MICROBIOLOGICAL, PHYSICO-CHEMICAL AND TOXICOLOGICAL QUALITY OF TRADITIONAL TURKISH CHEESE DESSERTS

jfq_271 590..606

MICROBIOLOGICAL, PHYSICO-CHEMICAL ANDTOXICOLOGICAL QUALITY OF TRADITIONAL TURKISH

CHEESE DESSERTS

ALI AYDIN1,4, HARUN AKSU1, NEDIM TASKANAL2 and UGUR GUNSEN3

1Department of Food Hygiene and TechnologyFaculty of Veterinary Medicine

Istanbul UniversityAvcilar Istanbul 34320, Turkey

2B type Food Control Detachment CommandEdirne, Turkey

3Department of Food TechnologyBandirma Vocational High School

Balikesir, Turkey

Received for Publication May 30, 2007Accepted for Publication July 22, 2008

ABSTRACT

A total of 100 fresh-cheese-based desserts (Hosmerim and Cheese helva)from nine different production areas in Marmara Region of Turkey werestudied. There were no statistically significant differences in microbiologicalcomposition between Hosmerim and Cheese helva. Mean values of APC,Staphylococcus aureus, molds, yeasts, osmophilic yeasts for Hosmerim were5.7 ¥ 104, 8.0 ¥ 102, 1.8 ¥ 103, 2.8 ¥ 103, 1.6 ¥ 103 cfu/g, respectively, whilecoliform bacteria, Escherichia coli and Bacillus cereus were <10 cfu/g. Resultsfor Cheese helva were slightly higher. Salmonella spp. and staphylococcalenterotoxin were not detected in 25 g of any sample.

Cheese helva, however, had a significantly lower pH and significantlyhigher contents of protein, fat and carbohydrates, and thus, also a highercontent of dry matter.

Within each product category, a large variation was observed for bothmicrobiological counts as well as for the chemical composition. This indicatesa lack of standardization in the manufacturing process and prompts for theestablishment of appropriate process control measures.

4 Corresponding author. TEL: +90-212-4377070/17182; FAX: +90-212-4737241; EMAIL: [email protected]

Journal of Food Quality 32 (2009) 590–606.DOI: 10.1111/j.1745-4557.2009.00271.x590© 2009 The Author(s)Journal compilation © 2009 Wiley Periodicals, Inc.

PRACTICAL APPLICATIONS

The aim of this study was to determine the chemical and hygienic qualitytraits of traditional cheese desserts, namely Cheese helva and Hosmerim. Forthis purpose, 50 Cheese helva and 50 Hosmerim samples obtained fromdifferent regions in Turkey were analyzed on account of their microbiological,physico-chemical and toxicological properties. The presence of some patho-gens in the samples and the variable chemical composition indicate thatthe production process should be defined in “Codes of Good ManufacturingPractice” and the product characteristics should be codified in order to achievea product with a defined level of microbiological safety.

INTRODUCTION

Desserts are a significant part of the Turkish cuisine. The most well-known ones are different types of Baklava, Kadayif, etc., mainly made fromflour with the addition of pistachio, walnut and hazelnut, and different types ofmilky desserts made from milk and dairy products (cream, cheese, etc.).Cheese is one of the most widely consumed dairy products and the mainconstituent of traditionally produced cheese desserts such as “Cheese dessert,”“Cheese helva,” “Hosmerim” and “Kunefe” (Unsal 1997).

Hosmerim is a traditional dessert produced locally in Turkey (Balikciet al. 2004). It is produced especially in Balikesir Province of Turkey, aswell as in the Black Sea and Middle Anatolian Regions (Anon 2004). It isalso known that it was present in the kitchens of the Ottoman Empire (Anon2006). Hosmerim is a product similar to “Cheese helva” and both are some-times considered as the same products (Demirel et al. 2005). But, it isreported that their constituents and production techniques are different(Demir 2005). The steps of Hosmerim production are shown in Fig. 1(Balikci et al. 2004).

