THE FORMATION OF HISTAMINE IN HERBY CHEESE DURING RIPENING

The purpose of this study is to observe the formation of histamine throughout the period of ripening in herby cheese. Herby cheese samples were made from raw milk and buried in soil where they mature in 3 months. Samples were taken on the first, seventh, 15th, 30th, 60th and 90th days of ripening. The moistness, content pH, salt and (total aerobic mesophile bacteria, lactic acid bacteria, coliform bacteria and yeasts and mold) changes were observed. The concentration of histamine are 2.19 mg/100 g on the first day of ripening. It gradually increased and reached 4.62 mg/100 g on the 90th day. Consequently, the histamine that was observed in herby cheese during the ripening appears to be not important for public health.     

Determination of Biogenic Amines in Herby Cheese

Herby cheese (Otlu peynir) is widely produced and consumed in eastern parts of Turkey, and is generally made from sheep milk. The biogenic amines and organic acids content, microbiological, and chemical properties of Herby cheese were determined on 30 samples obtained from retail markets in East Anatolia Region, Turkey. The most important biogenic amines were tyramine (range 18.0–1125.5 mg kg^?1), followed by cadaverine varied from not detected to 1844.5 mg kg^?1. Histamine content generally was found higher than 100 mg kg^?1. The concentration of amines in some cheeses was much higher than the toxic dose limits. Generally, total amine content was found high in samples that had high nitrogen fraction and organic acids value. Levels of biogenic amines were significantly correlated with the organic acids of Herby cheese. The basic organic acid was found the lactic acid ranging from 585.4 to 26480.3 mg kg^?1, followed by butyric acid varying between 314.8 and 7329.6 mg kg^?1 values. Lipolysis and nitrogen fraction were determined high in ripened Herby cheese samples. Coliform counts of samples showed lower than 100 cfu g^?1 in the samples. Significant (p < 0.01) positive correlation was observed between acetic acid and phenylethylamine, putrescine, cadaverin, histamine, and tyramine.     

A review of the chemical, biochemical and antimicrobial aspects of Turkish Otlu (herby) cheese

Otlu (herby) cheese, a traditional Turkish dairy product, is commonly made in Eastern Anatolia in Turkey. It is consumed in the various parts of Turkey, especially in the eastern and southeastern parts. Its popularity has been increasing because of industrialization of its production. It is manufactured from raw milk, is salty in taste and has a herby intense aroma because of the added herbs. The unusual processing steps of the cheese are that it is firmly filled in a plastic cheese container and stored under the soil during ripening. The flavour becomes highly acceptable after 3 months of ripening. The most common herbs used in the cheese are wild garlic ( Allium sp.) but other herbs ( Ferula sp., Prangos sp., Thymus sp., Mentha sp., Chaerophyllum macropodum and Silene vulgaris ) are also used individually or as appropriate mixtures. The herbs give the cheese its flavour, but also extend the shelf life of the cheese. The aim of this review was to outline the manufacture and chemical, biochemical and antimicrobial properties of Otlu herby cheese.     

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.     

Influence of pasteurised milk, raw milk and different ripening cultures on biogenic amine concentrations in semi-soft cheeses during ripening

In semi-soft cheeses, produced with pasteurised milk, raw milk and different starter cultures, the concentrations of cadaverine, histamine, phenylethylamine, putrescine and tyramine were investigated. The cultures (pasteurised milk cultures, raw milk cultures and starter cultures) strongly influenced the biogenic amine concentrations in the cheeses ripened for 5 months. Two cheeses made with identical pasteurised milk, but different ripening cultures, differed greatly in their total biogenic amine concentrations (51 vs 371?mg/kg). In general, the biogenic amine concentrations increased markedly between month 2 and month 3 of cheese ripening. The high content of enterococci and Enterobacteriaceae yielded the biogenic amine concentrations. In contrast, Lactobacilli did not seem to be important. However, unspecified bacteria have to be considered, since cheeses with comparable microbiological profiles differed enormously in their biogenic amine concentrations. Semi-soft cheeses produced from pasteurised milk showed remarkably lower total biogenic amine concentrations compared to semi-soft cheeses produced from raw milk (51–1096?mg/kg vs 1011–3133?mg/kg, depending also on the ripening cultures). The highest total biogenic amine concentration (4817?mg/kg) was detected in a cheese produced from raw milk that had been stored for 36?h. In this cheese, the concentrations of cadaverine, phenylethylamine, putrescine and tyramine were higher than in all other cheeses. The highest histamine concentration was found to be in another raw milk cheese (573?mg/kg).     

