A 100-Year Review: Cheese production and quality

In the beginning, cheese making in the United States was all art, but embracing science and technology was necessary to make progress in producing a higher quality cheese. Traditional cheese making could not keep up with the demand for cheese, and the development of the factory system was necessary. Cheese quality suffered because of poor-quality milk, but 3 major innovations changed that: refrigeration, commercial starters, and the use of pasteurized milk for cheese making. Although by all accounts cold storage improved cheese quality, it was the improvement of milk quality, pasteurization of milk, and the use of reliable cultures for fermentation that had the biggest effect. Together with use of purified commercial cultures, pasteurization enabled cheese production to be conducted on a fixed time schedule. Fundamental research on the genetics of starter bacteria greatly increased the reliability of fermentation, which in turn made automation feasible. Demand for functionality, machinability, application in baking, and more emphasis on nutritional aspects (low fat and low sodium) of cheese took us back to the fundamental principles of cheese making and resulted in renewed vigor for scientific investigations into the chemical, microbiological, and enzymatic changes that occur during cheese making and ripening. As milk production increased, cheese factories needed to become more efficient. Membrane concentration and separation of milk offered a solution and greatly enhanced plant capacity. Full implementation of membrane processing and use of its full potential have yet to be achieved. Implementation of new technologies, the science of cheese making, and the development of further advances will require highly trained personnel at both the academic and industrial levels. This will be a great challenge to address and overcome.     

Innovative Caciocavallo cheeses made from a mixture of cow milk with ewe or goat milk

This study assessed and compared the physicochemical, microbiological, and sensorial characteristics of Caciocavallo cheeses, made from cow milk and a mixture of cow with ewe or goat milk, during ripening. Different cheese-making trials were carried out on an industrial scale following the standard procedure of pasta filata cheeses, with some modifications. The percentage of the different added milk to cow milk influenced compositional and nutritional characteristics of the innovative products, leading to a satisfactory microbiological and sensorial quality.     

Comprehensive analysis of proteolysis during 8 months of ripening of high-cooked Old Saare cheese

We applied capillary electrophoresis, liquid chromatography coupled with tandem mass-spectrometry (MS/MS), and ultra-performance liquid chromatography to determine the composition of water-insoluble and water-soluble proteinaceous fractions of the cheese and to study in detail the degradation of caseins during 8 mo of ripening of Estonian high-temperature cooked hard cheese Old Saare. The application of high-resolution and high-accuracy MS/MS enabled identification of more than 3,000 small peptides, representing a fairly full casein peptidome containing peptides of 4 to 25 AA in length: 1,049 from β-casein (CN), 944 from α_S1-CN, 813 from α_S2-CN, and 234 from κ-CN. The majority of β-CN- and α_S1-CN-derived peptides originated from the N-terminal parts of the molecule, f6-93 and f1-124, respectively; peptides from α_S2-CN arose predominantly from the C-terminal end f100-162. At the beginning of ripening, we found a relatively high amount of peptides originating from the glycomacropeptide part of κ-CN, whereas peptides from para-κ-CN prevailed during the later stages of ripening of the cheese. The cleavage patterns of β-CN, α_S2-CN, as well as α_S1-CN, showed that primary proteolysis was started mainly by plasmin, although a low proteolytic activity of chymosin was also evident. Based on the analysis of cleavage sites, we observed a significant participation of proteolytic enzymes, including amino- and carboxypeptidases, of both mesophilic and thermophilic starter bacteria in further hydrolysis of oligopeptides during the ripening. Several new phosphopeptides were detected in the result of MS/MS data analysis. The profiles of the estimated concentrations of phosphopeptides revealed that those originating from β-CN and α_S1-CN accumulated during cheese maturation. In contrast, we did not notice any generation of phosphopeptides from the highly phosphorylated part of α_S2-CN, f25-80, presumably due to the inaccessibility of this region to the action of plasmin and chymosin. The analysis of cleavage sites and the combination of principal component and clustering analyses provided a characterization of the complex dynamics of formation and degradation of peptides during cheese maturation. We made an attempt to obtain a comprehensive picture of proteolysis during Old Saare cheese ripening on the basis of the detailed peptidomic data, including also the less abundant peptides determined by MS/MS, and complemented by the data on intact caseins and free AA and reported the results in the paper.     

