Influence of milk-clotting enzyme concentration on the alphas1-casein hydrolysis during soft cheeses ripening.

We studied the influence of the dose of milk-clotting enzyme on alphas1-CN degradation, soluble nitrogen production, and sensory profile for an Argentinean soft cheese: Cremoso Argentino. Five different types of cheeses were produced: 1) control cheeses with normal technology, 2) cheeses with inactivated milk-clotting enzyme, 3) cheeses with inactivated milk-clotting enzyme, without starter (acidified with glucono delta lactone), 4) cheeses with a half dose of milk-clotting enzyme, and 5) cheeses with a double dose of milk-clotting enzyme. Proteolysis was assessed by isoelectric focusing electrophoresis of the insoluble fraction at pH 4.6, followed by densitometric quantification. Soluble nitrogen at pH 4.6, expressed as a percentage of total nitrogen and defined as ripening index was also performed. A sensorial panel evaluated the cheeses at the end of ripening. The hydrolysis level of alphas1-CN depended on the milk-clotting enzyme dose used in cheese making. Cheeses without active coagulant did not show degradation at the end of ripening, while cheeses with half and whole doses showed proportional degradations to coagulant dose. Cheese with a double dose of coagulant did not show higher alphas1-CN hydrolysis than normal cheese. No difference was found between cheeses with and without microbiological starter, indicating that the selected culture, composed of thermophilic strains, was unable to attack the whole casein. A high linear correlation was found between ripening index and the relation Sensorial characteristics of cheeses agree with objective analysis. Cheeses without active coagulant were hard and crumbly, while cheeses with normal dose were soft and creamy.     

SENSORY CHARACTERISTICS OF EWE MILK CHEESE MADE WITH THREE TYPES OF COAGULANT: CALF RENNET, POWDERED VEGETABLE COAGULANT AND CRUDE AQUEOUS EXTRACT FROM CYNARA CARDUNCULUS

This article reports on a study of the sensorial characteristics of ewe milk cheese (Los Pedroches) made with animal rennet and two types of coagulant obtained from the cardoon Cynara cardunculus. The cheeses made with rennet displayed a less odor intensity: pungent odor and acid odor; a less acid taste; and a slightly lighter color. They were harder and firmer, but less creamy than those made with the vegetable coagulant (powdered vegetable coagulant [PVC] and crude aqueous extract [CAE] from C. cardunculus). However, the cheeses made with PVC showed organoleptic characteristics very similar to the cheeses made with CAE from C. cardunculus. After 90 days' ripening, the cheeses made with vegetable coagulant displayed a slightly more bitter taste than those made with rennet. In general terms, increased ripening time prompted the increased scores for most of the sensory attributes studied.     

Physicochemical,microbiological, textural and sensory changes during the ripening of pasteurised goat milk cheese made with plant coagulant (Cynara scolymus)

This study describes the changes that occur during the ripening of cheeses made with a plant coagulant derived from artichoke flowers (Cynara scolymus). The results indicate that the physicochemical composition during ripening evolves similarly to other cheeses. The texture and sensory features of the cheeses during ripening evolved differently from that observed for other goat cheeses. Although it is common for a bitter taste to develop during the ripening of cheeses elaborated with plant coagulants, bitterness was scored very low in the cheeses made with artichoke, so that these cheeses could be suitable for marketing.     

Influence of rennet milk-clotting activity on the proteolytic and sensory characteristics of an ovine cheese

Roncal cheese (regulated by an Apellation of Origin) is a traditional hard cheese manufactured from raw ewe's milk in the region of Navarre in Spain. Roncal cheeses, manufactured using two lamb rennets with different milk-clotting activity levels, were evaluated to compare their chemical, proteolytic, and sensory characteristics. A preliminary study of samples of lamb rennets indicated that a large proportion of such rennets did not fulfil current microbiological requirements and likewise revealed considerable variation in the milk-clotting activity of the samples examined. Trends in the overall physicochemical parameter values (pH, dry matter, fat, and protein) were similar in both cheese batches. Proteolysis of the nitrogen fractions was observed to take place at a faster rate in the cheeses made using the rennet with the higher milk-clotting activity (soluble nitrogen, non-protein nitrogen, and amino acid nitrogen values around 13–20% higher than in the cheeses made using the rennet with the lower milk-clotting activity after 180 days of ripening). Urea-PAGE electrophoretic analysis of the caseins from the cheeses manufactured using both types of rennet showed that the β-caseins were less susceptible to proteolysis than the α_s-caseins. The effect of the different milk-clotting activity levels was most pronounced on the α_s-caseins, in which the rennet with the higher milk-clotting activity gave higher breakdown. Nevertheless, the differences in the proteolysis rates did not yield any appreciable sensory differences.     