Cheese helva is a traditional dessert consumed especially in ThraceRegion and Canakkale Province of Turkey. Main constituents of Cheese helvaare fresh and nonsalty cheese. In addition, Cheese helva includes other con-stituents such as egg, sugar, flour, semolina and oil, with some local variations(Fig. 2) (Unsal 1997; Demir 2005; Demirel et al. 2005).

In the past, Hosmerim and Cheese helva were made mainly to supplyfamily needs. Nowadays, cheese desserts are commercial products withincreasing demand. Its commercial selling area is gradually extendedbecause of its acceptance in the supermarket chains as well as in localmarkets. This new mode of production and distribution raises questions withrespect to the safety and quality of this traditional food. Although a number

591QUALITY OF TURKISH CHEESE DESSERTS

of factors contribute to food quality, it is generally accepted that regulatoryauthorities should set limits or specifications regarding (1) the basic chemi-cal composition (in terms of water content, protein content, fat, etc.) byincluding this food commodity in a national food codex; and (2) the absenceof specific pathogenic bacteria (or bacterial toxins), or indicators for failurein the process, in the sense of “food safety criteria” and “process hygienecriteria” as defined in EU legislation (Commission Regulation [EC]2005).

The aim of this study was, therefore, to investigate the microbiological,physico-chemical and toxicological properties of Hosmerim and Cheesehelva samples obtained from the Marmara Region, in order to assess thehomogeneity of these food types and to evaluate the public health risks. Tothe best knowledge of the authors, this is the first survey about the presenceof staphylococcal enterotoxin and Salmonella spp. in Turkish cheesedesserts.

Pasteurization (63C, 30 min.) and

Cooling (34C) of Raw Milk

↓

Renneting ← Cheese starter culture (0.01%*)

↓

Incubation (30C, 60 min.)

↓ ← Egg yolk (0.98%*)

Cutting of Curd (50%*) ← Riboflavin /Tartrazin (0.01%*)

↓

Heating (65C, 10–15 min.) ← Sugar (40%*)

↓

Cooking (85C, 5–7 min.) ← Semolina (9%*)

↓

Hosmerim

↓

gnikcaPdnagnilooC

FIG. 1. PRODUCTION OF HOSMERIM*(v/w).

592 A. AYDIN ET AL.

MATERIALS AND METHODS

Sample Collection

A total of 100 dessert samples were randomly collected between February2006 and May 2006 from supermarkets, pastries and small family plants.

Pasteurization (63C, 30 min.) and

Cooling (34C) of Raw Milk

↓

Renneting ← Cheese starter culture (0.01%*)

↓

Incubation (30C, 60 min.)

↓

druCfognittuC

↓

druCfogniniarD

↓

gninepiR

↓

Crushing of Curd (50%*) ← Egg yolk (0.98%*)

↓

Heating (65C, 10–15 min.) ← Flour/Semolina (9%*)

↓

2nd Cooking (85C, 7–10 min.) ← Sugar (30–40%*)

↓

avleheseehC

↓

gnikcaPdnagnilooC

FIG. 2. PRODUCTION OF CHEESE HELVA*(v/w).


Hosmerim samples originated from Gönen (n = 21), Balıkesir (n = 21) andIstanbul (n = 8). Cheese helva were sampled in Istanbul (n = 5), Tekirdag(n = 9), Malkara (n = 7), Kesan (n = 5), Uzunköprü (n = 8), Edirne (n = 7) andÇanakkale (n = 9). Hosmerim samples consisted of one original package ofabout 500 g each. Cheese helva samples were one portion (300 g) in retailshops. All samples were at 4–6C and samples were analyzed within 24 h aftersampling.

Microbiological Analysis

All samples were analysed for the presence of Salmonella spp. in 25 g,and Escherichia coli, Staphylococcus aureus, Bacillus cereus, Aerobic PlateCount (APC), Coliforms, yeast-mold and osmophilic yeasts were enumeratedon selective agar media. Details concerning microbiological methods (exceptdetection of Salmonella spp.) are shown in Table 1.

From each sample, 10 g were transferred aseptically in sterile stomacherbags and homogenized for 2 min in 90 mL of sterile 0.1% peptone water(Oxoid, CM 9) using a stomacher (Lab-blender 400 Seward, London, U.K.).Serial decimal dilutions were prepared with the same diluents and countingplates were inoculated in duplicate (Midura and Bryant 2001).