The effects of using a starter culture,lipase, and protease enzymes on ripening of Mihalic cheese

The purpose of this study was to determine the effects of fungal lipase from Mucor miehei and a bacterial neutral protease from Bacillus subtilis alone and combined with a starter culture on ripening properties of traditional Turkish Mihalic cheese. The use of protease with lipase (Cult + Prot + Lip) resulted in better flavour and texture with accelerated ripening. The obtained results pointed out that the gross compositions of the cheeses were changed by the type of enzymes and ripening time (P < 0.01). The acid degree value (ADV) of all cheeses showed a linear increase with ripening. The highest lipolysis rate was noted in lipase‐added cheese batch (as 5.56 ADV) with highest γ‐CN ratio and β‐CN degradation. At the end of ripening time, it was observed that αs‐CN ratios decreased in starter‐added (Cult), starter + protease–added (Cult + Prot), and protease‐added (Prot) cheese batches. The use of protease with lipase (Cult + Prot + Lip) resulted in better flavour and texture with accelerated ripening. Protease‐added cheeses, which were characterized by bitterness and crumbly textural properties owing to the intense breakdown of β‐casein, scored lower than lipase‐added cheeses. It was determined that the use of mesophilic aromatic starter culture with lipase and protease could be used to accelerate ripening of Mihalic cheese made from pasteurised milk.     

Proteolysis during ripening of Manchego cheese made from raw or pasteurized ewes' milk. Seasonal variation

Changes in nitrogen compounds during ripening of 40 batches of Manchego cheese made from raw milk (24 batches) or pasteurized milk (16 batches) at five different dairies throughout the year were investigated. After ripening for six months, degradation of p-kappa- and beta-caseins was more intense in raw milk cheese and degradation of alpha(s2)-casein in pasteurized milk cheese. Milk pasteurization had no significant effect on breakdown of alpha(s1)-casein. Hydrophobic peptide content did not differ between raw and pasteurized milk cheese, whereas hydrophilic peptide content was higher in raw milk cheese. There were no significant differences between seasons for residual caseins, but hydrophobic peptides were at a higher level in cheese made in autumn and winter and hydrophilic peptides in cheese made in winter and spring. Raw milk cheese had a higher content of total free amino acids and of most individual free amino acids than pasteurized milk cheese. The relative percentages of the individual free amino acids were significantly different for raw milk and pasteurized milk cheeses. The relative percentages of Lys and lie increased, while those of Val, Leu and Phe decreased during ripening. There were also seasonal variations within the relative percentages of free amino acids. In raw milk cheeses, Asp and Cys were relatively more abundant in those made in autumn, Glu and Arg in cheeses made in winter, and Lys and Ile in cheeses made in spring and summer. Biogenic amines were detected only in raw milk cheese, with the highest levels of histamine, tryptamine and tyramine in cheeses made in spring, winter and spring, respectively.     

