed alongside qualitative views.FindingsThe study identified four critical issues: quality concerns in milk production, suboptimal managerial practices of cheese-processing plants, lack of compliance to regulations, particularly hygiene and environmental ones, and inadequate access to finance. The findings reveal a gap between the practices of the Puno region's dairy industry and world-class standards for cheese production. Urgent actions are required to improve product quality, increase access to finance, enhance managerial education and ensure compliance with regulations.Research limitations/implicationsResults suggest critical issues to be prioritized, but the article does not propose how to solve the problems identified. External factors, such as economic changes, were also not considered. Interviews were conducted exclusively with cheese processing entrepreneurs, not milk producers.Originality/valueThis case study provides an insight into the interior of Peru, an under-researched region facing several development challenges. The findings have significant implications for dairy value chain stakeholders in Peru and other similar contexts.

A Meta-Analysis of Bacterial Communities in Food Processing Facilities: Driving Forces for Assembly of Core and Accessory Microbiomes across Different Food Commodities.

Microbial spoilage is a major cause of food waste. Microbial spoilage is dependent on the contamination of food from the raw materials or from microbial communities residing in food processing facilities, often as bacterial biofilms. However, limited research has been conducted on the persistence of non-pathogenic spoilage communities in food processing facilities, or whether the bacterial communities differ among food commodities and vary with nutrient availability. To address these gaps, this review re-analyzed data from 39 studies from various food facilities processing cheese (n = 8), fresh meat (n = 16), seafood (n = 7), fresh produce (n = 5) and ready-to-eat products (RTE; n = 3). A core surface-associated microbiome was identified across all food commodities, including Pseudomonas, Acinetobacter, Staphylococcus, Psychrobacter, Stenotrophomonas, Serratia and Microbacterium. Commodity-specific communities were additionally present in all food commodities except RTE foods. The nutrient level on food environment surfaces overall tended to impact the composition of the bacterial community, especially when comparing high-nutrient food contact surfaces to floors with an unknown nutrient level. In addition, the compositions of bacterial communities in biofilms residing in high-nutrient surfaces were significantly different from those of low-nutrient surfaces. Collectively, these findings contribute to a better understanding of the microbial ecology of food processing environments, the development of targeted antimicrobial interventions and ultimately the reduction of food waste and food insecurity and the promotion of food sustainability.

Transfer of β-lactam and tetracycline antibiotics from spiked bovine milk to Dambo-type cheese, whey, and whey powder

The aim of this study was to investigate the transfer of residues of five β-lactam antibiotics (ampicillin, penicillin G, cloxacillin, dicloxacillin and cephalexin) and two tetracyclines (tetracycline and oxytetracycline) in the processing of cheese and whey powder, evaluating the effect of the processes and the final concentration in each product generated. Raw milk was fortified at two concentration levels with the seven antibiotics. The first concentration level (C1) was chosen according to the maximum residue limit (MRL) of each antibiotic (ampicillin and penicillin G: 4 µg kg−1; cloxacillin and dicloxacillin: 30 µg kg−1; cephalexin, tetracycline and oxytetracycline: 100 µg kg−1). The second concentration level (C2) was spiked as follows according to each antibiotic: 0.5 MRL (cloxacillin, dicloxacillin, cephalexin), 0.1 MRL (tetracycline and oxytetracycline) and 3 MRL (ampicillin and penicillin G). The antibiotics were analyzed by LC-MS/MS. No ampicillin or penicillin G residues were found in cheese or whey powder, although they were detected in whey at concentrations similar to those added to raw milk. Cephalexin was mostly distributed in whey between 82% and 96%, being the antibiotic that presented the highest concentration in whey powder (784 ± 98 µg kg−1) when milk was spiked at the MRL. The whey distribution of cloxacillin and dicloxacillin ranged from 57% to 59% for cloxacillin and from 46% to 48% for dicloxacillin, and both concentrated in whey powder. Tetracyclines were the antibiotics that concentrated in cheese, with retentions between 75% and 80% for oxytetracycline and between 83% and 87% for tetracycline. The distribution of antibiotics in the dissimilar stages of the cheese and whey powder production processes, as well as their concentration in the final products, depend on each type of antibiotic. Knowledge of the transfer of antibiotic residues during the process and final disposal is an input for the risk assessment of their consumption.