For detection of Salmonella spp., 25 g of each sample were pre-enrichedfor 24 h at 36 � 1C in 225 mL sterile Lactose Broth (Oxoid CM 137). Then,1 mL of the pre-enriched culture was transferred to Selenite Cystine (SC) Broth(Oxoid CM 395) and was incubated for 6–8 h at 36 � 1C. In parallel, 0.1 mL ofpre-enriched culture was transferred into 10 mL Rappaport Vasiliadis Soy(RVS) Broth (Oxoid CM 866) and incubated for 6–8 h at 41 � 1C. After theincubation period, 1 mL of SC broth was transferred into 10 mL Mannose (M)Broth (Merck, 1.10658; Darmstadt, Germany). One milliliter of RVS broth wasadded into another tube of 10 mL of M broth. The tubes were incubated for16–20 h at 41 � 1C.After incubation, both M broth tubes were mixed and 1 mLwas transferred into another tube. The tube was boiled at 95–100C for15 � 1 min and cooled. From this boiled enrichment culture, 0.5 mL waspipetted into VIDAS Salmonella (SLM) (bioMerieux® sa, Marcy I’Etoile,France) reagent strip and an enzyme-linked-fluorescent assay was performedautomatically (AOAC 2004a).

Physico-Chemical Analysis

Dry matter, fat, ash and pH were determined according to Kurt et al.(1993). Sugar (sucrose) content was determined according to Turk StandartlariEnstitusu (1990). Nitrogen content of samples was determined by using acombustion method (AOAC 2000) and Leco FP-528 Nitrogen analyzer (Leco,

594 A. AYDIN ET AL.

St. Joseph, MI). In addition, crude protein was calculated by using a multipli-cation factor of Nx 6.38 (Watt and Merril 1975).

Toxicological Analysis

For the direct detection of staphylococcal enterotoxins (A, B, C1, C2, C3,D and E) (SE) the VIDAS system was used (AOAC 2004b). From eachsample, 25 g were transferred to a vial, containing 25 mL of extraction buffer(10 g/L sodium Azide and 945 mL distilled water). After centrifugation for15 min (5,000 g, 18C), the supernatant was filtered through a cotton-pluggeddisposable plastic syringe and filtrate was collected. One molar NaOH was

TABLE 1.MICROBIOLOGICAL METHODS

Microorganisms Reference method Medium Incubation conditions

Aerobic platecount

USDA (2001a) Plate count agar(Oxoid, CM 325)

35 � 1C, 48 � 3 hAerobic

Coliform ISO 4832 (1991) Violet red bile agar (Oxoid, CM 107) 37 � 1C, 24 hAerobic

E. coli ISO 16649-2(2001)

Trypton Bile X glucuronide agar(Oxoid CM 945)

44 � 1C, 18–24 hAerobic

S. aureus Lancette andBennett (2001)

IsolationBaird Parker agarIdentificationDNA’se agar(Oxoid, CM 321)Coagulase testStaphylase test(Oxoid, DR 595)

35–37C, 46 � 2 hAerobic

35–37C, 24 hAerobic

B. cereus USDA (2001b) IsolationMannitol egg yolk polymyxin agar

(Merck, 1.05267)IdentificationNitrate broth (Merck, 1.10204)L-Tyrosine agarLysosyme brothVoges-Proskauer medium(Merck, 1.05712)

35C, 24 hAerobic

35C, 24 h35C, 48 h35C, 24 h35C, 48 � 2 h

Yeast-mold Beuchat andCousin (2001)

Dichloran Rose-Bengalchloramphenicol agar

(Oxoid, CM727)

22–25C, 5 daysAerobic

Osmophilicyeast

Harrigan (1998) Wort agar (Oxoid CM 247)With sucrose (35 g) and glucose

(10 g) in 100 mL

22–25C, 5 daysAerobic


used to adjust the pH to between 7.5 and 8.0. A 0.5 mL aliquot was introducedinto the sample well of the SE reagent test strip and the results were automati-cally obtained after 80 min.

