Fresh cheese from camel milk coagulated with Camifloc

Camel milk was processed into cheese using Camifloc and calcium chloride. Two types of cheeses were produced from camel milk, using Camifloc (CF cheese) and CaC_l2 in addition to Camifloc (CFCC cheese). The study revealed the usefulness of Camifloc in coagulation of camel milk. The time of coagulation was found to be about 2–3 h, and the yield of CFCC cheese was found to be higher than the CF cheese, while a shelf life of 4 days was obtained for both cheeses. Both cheeses showed nonsignificant variations in compositional content except for the percentages of protein and ash, which showed significant differences at P < 0.001 and P < 0.05. Sensory evaluation by taste panellists was conducted to determine the acceptability of cheeses during the storage periods. Differences were found between the CF cheese and the CFCC cheese in saltiness and overall acceptability, and higher mean scores were recorded for the CF cheese than the CFCC cheese. The study recommends the use of Camifloc in making cheese from camel milk; and if CaCl₂ is added, it can improve the cheese yield. However, we suggest that the rate of salting should be reduced, and further drying and storage of the cheese should be done.     

Influence of pH on retention of camel chymosin in curd

Retained coagulant in cheese initiates casein breakdown and influences cheese structure and flavour formation. This study investigated the influence of milk pH on retention of camel chymosin in curd and compared it with bovine chymosin. Milk at five different pH levels was coagulated with same coagulant activity of each chymosin and centrifuged. Chymosin activity in whey was determined using the synthetic peptide Pro-Thr-Glu-Phe-(NO₂-Phe)-Arg-Leu as substrate and HPLC analysis of the resulting product. Camel chymosin had 2.7 times lower activity in milk than bovine chymosin at the same coagulation activity. The retention of camel chymosin in curd was rather constant at ∼20% between pH 6.65 and 6.00, while it increased almost linear from 2 to 21% for bovine chymosin. The lower pH dependence for retention of camel chymosin than of bovine chymosin may be explained by a lower negative charge of the camel chymosin molecule.     

Effect of Plant Originated Coagulants and Chymosin on Ovine Milk Coagulation

The coagulation of ewe's milk was studied by using plant source coagulants namely the artichoke, Cynara scolymus L. cv. Blanca, and latex from the fig tree (Ficus carica L.). A turbidimetric method was used to evaluate and compare the coagulation properties of the novel coagulants with chymosin treated samples. Syneresis capacity and sensory evaluation of resultant cheese samples were studied and it was found that both cynara and chymosin produced sigmoidal increase in turbidity to the milk with three distinct phases. The coagulation kinetics was affected substantially by both coagulants. Plant coagulant induced shorter gelation time compared to chymosin however required longer time for restructuration (end of coagulation). The coagulum obtained with the latex of Ficus carica had a higher yield, owing to its high water retention capacity. With the exception of color, the overall sensory attributes did not show significant differences among coagulants.     

Interaction between sodium chloride and texture in semi-hard Danish cheese as affected by brining time,dl-starter culture,chymosin type and cheese ripening

Reduced NaCl in semi-hard cheeses greatly affects textural and sensory properties. The interaction between cheese NaCl concentration and texture was affected by brining time (0–28 h), dl-starter cultures (C1, C2, and C3), chymosin type (bovine or camel), and ripening time (1–12 weeks). Cheese NaCl levels ranged from <0.15 to 1.90% (w/w). NaCl distribution changed during ripening; migration from cheese edge to core led to a more homogeneous NaCl distribution after 12 weeks. As ripening time increased, cheese firmness decreased. Cheeses with reduced NaCl were less firm and more compressible. Cheeses produced with C2 were significantly firmer than those produced with C1; cheeses produced with C3 had higher firmness and compressibility. In NaCl reduced cheese, use of camel chymosin as coagulant resulted in significantly higher firmness than that given using bovine chymosin. Overall, cheese NaCl content is reducible without significant textural impact using well-defined starter cultures and camel chymosin.     

