Effect of partial or total substitution of bovine for caprine milk on the compositional,volatile, non-volatile and sensory characteristics of semi-hard cheeses

Semi-hard cheeses were manufactured from caprine milk and bovine milk mixed in ratios of 100:0; 75:25; 50:50; 25:75; 0:100 (caprine:bovine) and ripened at 12 °C for 150 d. Substitution of up to 75% bovine for caprine milks had no significant effect on levels of cheese protein, moisture-in-non-fat substances, salt, pH, whiteness, total or individual free amino acids and substitution of up to 50% had no significant effect on levels of primary proteolysis and free fatty acid and fruity flavours. Increased bovine milk content resulted in decreased levels of butanoic to octanoic acids, ethyl and methyl esters of acetic to octanoic acids and acyclic, mono and bicyclic terpenes and waxy/goaty flavours to a degree dependent on the proportion of each milk type. Partial substitution of caprine with bovine milks resulted in cheeses with chemical and sensorial characteristics that may provide an available alternative to consumers desiring caprine cheeses.     

Recent developments in antibody-based analytical methods for the differentiation of milk from different species

The antibody-based analytical methods for the detection of milk from different species that have been developed in recent years are, for the most part, various enzyme-linked immunosorbent assay (ELISA) configurations. Polyclonal and, more recently, monoclonal antibodies against total or individual caseins, whey proteins and synthetic peptides corresponding to milk proteins sequences have been used. The assays have been successfully applied to the detection of substitution of ovine or caprine milk by bovine milk and of ovine milk by caprine milk in raw and heat-treated milks and cheeses.     

Robust PCR‐based method for quantification of bovine milk in cheeses made from caprine and ovine milk

To prevent fraud and enhance quality assurance, credible analysis of dairy products is crucial. A common problem is the addition of cheaper bovine milk to caprine and/or ovine dairy products and when not declared addition of bovine milk constitutes fraud. The aim was to develop a rapid, robust and sensitive method for the identification of adulteration of caprine and/or ovine cheeses with bovine milk. New quantitative real‐time polymerase (qPCR) assays were designed for the specific determination of bovine DNA (Cow1) and bovine, caprine and ovine DNA (BoCaOv). These were applied to 17 samples of caprine cheese and 24 of ovine cheese. Results showed that 17% (7/41) of these cheeses contained >5% bovine milk. As bovine milk was not declared as an ingredient in any of the samples, this represents adulteration. Other cheeses that contained detectable bovine milk at ≤5% (22%; 5/41) might pose a health risk to people allergic to bovine milk.     

Changes during ripening in chemical composition,proteolysis, volatile composition and texture in Kashar cheese made using raw bovine,ovine or caprine milk

Kashar cheeses were manufactured from pure ovine (OV), bovine (BV) and caprine (CP) milk, and the chemical composition, cheese yield, proteolysis, hardness, meltability and volatile composition were studied during 90 days. Gross chemical composition, cheese yield and level of proteolysis were higher in OV cheeses than those of BV or CP cheeses. Glu, Val, Leu, Phe and Lys were the most abundant free amino acids (FAA) in the samples, and the concentrations of individual FAA were at the highest levels in OV cheeses with following BV and CP cheeses. Urea‐PAGE patterns and RP‐HPLC peptide profiles of the BV cheeses were completely different from the small ruminants’ milk cheeses (OV or CP). Higher and lower hardness and meltability values were observed in CP cheeses, respectively. OV cheeses resulted in higher levels of the major volatile compounds. In conclusion, the Kashar cheese made using OV milk can be recommended due to high meltability, proteolysis and volatiles.     