Statistical Analysis

Independent samples t-test were used to analyze the microbiologicalcounts and physico-chemical values. Statistical analyses were performed usingthe SPSS software (SPSS 1998).

RESULTS AND DISCUSSION

The results of microbiological and physico-chemical analysis ofHosmerim and Cheese helva samples are presented in Tables 2 and 3,respectively.

Concentrations of Total Aerobic Counts and Hygiene Indicator Bacteriain Turkish Cheese Desserts

Aerobic plate count is an indicator of the hygienic quality and microbio-logical load of foodstuffs (Morton 2001). Published surveys on APC ofTurkish cheese desserts report an enormous variation in average counts,ranging from <10 up to 4.9 ¥ 107 cfu/g. In particular, Evyapan (1995) foundthat the mean APC were 2.2 ¥ 103 and 2.3 ¥ 104 cfu/g in Cheese helva samplesobtained from Tekirdag and Balikesir Provinces of Turkey, respectively.Recently, Sahan et al. (2006) has reported APC values from 1.8 ¥ 102 to3.2 ¥ 103 cfu/g in Hosmerim samples. Although Demirel et al. (2005) noticedthat APC values ranged from 1.7 ¥ 102 to 4.1 ¥ 104 cfu/g in baked Cheesehelva samples and also ranged from <10 to 2.8 ¥ 102 cfu/g in unbaked Cheesehelva samples, Sengul and Ertugay (2006) reported consistently higher APC inCheese helva (4.9 ¥ 107 cfu/g).

Our results for Cheese helva samples were higher than those reported byEvyapan (1995) and Demirel et al. (2005) but lower than those from Sengul andErtugay (2006). TheAPC of Hosmerim samples were similar to those presentedby Evyapan (1995), but higher than the results of Sahan et al. (2006). Based onthe APC criteria for desserts used by Eleftheriadou et al. (2002) (i.e., APC>105 cfu/g), 37.2% (1991–1995) and 31.4% (1996–2000) samples should beconsidered as unacceptable. The magnitude of theAPC gives, however, no clearindication if the use of raw ingredients or deficiencies in production hygiene ortemperature control were causative (Eleftheriadou et al. 2002).

Counts of coliform bacteria and E. coli are widely used to assess thehygienic condition (indicator bacteria) of foodstuffs (Ugur et al. 2001). It is

596 A. AYDIN ET AL.

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598 A. AYDIN ET AL.

expected that coliform bacteria and E. coli as well as other related microor-ganisms will be absent from the end product because of the heat treatmentapplied during the production of Hosmerim and Cheese helva. Likewise, in ourstudy, coliform bacteria and E. coli were consistently <10 cfu/g in Hosmerimdesserts. This is in accordance with Sahan et al. (2006). Evyapan (1995)reported coliform counts of 5.2 ¥ 101 cfu/g in Hosmerim. In our Cheese helvasamples, counts of coliform bacteria ranged from <10 to 5.4 ¥ 103 cfu/g, witha mean value of 6.9 ¥ 102 cfu/g. A number of studies report coliform counts inCheese helva to be higher than those in Hosmerim (Evyapan 1995; Kurultayet al. 1999; Sengul and Ertugay 2006), with mean values up to 5.1 ¥ 103 cfu/g.In contrast to these reports, Demirel et al. (2005) reported that coliformbacteria counts were <10 cfu/g in baked Cheese helva, and even in unbakedhelva, prevalence was low, and the maximum concentration was 1.9 ¥ 102 cfu/g.

In our study, E. coli was isolated in only three samples (6%). Similarly,Demirel et al. (2005) reported that E. coli was not detected in the samples ofbaked and unbaked Cheese helva. The presence of E. coli, although at lowlevels and with low prevalence, is an indication of risk to public health.

It must be noted that our results as well as previously published findingsclearly demonstrate that there is a considerable variation in microbiologicalcontamination of samples of the same product type. These differences could berelated to nonstandardized production techniques, post-process contaminationand inadequate preservation conditions.

