This investigation was conducted to determine the contents of some heavy metals in milk samples collected from three different regions, an industrial region, a rural and heavy traffic intensity region around Bursa, a province of Turkey. A total of 75 raw milk samples were collected from these different regions, and the contents of lead, arsenic, copper, zinc, mercury and iron were determined. The average amounts in the samples from these three regions were for Pb 0.032, 0.049, 0.018 mg/kg; for As 0.05, 0.009, 0.0002 mg/kg; for Zu 4.49, 5.01, 3.77 mg/kg; for Cu 0.58, 0.96, 0.39 mg/kg; for Fe 1.78, 4.27, 1.01 mg/kg, while no mercury was detected in the samples. The highest heavy metal content was found in the milk samples collected from industrial region followed by traffic intensive region and rural region.

The purpose of this research was to explain the combined effects of different total solid (TS) contents (20, 30 and 40%), stabilizer types (guar gum [GG], locust bean gum [LBG], carboxymethyl cellulose [CMC]) and overrun rates (OR) (30, 60 and 90%) on mix viscosity, melting time and hardness properties, which are the most important quality characteristics on industrial ice cream production. According to the investigation parameters; GG gave significantly less viscosity to the mix than LBG and CMC. In other words, LBG and CMC may be preferred to increase the viscosity of the mix or to limit the growth rate of ice crystals during recrystallization. Softness of ice creams and melting rapidity were linearly proportional to the increase of TS and ORs. PRACTICAL APPLICATIONS The most important parameters affected ice cream structure and quality are total solid, overrun and stabilizers. In many researches, the investigators have been focused of these parameters on only one or rarely two. In this research, the combined effects of different total solids (20, 30 and 40%), stabilizer types (guar gum, locust bean gum, carboxymethyl cellulose) and overrun levels (30, 60 and 90%) were investigated together in same mix and in industrial production conditions.

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Cheese halva (Ho¨s¸merim) is a popular Turkish dessert composed mainly of unsalted fresh cheese. In this research, the effects of critical process parameters such as different fat and pH levels on some compositional and structural characteristics of cheese halva were investigated. The fat levels of unsalted fresh cheese at four different pH values (4.8, 5.0, 5.2 and 5.4) were adjusted to 5%, 15%, 20% and 25% by the addition of pasteurised fresh cream. According to the results, some compositional and structural properties of experimental samples, determined for both parameters (fat, pH), are as follows, respectively: dry matter (%): 51.76-65.72, 58.24-61.21; total sugar (%): 21.16-25.64, 22.19-23.79; starch (%): 12.17-13.49, 12.21-14.18; protein (%): 6.70-7.46, 6.79-7.35; titratable acidity (%): 0.22-0.24, 0.20-0.28; ash (%): 0.87-0.93, 0.83-0.94; hardness (loadgram): 43. 75-55.75, 34.50-78.75. Both of the investigated parameters were affected significantly by dry matter, total sugar and starch contents of the samples (P < 0.01). Decrease in the pH value from 5.4 to 5.2 caused approximately 1-2 units increase in dry matter and starch contents. In the manufacturing of Cheese Halva, 5% fat and pH 5.2 for fresh cheese were determined as the most suitable process parameters.

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Propionic acid bacteria (PAB) are responsible for characteristic properties of Mihaliç cheese, which is one of the most prevalent traditional cheese types produced in Turkey. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been reliable and rapid method for identifying bacterial isolates. The aim of this study was to evaluate the PAB profile of Mihaliç cheese by their identification by MALDI-TOF MS system. In this study, a total of 25 cheese samples were analyzed and 95 isolates were determined as probable PAB based on their morphological characteristics, gram staining, catalase activity and pigment production. All isolates were analyzed by MALDI-TOF MS and 21 of them were belong to PAB. Isolates were identified as Propionibacterium freudenreichii ssp. freudenreichii (57%), Propionibacterium freudenreichii ssp. shermanii (33%) and Propionibacterium thoenii (10%). This study indicates that the diversity of PAB found in Mihaliç cheese can be determined rapidly and economically by MALDI-TOF MS. ÖzTürkiye'de üretilen önemli geleneksel peynirlerden biri olan Mihaliç peyniri, karakteristik özelliklerini Propiyonik asit bakterileri (PAB) sayesinde kazanmaktadır. Matris destekli lazer desorpsiyon / iyonizasyon uçuş süresi kütle spektrometresi (MALDI-TOF MS), son yıllarda bakteriyel izolatları tanımlamak için güvenilir ve hızlı bir yöntem olarak popüler olmuştur. Bu çalışmanın amacı Mihaliç peynirinde bulunan propiyonik asit bakterilerini MALDI-TOF MS sistemi ile tanımlamaktır. Bu çalışmada toplam 25 adet geleneksel Mihaliç peynir örnekleri incelenmiş ve morfolojik özelliklerine, gram boyamaya, katalaz aktivitesine ve pigment üretimlerine dayanarak 95 adet izolat elde edilmiştir. Bu izolatlar MALDI-TOF MS ile tanımlanmış ve 21 tanesi PAB olarak belirlenmiştir. Tanımlanan izolatlar; Propionibacterium freudenreichii ssp. freudenreichii (% 57), Propionibacterium freudenreichii ssp. shermanii (% 33) ve Propionibacterium thoenii (% 10) dir. Bu çalışma, Mihaliç peynirinde bulunan PAB çeşitliliğinin ilk kez MALDI-TOF MS tarafından hızlı ve ekonomik olarak belirlenebileceğini göstermiştir.