Effects of blends of camel and calf chymosin on proteolysis,residual coagulant activity,microstructure, and sensory characteristics of Beyaz peynir

Beyaz peynir, a white brined cheese, was manufactured using different blends of camel chymosin (100, 75, 50, 25, and 0%) with calf chymosin and ripened for 90 d. The purpose of this study was to determine the best mixture of coagulant for Beyaz peynir, in terms of proteolysis, texture, and melting characteristics. The cheeses were evaluated in terms of chemical composition, levels of proteolysis, total free amino acids, texture, meltability, residual coagulant activity, microstructure, and sensory properties during 90 d of ripening. Differences in the gross chemical composition were statistically significant for all types of cheeses. Levels of proteolysis were highly dependent on the blends of the coagulants. Higher proteolysis was observed in cheeses that used a higher ratio of calf chymosin. Differences in urea-PAGE and peptide profiles of each cheese were observed as well. Meltability values proportionally increased with the higher increasing levels of calf chymosin in the blend formula. These coagulants had a slight effect on the microstructure of cheeses. The cheese made with camel chymosin had a harder texture than calf chymosin cheese, and hardness values of all cheese samples decreased during ripening. The cheeses with a high ratio of calf chymosin had higher residual enzyme activity than those made with camel chymosin. No significant difference in sensory properties was observed among the cheeses. In conclusion, cheeses made with a high level of calf chymosin had a higher level of proteolysis, residual coagulant activity, and meltability. The cheeses also had a softer texture than cheeses made with a high content of camel chymosin. Camel chymosin may be used as a coagulant alone if low or limited levels of proteolysis are desired in cheese.     

Can the use of Australian cardoon (Cynara cardunculus L.) coagulant overcome the quality problems associated with cheese made from ultrafiltered milk?

Concentrated cow's milk, obtained by either limited ultrafiltration to arrive at a concentration factor of 1.4× (UF) or by mixing 4× UF milk with regular milk (MX) was used to manufacture cheeses coagulated with calf rennet or aqueous extract from Cynara cardunculus L. (cardoon). The manufactured cheeses were tested and compared with those made from regular milk for chemical and sensory properties, yield, textural and biochemical indices over a 60-day ripening period. There was no significant difference (P > 0.05) in the chemical properties with the type of coagulant but in general, a lower yield and greater bitterness were observed in the cheeses made using cardoon, while ultrafiltration led to reduced casein hydrolysis, less bitterness and harder, more crumbly cheeses irrespective of coagulant type. The MX process was successful in reducing the textural problems which occurred in cheese made with UF milk alone. The ultrafiltration process itself was apparently detrimental to the textural quality of cheeses, rather than the associated increase in concentration.     

Effect of a bacteriocin‐producing strain of Lactobacillus paracasei on the nonstarter microflora of Cheddar cheese

In this study, the growth of chloramphenicol‐resistant bacteriocin‐sensitive indicator strain Lactobacillus casei DPC 2048^CM was evaluated in Cheddar cheese made with bacteriocin‐producing Lactobacillus paracasei DPC 4715. No suppression of growth of the indicator strain was observed in the cheese during ripening, and no bacteriocin production by L. paracasei DPC 4715 was detected by the well diffusion method in cheese and cheese extracts. The bacteriocin produced by L. paracasei DPC 4715 was sensitive to chymosin and cathepsin D, and it may have been hydrolysed by the rennet used for cheese manufacture or by indigenous milk proteases.     

Factors influencing the gelation and rennetability of camel milk using camel chymosin

The effects of temperature, pH, concentration of camel chymosin and addition of CaCl₂ on the hydrolysis of κ-casein (κ−CN) and the coagulation kinetics of camel milk were investigated. The rate of κ−CN hydrolysis was higher at 40 °C than at 30 °C and with increasing addition of chymosin and decreasing pH. For all samples gelation was initiated at levels of camel milk κ−CN hydrolysis >95%. The gelation time (T_g) of camel milk was significantly reduced (from 717 to 526 s) at 30 °C when the concentration of chymosin was increased, but was independent of chymosin concentration at 40 °C. Reducing pH also reduced T_g. The gel firmness increased at 40 °C (58 Pa) compared with 30 °C (44 Pa) and effect of CaCl₂ addition on the gelation properties of camel milk was found to be dependent on pH; a significant improvement was only found at pH 6.3.     