Proteolysis in Mozzarella cheeses manufactured by different industrial processes

The objective of the present study was to investigate the influence of stretching temperature, fat content, and time of brining on proteolysis during ripening of Mozzarella cheeses. Seventeen cheese-making experiments (batches) were carried out on an industrial scale on successive days, following the standard procedure with some modifications. Fat content of cheese milk, temperature at the stretching step, and time of brining varied from one batch to another as required by the experimental design, outlined by a surface response model. Proteolysis was assessed during ripening of samples, which was prolonged for at least 3 mo, by means of electrophoresis, nitrogen fractions, and soluble peptide mapping. The amount of soluble nitrogen at pH 4.6 was not significantly different in cheeses obtained by diverse procedures, but it increased during ripening of all samples. This result was coincident with the breakdown of α_s1- and β-caseins evidenced by electrophoresis, which reached similar extents at late stages of ripening, regardless of the cheese-making process. Multivariate analysis on soluble peptide profiles obtained by liquid chromatography also detected sample grouping according to ripening time, but did not evidence any separation caused by the cheese-making technology. We concluded that the changes in the cheese-making process assayed in this work were insufficient to produce significant differences in proteolysis of the cheeses. Ripening time had more influence on proteolysis of Mozzarella cheeses than any other assayed variable.     

Manufacture of magnesium-fortified Chihuahua cheese

The aim of this study was to manufacture magnesium-fortified Chihuahua cheese and to evaluate the effect of magnesium fortification on quality parameters. Addition of magnesium chloride to milk during pasteurization (5.44, 10.80, 16.40, 22.00, and 25.20 g of MgCl₂·6H₂O/L of milk) resulted in cheese with increased magnesium content, proportional to the amount of magnesium added (up to 2,957.13 mg of Mg/kg of cheese). As magnesium content increased, coagulation time and moisture content also increased, whereas calcium content decreased. Higher levels of magnesium fortification (16.40 g of MgCl₂·6H₂O/L of milk or more) induced the development of bitter-acid flavors and softer texture. Addition of 10.80 g of MgCl₂·6H₂O/L to milk resulted in Chihuahua cheese that meets regulatory standards and possesses physicochemical and sensory characteristics similar to those of nonfortified Chihuahua cheese. Under this milk fortification level, the manufactured cheese is able to provide 148.4 mg of magnesium per day (35% of the recommended daily intake of magnesium for adult males and 46% for adult females) assuming 3 portions (28 g each) are consumed.     

Effects of changes during ripening and frozen storage on the physicochemical and sensory characteristics of Cabrales cheeses

The physicochemical and organoleptic characteristics of two batches of Cabrales cheese, stored at −20°C for 4 and 8 months, respectively, were studied during subsequent ripening. Frozen storage did not result in significant alterations in overall compositional, rheological and sensory properties or the level of lipolysis. The extent of proteolysis was slightly lower in the cheeses frozen prior to ripening.     

Short communication: comparison of covered and uncovered Schreiber test for cheese meltability evaluation

Schreiber meltability tests were performed on glass Petri dishes, with and without the Petri dish cover placed over the cheese samples, at 100, 150, and 232 degrees C. Meltability of different process cheese and Cheddar cheese samples was determined based on the melt spread distance and area. At the test temperature of 232 degrees C, the covered Schreiber was significantly superior to the uncovered test because of no crust formation, no browning, and a circular melting pattern, which were attributed to the barrier effect of covering the cheese samples (which inhibits moisture loss during the test). The covered Schreiber test data were statistically more robust as measured by the lower average coefficient of variation than the data from the traditional uncovered Schreiber test.     