Influence of ovine milk in mixture with bovine milk on the quality of reduced fat Muenster-type cheese

Reduced fat Muenster-type cheeses were manufactured from a mixture of bovine skim milk and ovine whole milk and from bovine milk only (control). Cheeses were evaluated at 15, 30, 60, 90, 120, and 180 d of age for numbers and type of microflora, casein hydrolysis, and amounts of free fatty acids. alpha(s1)-Casein degradation was similar for both cheeses during the aging period, but beta-casein degradation proceeded at a faster rate in the control cheese. The total amounts of free fatty acids remained constant throughout the ripening time; however, the cheeses produced with bovine/ovine milk yielded a significantly larger amount of caprylic (C8:0) and capric (C10:0) acids compared with the bovine milk cheeses. Lactobacilli increased during the aging period, while the populations of lactic acid bacteria, yeast and molds, and lipolytic organisms did not increase. Both cheeses had comparable cheese flavor intensity, but the bovine/ovine milk cheese had a greater occurrence of off flavors. The bovine/ovine milk cheeses were firmer than the bovine cheeses throughout the aging period.     

Comparison of the characteristics of halloumi cheese made from ovine milk, caprine milk or mixtures of these milks

The aim of this work was to study the rheological, physicochemical and organoleptic characteristics of four types of halloumi cheese made from pure ovine milk, pure caprine milk or mixtures containing 15 or 30% caprine milk. All the milks were standardized for casein to fat ratio. Pure ovine milk gave the highest yield of halloumi cheese and caprine the lowest. No significant differences in acidity, pH, moisture, total protein and ash contents of the four types of cheese were found. In contrast, significant differences in soluble proteins, non-protein nitrogen, acid degree value and calcium contents were noted. Rheological examinations showed the hardness and the force at the point of fracture of caprine halloumi cheese to be lower than those of the other types of cheese. The same cheese presented the highest compression at the point of fracture and cohesiveness, while there were no differences in gumminess or chewiness. Members of the assessment panel showed a preference for halloumi cheese made from 30% caprine milk and 70% ovine milk.     

Seasonal variation of the free fatty acids contents of Spanish ovine milk cheeses protected by a designation of origin: A comparative study

The extent and pattern of lipolysis in Spanish PDO raw ewes’ milk cheeses, Manchego, Zamorano and La Serena, were studied. Semi-cured and cured cheeses were analysed. Significant differences were found among the PDO cheeses in all free fatty acid (FFA) concentrations, except for the medium chain fatty acids (MCFAs; C10:0 to C14:0). All individual FFA concentrations increased significantly with ripening time. Seasonality was also significant: the highest concentrations of total FFAs were found in cured cheeses manufactured in spring. Ratios of short, medium and long chain fatty acids to total FFAs in the different cheeses were indicative of the types of cheeses and of the season in which they were made. Discriminant analysis classified correctly 84% of Manchego cheeses, 93% of La Serena cheeses and 92% of Zamorano cheeses in the respective variety. All of the cured Manchego and Zamorano cheeses were correctly classified for the season of manufacture.     

Lipolysis in Urfa cheese produced from raw and pasteurized goats’ and cows’ milk with mesophilic or thermophilic cultures during ripening

Lipolysis was evaluated in Urfa cheese made from raw and pasteurized goats’ and cows’ milk with mesophilic or thermophilic cultures. The acid degree values (ADVs) of the cows’ milk cheeses were significantly (P < 0.05) higher until 60 d of storage than that of cheese made from goats’ milk. Total free fatty acid (FFA) contents of goats’ milk cheese were significantly (P < 0.001) lower than that of cows’ milk cheese throughout ripening, whereas goats’ milk cheese flavour was higher (P < 0.05) than cows’ milk cheese. Pasteurization of milk prior to cheese-making has a negative influence, not only on the level of lipolysis throughout ripening, but also on the relative amounts of short chain FFAs and sensory properties of the cheeses (P < 0.001). Cheese produced without starter bacteria underwent significantly (P < 0.05) higher lipolysis than cheeses produced with mesophilic or thermophilic starter bacteria, while cheese made with thermophilic starter culture had similar flavour to cheese made without starter culture.     