添加酿酒酵母的类Cheddar干酪生产工艺

开发具有特色风味的干酪产品是提高我国消费者对干酪接受度的重要手段.以新鲜牛乳为原料,选取蔗糖添加量、干酪发酵剂添加量、凝乳酶添加量为因素,以干酪产率、感官评定为主要检测指标,通过单因素实验和正交实验对添加酿酒酵母的类Cheddar干酪的加工工艺进行优化,并以感官评定为主要检测指标,对最佳工艺进行验证.结果表明,添加酿酒...     

Isolation and characterisation of lactic acid bacteria strains from raw camel milk for potential use in the production of fermented Tunisian dairy products

The aim of this work was to study the suitability of camel milk for the production of dairy products by lactic acid fermentation. Sixty strains of lactic acid bacteria (LAB) were isolated from camel milk. The strains were tested for their acidification activity, ability to use citrate, exopolysaccharide production, lipolytic, proteolytic activities and resistance to antibiotics. Ten strains were investigated for their ability to metabolize carbohydrates and that resulted in the identification of 5 Lactococcus lactis, 1 Lactobacillus pentosus, 2 Lactobacillus plantarum, 1 Lactobacillus brevis and 1 Pediococcus pentosaceus strains. Two strains of Lactococcus lactis SCC133 and SLch14 were selected to produce traditional Tunisian fermented dairy products (Lben, Raib, Jben cheese and Smen). These strains were chosen based on their acid production capacity and their ability to produce a high yield of biomass.     

Influence of proteolytic Lactococcus lactis subsp. cremoris on ripening of reduced-fat Cheddar cheese made with camel chymosin

This study investigated proteolysis in reduced-fat Cheddar cheese produced with camel chymosin and Lactococcus lactis subsp. cremoris with the ability to cleave the N-terminus of α_S1-casein. The aim was to match the activity of bovine chymosin, which leads to softer cheese structure than camel chymosin. Cheeses were analysed for gross composition, casein and peptide breakdown, release of free amino acids, structure parameters and sensory characteristics. Selected Lc. lactis subsp. cremoris increased the amount of peptides and, to a limited extent, the total amount of free amino acids in the cheeses. One group of experimental cheeses was found to have a significantly firmer structure, higher stress at fracture and modulus of deformability than the reference cheeses. The addition of the selected proteolytic dairy strains of Lc. lactis subsp. cremoris to the cheeses did not result in extended breakdown of α_S1-casein or a softer cheese structure.     

Pre-treatment methods of Edam cheese milk. Effect on cheese yield and quality

The effect of high-temperature heat treatment (HH), microfiltration (MF) and ultrafiltration (UF) on the Edam vat milk composition, processing and cheese yield, ripening and functional characteristics were studied. The protein level of the MF and UF cheese milk was adjusted to 42 g/kg, whereas the level in the reference (REF) and HH milk was 34 g/kg. The cheese yield from ultrafiltration and microfiltration milk (CY_v) was 12.8 g/100 g milk, yield from reference and high-temperature heat treatment milk was 10.1 and 10.2 g/100 g milk, respectively. The adjusted cheese yield (ACY_r), calculated from raw milk, was lowest when MF was used. The pre-concentration method had little effect on the starter activity: no differences were observed in the pH of cheeses. The compositions of the ripened cheeses were comparable. The casein to fat ratio of MF cheese was elevated, possibly due to elevated casein to fat ratio of vat milk. Even though the high-temperature heat treatment, ultrafiltration and microfiltration cheeses were harder than reference cheese, they retained their elasticity. Resilience was significantly higher with microfiltration and ultrafiltration cheeses. The sensory quality of all cheeses was considered according to specification. The pre-treatment methods had little effect on the processing characteristics, cheese quality or yield when calculated on the basis of the quantity of original milk.     