Concentrations of Molds and Yeasts in Turkish Cheese Desserts

Mould and yeasts are related to mycotoxin production, infection and evenallergic reactions, and thus, should be tolerated only at low levels in foodproducts. High levels of molds and yeasts are directly related to raw materialused in production, inadequate plant and equipment hygiene, and inappropri-ate storage facilities (Beuchat and Cousin 2001). In our study, mold and yeastcounts ranged from <10 to 4.0 ¥ 103 cfu/g (mean level of 1.2 ¥ 103 cfu/g) and<10 to 8.2 ¥ 105 cfu/g (mean level of 3.0 ¥ 103 cfu/g) in the samples of Cheesehelva. This is in accordance with results from Evyapan (1995), who reportedmean concentrations of 4.0 ¥ 105 cfu/g. Similarly, Sengul and Ertugay (2006)report mold and yeast counts from 1.0 ¥ 103 to 4.8 ¥ 105 cfu/g (mean level of6.4 ¥ 104 cfu/g) in Cheese helva samples. Kurultay et al. (1999) and Demirelet al. (2005), however, reported yeasts and mold concentration approximatelyone log unit below those of the studies mentioned above.

Mold and yeast counts for Hosmerim ranged from <10 to 4.2 ¥ 104 cfu/g(mean level of 1.8 ¥ 103 cfu/g) and <10 to 8.6 ¥ 104 cfu/g (mean level of2.8 ¥ 103 cfu/g), respectively. This confirms the findings of Evyapan (1995)and Sahan et al. (2006).


Osmophilic yeasts can cause spoilage by growing in acidic and high sugarconcentrated foods. Osmophilic yeasts are of no public health significance, butare of economic importance to the food industry (Ugur et al. 2001). In ourstudy, mean levels of osmophilic yeast were 1.6 ¥ 103 and 1.5 ¥ 103 cfu/g inHosmerim and Cheese helva samples, respectively. Osmophilic yeasts wereisolated from 30 (60%) of Cheese helva samples and 20 (40%) of Hosmerimsamples. On the other hand, Demirel et al. (2005) reported that osmophilicyeasts were isolated in higher ratio in Cheese helva samples. The presence ofyeasts in food can be because of insufficient hygiene of raw material used inproduction process, production technique and inadequately general hygieneand preservation conditions.

Prevalence and Concentrations of Selected Pathogenic Bacteria

B. cereus is an aerobic, spore-forming, pathogenic microorganism whichcan be isolated from many kinds of foodstuffs. In particular, products rich incarbohydrates (boiled and fried rice, cooked pasta), puddings, soups, cookedmeats, salads and vegetable sprouts have been incriminated in outbreaks(Bennett and Belay 2001). Eleftheriadou et al. (2002) reported B. cereuscounts in 35 out of total 2,402 dessert samples higher than >104 cfu/g.

In our study, B. cereus was not isolated from any of the Hosmerimsamples. However, Evyapan (1995) reports for the same product group meanlevels of B. cereus of 1.3 ¥ 103 cfu/g. As for coliform bacteria, B. cereus countswere higher in Cheese helva than in Hosmerim samples. In our study, B. cereuswas detected in 2 (4%) of Cheese helva samples with a maximum concentra-tion of 8.0 ¥ 102 cfu/g. Comparably low levels were reported by Kurultay et al.(1999) with <10–15 cfu/g for products from Tekirdag Province of Turkey,whereas Evyapan (1995) reported B. cereus counts from 1.0 ¥ 103 to1.7 ¥ 104 cfu/g (mean level of 9.9 ¥ 103 cfu/g).

The presence of B. cereus could be related to insufficient heat treatment,raw materials and inadequate preservation conditions. Although the levels ofB. cereus in analyzed samples have not been found to be sufficient to causefood poisoning (legal limits usually are �104 cfu/g; Becker 2005), it could beconsidered to represent a risk of poisoning especially in conditions of storagetemperature increase (Ugur et al. 2001).

