Microstructure Of Cheese Research Articles

Impact of Pressing Time on the Microstructure of Two Types of Goat Cheeses and Its Relationship With Sensory Attributes.

The objective of this study was to study the impact of pressing time on the microstructure of goat cheese and its relationship with sensory attributes. The microstructure of the artisanal cheeses was performed by scanning electron microscopy and image analysis. The validation of the microstructural complexity was carried out experimentally with sensory attributes. The pressing time influenced the microstructural parameters Feretmax, Geodiam, and τ and the cheese type influenced the parameters Feretmax, Geodiam, and Geoelong. The correlation values between microstructural complexity and sensory attributes were 0.85 and 0.84 for fresh cheeses and matured cheeses, respectively. The pressure times of 12 and 18 h resulted in cheese microstructures with the highest complexity in terms of Feretmax, Geodiam, Geoelong, and τ parameters. The obtained results are supported by the correlation values between microstructural complexity and sensory attributes.

Effect of the whey protein isolate-pectin bilayer emulsion system on the textural properties and oil release characteristics of room-temperature stored processed cheese

Processed cheeses stored at room temperature exist some texture defects, such as texture softening and free oil release. The emulsion obtained by pre-emulsifying butter with whey protein isolate (WPI) can significantly improve the texture softening, but it was unable to mitigate the release of free oil during storage. Therefore, in this study, a WPI-pectin bilayer emulsion system was manufactured and applied in the production of processed cheese. The effects of adding the WPI-pectin bilayer emulsion system on the texture and functional characteristics of processed cheese during storage were investigated. The results of the study showed that the WPI-pectin bilayer emulsion system significantly improved the texture softening and free oil release characteristics of the room-temperature stored (RTS) processed cheese. Scanning electron microscopy revealed that the addition of the WPI-pectin bilayer emulsion system increased the uniformity of cheese microstructure and the number of small free fat pools after pre-emulsification. This study provided a method for improving the texture defects of RTS processed cheese, which is important for the processing and promotion of RTS processed cheese.

The role of microbial coagulants on the physicochemical, proteolysis, microstructure and sensory properties of low-fat Edam cheese manufactured from ultrafiltered buffalo milk

This work investigates the influence of using microbial coagulants, including Rhizomucor miehei (MCR) protease and Cryphonectria parasitica (MCC) protease, on the quality characteristics of low-fat Edam cheese made from ultrafiltered buffalo milk (LFUE). Concurrently, a benchmark with calf rennet (CR) has been also performed. Throughout a 90-day ripening period, the cheeses were assessed for their physicochemical features, proteolysis, texture, free amino acid and free fatty acid content, microstructure, and sensory attributes. The study revealed that both microbial coagulants had no significant impact on the physicochemical composition and firmness of the cheeses while slightly affected the free fatty acids. Cheeses made with microbial coagulants displayed higher proteolysis, with MCR and MCC cheeses exhibiting greater levels of water-soluble nitrogen and 12% trichloroacetic acid-soluble nitrogen than CR cheese. MCR and MCC cheeses exhibited more extensive breakdown of αs- and β-caseins, as indicated by the SDS-PAGE electrophoretogram, compared to CR cheese during ripening. As for the proteolytic activity, the microbial coagulant contributed to shaping the free amino acid content, microstructure, and sensory qualities of the cheeses. Notably, MCC cheese outperformed MCR or CR cheeses in terms of free amino acid levels. MCR and MCC cheeses resulted in smooth microstructures with uniform protein networks as observed by microscopy, while CR cheese displayed rough, granular surfaces. With the highest scores for appearance, body, texture, and flavor, MCC cheese demonstrated superior sensory properties compared with MCR and CR cheeses.

Autochthonous cultures to improve the quality of PGI Castellano cheese: Impact on proteolysis, microstructure and texture during ripening

