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     

Characteristics of traditional Croatian ewe's cheese from the island of Krk

Krk cheese is a hard, full-fat cheese made from raw sheep's milk, characterized by a delicate, full and strong flavour. The aim of this study was to determine farm influence on the chemical composition of sheep's milk for Krk cheese production, and the chemical characteristics of Krk cheese during ripening. Gross composition of the milk used complies with the average sheep's milk composition from the Croatian Adriatic region. During ripening, fat, protein, salt content and lactic acid concentration increased ( P <  0.01), as well as the water-soluble nitrogen fraction and the 12%-trichloroacetic-acid-soluble nitrogen fraction ( P <  0.05). Degradation of β-casein could be an indicator of the ripening quality of Krk cheese.     

Changes of lactose, lactic acid, and acetic acid contents in Serra cheese during ripening

 Changes in the quantities of lactose, lactic acid and acetic acid in Serra cheese were monitored using a triplicate two-way factorial design over a ripening period of 35 days (sampling at 0, 7, 21 and 35 days) throughout the cheesemaking season (sampling in November, February and June). The amount of lactose in total solids of cheese (TS) decreased slowly from 6.17% to 0.21% (w/w_TS) as ripening time elapsed. As a result of sugar metabolism, the lactic acid content increased from 0.07% at day 0 to 2.10% (w/w_TS) by 35 days, whereas the acetic acid content increased from 0.00% to 0.24% (w/w_TS) during the first week. The lactose content was statistically correlated with the lactic acid content but not with the acetic acid content. Received: 18 November 1996     

Biochemical changes during the ripening of homemade 'San Simón da Costa' raw milk cheese

'San Simón da Costa' cheese is a traditional smoked variety produced in the northwest of Spain from cow's milk. Biochemical changes were determined during its ripening. Its high calcium and phosphorus content and its low NaCl and sodium content stand out. This cheese undergoes moderate proteolysis. The most abundant free amino acid at the end of the ripening was glutamic acid, followed by tryptophan, leucine, arginine and phenylalanine. The lipolysis throughout ripening is slight; the most abundant free fatty acid being oleic, followed by palmitic and butyric acid.     

Headspace analysis of volatile flavour compounds of teleme cheese made from sheep and goat milk

The headspace compounds of teleme cheese made from sheep's milk, goats' milk or mixture of sheep's and goats' milk (50:50) were analysed during ripening by static headspace gas chromatography–mass spectrometry. A total of 21 major compounds were identified, including aldehydes (7), alcohols (5), ketones (4), and acids (2). All types of cheeses contained approximately the same volatiles at different concentrations. The total volatile compounds (TVC) increased during ripening. Cheeses made from sheep's milk showed the highest level of TVC, whereas cheeses made from goats' milk showed the lowest one.     

Changes in the microbiological and chemical characteristics of an artisanal, low-fat cheese made from raw ovine milk during ripening

Changes in the microbial flora of batzos cheese made from raw ovine milk were studied during ripening. Lactic acid bacteria and Enterobacteriaceae were the predominant groups of micro-organisms. Cheeses manufactured in summer had higher microbial counts than those made in spring, with the exception of staphylococci. Nevertheless, Enterobacteriaceae and coliforms decreased more rapidly in cheese made in summer and counts at the end of storage were lower than those in spring cheese.
Enterococci predominated in the ripened curd of cheese made in spring, whereas lactobacilli were the most abundant lactic acid bacteria in cheese made in summer. Enterococcus faecium was the predominant species in spring, and Lactobacillus paracasei ssp. paracasei predominated in cheese made in summer. The pH of the cheeses was > 5.0 throughout ripening, and NaCl-in-moisture content (> 8.0%) permitted the growth and survival of salt-tolerant micro-organisms. α_s1-Casein degraded at a faster rate than β-casein; both caseins were hydrolysed more rapidly in spring than in summer. The free amino acid content became higher in summer cheese (566.24–3460.25 µg/g of glycine equivalent) than in spring cheese because of the progress of ripening. Moreover, the milk fat of the cheese was degraded more in the summer than in the spring. The results suggest that there could be advantages to using starter cultures and improving the level of hygiene during milk and cheese production in order to eliminate undesirable micro-organisms and standardize cheese quality.     