S. aureus exist in many kinds of foodstuffs, especially meat and dairyproducts. This bacterium can also be frequently isolated from the personnel.Food poisoning occurs only when a sufficient number of enterotoxin formingbacteria is present (>105 cfu/g; Lancette and Bennett 2001; Ugur et al. 2001).In our study, S. aureus were isolated from 22 (44%) of 50 Hosmerim samples,with concentrations of <10 to 4.0 ¥ 103 cfu/g (mean level of 8.0 ¥ 102 cfu/g).In Cheese helva, S.aureus counts were in the range from <10 to 2.8 ¥ 104 cfu/g

600 A. AYDIN ET AL.

(mean level of 2.3 ¥ 103 cfu/g). Sahan et al. (2006) reported that S. aureus wasisolated from 4 (20%) of Hosmerim samples at levels between 15 and 58 cfu/g.Evyapan (1995) reported mean levels of S. aureus of 2.0 ¥ 102 and 34 cfu/g inHosmerim and Cheese helva, respectively. Kurultay et al. (1999) reported thatS. aureus counts from <10 to 45 cfu/g. Demirel et al. (2005) determined S.aureus in two unbaked Cheese helva samples at low levels (1.0 ¥ 102 and2.0 ¥ 102 cfu/g), but could not isolate this bacterium from baked Cheese helvasamples. Similarly, Sengul and Ertugay (2006) did not isolate S. aureus fromany of the Cheese helva samples. Aragon-Allegro et al. (2007) reported S.aureus levels in 19 (36.5%) of 71 dessert samples were higher than thedetection limit of Brazilian microbiological standards. Another study, S.aureus levels in 6% dessert samples of 28,835 food samples were higher thanthe >104 cfu/g (Eleftheriadou et al. 2002). In our study, S. aureus was detectedin 39% of the samples of Cheese helva and Hosmerim. The presence of S.aureus in both Cheese helva and Hosmerim samples could be related toenvironmental contamination after heat treatment, especially inadequatepersonnel hygiene and insufficient preservation conditions.

The growth of S. aureus in foods presents a potential public health hazardas many strains of S. aureus produce enterotoxins that cause food poisoning(Lancette and Bennett 2001). Preserving milk in inconvenient time and tem-perature after milking, inadequate pasteurization or contaminations after pas-teurization, inadequate personnel and plant hygiene in dairy products increasethe risk of enterotoxin production (Muller 1996). In a study performed inAnkara Province of Turkey, it was determined that enterotoxins could be formedby S. aureus in 26% of cream pastry samples obtained from 16 different pastryshops (Kisa et al. 1996). Aragon-Allegro et al. (2007) analyzed 12 of 24 dessertsamples (50%) in Brazil and detected staphylococcal enterotoxins A (n = 6),B (n = 1), C (n = 3) and the simultaneous presence ofA + C (n = 2). In our study,staphylococcal enterotoxins were not determined in the samples. This can beexplained by the relatively low numbers of S. aureus because of preservation ofthe samples in cold conditions. Likewise, researches reported that the use ofnonhygienic raw material, long-term storage of end-products in inconvenienttemperature, inadequate equipment and deficiencies in personnel hygiene con-tribute to staphylococcal contamination (Kisa et al. 1996).

Salmonella spp. are pathogenic bacteria that cause diseases such astyphoid fever, paratyphoid fever and food poisoning, and should not be presentin foods (Ugur et al. 2001). In our study, Salmonella spp. could not be detectedin the Cheese helva and Hosmerim samples. Similarly, Aksu (1996) could notisolate Salmonella spp. from different dessert and pastry samples (n = 100)consumed in Istanbul. On the other hand, Eleftheriadou et al. (2002) reportedin 38 of 2,402 dessert samples in Cyprus to be contaminated with Salmonellaspp. The researchers concluded that desserts were the primary vehicle of this


food-poisoning organism in Cyprus. This was a surprising, but not inexpli-cable discovery. Desserts are prepared mainly with either whipped cream orwith patisserie cream and a substantial amount of handling takes place duringpreparation (Eleftheriadou et al. 2002).

Chemical Properties and Other Quality Traits

Foods have different pH values depending on their physico-chemicalstructures. The pH value affects the growth of microorganisms and the spoil-age of foodstuffs (Ugur et al. 2001). In our study, the mean pH value ofHosmerim samples was higher (6.14) than those of Cheese helva samples(5.04). Similar results were reported by Sahan et al. (2006) for Hosmerim, bySengul and Ertugay (2006) for Cheese helva samples and Evyapan (1995),with 6.36 and 5.04 for Hosmerim and Cheese helva, respectively.