Biochemical,microbial and sensory evaluation of white soft cheese made from cow and lupin milk

The aim of the present study was to evaluate some physicochemical, microbiological and sensory properties of fresh and matured (75 days) soft cheeses made with mixtures of cow milk and 0, 25, 50 and 75 mL/100 mL of lupin milk. A remarkable increase in cheese yield was observed with increasing the level of lupin milk to the mixture. Compared to cow milk cheese, the protein content was significantly (P ≤ 0.05) increased while ash was decreased with the increase in the level of lupin milk for both fresh and matured cheese. However, fat content, total solids and acidity were increased only for fresh cheese and decreased for mature one compared to that of cow milk. The pH showed significant (P ≤ 0.05) reduction when the levels of lupin milk increased for fresh cheese while for matured cheese it slightly decreased. The total bacterial count is within the range that naturally exists in milk containing foods. The others microorganisms such as fungi, mold, Escherichia coli, and Salmonella were not existed in both types of cheese. Regardless of cheese color, incorporation of lupin milk at low concentration (25 mL/100 mL) significantly (P ≤ 0.05) enhanced the taste, texture, flavor, and overall acceptability of both fresh and mature cheese.     

Effect of camel chymosin on the texture,functionality, and sensory properties of low-moisture,part-skim Mozzarella cheese

The objective of this study was to compare the effect of coagulant (bovine calf chymosin, BCC, or camel chymosin, CC), on the functional and sensory properties and performance shelf-life of low-moisture, part-skim (LMPS) Mozzarella. Both chymosins were used at 2 levels [0.05 and 0.037 international milk clotting units (IMCU)/mL], and clotting temperature was varied to achieve similar gelation times for each treatment (as this also affects cheese properties). Functionality was assessed at various cheese ages using dynamic low-amplitude oscillatory rheology and performance of baked cheese on pizza. Cheese composition was not significantly different between treatments. The level of total calcium or insoluble (INSOL) calcium did not differ significantly among the cheeses initially or during ripening. Proteolysis in cheese made with BCC was higher than in cheeses made with CC. At 84 d of ripening, maximum loss tangent values were not significantly different in the cheeses, suggesting that these cheeses had similar melt characteristics. After 14 d of cheese ripening, the crossover temperature (loss tangent = 1 or melting temperature) was higher when CC was used as coagulant. This was due to lower proteolysis in the CC cheeses compared with those made with BCC because the pH and INSOL calcium levels were similar in all cheeses. Cheeses made with CC maintained higher hardness values over 84 d of ripening compared with BCC and maintained higher sensory firmness values and adhesiveness of mass scores during ripening. When melted on pizzas, cheese made with CC had lower blister quantity and the cheeses were firmer and chewier. Because the 2 types of cheeses had similar moisture contents, pH values, and INSOL Ca levels, differences in proteolysis were responsible for the firmer and chewier texture of CC cheeses. When cheese performance on baked pizza was analyzed, properties such as blister quantity, strand thickness, hardness, and chewiness were maintained for a longer ripening time than cheeses made with BCC, indicating that use of CC could help to extend the performance shelf-life of LMPS Mozzarella.     

Correlation between instrumental texture and colour quality attributes with sensory analysis of selected cheeses as affected by fat contents

This study evaluated several physical and sensory parameters of different types of cheese available in the Polish market. The measurements of textural properties were conducted in an Instron universal testing machine, while the colour properties of cheeses were measured using a Minolta chromameter. The chemical composition was determined by means of the near‐infrared spectroscopy (NIRs). Moreover, a trained sensory panel was invited to assess the cheese texture‐related properties. Generally, cheeses with reduced fat content were characterised by higher hardness, adhesiveness, cohesiveness and elasticity. Texture‐related parameters of cheese with canola oil were comparable to that of most of full‐fat cheeses. The correlation analysis between physical and sensory attributes related to cheese textural properties indicated the potential applications of TPA, shear and penetration tests (r = 0.766, r = 0.75 and r = 0.765, respectively) for the evaluation of sensory properties related to the hardness. Meanwhile, the elasticity of cheese obtained from sensory evaluation was strongly correlated with the elasticity determined from the shear test (r = 0.722) and moderately correlated with the elasticity from penetration test (r = 0.588), indicating a need to refine the method of penetration test. In addition, cheeses exhibited higher meltability during convection heating at 230 °C than microwave heating. The values of meltability for cheese with reduced fat content were lower than those of full‐fat cheese.     