Manufacture of loaf‐type processed cheese products using transglutaminase crosslinked micellar casein concentrate and milk protein concentrate

The aim of this research was to determine the effect of transglutaminase (TGase; 0, 0.3 and 3.0 units/g of protein) crosslinked micellar casein concentrate (MCC) and milk protein concentrate (MPC) on the functionality of process cheese product (PCP) loaf‐type formulation. The results showed that TGase significantly (P ≤ 0.05) increased viscosity after manufacture. Higher TGase levels also significantly (P ≤ 0.05) affected post‐manufacture melt characteristics such as melt viscosity and melt area measured using a rapid visco analyser and Schreiber melt test respectively. The study shows that the TGase treatment alters meltability of PCP.

Comparative Study of some Characteristics for Whey Cheese Produced by Heat Acid Coagulation

In the current study sweet whey obtained from white soft cheese was used for processing of Ricotta cheese using heat treatment with acid and Best Ricotta which manufactured by heating without addition of acid. Cheese samples were analyzed for some physicochemical analysis (moisture, total solids, pH, protein, yield and hardness) and organoleptic characteristics including (Appearance, texture, flavor, color, and overall acceptability) during 7 days of storage at 4±1ºc. It was found that the moisture content of Ricotta cheese was76.50% which was lower than that of Best ricotta 79.266%, the total solid of Best ricotta cheese was 17.733 %, while for Ricotta cheese was 21.50 %. Ricotta cheese characterized by lower pH value of 5.48 and higher acidity, protein contain, yield and hardness 0.103 %, 14.2%, 8.7% and 6g as compared to Best Ricotta cheese which were 6.40, 0.054 %, 12.26%, 6.49% and 3.66 g respectively at the first day of cold storage. It was noted that with the prolonged of the storage time, there was an increase in the values of some characteristics, including the percentage of total solids, acidity and hardness, while there was a decrease in the values of pH, moisture and protein percentage. Ricotta cheese gets the highest score by sensory panelists for the texture and appearance and unlike for, flavors and color than the Best Ricotta. Those degrees decreased slightly during the storage period.

Fluidized bed drying of dairy gel granules supported by in-line monitoring of the water content

New flexibility in cheese processing is gained with this work, by producing a storable intermediate via drying of dairy gel granules. The granules tend to agglomerate without agitation and oil-out or transition from gel to sol at high temperatures. A fast drying is necessary to ensure quality, shelf life, and rehydration. Due to its high heat transfer and homogenous mixing fluidized bed drying was selected. However, the large and dense granules are a highly challenging product for fluidized bed drying. Consequently, two different in-line measurement techniques were installed and calibrated for monitoring the water content of the samples. A design of experiments with varying temperatures and volume flows was performed and different granule properties were optimized as responses. A capacitive and a near-infrared sensor were successfully calibrated to the water content for in-line monitoring as a first step to a smart and dynamic drying process.