According to our results, the ratio of dry matter of Hosmerim samples(61.77%) was lower than that of the Cheese helva samples (77.13%). Evyapan(1995) found that the value of dry matter was 59.87 and 76.10% in Hosmerimand Cheese helva, respectively. These results were similar to our findings. Inother studies performed by Balikci et al. (2004), Demir (2005), Demirel et al.(2005), Sahan et al. (2006) and Sengul and Ertugay (2006), it was observedthat dry matter content of Hosmerim samples were lower than Cheese helvasamples, which agrees with our results. However, there is considerable varia-tion in dry matter content of Hosmerim and Cheese helva. This can be relatedto different types of product components and the lack of standardization.Likewise, it was reported that this difference depended on the higher waterbinding capacity of flour used in the production of Cheese helva than ofsemolina used in the production of Hosmerim and filtering the water of cheeseused in the production (Evyapan 1995).

The fat percentage of Cheese helva samples (average 4.68%) was higherthan that of Hosmerim samples (average 0.49%). Our results were similar tothe findings of Demir (2005), Demirel et al. (2005), Evyapan (1995), Kurultayet al. (1999) and Sahan et al. (2006).

In our study, the mean level of protein (3.58%) of Cheese helva sampleswas higher than those of Hosmerim samples (0.98%). For Cheese helva,similar results were reported by Evyapan (1995) and Balikci et al. (2004), andlower results were reported by Demirel et al. (2005), Kurultay et al. (1999),and Sengul and Ertugay (2006). For Hosmerim, other reearchers reporthigher protein concentrations (Evyapan 1995; Balikci et al. 2004; Sahan et al.2006).

In this study, sugar contents of Hosmerim samples were lower than thoseof Cheese helva samples. Similarly, Evyapan (1995) reported that the meanlevel of sugar content was found to be 42.43 and 44.22% in the samples of

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Hosmerim and Cheese helva, respectively. In another study, sugar content ofHosmerim samples was reported as 35.34% Sahan et al. (2006). Kurultayet al. (1999) reported that sugar contents of Cheese helva samples rangedbetween 19.00 and 30.00%. Sugar content of Hosmerim samples in our studywas lower than the levels reported by the other researchers.

It is seen that the mean ash ratio of Cheese helva samples was higherthan those of Hosmerim samples. Our results agree with studies related toHosmerim performed by Balikci et al. (2004) and Sahan et al. (2006), andfrom studies related to Cheese helva performed by Demir (2005), Kurultayet al. (1999), and Sengul and Ertugay (2006).

Recently, research has been conducted to elucidate which chemicalfactors significantly contribute to Cheese helva/Hosmerim (Kurultay et al.2008). Our study demonstrates that, in practice, considerable variations inchemical composition (Table 3) are encountered. It is conceivable that thesedifferences could also affect microbiological quality and safety traits.

In the present study, the results of microbiological and physico-chemicalanalysis of Hosmerim and Cheese helva samples were evaluated by statisticalanalysis. No significant differences were found for microbiological dataobtained from of Hosmerim and Cheese helva samples (P > 0.05). Statisticallysignificant differences were found for pH, humidity, dry matter, fat, protein,sugar and ash (P < 0.001). The samples of Cheese helva and Hosmerimshowed significant differences in their physico-chemical properties, mostprobably because of the production facilities, lack of standardization inproduction conditions and techniques. Therefore, further studies are requiredto assess the mode and hygiene of production. Moreover, Guides toGood Hygiene Practice should be developed to allow the modernization andstandardization of Turkish Cheese desserts production.

ACKNOWLEDGMENTS

Authors thank Peter Paulsen of Vienna Veterinary University, Instituteof Meat Hygiene, Meat Science and Food Science for critical reading ofthe manuscript. This work was supported by the Research Fund of IstanbulUniversity, Project No: UDP-2026/23012008.

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MICROBIOLOGICAL, PHYSICO-CHEMICAL AND TOXICOLOGICAL QUALITY OF TRADITIONAL TURKISH CHEESE DESSERTS