Evaluation of real-time PCR assays for detection and quantification of fraudulent addition of bovine milk to caprine and ovine milk for cheese manufacture

Many typical Italian cheeses made from ovine milk are certified as Protected Designation of Origin (PDO). Because caprine and ovine milk production is limited, the fraudulent addition of cows' milk is widespread. In addition, some compounds in bovine milk have high allergenic potential; therefore, such fraud also has implications for consumer health. In this study, a real-time polymerase chain reaction (real-time PCR) test was developed to detect and quantify cow's milk in caprine and ovine cheeses, based on two target genes. The mitochondrial Cytochrome b gene (Cytb) of Bos taurus was used to detect and quantify bovine DNA. The nuclear gene myostatin (Myo), nuclear ribosomal gene 18S, or mitochondrial gene 16S were used alternatively as universal reference markers. Caprine (n = 30) and ovine (n = 51) cheese samples were purchased and analyzed and most were shown to be contaminated by bovine milk. Pairwise analysis of quantification data using a Spearmann Rank Correlation test demonstrated a highly significant correlation between data obtained with the different reference assays.     

Ripening of Camembert-type cheese made from caprine milk using calf rennet or kid rennet as coagulant

Camembert-type cheese was made from caprine milk using either calf rennet or kid 'Grandine' rennet as coagulant. The pH of all cheeses increased throughout ripening and levels of pH 4.6-soluble nitrogen increased from 8.1 to 18.2% of total nitrogen (TN) and from 6.9 to 20% TN for the cheeses made using calf rennet and kid rennet, respectively. Degradation of β-casein, measured by urea–polyacrylamide gel electrophoresis, and total and free amino acids were greater in the cheese made using kid rennet. Production of peptides, analysed by high performance liquid chromatography (HPLC), was slightly more extensive in the Camembert-type cheese made using calf rennet as coagulant. In general, a higher degree of proteolysis was found in Camembert-type cheese made from caprine milk using kid rennet than in cheese made using calf rennet as coagulant.     

Species origin of milk in Italian mozzarella and Greek feta cheese

Several animal species such as cattle, goats, sheep, and water buffalo provide milk for dairy products. We describe a simple procedure for detecting the species origin of milk used for cheese production. DNA was isolated from Italian mozzarella or Greek feta by sequential organic extractions and resin purification. This DNA was analyzed by polymerase chain reaction-restriction fragment length polymorphism as described previously for meat samples. This procedure differentiated mozzarella made from water buffalo milk and from less expensive bovine milk and also feta cheeses made from bovine, ovine, and caprine milk.     

Hard ewe's milk cheese manufactured from milk of three different groups of somatic cell counts

As ovine milk production increases in the United States, somatic cell count (SCC) is increasingly used in routine ovine milk testing procedures as an indicator of flock health. Ovine milk was collected from 72 East Friesian-crossbred ewes that were machine milked twice daily. The milk was segregated and categorized into three different SCC groups: < 100,000 (group I); 100,000 to 1,000,000 (group II); and > 1,000,000 cells/ ml (group III). Milk was stored frozen at -19 degrees C for 4 mo. Milk was then thawed at 7 degrees C over a 3-d period before pasteurization and cheese making. Casein (CN) content and CN-to-true protein ratio decreased with increasing SCC group 3.99, 3.97, to 3.72% CN, and 81.43, 79.72, and 79.32% CN to true protein ratio, respectively. Milk fat varied from 5.49, 5.67, and 4.86% in groups I, II, and III, respectively. Hard ewe's milk cheese was made from each of the three different SCC groups using a Manchego cheese manufacturing protocol. As the level of SCC increased, the time required for visual flocculation increased, and it took longer to reach the desired firmness for cutting the coagulum. The fat and moisture contents were lower in the highest SCC cheeses. After 3 mo, total free fatty acids (FFA) contents were significantly higher in the highest SCC cheeses. Butyric and caprylic acids levels were significantly higher in group III cheeses at all stages of ripening. Cheese graders noted rancid or lipase flavor in the highest SCC level cheeses at each of the sampling points, and they also deducted points for more body and textural defects in these cheeses at 6 and 9 mo.     