Effect of some technological parameters on microbiological, chemical and sensory qualities of Civil cheese during ripening

The objective of this research was to determine the effects of different ripening methods [brine salting, dry salting, incorporating with Lor cheese (LR) and vacuum packaging] of Civil cheeses on its microbiological, chemical and sensory properties. Civil cheeses were analysed on the 2nd, 30th, 60th and 90th day of ripening. Chemical compositions of the cheeses were significantly different. While the highest dry matter and titratable acidity values were determined on dry salted cheeses, the highest fat and fat in dry matter contents were found in Civil cheese ripened together with LR. The water-soluble nitrogen and ripening index values were lower in cheese ripened incorporating with LR. Excessive proteolysis was not seen in any of cheese samples. The ripening in different methods affected microbiological and sensory properties of Civil cheese. Panellists preferred vacuum packaging and dry-salting cheeses compared to the other samples on the 90th day of ripening.     

Residual clotting activity and ripening properties of vegetable rennet from Cynara cardunculus in La Serena cheese

Vegetable rennet extracted from Cynara cardunculus flowers is traditionally used in the manufacture of La Serena cheese. High levels of proteolytic enzymes of the flowers are responsible for its clotting activity and strong proteolytic action. The presence of residual coagulant in cheese and whey was measured by adding known amounts of vegetable rennet as internal standard. We found no differences between the residual coagulant activity of La Serena cheese compared with other types of cheese. The coagulant content detected at the end of four cheesemakings (vat of 830 l) in cheese and whey represented 27 and 78%, respectively, of the total amount added to milk. When measurements were carried out in 16 different cheeses, vegetable rennet appeared to be highly stable during cheese ripening. Cheese composition (moisture, pH, NaCl, fat and protein) was kept relatively constant during ripening, which seems to contribute to stability of residual activity. Electrophoretic analyses of water insoluble fractions from cheeses manufactured with vegetable rennet showed that α_s-casein was less susceptible to proteolysis than β-casein. The water soluble nitrogen/total nitrogen (WSN/TN) exhibited higher levels only during the first 30 days of ripening although non-protein nitrogen/total nitrogen (NPN/TN) ratio and amino acid nitrogen (NH₂-N) increased with ripening time.     

Incidence of autochthonous Argentinean mixed starter cultures in ripening of slurry cheese models

The effect of three mixed autochthonous starter cultures in ripening profiles of experimental semihard goat cheeses was evaluated under controlled microbiological conditions. Enterococcus faecium ETC3 and ETC6, Lactobacillus plantarum ETC17 and L. rhamnosus ETC14 were used. Combination of all strains showed the highest level of water soluble nitrogen fraction and total free amino acids (TFAA) at ripening day 1, the lowest level of phosphotungstic acid nitrogen soluble fraction and TFAA at ripening day 64 and the highest global impression. Principal component analyses were performed to establish amino acid profiles relations in the samples.     

Effects of different ripening procedures on the final characteristics of Picante cheese

 Picante da Beira Baixa (or Picante) cheese is a hard, piquant, salted traditional cheese manufactured in Portugal from raw sheep's and goat's milks. The purpose of this work was to quantitatively assess the influence of various ripening procedures on the final characteristics of Picante cheese. Two alternative ripening protocols were considered, the traditional one and another with controlled environmental conditions via use of maturation chambers set at different preselected temperatures. The experimental cheeses were characterised in terms of microbiological, physicochemical, biochemical, sensorial and textural properties. Ripening time and temperature were statistically significant parameters for all microflora. The two ripening methods led to statistically significant differences in all physicochemical and biochemical parameters, especially the moisture content and the soluble nitrogen fractions (i.e. water loss was slower and proteolysis was faster in cheeses ripened via the traditional method). Differences in microbiological, physicochemical and biochemical properties were probables implicated in differences in textural and sensorial properties, especially cheese hardness and flavour. It was concluded that the standard ripening method was closest to the traditional one in terms of final cheese characteristics when the ripening temperature was above 11.5  °C. Received: 3 February 1998     

Effects of different ripening procedures on the final characteristics of Picante cheese