The current trends of bioethanol production from cheese whey using yeasts: biological and economical perspectives

Besides organic compounds such as lactose and proteins, cheese whey is rich in other nutrients. Damping of these valuable compounds to the environment, first, harms the environment, and second, it wastes valuable resources. Therefore, this review aims to find out the current progress on the valorization of cheese whey for ethanol production. Efficient ethanol-producing yeasts like Saccharomyces cerevisiae have no pathway to utilize lactose and, therefore, they can be co-cultured with microbes that can produce β-galactosidase. In addition, chemical, biological, and physical hydrolysis of lactose can be used to produce ethanol from cheese whey. Ethanol production from unsterilized or unpasteurized whey is very promising and this reduces the production cost significantly. This suggests that the ethanol-producing yeasts are competent against the lactic acid bacteria that are commonly found in cheese whey. Despite the presence of central metabolic genes associated with ethanol production from different sugars in some yeasts, these yeasts can’t ferment the different sugars and this is basically due to a lack of the different sugar transport systems in the yeasts. Therefore, additions of different sugars to whey to increase the sugar content for economical ethanol production are impaired by catabolite repressions. However, catabolite repression can be significantly reduced by metabolic engineering by targeting sugar transporter proteins like the major facilitator superfamily (MFS), particularly LAC, CEL2, HGT, RAG, and KHT. Therefore, this enhances ethanol production from cheese whey supplemented with a variety of sugars. Currently, nanoparticles and metal-organic frameworks coated immobilization of S. cerevisiae produced higher ethanol from lignocellulosic substrates than the classical carries such as alginates; however, studies of such immobilizing materials on Kluveromyces spp for ethanol production are very limited, and open for research. Electro-fermentation, an emerging bioprocess to control microbial fermentative metabolism, boosts ethanol production, enables the production of 14% (v/v) ethanol, and shortens the fermentation time of high sugar-containing whey. Generally, utilizing efficient yeast (possibly by adaptive evolution and genetic engineering) at optimal fermenting conditions enabled to production of economical ethanol from cheese whey that contains higher sugars (greater than 15%) at the large-scale cheese processing industries.

Bactericidal and bacteriostatic effects of sodium polyphosphate emulsifying salts on selected targets in processed cheese

Processed cheeses (PC) are products with extended shelf-lives, they have in their composition such additives as emulsifying salts and preservatives. Emulsifying salts are used due their desirable emulsification properties, however, little is known about their inhibitory activity against microorganisms that can survive and multiply in these products; jeopardizing cheese quality or even posing as hazards to consumers. The aim is to determine how mixtures of emulsifying salts (ESSP: emulsifying salt composed of short polyP; BSLP: bacteriostatic salt composed of long polyP; and trisodium citrate) can influence the microbial populations in PC during 90 days of storage. A total of 14 treatments (T1 - T14) were evaluated against eight target strains (Bacillus cereus INV 10(3); Bacillus subtilis ATCC 19659; Bacillus thuringiensis CFBP 3476; Clostridium perfringens ATCC 13124; Enterococcus faecalis FAIR-E 179; Listeria monocytogenes Scott A; Pseudomonas fluorescens 07A; and Staphylococcus aureus ATCC 6538) inoculated into PC. A treatment composed of emulsifying salts without antimicrobial effect (ESSP 1.5%) was considered as the positive growth control, and another treatment composed of antimicrobial additives (nisin and potassium sorbate) was considered as the negative growth control. Bacterial growth was analyzed using ANOVA and Tukey (p < 0.05), based on selected treatment grouping. Most treatments resulted in some level of bactericidal or bacteriostatic effect against the target microorganisms. Bactericidal activity was evident against Bacillus spp., and bacteriostatic effect was clear against C. perfringens, E. faecalis, L. monocytogenes and S. aureus (p < 0.05) during the storage period. T13, composed of 1.5% BSLP, presented results comparable to those observed for the negative control for bacterial inhibition in PC samples during 90 days of storage. T13 was able to reduce the B. cereus INV 10(3) and B. thuringiensis CFBP 3476 population more than the negative control (p < 0.001), as well as present better results for the inhibition of C. perfringens ATCC 13124 and L. monocytogenes Scott A by the end of storage. The performance of the negative control was better than T13 only against S. aureus - ATCC 6538 (p < 0.001). Taken together, the results contribute to expanding the understanding of emulsifying salt application in PC, with a focus on microbiological safety and shelf-life.