The aim of this research was to find out the effect of different combinations of starter and non-starter cultures on the proteolysis of Castellano cheese during ripening. Four cheese batches were prepared, each containing autochthonous lactobacilli and or Leuconostoc, and were compared with each other and with a control batch, that used only a commercial starter. To achieve this, nitrogen fractions (pH 4.4-soluble nitrogen and 12 % trichloroacetic acid soluble nitrogen, polypeptide nitrogen and casein nitrogen), levels of free amino acids and biogenic amines were assessed. Texture and microstructure of cheeses were also evaluated. Significant differences in nitrogen fractions were observed between batches at different stages of ripening. The free amino acid content increased throughout the cheese ripening process, with a more significant increase occurring after the first 30 days. Cheeses containing non-starter lactic acid bacteria exhibited the highest values at the end of the ripening period. Among the main amino acids, GABA was particularly abundant, especially in three of the cheese batches at the end of ripening. The autochthonous lactic acid bacteria were previously selected as non-producers of biogenic amines and this resulted in the absence of these compounds in the cheeses. Analysis of the microstructure of the cheese reflected the impact of proteolysis. Additionally, the texture profile analysis demonstrated that the cheese's hardness intensified as the ripening period progressed. The inclusion of autochthonous non-starter lactic acid bacteria in Castellano cheese production accelerated the proteolysis process, increasing significantly the free amino acids levels and improving the sensory quality of the cheeses.

Microstructural studies of imitation cheese with a shift in continuous phase

When casein is replaced with starch in imitation cheese, the functionality changes. Three different microscopy methods were applied to understand the microstructural differences in the product depending on which component dominates the microstructure. Confocal Laser Scanning Microscopy (CLSM) for component identification. Scanning Electron Microscopy (SEM) and Cryogenic Scanning Electron Microscopy (Cryo-SEM) for studying surface structures. Differences in the surface structures were detected between SEM and Cryo-SEM. In SEM, starch appeared rough and protein smooth, while in Cryo-SEM no starch roughness of the surface was found. A change in starch modification and effects of protein prehydration was also analysed. Adding octenyl succinic anhydride (OSA) modified starch for emulsifying properties resulted in a microstructure with fragmented protein at a protein level of 7 %, but not at 9 or 12 %. Protein prehydration had limited effect on microstructure. On a macrostructural level, the change to an emulsifying starch increased hardness in imitation cheese with 7 and 9 % protein. Protein prehydration slightly decreased the hardness, but the difference was not significant at all concentrations. This research provides valuable information about the microstructure of imitation cheese at a 50/50 composition, how the microstructure changes with an emulsifying starch and what occurs after a protein prehydration was included in the production.

Understanding mozzarella cheese microstructure with Raman confocal imaging

Raman confocal microscopy has the unique ability to interrogate the chemical structure of food samples; here we used the technique to investigate the microstructure in mozzarella cheese. Confocal and Raman confocal images were obtained on mozzarella samples immediately after production and then when aged over 112 d. A previously unseen level of heterogeneity in both the fat and casein regions of the mozzarella was apparent. The results illustrate the potential of Raman confocal imaging to understand both the microstructure and chemistry in complex dairy matrices.

Physicochemical, texture, microstructure, and antioxidant characteristics of karish cheese made from ultrasonic-treated skimmed buffalo milk

The effect of ultrasonic-treated skimmed buffalo milk on the antioxidant, physicochemical, texture, microstructure, microbiological, and organoleptic properties, as well as the yield of karish soft cheese was estimated. Ultrasonic processing of buffalo milk at 35 KHz for 10 and 20 min reduced the curdling time, and improved texture, microstructure, antioxidant, and sensory characteristics of cheese, while cheese yield was not affected compared with the control. On the contrary, prolonged ultrasound treatment (30 min) decreased the quality and acceptability of karish cheese. This study recommends the use of ultrasonically treated skimmed buffalo milk for 20 min in the production karish soft cheese.

Quarg Cheese: The Impact of Fat Content Change on its Microstructure, Characterization, Rheology, and Textural Properties

This study aimed to investigate the impact of different levels of fat content on the microstructure, rheology, and textural characteristics of Quarg cheese. Quarg is a soft unripened cheese variety made by the addition of mesophilic starter cultures (Lactococcus lactis subsp. lactis, Leuconostoc citrovorum) and a trace of rennet. The fat levels of cheese were; 6.0 ± 0.01 (QC1), 3.5 ± 0.03 (QC2), 1.5 ± 0.03 (QC3), and 0.5 ± 0.02 (QC4). Statistically significant changes (p< 0.05) were observed in the values of textural parameters. Furthermore, rheological investigations indicated a positive correlation between the reduction in fat percentages and an increase in the hardness of the cheese. The characterization of the sample was conducted using Fourier Transform Infrared (FTIR) and Ultraviolet-Visible (UV-Vis) spectrophotometric techniques. The microstructure of quarg cheese was analyzed using fluorescence microscopy and helped depict the distribution of fat and protein in the cheese matrix. Sensorial properties were superior in cheese samples with higher fat percentages as a virtue of fat content.