The effect of heat treatment and starter culture on colour intensity and sensory properties of Kulek cheese

The effect of the heat treatment on colour intensity and sensory properties of Kulek cheese made from raw milk with (RS) or without starter culture (R) and heated milk with starter culture (HS) was investigated during ripening. Colour L, a and b values of Kulek cheeses were determined for both interior and surface. The values for cheese R were 82.4 and 74.5 for L, ?5.2 and ?5.5 for a, 31.0 and 34.7 for b interior and surface respectively. The equivalents for RS cheese were 82.8 and 75.7 for L, ?4.8 and ?5.0 for a, 31.0 and 34.0 for b. The values for HS cheese were 88.9 and 88.4 for L and ?3.3 and ?3.3 for a, 22.8 and 24.2 for b. L values (lightness) were the highest in cheeses made from heated milk while b and negative a values were the highest in cheeses made from raw milk. Aroma scores of raw and heat‐treated milk cheeses made with starter were not significantly different. The panelists scored cheeses made from raw milk without starter as the best in body and texture.     

EFFECT OF LIPASE ENZYME ON THE RIPENING OF WHITE PICKLED CHEESE

The effect of addition of pregastric lipase enzyme on the accelerated ripening of white pickled cheese was investigated. Commercial pregastric lipase was added to milk before rennet addition at a level of 0,5, 8, 11 g per 100 L of milk and cheeses were made from this milk. Total solids, fat, total nitrogen, salt, titratable acidity, pH and free fatty acids (C₂-C_18:1) were analysed in the samples during 1–90 days of ripening period at 15 days intervals. Total solids, fat, total nitrogen, salt, titratable acidity, and pH of cheeses slightly increased during the ripening period. Free fatty acids and volatile free fatty acid contents in cheeses made from pregastric lipase added milk were affected by pregastric lipase and their contents were increased significantly (P<0.01) during the ripening period. Particularly, when cheese had a high level (11 g per 100 L milk) pregastric lipase, the amounts of butyric, caproic and caprylic acids in white pickled cheese were quite high. The relative amounts of volatile free fatty acids varied with storage time and pregastric lipase levels.     

Ripening of Cheddar cheese made from blends of raw and pasteurised milk

Cheddar cheeses were made from pasteurised milk (P), raw milk (R) or pasteurised milk to which 10 (PR10), 5 (PR5) or 1 (PR1) % of raw milk had been added. Non-starter lactic acid bacteria (NSLAB) were not detectable in P cheese in the first month of ripening, at which stage PR1, PR5, PR10 and R cheeses had 10⁴, 10⁵, 10⁶ and 10⁷ cfu NSLAB g⁻¹, respectively. After ripening for 4 months, the number of NSLAB was 1–2 log cycles lower in P cheese than in all other cheeses. Urea–polyacrylamide gel electrophoretograms of water-soluble and insoluble fractions of cheeses and reverse-phase HPLC chromatograms of 70% (v/v) ethanol-soluble as well as -insoluble fractions of WSF were essentially similar in all cheeses. The concentration of amino acids were pro rata the number of NSLAB and were the highest in R cheese and the lowest in P cheese throughout ripening. Free fatty acids and most of the fatty acid esters in 4-month old cheeses were higher in PR1, PR5, PR10 and R cheeses than in P cheese. Commercial graders awarded the highest flavour scores to 4-month-old PR1 cheeses and the lowest to P or R cheese. An expert panel of sensory assessors awarded increasingly higher scores for fruity/sweet and pungent aroma as the level of raw milk increased. The trend for aroma intensity and perceived maturity was R>PR10>PP5>PR1>P. The NSLAB from raw milk appeared to influence the ripening and quality of Cheddar cheese.     

Comparison of basic nutrients, mineral and heavy metal contents of herby dairy products

The aim of this study was to determine basic nutrients, some minerals and heavy metal contents of herby cheese, cacik and lor. Herby cheese is a cheese made from cow and/or sheep milk mixed with some herb. Herby cacik is a dairy product manufactured from light yoghurt (non-fat), ayran (liquid yoghurt) and/or a small amount of cheese whey. Herby lor cheese is a product traditionally made in Turkey, produced from cheese whey and occasionally some whole milk added. These dairy products are mixed with wild herb species (Allium sp., Chaerophyllum macropodum, Antriscus nemorosa, Ferula sp., Prangos sp., Silene vulgaris, Tymus sp. and Mentha sp.). In this study, herby cacik, cheese and lor samples were analysed for some physicochemical, mineral and heavy metal contents. The dry matter, protein, fat, salt and ash contents among herby dairy products were found significantly different (P < 0.05). There were significant differences in Ca, P, Na, Mg, Fe, Cu and Mn content of herby dairy products (P < 0.05). Zn, Co, Cr, Ni and Cd contents of analysed samples were not significantly different (P > 0.05).     