 Picante da Beira Baixa (or Picante) cheese is a hard, piquant, salted traditional cheese manufactured in Portugal from raw sheep's and goat's milks. The purpose of this work was to quantitatively assess the influence of various ripening procedures on the final characteristics of Picante cheese. Two alternative ripening protocols were considered, the traditional one and another with controlled environmental conditions via use of maturation chambers set at different preselected temperatures. The experimental cheeses were characterised in terms of microbiological, physicochemical, biochemical, sensorial and textural properties. Ripening time and temperature were statistically significant parameters for all microflora. The two ripening methods led to statistically significant differences in all physicochemical and biochemical parameters, especially the moisture content and the soluble nitrogen fractions (i.e. water loss was slower and proteolysis was faster in cheeses ripened via the traditional method). Differences in microbiological, physicochemical and biochemical properties were probables implicated in differences in textural and sensorial properties, especially cheese hardness and flavour. It was concluded that the standard ripening method was closest to the traditional one in terms of final cheese characteristics when the ripening temperature was above 11.5  °C. Received: 3 February 1998     

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 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.     

Influence of the season on proteolysis and sensory characteristics of Idiazabal cheese

The present study examined the influence of the manufacturing time on proteolysis and sensory characteristics of Idiazabal cheese. Samples of Idiazabal cheeses made using traditional manufacturing methods at two different times of year were collected at a plant operating under the auspices of the Idiazabal Cheese Appellation of Origin. The cheeses were made in February and June, roughly the beginning and the end of the manufacturing season. Chemical analyses were performed on d 1, 90, and 180 of ripening and sensory analyses on d 90, 120, and 180 of ripening. Higher nitrogen fraction (soluble and nonprotein nitrogen) levels and free amino acid contents were observed in the cheeses manufactured during the month of June. Degradation of the alphas- and beta-caseins was also greater in the cheeses made at that time of year. The cheeses manufactured in February earned higher sensory analysis scores for characteristic odor and taste and higher total sensory scores. The cheeses manufactured in June earned higher scores for the sensory attributes sweet flavor and bitter taste.     

Effect of Free or Encapsulated Recombinant Aminopeptidase of Lactobacillus rhamnosus S93 on Acceleration of Cheddar Cheese Ripening

The use of recombinant aminopeptidase (PepN) from Lactobacillus rhamnosus S93 in free or encapsulated form was investigated to shorten the duration of Cheddar cheese ripening. Proteolysis was determined by measuring the soluble nitrogen as phosphotungstic acid (PTA-N) derivatives and free amino acids (FAA) over a 6-month period. The experimental cheeses received higher scores for sensory properties than the control cheese. The amounts of PTA-N and total FAA in the cheese with the encapsulated enzyme after 2 months of ripening were close to those of the control cheese after 6 months, suggesting the acceleration in proteolysis by about 4 months.     

Effects of coagulant type on the physicochemical and organoleptic properties of Kashar cheese

Kashar cheeses were manufactured using different coagulants (calf rennet, chymosin derived by fermentation and proteases from Rhizomucor miehei and Cryphonectria parasitica) and ripened for 90 days. Use of different coagulants did not influence the dry matter, fat, protein, salt, pH, titratable acidity, total free fatty acids and texture profile analyses. The levels of water‐soluble nitrogen, 12% trichloroacetic acid‐soluble nitrogen, and for 5% phosphotungstic acid‐soluble nitrogen, the sensory properties were significantly influenced by the use of different coagulants. β‐casein was more hydrolysed in the cheese manufactured using protease from Cryphonectria parasitica than the other cheeses during 90 d of ripening.     

Substitution of natural whey starter by mixed strains of Lactobacillus helveticus in the production of Reggianito Argentino cheese

Reggianito Argentino cheeses were manufactured with mixed strains of Lactobacillus helveticus cultured in free viable bacteria whey. As controls, cheeses with natural whey starter were made. Gross composition of cheeses did not differ significantly. The number of total termophilic lactic acid bacteria at the end of ripening was near 10⁷ CFU/g, but when the strain Lh 209 was present in the mixture, this number was 10⁶ CFU/g. Soluble nitrogen at pH 4.6 did not differ between control and experimental cheeses, but soluble nitrogen in tricloroacetic acid 12% and phosphotungstic acid 2.5% showed significant differences at the end of ripening, being higher the values when the strain Lh 209 was present in the mixture. Electrophoretic profiles for control and experimental cheeses were very similar at 0, 90 and 180 days of ripening. An increase in the acid degree value of fat during ripening was noticeable indicating a lipolytic activity in the cheese matrix that was similar for the different strains mixtures. Results from sensory analysis did not show differences among the cheeses of these tests. Despite some differences in the production tricloroacetic and phosphotungstic acid soluble nitrogen were observed for mixtures in which Lh 209 was present, all cheeses were good quality Reggianito Argentino cheeses. These results open and interesting prospective for the use of selected strains culture in whey in substitution of natural whey.     