Properties of low-fat Cheddar cheese prepared from bovine–camel milk blends: Chemical composition, microstructure, rheology, and volatile compounds

Making cheese from camel milk (CM) presents various challenges due to its different physicochemical properties compared with bovine milk (BM). In this study, we investigated the chemical composition, proteolysis, meltability, oiling off, texture profile, color, microstructure, and rheological properties of low-fat Cheddar cheese (LFCC) prepared from BM-CM blends. LFCC was produced from BM or BM supplemented with 15% CM (CM15) and 30% CM (CM30), and analyzed after 14, 60, 120, and 180 d of ripening at 8°C. Except for salt content, no significant differences were observed among LFCC from BM, CM15, and CM30. The addition of CM increased the meltability and oiling off in the resulting cheese throughout storage. With respect to color properties, after melting, LFCC CM30 showed lower L* values than LFCC made from BM and CM15, and a* and b* values were higher than those of BM and CM15 samples. LFCC from CM30 also exhibited lower hardness compared with the other cheeses. Moreover, LFCC made from BM showed a rough granular surface, but cheese samples made from BM-CM blends exhibited a smooth surface. The rheological parameters, including storage modulus, loss modulus, and loss tangent, varied among cheese treatments. The determined acetoin and short-chain volatile acids (C2-C6) in LFCC were affected by the use of CM, because CM15 showed significantly higher amounts than BM and CM30, respectively. The detailed interactions between BM and CM in the cheese matrix should be further investigated.

Influence of acoustic cavitation on physico-chemical, organoleptic indicators and microstructure of Adyghe cheese produced from cow and goat milk

In this article, we studied the effect of acoustic cavitation on the physicochemical and organoleptic parameters, the microstructure of Adyghe cheese made from cow's and goat's milk, and their mixture. The experimental conditions, optimal modes of ultrasonic cavitation treatment of cow and goat milk, and their mixtures are determined. It was found that high-frequency acoustic cavitation improves the physico-chemical and organoleptic indicators of cheese. The 45 kHz mode, with 17 min a processing time, is optimal, improving the microstructure of cheese, organoleptic, physico-chemical indicators.

Utilization of two plant polysaccharides to improve fresh goat milk cheese: Texture, rheological properties, and microstructure characterization

This study aimed to evaluate the effects of added jujube polysaccharide (JP) and Lycium barbarum polysaccharide (LBP) on the texture, rheological properties, and microstructure of goat milk cheese. Seven groups of fresh goat milk cheese were produced with 4 levels (0, 0.2, 0.6, and 1%, wt/wt) of JP and LBP. The goat milk cheese containing 1% JP showed the highest water-holding capacity, hardness, and the strongest rheological properties by creating a denser and more stable casein network structure. In addition, the yield of goat milk cheese was substantially improved as a result of JP incorporation. Cheeses containing LBP expressed lower fat content, higher moisture, and softer texture compared with the control cheese. Fourier-transform infrared spectroscopy and low-field nuclear magnetic resonance analysis demonstrated that the addition of JP improved the stability of the secondary protein structure in cheese and significantly enhanced the binding capacity of the casein matrix to water molecules due to strengthened intermolecular interactions. The current research demonstrated the potential feasibility of modifying the texture of goat milk cheese by JP or LBP, available for developing tunable goat milk cheese to satisfy consumer preferences and production needs.

Effects of pre-emulsification with whey protein and high temperature sterilisation on texture, functional characteristics and Maillard reaction products of room temperature stored processed cheese

The emulsion and emulsion gel obtained by pre-emulsifying butter with whey protein isolate (WPI) were applied in processed cheese making. The processed cheese was sterilised at 121 °C or pasteurised at 100 °C for 15 min, then stored at 25 °C or 4 °C. The effects of pre-emulsification and pasteurisation on texture, functional characteristics and Maillard reaction of processed cheese during storage were investigated. WPI emulsions significantly improved the texture and inhibited the free oil released from 25 °C stored cheese, while WPI emulsion gels softened the texture and increased the free oil released. Scanning electron microscopy revealed decreased uniformity of cheese microstructure and an increase in the number of large free fat pools after pre-emulsification. Pre-emulsification process slowed the Maillard reaction of refrigerated stored cheese and reduced the content of Maillard reaction products. This study provided a method for improving the texture defects of room temperature stored cheese.