Real time quantitative PCR detection of histamine-producing lactic acid bacteria in cheese: Relation with histamine content

Biogenic amines (BAs) are low molecular weight organic bases with biological activity, mainly formed by the microbial decarboxylation of amino acids. The consumption of food containing large amounts of some BAs can have toxicological consequences. Histamine is the most active BA and the most frequently involved in food-borne intoxications. This article reports the concentrations of histamine found in 80 cheeses made from different types of milk and subjected to different ripening periods. Histamine was detected in 41.25% of the samples, with values ranging from 20 to over 1000 mg per Kg of cheese. The highest histamine concentrations were recorded in long ripening cheeses made from raw milk. The presence and quantification of histamine-producing lactic acid bacteria was determined by RT-qPCR, and a good association was obtained between the C_t values and histamine concentrations determined by HPLC.     

Characterization and Comparison of Free Fatty Acid Profiles of Eleven Varieties of Turkish Cheeses

Free fatty acids profiles of 11 different cheese varieties sold in Turkey were determined to assess the development of lipolysis. Results obtained showed that the concentrations of short chain fatty acids (C₄ and C₆ free fatty acids) were close in all cheeses (P > 0.05), except for Canak cheese. However, significant differences were noted among the samples for other free fatty acids including C₈ to C_18:2 (P < 0.05). Palmitic (C₁₆) and oleic (C_18:1) acids were the most abundant free fatty acids in all cheese samples. Principal component analysis was applied to simplify interpretation of the data and distinguish the variety of the cheeses on the plot. Canak cheese gave a dramatically different free fatty acid profile from the other cheeses, probably because of the fact that ripening of this variety is achieved in the earthenware pots for about 1 year. Van Otlu (ripened with special herbs) and Civil (ripened by spontaneously molding on its surface) cheeses differed from the others by ANOVA and principal component analysis techniques. In conclusion, the degree of lipolysis in the cheeses could be classified into extreme (Canak), high (Civil, Divle Tulum, Mihalic, and Van Otlu), mild (Ezine, Orgu, and Urfa), and low (Dil, Hellim, and Malatya) based on their FFA profiles.     

Utilization of microfiltration or lactoperoxidase system or both for manufacture of Cheddar cheese from raw milk