Effects of Penicillium roqueforti and whey cheese on gross composition,microbiology and proteolysis of mould‐ripened Civil cheese during ripening

Four different types of mould‐ripened Civil cheese were manufactured. A defined (nontoxigenic) strain of a Penicillium roqueforti (SC 509) was used as the secondary starter with and without addition of the whey cheese (Lor); in parallel, secondary starter‐free counterparts were manufactured. Chemical composition, microbiology and proteolysis were studied during the ripening. The incorporation of whey cheese in the manufacture of mould‐ripened Civil cheese altered the gross composition and adversely affected proteolysis in the cheeses. The inoculated P. roqueforti moulds appeared to grow slowly on those cheeses, and little proteolysis was evident in all cheese treatments during the first 90 days of ripening. However, sharp increases in the soluble nitrogen fractions were observed in all cheeses after 90 days. Microbiological analysis showed that the microbial counts in the cheeses were at high levels at the beginning of ripening, while their counts decreased approximately 1–2 log cfu/g towards the end of ripening.     

Chemical, microbiological, textural, color, and sensory characteristics of pressed ewe milk cheeses with saffron (Crocus sativus L.) during ripening

Adding saffron to dairy products represents an innovative practice to introduce them to niche markets. This paper represents a contribution to this field, as few studies have evaluated the influence of this spice on general aspects and ripening parameters of cheese. In this work, pasteurized ewe milk pressed cheeses with saffron were made to study compositional, microbiological, color, textural, and sensory characteristics in relation to saffron concentration and ripening time. The main changes were observed on sensory characteristics and color. In addition, compositional, textural, and microbiological changes could be observed; among them, saffron cheeses were firmer and more elastic but less prone to fracture. A remarkable result that could lead to further studies is that saffron addition slightly slowed down growth of total and lactic acid bacteria. This resulted in a slightly lower rate of pH decrease during pressing and, as a consequence, lower salt and water content. Compositional differences were not evident by the end of the ripening period.     

Characterisation of proteolysis profile of Argentinean sheep cheeses made by two different production methods

BACKGROUND: In this work the proteolysis profiles of Argentinean sheep cheeses made by two different production methods were studied in order to develop products with typical and defined features. Cheeses with a starter of Streptococcus thermophilus, curd cut to corn grain size, washed and heated to 43 °C (S cheeses) and cheeses with a mixed starter of Streptococcus thermophilus, Lactobacillus helveticus and Lactobacillus bulgaricus, curd cut to rice grain size, unwashed and heated to 47 °C (L cheeses) were manufactured. The cheeses were ripened at 12 °C and 80% relative humidity for 180 days and samples were taken throughout this period. RESULTS: Gross composition and primary proteolysis were similar for both types of cheeses. Streptococci counts diminished from 10⁹ to 10⁷ colony‐forming units g^?1 during ripening in both S and L cheeses. Lactobacilli counts in L cheeses decreased during ripening and disappeared at 180 days. L cheeses had significantly lower pH values and showed higher peptidolysis than S cheeses. Triangle sensory evaluation indicated important differences between the two types of cheeses. CONCLUSION: S cheeses had a low proteolysis level and a soft flavour, making them appropriate for consumption after a short ripening time. L cheeses had a higher proteolysis level and more intense sensory characteristics, making them appropriate for consumption after a longer ripening time. Copyright © 2009 Society of Chemical Industry     

The effect of mendi (Chaerophyllum sp.) on ripening of vacuum-packed herby cheese

The composition, biochemical and sensory parameters of control cheese (without herbs) and four herby cheeses at 0.5, 1, 2 and 3% herb levels (mendi, Chaerophyllum sp.) ripened at 4 ± 1°C for 90 days were compared. As herb levels increased from 0.5 to 3%, dry matter and pH value decreased significantly. However, dry matter of all cheeses showed similar changes during ripening. The salt content of samples changed from 3.44 to 5.47% during ripening. There was a tendency toward slightly higher titratable acidity in cheeses with more added herbs. Ripening index, trichloroacetic acid-soluble nitrogen/total nitrogen, phosphotungstic acid-soluble nitrogen/total nitrogen, and lipolysis values of the cheese samples were affected by adding herbs and by ripening time. The most acceptable sensory score was obtained with 1% added herbs.