Free fatty acid composition of regionally-produced Spanish goat cheese and relationship with sensory characteristics

A study was made of free fatty acid composition and sensory characteristics (odour and taste) in regionally-produced Spanish goat cheeses. The most abundant FFAs were oleic, palmitic, stearic, capric and myristic acid which together accounted for roughly 85% of total FFAs. These cheeses generally underwent a lower degree of lipolysis than did other goat cheeses. Panellists judged the cheeses as having considerable odour and flavour intensity. However, both total FFA content and sensory attributes varied considerably among cheeses due, in all likelihood, to differences in ripening time and to production by different manufacturers. Principal component analysis generated three principal components (PC) that accounted for 70% of total variance; the variables that best correlated with them were long-chain and medium-chain free fatty acids (PC1), brine odour, bitterness and goat milk odour (PC2) and short-chain free fatty acids (PC3).     

Microbiological,chemical, textural and sensory characteristics of Hispánico cheese manufactured using frozen ovine milk curds scalded at different temperatures

Hispánico cheese is a semi-hard variety, manufactured in Spain from a mixture of pasteurized bovine and ovine milk. To study one strategy for overcoming a seasonal shortage of ovine milk in summer and autumn, curds made from ovine milk, scalded at 32, 35 or 38 °C, were pressed for 30 min and frozen at ?24 °C for 4 months. After thawing, they were added to fresh bovine milk curd for the manufacture of experimental Hispánico cheeses. Control cheese was made from a mixture of pasteurized bovine and ovine milk in the same (80:20) proportion. No significant effect of the addition of frozen ovine milk curd or scalding temperature was found for lactic acid bacteria counts, dry matter content, hydrophilic and hydrophobic peptides, 45 out of 65 volatile compounds, texture, and sensory characteristics throughout a 60-day ripening period. Differences between cheeses, of low magnitude and little practical significance, were found for pH value, aminopeptidase activity, proteolysis, free amino acids, free fatty acids, and the remaining 20 volatile compounds. Thus, the addition of frozen ovine milk curd to fresh bovine milk curd does not alter the main physicochemical and sensory characteristics of Hispánico cheese.     

Nutritional and therapeutic value of fermented caprine milk

Caprine milk is a nutritional and therapeutic food. The unique and beneficial characteristics of caprine milk that are superior to bovine milk include: better digestibility; greater buffering capacity; fat globules that are smaller in diameter and better distributed in the milk emulsion; higher content of short‐chain fatty acids in the milk fat; higher content of zinc, iron and magnesium; stronger lactoperoxidase (antimicrobial) system as well as better immunological and antibacterial characteristics. The larger amounts of some minerals, such as calcium, zinc and magnesium, in caprine milk may influence the growth of lactic acid bacteria since they are a normal part of some enzymatic complexes involved in lactose fermentation. The higher whey protein content could also be significant because Lactobacillus acidophilus and bifidobacteria grow better in the presence of higher levels of some amino acids (valine, glycine, hystidine). The use of caprine and ovine milk in cheesemaking is well known, but the production of fermented caprine milk via probiotics has not yet been developed, although many studies have highlighted the requirements for production of that kind of healthy food. During fermentation caprine milk loses its characteristic ‘goaty’ taste, which is unacceptable to many consumers. Moreover, the nutritive value of caprine milk increases during fermentation. The rise in the number of goat farms in Croatia has created the need to find other products that can be produced using caprine milk. According to the present situation in Croatia, there is no real possibility of producing fermented caprine milk for the global market, but many studies of fermented caprine milk have been performed.     

Some Volatile Plant Compounds in Halloumi Cheeses made from Ovine or Bovine Milk

The volatile flavour componds in commercial samples of fresh Halloumi cheese made from either bovine milk or a mixture of ovine and caprine milks were compared. Terpenes, such as α-pinene, β-pinene, copaene, thymol, α-caryophyllene, β-caryophyllene and δ-cadinene were all present in the ovine/caprine cheeses and, in some cases, at concentrations above their reported flavour threshold values. Only low levels of α-pinene and β-caryophyllene were found in the bovine samples, along with D -carvone and eucalyptol from mint added during manufacture. Analysis of some plants that dominated the feeds of the sheep/goats or cows that produced the original milk indicated that the terpenes are likely to have originated in the plants eaten by the animals. It was suggested that the presence of the terpenes may explain the preference of some consumers for the fresh ovine/caprine cheese.     