Microbiological and chemical characterization of Fiore Sardo, a traditional Sardinian cheese made from ewe's milk

The purpose of this study was to assess the chemical and microbial characteristics of 12 batches of artisanal Fiore Sardo, a protected designation of origin (PDO) hard cheese made from raw ewe's milk without addition of starters, during maturation. High standard deviations were observed for moisture percentage, total solids percentage and NaCl percentage content, possibly owing to differences in manufacturing processes and/or milk composition. Total mesophilic bacteria varied between 10 log₁₀ cfu/g in 48-h-old cheese samples and 3 log₁₀ cfu/g in 9-month-old samples. Total coliforms and staphylococci showed the highest counts at 48 h of ripening then decreased significantly, dropping to levels below 2 log₁₀ cfu/g at 3 months of maturation. Lactic acid bacteria and enterococci were the dominant micro-organisms throughout maturation. They were mainly represented by the species Lactococcus lactis ssp. lactis, Enterococcus faecium, Lactobacillus plantarum and Lactobacillus casei group. Low levels of yeasts were detected throughout the maturation period of the cheese. Debaryomyces hansenii and Kluyveromyces lactis var. lactis were the prevalent yeast species isolated.     

Influences of rennet and container types on proteolysis of traditional Kurdish cheese during the ripening

The effect of rennet and container types was evaluated on proteolysis of traditional Kurdish cheese during 60 days ripening. The enzymes involved were commercial chymosin and traditional rennet from lamb abomasum. Goat skin (traditional container) and plastic containers were used as storage containers. The trend of proteolysis was determined by measuring the content of nitrogen (N) in compounds soluble in water, 12% trichloroacetic acid and 5% phosphotungstic acid along with the urea–polyacrylamide gel electrophoresis method. The results showed that the nitrogen in compounds soluble in water, 12% trichloroacetic acid and 5% phosphotungstic acid was higher in ripened cheeses into plastic containers; however, the containers had no significant effect on the breakdown of α‐ and β‐caseins (P < 0.05). Using commercial rennet caused the breakdown of α‐ and β‐caseins and the level of nitrogen in compounds soluble in water to increase. Finally, however, the amount of α‐ and β‐caseins breakdown was trivial, and α‐casein was decreased more than β‐casein in all samples.     

Effects of high pressure treatment on volatile profile during ripening of ewe milk cheese

The effect of high-pressure treatment on the volatile profile of ewe milk cheeses was investigated. Cheeses were submitted to 200, 300, 400 and 500 MPa at 2 stages of ripening (after 1 and 15 d of manufacturing) and volatile compounds were assayed at 15 and 60 d of ripening. High-pressure treatment altered the balance of volatile profile of cheeses, limiting the formation of acids, alcohols, ketones, aldehydes, and sulfur compounds and enhancing the formation of 2,3-butanedione. In general, cheeses pressurized at 15 d of ripening were more similar to untreated cheeses than those treated at 1 d. Cheeses treated at 300 MPa after 1 d of manufacturing were characterized by higher levels of free amino acids, ethanol, ethyl esters, and branched-chain aldehydes, whereas cheeses treated at 500 MPa after 1 d of manufacturing had lower microbial populations, showed the highest abundance of 2,3-butanedione, pyruvaldehyde, and methyl ketones, and the lowest abundance of alcohols.     

Compositional,biochemical and textural changes during ripening of Tulum cheese made with different coagulants

In the present study, biochemical, chemical and texture changes in Tulum cheeses made using calf rennet and microbial rennets (Aspergillus niger protease and Rhizomucor miehei protease) were compared during ripening for up to 90 days. A total of 15 free fatty acids (FFAs) were detected in the cheese samples. The peroxide values (PV) of the cheeses increased significantly (P < 0.05) during ripening and the cheese made with calf rennet had the highest PV. Proteolysis in the cheeses increased as the ripening time increased. α_s1‐casein and β‐casein degradation was higher in cheeses manufactured with R. miehei protease. Cheeses made with calf rennet were significantly (P < 0.05) harder, more adhesive, more cohesive and more resilient than those made with microbial rennet.     

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.     