Influence of emulsifying salts on the textural properties of nonfat process cheese made from direct acid cheese bases

The objective of this study was to investigate the influence of several types of emulsifying salts (ES) on the texture of nonfat process cheese (NFPC). Improperly produced nonfat cheese tends to exhibit several problems upon baking including stickiness, insufficient or excessive melt, pale color upon cooling, formation of a dry skin (skinning) often leading to dark blistering, and chewy texture. These attributes are due to the strength and number of interactions between and among casein molecules. We propose to disrupt these interactions by using suitable emulsifying salts (ES). These ES chelate Ca and disperse caseins. Stirred curd cheese bases were made from skim milk using direct acidification with lactic acid to pH values 5.0, 5.2, and 5.4, and ripened for 1 d. Various levels of trisodium citrate (TSC; 0.5, 1, 1.5, 2, 2.5, 3, and 5%), disodium phosphate (DSP; 1, 2, 3, and 4%), or trisodium phosphate (TSP; 1, 2, 3, and 4%) were blended with the nonfat cheese base. Cheese, ES, and water were weighed into a steel container, which was placed in a waterbath at 98°C and then stirred using an overhead stirrer for 9 min. Molten cheese was poured into plastic containers, sealed, and stored at 4°C for 7 d before analysis. Texture and melting properties were determined using texture profile analysis and the UW-Melt-profiler. The pH 5.2 and 5.4 cheese bases were sticky during manufacture and had a pale straw-like color, whereas the pH 5.0 curd was white. Total calcium contents were approximately 400, 185, and 139 mg/100 g for pH 5.4, 5.2, and 5.0 cheeses, respectively. Addition of DSP resulted in NFPC with the lowest extent of flow, and crystal formation was apparent at DSP levels above 2%. The NFPC manufactured from the pH 5.0 base and using TSP had reduced melt and increased stickiness, whereas melt was significantly increased and stickiness was reduced in NFPC made with pH 5.4 base and TSP. However, for NFPC made from the pH 5.4 cheese and with 1% TSP, the pH value was >6.20 and crystals were observed within a few days. Use of TSC increased extent of flow up to a maximum with the addition of 2% ES for all 3 types of cheese bases. Addition of high levels of TSC to the pH 5.2 and 5.4 cheese bases resulted in increased stickiness. Similar pH trends for attributes such as extent of flow, hardness, and adhesiveness were observed for both phosphate ES but no consistent pH trends were observed for the NFPC made with TSC. These initial trials suggest that the pH 5.0 cheese base was promising for further research and scale-up to pilot-scale process cheese making, because cheeses had a creamy color, reasonable melt, and did not have high adhesiveness when TSC was used as the ES. However, the acid whey produced from the pH 5.0 curd could be a concern.     

Mozzarella干酪成熟过程中菌相变化规律的研究

为了研究Mozzarella干酪成熟过程中发酵剂菌种对干酪成熟的影响,本试验制作了模拟干酪,并以此为试验模型,分析了全脂Mozzarella干酪成熟过程中菌群的变化规律。结果表明:发酵剂乳酸菌是Mozzarella干酪成熟过程中的主要菌群,而且球菌在干酪成熟过程中占绝对优势;NSLAB对Mozzarella干酪成熟的作用不大。由于采用了真空包装,Mozzarella干酪中的杂菌数始终保持在很低的水平〔大肠菌群≤60MPN/100g,酵母霉菌≤45lg(cfu/g)〕,并且对干酪的成熟无影响。在Mozzarella干酪成熟过程中,乳糖含量逐渐下降,随着乳酸菌的自溶,使LDH增加,对干酪后期的成熟产生积极影响。     

不同亲水胶体对再制奶油奶酪品质的影响

通过研究刺槐豆胶、卡拉胶、海藻酸钠、瓜尔豆胶和黄原胶5种不同亲水胶体对以切达奶酪为原料,直接酸化法得到的再制奶油奶酪品质的影响,来选择较佳的亲水胶体方案。实验结果表明,亲水胶体对样品各方面的性质影响显著,对持水性和持油性的影响尤为明显。本体系适用不凝胶的亲水胶体。黄原胶和刺槐豆胶是最佳的选择,并建议2种胶体单独使用。     