Changes of composition and free fatty acid contents of Urfa cheeses (a white-brined Turkish cheese) during ripening: Effects of heat treatments and starter cultures

The influences of heat treatments (at 65 °C for 20 min or 72 °C for 5 min) applied to the milk and addition of mesophilic or thermophilic starter cultures, prior to cheese-making, on the composition and free fatty acid contents of Urfa cheeses were evaluated throughout the ripening period. Sensory evaluation of cheese samples was also performed on 90th day. The basic composition of ripened cheese samples was not significantly affected by the heat treatments and starter cultures. Heat treatments adversely affected the lipolysis and sensory properties of Urfa cheeses, particularly at 72 °C. The FFA contents of cheeses made from mesophilic and thermophilic cultures were similar. Cheese made from raw milk had a higher level of lipolysis than the cheeses made from milk inoculated with mesophilic or thermophilic lactic starters (p < 0.05).     

Characteristics of set type yoghurt made from caprine or ovine milk and mixtures of the two

Rheological, physico‐chemical and organoleptic studies were made on five types of yoghurt originally from pure caprine milks of an Alpine breed and local breeds, pure ovine milk of the Lacaune breed, and two mixtures containing 50% caprine milk from an Alpine breed + 50% ovine milk of the Lacaune breed and 70% caprine milk of local breeds + 30% ovine milk of the Lacaune breed. Comparison of the yoghurts showed that it was possible to produce yoghurt of good quality from the last four types of milk. In contrast, pure caprine milk from an Alpine breed was not suitable for the production of yoghurt as this milk is low in dry matter and the yoghurt that was produced had the lowest firmness and significantly inferior organoleptic characteristics. Yoghurts prepared from mixtures of 50% caprine milk of an Alpine breed + 50% ovine milk of the Lacaune breed, and 70% caprine milk of local breeds + 30% ovine milk of the Lacaune breed, were of good quality, with similar consistency, rheological and organoleptic characteristics.     

EVALUATION OF pH CHANGE KINETICS DURING DIFFERENT STAGES OF KASHAR CHEESE PRODUCTION FROM BOVINE, OVINE AND CAPRINE MILK

The objective of this study was to determine the pH change kinetics during Kashar cheese production from bovine, ovine and caprine milk. Kinetics of pH change were determined during milk ripening, cooking/holding and pressing/fermentation phases of Kashar cheese. The pH decreased logarithmically, nonlinearly, with time in the milk ripening period and was reduced linearly with time in the cooking/holding and pressing/fermentation stages. The time of pH decrease in cow's, ewe's and goat's milk was significantly different, except cooking/holding time, for three stages. There was no difference between bovine and caprine milk in cooking/holding time; however, ovine milk was significantly different from the other two kinds of milk. The shortest and the longest overall times were determined for caprine and ovine milk cheeses, respectively. The rate of change in milk pH of the three species was significantly different for three stages. The rate followed the pattern caprine  >  bovine  >  ovine milk.

PRACTICAL APPLICATIONS

Optimum acid development is essential to creating the desired cheese mass. For each major cheese type, lactic acid must develop in the appropriate time, usually not too rapidly or too slowly, and in a specific concentration. The progress of acidification is monitored by pH change in the industrial Kashar cheese production. The final pH of cheese is determined not only by the amount of lactic acid but also by the buffering capacity (BC) of the milk and curd. However, the BC is different between milk species. This study evaluates and compares the pH change kinetics during various stages of Kashar cheese making using cow's, ewe's and goat's milk. This work may help to compare milk and cheese curds made from bovine, ovine and caprine milk.