Secondary proteolysis in Serra cheese during ripening and throughout the cheese-making season

 Experimental Serra cheeses were manufactured from raw ewe’s milk and thistle flowers following a two-way factorial design. The content of nitrogen soluble in water (WSN), in 2% trichloroacetic acid (2% TCA-N), in 12% TCA (TCA-N) and in 5% phosphotungstic acid (5% PTA-N), and the pH and salt-in-moisture concentration were measured throughout the ripening period (sampling at 0, 7, 21 and 35 days) and the cheese-making season (sampling in November, February and May). Proteolysis in 35-day-old Serra cheese was quantitatively high [average values of 34.6% and 11.9% for WSN/TN (total nitrogen) and 2% TCA-N/TN, respectively], but qualitatively low (average values of 5.8% and 1.2% for 12% TCA-N/TN and 5% PTA-N/TN, respectively). The ratios WSN/TN and 2% TCA-N/TN were lowest for cheeses ripened in February, whereas the ratio 12% TCA-N/TN was highest for cheeses ripened in November. By 35 days of ripening, the average pH and salt-in-moisture concentration values were 5.2 and 4.8%, respectively. No correlation was found to occur between the measured pH or salt-in-moisture concentration and the values of soluble nitrogen fractions throughout the cheese-making season. Received: 14 February 1996/Revised version: 4 June 1996     

Evolution of chemico-physical characteristics during manufacture and ripening of Castelmagno PDO cheese in wintertime

Biochemical, volatile and textural profiles during manufacture and ripening were determined in samples of Castelmagno PDO cheese obtained from three different batches in the main artisan cheese plant of Castelmagno PDO production area. At the end of manufacture, samples were characterised by a pH of 6.57% and 52.4% moisture content. The HPLC analysis of organic acids and sugars showed the exhaustion of lactose content, while Urea-PAGE indicated extensive primary proteolysis of both β-casein and α_s1-casein. During ripening, cheeses were characterised by high degradation of β-casein and α_s1-casein, due to bacterial action. RP-HPLC profiles showed a high production of peptides eluted between 20 and 30 min. In total, 92 volatile compounds were identified in cheese headspace. Texture profiles showed an increase in hardness, gumminess, chewiness and adhesiveness values, as well as a decrease in cohesiveness during ripening.     

Influence of autochthonous Argentine goat lactobacillus in ripening of slurry cheese models

Three indigenous lactobacilli isolated from autochthonous Argentinean goat cheeses were evaluated in models of ripening of semihard goat cheeses made under microbiologically controlled conditions. Batches A, B and C were manufactured with single strain of Lactobacillus plantarum ETC17, Lactobacillus rhamnosus ETC14 and Lactobacillus casei ETC19, respectively. Lactobacilli counts showed higher values on batch C until ripening on day 18. Chemical composition did not show differences between batches. Batch C showed a higher decrease in pH on day 1, higher liberation of nitrogen water-soluble cheese extracts and higher free amino acids content up to day 18. Amino acid distribution was analysed by studying the main components.     

水牛乳和荷斯坦牛乳切达干酪成熟期间质量特性对比

为了了解水牛乳和荷斯坦牛乳切达干酪成熟期间的质量特性,采用了理化测定、质构测定和感官评定相结合的方法对其进行研究.结果表明:在成熟期90 d内,不同成熟温度下,两种干酪的蛋白质质量分数减少约为1％～4％,脂肪质量分数减少约为4％～10％,且成熟温度越高,质量分数下降越大,水牛乳干酪中蛋白和脂肪质量分数均高于荷斯坦牛乳干酪且两种成分的下降量也是水牛乳干酪更高;pH值呈现先下降后上升趋势.在90 d成熟期间,两种干酪的硬度先上升后下降,凝聚性上升,弹性下降.经感官评价,两种干酪在10℃成熟60天时风味最佳,水牛乳切达干酪略受偏爱.可用于水牛乳切达干酪成熟期内质量控制.     