The objective of the present study was to determine if application of microfiltration (MF) or raw milk lactoperoxidase system (LP) could reduce the risk of foodborne illness from Escherichia coli in raw milk cheeses, without adversely affecting the overall sensory acceptability of the cheeses. Escherichia coli K12 was added to raw milk to study its survival as a non-pathogenic surrogate organism for pathogenic E. coli. Five replications of 6 treatments of Cheddar cheese were manufactured. The 6 treatments included cheeses made from pasteurized milk (PM), raw milk (RM), raw milk inoculated with E. coli K12 (RME), raw milk inoculated with E. coli K12 + LP activation (RMELP), raw milk inoculated with E. coli K12 + MF (MFE), and raw milk inoculated with E. coli K12 + MF + LP activation (MFELP). The population of E. coli K12 was enumerated in the cheese milks, in whey/curds during cheese manufacture, and in final Cheddar cheeses during ripening. Application of LP, MF, and a combination of MF and LP led to an average percentage reduction of E. coli K12 counts in cheese milk by 72, 88, and 96%, respectively. However, E. coli K12 populations significantly increased during the manufacture of Cheddar cheese for the reasons not related to contamination. The number of E. coli K12, however, decreased by 1.5 to 2 log cycles during 120 d of ripening, irrespective of the treatments. The results suggest that MF with or without LP significantly lowers E. coli count in raw milk. Hence, if reactivation of E. coli during cheese making could be prevented, MF with or without LP would be an effective technique for reducing the counts of E. coli in raw milk cheeses. The cheeses were also analyzed for proteolysis, starter and nonstarter lactic acid bacteria (NSLAB), and sensory characteristics during ripening. The concentration of pH 4.6 soluble nitrogen at 120 d was greater in PM cheese compared with the other treatments. The level of 12% trichloroacetic acid-soluble nitrogen at 120 d was greater in RM, RME, and RMELP cheeses compared with PM, MFE, and MFELP cheeses. This could be related to the fact that cheeses made from raw milk with or without LP (RM, RME, and RMELP) had greater levels of NSLAB compared with PM, MFE, and MFELP cheeses. Cheeses at 60 d, as evaluated by 8 trained panelists, did not differ in bitterness, pastiness, or curdiness attributes. Cheeses at 120 d showed no differences in acid-taste, bitterness, or curdiness attributes. Sensory analysis at 60 d showed that PM and MFELP cheeses had greater overall sensory acceptability than RM and RME cheeses. The overall sensory acceptability of the cheeses at 120 d showed that PM, MFE, and MFELP cheeses were more acceptable than RM and RME cheeses.     

Occurrence of moulds associated with ovine raw milk and cheeses of the Spanish region of Castilla La Mancha

The distribution of mould species was examined at several points of the processing chain in a Manchego cheese plant and associated dairy farms. Geotrichum and Fusarium were the genera most frequently isolated from milk samples as well as in cheeses ripened for one month, evidencing a direct transfer from raw milk. Conversely, the mycobiota of long‐ripened cheeses consisted mainly of Penicillium species, which gained entry to the cheese through the air of ripening rooms. This study contributes to the understanding of the dynamics of fungal populations in semihard and hard cheeses, highlighting that airborne transfer from the stables could have a direct impact on their quality.     

The effect of varying casein/fat ratio on physicochemical and sensory qualities of Feta‐type cheese made using buffalo milk

The Feta‐type cheese was prepared with different casein/fat (C/F) ratios of buffalo milk using microbial rennet. The manufactured Feta cheeses were subjected to physicochemical and sensory quality at 15‐day interval up to 60 days of ripening. Sensory analysis discriminated the different level of C/F ratio of buffalo milk cheeses predominantly by age. There was no significant difference (P < 0.01) observed in cheese made from C/F ratio of 0.6–0.7 in terms of flavour. The titratable acidity (TA), soluble protein and free fatty acid appear to be age‐dependent and increased throughout the ripening in all experimental cheeses.     

Factors affecting consumers' preferences for and purchasing decisions regarding pasteurized and raw milk specialty cheeses

Eight hundred ninety consumers at a local food festival were surveyed about their specialty cheese purchasing behavior and asked to taste and rate, through nonforced choice preference, 1 of 4 cheese pairs (Cheddar and Gouda) made from pasteurized and raw milks. The purpose of the survey was to examine consumers’ responses to information on the safety of raw milk cheeses. The associated consumer test provided information about specialty cheese consumers’ preferences and purchasing behavior. Half of the consumers tested were provided with cheese pairs that were identified as being made from unpasteurized and pasteurized milk. The other half evaluated samples that were identified only with random 3-digit codes. Overall, more consumers preferred the raw milk cheeses than the pasteurized milk cheeses. A larger portion of consumers indicated preferences for the raw milk cheese when the cheeses were labeled and thus they knew which samples were made from raw milk. Most of the consumers tested considered the raw milk cheeses to be less safe or did not know if raw milk cheeses were less safe. After being informed that the raw milk cheeses were produced by a process approved by the FDA (i.e., 60-d ripening), most consumers with concerns stated that they believed raw milk cheeses to be safe. When marketing cheese made from raw milk, producers should inform consumers that raw milk cheese is produced by an FDA-approved process.     