Influence of cheese-making recipes on the composition and characteristics of Camembert-type cheese

Bloomy rind cheeses, including Camembert and related varieties, can be produced using alternative processes that vary based on milk preacidification, cutting, curd handling, and ripening parameters. Modification of these parameters creates distinct cheeses such as lactic curd, stabilized curd, and hybrids of the two. The objective of this study was to determine the influence of 5 Camembert-type cheese recipes on the composition and characteristics during ripening. Five varieties of Camembert-type cheese were produced: (1) lactic curd, (2) sweet curd, (3) washed curd, (4) solubilized curd, and (5) stabilized curd. Cheeses were aged at 13°C for 10 d, during the mold growth phase, and 7°C from d 11 until 50. Key quality metrics including texture development, pH (center and surface), and color were monitored throughout shelf-life. Compositional evaluation (d 5; fat, protein, moisture, salt, and minerals) grouped cheeses into 3 categories: (1) lactic curd, (2) sweet and washed curd, and (3) solubilized and stabilized curd. The lactic curd and stabilized curd were consistently the most different varieties for composition and quality metrics. Moisture content of Camembert-type varieties ranged from 53.15 to 57.99%, Ca ranged from 0.23 to 0.45%, and P ranged from 0.21 to 0.40%. All varieties followed the expected pH evolution on the rind and in the paste with the pH of the rind reaching 7 by d 10, and paste pH reaching 7 between 35 and 50 d. The displacement of the paste (distance traveled upon cutting) for the lactic curd was the greatest among the 5 varieties, reaching an average of 27 ± 1.9 mm (mean ± standard error) after 50 d of ripening and 60 min of flow time. The stabilized curd on the other hand traveled the shortest distance, reaching an average of 4 ± 0.4 mm at the same time point. Browning, considered a defect in mold-ripened cheeses, was observed in all varieties, but was most substantial for lactic curd (lightness, L*, decreased from 87.19 to 68.58). Based on these quality metrics the shelf-life of these recipes was estimated with the lactic curd having the shortest, and the stabilized curd having the longest. Examining Camembert-type cheese quality metrics for these 5 varieties can assist cheesemakers during recipe formulation and selection of cheese-making practices to achieve optimum product quality.     

Mycotoxins in two Spanish cheese varieties

Samples of cheeses naturally contaminated with moulds (12 samples of mouldy Manchego cheese and 10 of a naturally ripened blue cheese) were analysed for the presence of mycotoxins (aflatoxins BI and MI, sterigmatocystin, patulin, penicillic acid and mycophenolic acid in Manchego cheese, and mycophenolic acid and roquefortine in blue cheese). In addition, 24 Penicillium and Aspergillus strains isolated from the samples were assessed for their mycotoxigenicity. Four of Manchego cheese samples were positive to mycophenolic acid and one sample of blue cheese contained roquefortine. The rest of mycotoxins investigated were not found. One Aspergillus strain isolated from Manchego cheese showed the ability to produce aflatoxin MI. The rest of strains from these samples being no producers. In contrast, 7 out of 9 Penicillium (P. roqueforti) strains isolated from blue cheese were able to produce roquefortine, with one strain also producing mycophenolic acid.     

A review on stringiness property of cheese and the measuring technique

This review paper provides a deep understanding of stringiness property in a cheese product. Stringiness is used to describe the extended continuous strand of a molten cheese, especially mozzarella cheese. Stringiness is often described quantitatively by stretch length, as well as qualitative definition which focuses on the dimension of strand and ease of extensibility. Very often, the scope of defining stringiness attributes is limited by the measuring techniques because a complete experimental setup is required to obtain information on both stretch quantity and stretch quality. Among the measuring methods, cheese extensibility rig stands out to be the best method to assess stringiness attribute of a cheese as it is an objective method. In addition, a detailed study on the molecular behavior and interactions among natural and imitation cheese components in delivering stringiness, and the challenges faced therein have been reviewed. Thus, the review provides a foundation for the development of vegan cheese or plant-based cheese with stringiness properties.     