Effect of production variations on the composition, textural and microstructural properties, and volatile compounds of Turkish white cheese during ripening

Full-fat (WC1) and half-fat (WC2) Turkish white cheeses were manufactured on an industrial scale and ripened for 180 days. The objective of this study was to evaluate the variation in chemical and volatile compounds as well as the textural and microstructural characteristics during ripening of Turkish white cheese produced by different production methods from full-fat and half-fat milk. There were significant variations in the volatile compounds. For WC1 cheese, the values of hardness, cohesiveness, gumminess and chewiness values decreased towards 60 days in all cases, and then showed significant increases until the end of ripening. By contrast, the values of the different textural parameters in WC2, overall showed a tendency to decrease throughout ripening. Different effects on cheese microstructure were seen depending on milk fat content, whether or not the starter culture was added and the thermal treatment employed. Regarding volatile compounds, a total of 57 components were identified: alcohols (13), ketones (11), esters (10), acids (8), miscellaneous compounds (9) and aldehydes (6). Acids were the main components of both Turkish white cheeses. At the end of 180 days, esters and miscellaneous compounds were the highest in WC1 cheese, whereas acids, ketones and alcohols were the most abundant in WC2 cheese.

The effects of the use of whey protein as a fat replacer on the composition, proteolysis, textural, meltability, microstructural, and sensory properties of reduced-fat Boru-type Künefe cheese during storage

Boru-type Künefe cheeses were produced from standardised cow milk (fat ratios: 2, 1.5, 1, 0.5%) using whey protein concentrates (whey protein ratios: 0, 0.5, 1, 1.5%, respectively) and stored at 4 °C for 90 days. The composition, proteolysis, texture, meltability, microstructure, and sensory properties of cheeses were examined during storage. The effects of using different fat and whey protein ratios were determined to be significant (p <0.05) on the composition (except pH), texture (except springiness and cohesiveness), meltability and sensory properties of cheeses. Storage period affected significant (p <0.05) pH, titration acidity, fat content, meltability values, odour score, hardness, texture (except springiness) and proteolysis properties. It was determined that there were differences in the microstructure of the cheeses. Overall, the cheeses produced with 0.5% whey protein and 1.5% fat milk were similar to the control cheese and determined the most suitable cheese in terms of some properties.

Effect of the recombinant chymosins of different origins on the quality and shelf life of soft cheeses

The effect of the type (bovine chymosin (Chy-max Extra), camel chymosin (Chy-max M), and modified camel chymosin (Chy-max Supreme)) and applied dose (1500, 2500, or 3500 IMCU/100 kg of milk) of milk-clotting enzyme (MCE) on the proteolysis degree, microstructure, rheological and sensory properties of Crescenza soft cheese was studied. The proteolysis degree of cheeses was directly proportional to the general proteolytic activity (PA) and dose of the MCEs added into milk during the cheese production. With an equal dose of the MCEs added into milk, the highest level of proteolysis was noted in the cheese options produced with recombinant bovine chymosin (Chy-max Extra). There were no statistically significant differences (p &gt; 0.05) in the proteolysis degree between the cheese options made with the same doses of the camel chymosin (Chy-max M) and modified chymosin (Chymax Supreme). After 21 days of storage, the cheeses with Chy-max Extra MCE had the most plastic consistency, while the cheeses with Chy-max Supreme MCE had the hardest and most elastic one. Cheeses produced with Chy-max M MCE occupied an intermediate position in terms of consistency density. Recombinant MCEs based on camel chymosin (Chy-max M) and modified chymosin (Chy-max Supreme) with low level of PA, may be recommended for use in the production of soft cheeses. This will extend the shelf life of cheeses by slowing-down the plasticization rate of their consistency.

Study of the chemical, rheological, functional, microstructure, microbial, and sensory properties of Kareish cheese fortified with germinated quinoa seeds and processed using ultrasound technology.

Study of the chemical, rheological, functional, microstructure, microbial, and sensory properties of Kareish cheese fortified with germinated quinoa seeds and processed using ultrasound technology.

Raman confocal microscopy to assess changes in cheddar cheese during maturation

Raman confocal microscopy is an increasingly useful technique when applied to food samples. It has the unique ability to interrogate the chemical structure, aligned with the same confocality capability that is available when using standard confocal microscopy. In this research, we used Raman confocal microscopy to investigate the effects of maturation on the microstructure of cheddar cheese. Statistical analysis of the spectral data showed significant protein structural changes as the cheese matured. The results illustrate the potential of Raman confocal microscopy in conjunction with spectroscopy and imaging to understand chemical changes in complex dairy matrices.

