Deniz V.,Hitit University
Particulate Science and Technology | Year: 2011
In this study, a comparison of breakage parameters with some porous materials (pumice, trass, and amorphous silica) and the effects on breakage kinetics of powder filling of diatomite were investigated on at batch grinding conditions. For this purpose, first, standard Bond grindability tests were performed for four porous samples. Second, eight different mono-size fractions of all samples were carried out between 1.7mm and 0.106mm formed by a a√2 sieve series. Then, Si and Bi,j equations were determined for the size distributions at different grinding times, and the model parameters (Si, aT, α, γ, φj, and β) were tested for four different porous materials. Finally, model parameters were discussed for four different powder filling (3.5, 7, 10.5, and 14%) of diatomite samples. From the results of test, the validity of the relationships between Bond grindability and breakage parameters has been not confirmed with good correlation coefficients. The reason of this negative result could be attributed to different of the geological origin of porous materials. In addition, the results of the effect of powder filling on the grinding were found different than other investigators. Copyright © Taylor & Francis Group, LLC.
Deniz V.,Hitit University
Advanced Powder Technology | Year: 2011
Gypsum is an industrial material used in many applications such as building and chemical industry, fertilizer manufacture, medicine and dentistry. In these industries, there is need for finely ground gypsum. Energy consumption is very high in grinding processes. Therefore, the effects on breakage kinetics of powder filling and ball filling were investigated on gypsum samples taken from the Denizli-Honaz region (Turkey), for batch grinding conditions based on a kinetic model. For this purpose, firstly, eight different mono-size fractions between 1.7 mm and 0.106 mm formed by a √2 sieve series were obtained. Then, Si and Bi,j equations were determined from the size distributions at different grinding times, and the model parameters (Si, aT, α, γ and φj) were compared for five different proportions of powder filling (5%, 7.5%, 10%, 15% and 20%), and three different proportions of ball filling (25%, 35% and 45%). Finally, model parameters are discussed for each test. From the result of tests, obtained of the effect of ball filling and powder filling on the grinding, it was found our results differed from those of other investigators. © 2010 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.
Kabak B.,Hitit University |
Dobson A.D.W.,University College Cork
Critical Reviews in Food Science and Nutrition | Year: 2011
Fermented foods and beverages,whether of plant or animal origin, play an important role in the diet of people in many parts of the world. Fermented foods not only provide important sources of nutrients but have also great potential in maintaining health and preventing diseases. Lactic acid bacteria and yeasts are the major group of microorganisms associated with traditional fermented foods. Many different types of traditional fermented foods and beverages are produced at household level in Anatolia. These include fermented milks (yoghurt, torba yoghurt, kurut, ayran, kefir, koumiss), cereal-based fermented food (tarhana), and non-alcoholic beverage (boza), fermented fruits, and vegetables (turşu, şalgam, hardaliye), and fermented meat (sucuk). However, there are some differences in the preparation of traditional foods and beverages from region to region. The focus of this article is to describe the traditional fermented foods and beverages of Turkey. © Taylor and Francis Group, LLC.
Kabak B.,Hitit University
Food Control | Year: 2012
In this study, a total of 110 retail cereal products from Turkey were analysed for aflatoxins (AFB 1, AFB 2, AFG 1 and AFG 2) and ochratoxin A (OTA). The mycotoxins were determined by liquid-solid extraction, immunoaffinity column clean-up and high performance liquid chromatography with fluorescence detection (HPLC-FD). Recoveries (83.9-92%) and both intra-day and inter-day repeatability (RSD < 12) of the method, meet the performance criteria set by EC regulation No. 401/2006 for the determination of the levels of mycotoxins in foodstuffs. OTA was the most prevalent toxin, with an incidence of 43.6% (range = 0.066-1.125 μg kg -1), but at levels below the European legislation limit of 3 μg kg -1. Aflatoxins were found in 27 of 110 analysed samples: twenty-seven samples with AFB 1, fourteen samples with AFB 2, seven samples with AFG 1 and two samples with AFG 2. The ranges for positive samples were 0.052-0.233 μg AFB 1 kg -1, 0.022-0.044 μg AFB 2 kg -1, 0.053-0.149 μg AFG 1 kg -1 and 0.033-0.037 μg AFG 2 kg -1. The co-occurrence of AFB 1 and OTA was observed in 14.6% of the samples. This is the first study concerning the simultaneous occurrence of aflatoxins and OTA in retail cereal products from Turkey. © 2012 Elsevier Ltd.
Bahceci K.S.,Hitit University
International Journal of Food Science and Technology | Year: 2012
The central composite design with a quadratic model was used to investigate the effect of temperature (20-40°C) and transmembrane pressure (TMP) (100-300kPa) as well as pretreatment with gelatin and bentonite (0:0-300:1500mgL -1) on permeate flux and fouling resistance during ultrafiltration of apple juice. The changes in some physicochemical properties were also investigated. Pretreatment of apple juice with gelatin and bentonite and an increase in the temperature and TMP significantly improved the permeate flux. In general, physicochemical properties of apple juice other than polyphenolics were not affected by the applied parameters. Using 150mgL -1 of gelatin and 750mgL -1 of bentonite for fining significantly reduced the total phenolic content and so did the fouling resistance. Fouling resistance also decreased with increasing temperature, and increasing pressure increased the fouling resistance. © 2011 Institute of Food Science and Technology.