Texture Assessment of French Cheeses

The texture of a variety of French cheeses was studied by examining their compositional and mechanical parameters. The data obtained were correlated to those derived from a panel assessment of the sensory textural attributes of the samples. Statistical treatment of the results employing cluster analysis, analysis of variance, and redundancy analysis revealed that the most influential objective variables to characterize the cheese texture are the dry matter content and the resistance to force compression at 10% deformation of the initial sample height. These variables were highly correlated with sensory attributes such as hardness, brittleness, cohesiveness, and adhesiveness.     

Small scale imitation cheese manufacture using a Farinograph

Imitation cheeses with moisture levels of 48, 50 and 52 g/100 g were manufactured on a small-scale using a Farinograph. The batch size and mixing speed were optimised at 800 g and 50 rpm, respectively, based on observations during manufacture and torque profile obtained. Subsequently, the texture, meltability and water mobility (by NMR relaxometry) of Farinograph cheeses were compared to cheeses of similar composition made in a Blentech, a traditional pilot-scale cooker. Although Farinograph cheeses tended to have lower hardness and heat-induced flowability values than Blentech cheeses, the response of both parameters to changes in moisture content was similar. In addition, no significant differences (p ≤ 0.05) in dynamic rheology parameters, water activity and NMR T₂ relaxation times between cheeses of both mixers were found. This suggests that the Farinograph is a suitable instrument for small-scale manufacture of imitation cheese which is representative of that made in a traditional pilot-scale cooker.     

A comparison of the physicochemical characteristics of the regional cheese Oscypek and the traditional cheese Gazdowski from the Polish Podhale

The quality of two types of traditional cheese manufactured in Podhale (southernmost region of Poland), that is, Oscypek (regional PDO) and Gazdowski (native traditional product ‐ NTP), was compared. The appearance, sensory qualities, proximate composition and intrinsic traits were evaluated. Oscypek manufactured from mixed (sheep and cow) milk received higher sensory scores for texture, taste and aroma than the traditional Gazdowski cheese made from cow's milk. Furthermore, the Oscypek cheese contained significantly more total solids and protein, but less salt. Composition could be responsible for its more cohesive texture which was defined by significantly greater cohesiveness, greater hardness, springiness, shear force and shear energy.     

Improvement of sensory quality of lowfat kefalograviera-type cheese by using commercial special starter cultures

Two commercially available special starter culture systems, Alp DIP and a mixture of Alp DIP D and Joghurt V1, were compared with one commercial regular starter culture, CH-1, for their effects on the compositional, sensory and textural characteristics of lowfat (9.5%) high moisture (49.6%) Kefalograviera-type cheese during aging. A full-fat control Kefalograviera cheese (30.8% fat, 37.8% moisture) was also made with the regular starter culture. The results indicated that the type of starter did not affect the composition (moisture, fat, protein, salt and pH) of the lowfat cheese. Sensory analysis showed that the lowfat cheeses made with the special cultures received greater body and texture scores and significantly higher flavor scores than the lowfat control cheese after aging for 90 and 180 d. Moreover, the former cheeses received body and texture and flavor scores not significantly different from those of the full-fat cheese. Texture profile analysis by Instron showed that there were no significant differences in the textural characteristics (force and compression to fracture, cohesiveness, springiness, gumminess and chewiness) between lowfat cheeses made with the special cultures and that made with the regular starter, except for hardness which was significantly lower in the former cheeses.     

农家干酪在中国的发展优势

干酪的营养价值极高,是乳品行业将来发展的方向。从农家干酪的营养和加工特点出发,介绍了农家干酪所具有的发展优势,阐述了农家干酪的研究状况,并对农家干酪在中国的开发提出了一些建议。