Microencapsulation of Plant Phenolic Extracts Using Complex Coacervation Incorporated in Ultrafiltered Cheese Against AlCl3-Induced Neuroinflammation in Rats.

Plant-derived phenolic compounds have numerous biological effects, including antioxidant, anti-inflammatory, and neuroprotective effects. However, their application is limited because they are degraded under environmental conditions. The aim of this study was to microencapsulate plant phenolic extracts using a complex coacervation method to mitigate this problem. Red beet (RB), broccoli (BR), and spinach leaf (SL) phenolic extracts were encapsulated by complex coacervation. The characteristics of complex coacervates [zeta potential, encapsulation efficiency (EE), FTIR, and morphology] were evaluated. The RB, BR, and SL complex coacervates were incorporated into an ultrafiltered (UF) cheese system. The chemical properties, pH, texture profile, microstructure, and sensory properties of UF cheese with coacervates were determined. In total, 54 male Sprague–Dawley rats were used, among which 48 rats were administered an oral dose of AlCl3 (100 mg/kg body weight/d). Nutritional and biochemical parameters, including malondialdehyde, superoxide dismutase, catalase, reduced glutathione, nitric oxide, acetylcholinesterase, butyrylcholinesterase, dopamine, 5-hydroxytryptamine, brain-derived neurotrophic factor, and glial fibrillary acidic protein, were assessed. The RB, BR, and SL phenolic extracts were successfully encapsulated. The RB, BR, and SL complex coacervates had no impact on the chemical composition of UF cheese. The structure of the RB, BR, and SL complex coacervates in UF cheese was the most stable. The hardness of UF cheese was progressively enhanced by using the RB, BR, and SL complex coacervates. The sensory characteristics of the UF cheese samples achieved good scores and were viable for inclusion in food systems. Additionally, these microcapsules improved metabolic strategies and neurobehavioral systems and enhanced the protein biosynthesis of rat brains. Both forms failed to induce any severe side effects in any experimental group. It can be concluded that the microencapsulation of plant phenolic extracts using a complex coacervation technique protected rats against AlCl3-induced neuroinflammation. This finding might be of interest to food producers and researchers aiming to deliver natural bioactive compounds in the most acceptable manner (i.e., food).

Influence of chymosin type and brine concentration on chemical composition, texture, microstructural and colour properties of Turkish white cheeses

The effects of chymosin type and brine concentration on chemical composition, texture, microstructure and colour of white cheese were studied during ripening. The cheeses were manufactured from cows’ milk using microbial rennet (Rhizomucor miehei), commercial calf rennet or recombinant chymosin (Kluyveromyces lactis), and ripened in whey brines containing 10% or 12% NaCl. Increasing the brine concentration increased the ratio of salt to moisture, hardness, gumminess, chewiness and whiteness values of cheeses and decreased the moisture, the ratio of moisture to protein and extent of proteolysis. The similar trends were observed in cheeses with microbial rennet compared with those with calf rennet or recombinant chymosin. pH values of all the cheeses unchanged during ripening but their brine pHs increased. A marked effect of rennet type on microstructure of the cheeses was visualised. In microbial rennet cheese brine salt content can be reducible to obtain satisfactory results in terms of quality parameters.

Physicochemical, antioxidant, microstructure, textural, and organoleptic characteristics of soft cheese incorporated corn milk

Corn milk has been recently considered an innovation in milk products. In this regard, the current study was conducted to study the chemical composition of soft cheese made by replacing cow milk with corn milk at different concentrations of up to 40%. The moisture, acidity, total protein, fat, ash, bioactive components (total phenolic compounds and antioxidant activity), cheese yield, microstructure, textural characteristics, and organoleptic characteristics of this soft corn-supplemented cheese were studied. Results obtained indicate that the increasing ratio of corn milk led to an increase in the content of phenolic components and DPPH scavenging activity. Cheese yield was increased by increasing the replacement ratio. The cheese, made by replacing up to 20% of cow milk with corn milk, had the highest sensory evaluation score. An electron microscopy examination showed that adding corn milk to soft cheese improved the microstructure. Novelty impact statement The industrialization of corn milk into cheese is very appealing in order to address the issues associated with low solid corn milk content. We produced potential, beneficial, and low-cost soft cheese by replacing cow milk with corn milk by up to 40%. The nutritional and technological value of the resulting cheese has significantly increased.