MILK CLOTTING AND CHEESE MAKING PROPERTIES OF A CHYMOSIN-LIKE ENZYME FROM HARP SEAL MUCOSA

Pepsin A was isolated from the gastric mucosa of two year old harp seal (Pagophilus groenlandicus). Seal pepsin A has a relatively high CU/PU ratio of 0.074, although it is lower than that of calf chymosin (0.170). Equivalent milk clotting units of chymosin and seal pepsin A catalyzed formation of the same amount of nonprotein nitrogen (NPN) when incubated with 2% casein and for both there was no appreciable increase in NPN formation in the second hour of incubation. Seal pepsin A was similar to chymosin in clotting milk substrate with respect to the influence of pH, dilution, calcium chloride and temperature. Cheddar cheeses prepared with either calf rennet or pepsin A as coagulating agent were similar in yield, chemical composition and taste as judged by sensory preference tests. Estimation of protein degradation in the aged cheeses by ultraviolet absorption of citrate-HC1 extracts, gel filtration chromatography of protein soluble in 6 N urea, and determination of amino acids indicated there was slightly more protein degradation in cheese prepared with calf rennet after 30 weeks aging. Sal pepsin A appears to make a major contribution to the excellent cheese-making characteristic of crude seal pepsin(s). However, other components of the seal mucosa extract are probably responsible for the accelerated aging of Cheddar cheese noted in previous reports.     

Inclusion of microalgae in the caprine diet improves nutritional profile of milk and its Camembert cheese

The experiment was carried out to investigate the effects of supplementation with microalgae (Schizochytrium sp.) on the nutritional characteristics of milk and Camembert cheese from dairy goats. The yield and composition of milk and cheese and the sensory quality of cheese were not affected by the supplementation. As the level of supplementation increased, the concentration of docosahexaenoic acid and total n-3 fatty acids increased, whereas the ratio of n-6/n-3 and total saturated fatty acids decreased in the milk and cheese. In conclusion, supplemented goats, especially goats that received 35 g/head/day produced milk and cheese with better fatty acid composition for human consumption, without affecting the production and composition.     

Impact of Using Exopolysaccharides (EPS)-Producing Strain on Qualities of Half-Fat Cheddar Cheese

Yield, textural, proteolysis, melting, and sensory properties of exopolysaccharide-producing Lactobacillus paracasei on properties of half-fat (about 16 g fat/100 g cheese) Cheddar cheese during ripening at 8℃ for up to six months were investigated. The results revealed that B-3 cheese, made with 2.0% (v/v) high yield exopolysaccharide-producing L. paracasei in combination with 0.011% (w/w) commercial Cheddar culture (B-3 cheese), had a 10.15, 7.71, and 10.04% separately increase in moisture content and had a 7.70, 5.05, and 6.76% separately increase in yield compared with B-2, B-4, and B-5 cheese, texture and melting characteristics were significantly improved (P < 0.05), sensory score surpassed B-4 and B-5 cheese and was similar to the full-fat one. Any differences of B-3 cheese detected among half-fat Cheddar cheeses were attributed to the presence of high yield exopolysaccharide-producing L. paracasei.     

Effect of minor milk proteins in chymosin separated whey and casein fractions on cheese yield as determined by proteomics and multivariate data analysis

The objective of this work was to find regressions between minor milk proteins or protein fragments in the casein or sweet whey fraction and cheese yield because the effect of major milk proteins was evaluated in a previous study. Proteomic methods involving 2-dimensional gel electrophoresis and mass spectrometry in combination with multivariate data analysis were used to study the effect of variations in milk protein composition in chymosin separated whey and casein fractions on cheese yield. By mass spectrometry, a range of proteins significant for the cheese yield was identified. Among others, a C-terminal fragment of β-casein had a positive effect on the cheese yield expressed as grams of cheese per 100 g of milk, whereas several other minor fragments of β-, α_s1-, and α_s2-casein had positive effects on the transfer of protein from milk to cheese. However, the individual effect of each identified protein was relatively low. Therefore, further studies of the relations between different proteins/peptides in the rennet casein or sweet whey fractions and cheese yield are needed for advanced understanding and prediction of cheese yield.