干酪成熟过程中发酵剂的作用

介绍干酪成熟过程中乳酸菌发酵剂及二级发酵剂的作用,包括在干酪风味、质地、加速干酪成熟、产生抗菌素及营养和颜色等多方面作用,同时分析成熟期间发酵剂控制不当会引起的负面作用,提出应用具有选择性的发酵剂或经遗传修饰的发酵剂生产干酪具有较强的应用前景。     

Electrophoretic ripening index for the evaluation of proteolysis and the deduction of the age of Parmesan cheese

We have established an electrophoretic method to evaluate proteolysis in Parmesan cheese by means of an objective ripening index. The separation of caseins by alkaline polyacrylamide gel electrophoresis (PAGE) (12% T, 2.6% C, pH 8.9, 5 M urea) is followed by the densitometric analysis of the- and-casein fractions. The relationship between the resulting coefficients (-Cn/-Cn) and the age of reference samples of Original Italian Grana Padano (6–22 months) was linear up to 15 months, allowing an evaluation of the extent of proteolysis and therefore a deduction of the age of the Parmesan samples analysed. Based on this calibration we propose to use a threshold level of 1.3 (-Cn/-Cn) to verify the required age, i.e. 12 months, of Parmesan cheese, retailed as a loaf or prepacked slices. Commercially grated Parmesan samples may contain 20% cheese rind, which has a very low degree of casein breakdown. So a threshold level of 0.8 (-Cn/-Cn) is proposed for all grated Parmesan products. The preparation of reference solutions with defined coefficients (-Cn/-Cn), corresponding to the proteolysis indices of reference samples of different aged Grana Padano is described. The coefficients (-Cn/-Cn) as well as the-casein content of two additional series of reference samples and of 49 commercial Parmesan samples taken from retail outlets in Austria and Italy are presented.     

Effect of supplementation of brine with calcium on the Feta cheese ripening

Feta blocks ripened in plain or calcium‐supplemented brine were analysed with respect to biochemical characteristics, proteolysis and inorganic fractions; moreover, the inorganic and N content of the respective brines was estimated. The acidification of Feta in supplemented brine was faster, the moisture content was lower, secondary proteolysis was more extended, and the organoleptic scores were higher compared to control Feta ripened in plain brine. The TCASN fraction of cheeses contributed more than that of WSN to the N enrichment of brine. It was concluded that calcium supplementation of the brine retarded the diffusion of cheese N and Ca into the brine.     

Effect of the inclusion of artichoke silage in the ration of lactating ewes on the properties of milk and cheese characteristics during ripening

The effect of including artichoke silage in the rations of dairy ewes on milk characteristics and biochemical changes of ripened cheeses was evaluated. Four groups of lactating ewes were fed rations containing 0, 10, 20, or 30% artichoke silage on a dry matter basis. Bulk milk samples were collected 3 times during the feeding period, and semi-hard cheeses were manufactured and sampled during ripening. Milk composition and cheese yield were not affected by diet. Inclusion of 20 and 30% artichoke silage reduced the firmness of the curds at a level only detected by the Gelograph (Gelograph-NT, Gel-Instrumente, Thalwil, Switzerland) probe. Inclusion of artichoke silage in ewes’ diet decreased fat and total free fatty acids content of these cheeses and increased total free amino acids content. Despite the effect of diet on cheese ripening characteristics, the overall sensory scores for cheeses corresponding to artichoke silage diets were statistically higher than those for the control cheeses.     

Effect of the inclusion of whole citrus in the ration of lactating ewes on the properties of milk and cheese characteristics during ripening

The effect of including citrus fruits (CF) in the rations of dairy ewes on the milk characteristics and biochemical changes of cheeses during ripening was evaluated. For this purpose, 48 lactating ewes (Guirra breed) were divided into 4 homogeneous groups and fed with isoenergetic and isoprotein rations containing CF at 0, 10, 20, and 30% on a dry matter basis in substitution of dry barley and pelleted beet pulp. During the experimental period, 3 batches of bulk milk were collected from each group and semi-hard cheeses were manufactured. Cheeses were sampled at 15, 30, and 60 d of ripening. Milk coagulation parameters and cheese yield were not negatively affected by the inclusion of CF in the ration. Physicochemical composition of cheeses at 60 d showed statistical differences for lower total solids and fat content of 30% CF cheeses. Proteolysis of cheeses measured by water-soluble nitrogen and total free amino acids content was not influenced by the ration. Differences between rations with respect to free fatty acids were significant for medium- and long-chain free fatty acids, and therefore for total content, but differences did not show a trend related to the increase of CF in the diet. The inclusion of CF in the ration of lactating ewes up to levels of 30% did not negatively affect the properties of milk and the biochemical and sensory characteristics of cheeses.