Ripened Semihard Cheese Covered with Lard and Dehydrated Rosemary (Rosmarinus officinalis L.) Leaves: Processing,Characterization, and Quality Traits

This study aimed to establish a manufacturing protocol and to characterize semihard cheese covered with lard and rosemary during ripening. After the manufacturing protocol was defined, the cheeses were produced with pasteurized and raw milk from Holstein cows, with and without (control) coating, and then ripened for 60 d. During this period the physicochemical properties, color, proteolysis, texture profile, and sensory acceptance were performed. The early‐ripening cheeses differed from the others in terms of color and moisture content. Multivariate statistical analysis separated chesses in groups differentiated by the effects of heat treatment of milk and ripening period. The ripened cheeses obtained from raw milk were sensorially more preferred. The coating gave the final products higher moisture content and favored color and texture characteristics. Consumer testing showed that the cheese obtained from raw milk and coated with lard and rosemary was the most preferred (acceptance of 82%) due to the specific coating of rosemary (aroma and flavor). This product has potential to add value and to diversify the production of semihard cheeses.     

Effect of added proteinases and level of starter culture on the formation of biogenic amines in raw milk Manchego cheese

The influence of two proteinases (Bacillus subtilis neutral proteinase and Micrococcus sp. cysteine proteinase) and two starter culture levels (0.1% and 1%) on biogenic amine formation has been studied in raw ewes' milk Manchego cheese. Amino acid decarboxylating micro-organisms were determined on tyrosine enriched selective media. Biogenic amines were analysed by capillary electrophoresis in citrate buffer at pH 3.6. Addition of proteinases and level of starter culture did not influence the population of micro-organisms with amino acid decarboxylating activity, which represented on average 1% of the bacterial population in 30-day-old cheeses. Tyramine and histamine were detected in all batches of cheese from day 30. Concentrations of tyramine and histamine were higher in cheeses made from milk with neutral proteinase (up to 356 and 284 mg kg(-1), respectively, after 90 days) than in cheeses made from milk with cysteine proteinase (up to 269 and 189 mg kg(-1), respectively) or with no proteinase added (up to 305 and 226 mg kg(-1), respectively). Formation of tyramine and histamine was also favoured in cheeses made with 1% starter culture with respect to cheeses made with only 0.1% starter culture, probably due to the higher pH values of the former cheeses. After 90 days of ripening, concentrations of 10-20 mg kg(-1) phenylethylamine were observed in 9 of the 12 batches, and levels < 10 mg kg(-1) tryptamine were only detected in 3 batches, with no significant relationship between the concentration of these amines and proteinase addition or level of starter culture.     

Microbiological changes throughout ripening of goat cheese made from raw,pasteurized and high-pressure-treated milk

The bacteriological quality during ripening of raw (RA), pasteurized (PA; 72°C, 15 s) and pressure-treated (PR; 500 MPa, 20°C, 15 min) goat milk assessed by enumeration of total bacteria, psychrotrophic bacteria, Enterobacteriaceae, lactobacilli, enterococci, Micrococcaceae and lactococci was evaluated. The high pressure treatment applied was as efficient as pasteurization in reducing the bacterial population of milk. Experimental cheeses were made from RA, PA and PR milks to study the microbial population during ripening. Lactobacilli and lactococci were the predominant microbiota present during ripening in all the cheeses. There were no differences in numbers of starter bacteria during ripening. However, lactobacilli counts for RA milk cheese were significantly higher than for PA and PR cheeses in all the ripening stages studied. Micrococcaceae and enterococci remained at a secondary level, and no differences were observed between cheeses at the end of ripening. On the other hand, the number of Enterobacteriaceae decreased during ripening, but faster in PR milk cheese than in PA and RA milk cheeses. The results of this study suggest that goat cheese made from PR milk had similar microbiological characteristics to PA milk cheeses.