Browsing by Author "Zorba, Ö"

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Some Selected Analytical and Sensory Data of Frozen Stored Yoghurt
(Wiley-v C H verlag Gmbh, 1999) Özdemir, S; Zorba, Ö; Bodur, AE; Özdemir, C
The Effects of Different Levels of Skim Milk Powder and Whey Powder on Apparent Yield Stress and Density of Different Meat Emulsions
(Elsevier Sci Ltd, 2005) Zorba, Ö; Kurt, S; Gençcelep, H
The effects of different levels (0.00, 0.25, 0.50%) of skim milk powder (SMP) and whey powder (WP) on emulsion density (ED) and apparent yield stress values of emulsion (raw emulsion) and emulsion gel (cooked emulsion) of beef, chicken and turkey meats were studied by using a model system. The effects of meat and WP were statistically significant (p < 0.01) on ED. Chicken meat and 0.25% WP had the lowest ED values. The effects of meat, WP and SNIP were statistically significant (p < 0.01) on apparent yield stress of emulsion and emulsion gels. Chicken had lower apparent yield stress of emulsion than beef and turkey. In general, addition of WP and SMP decreased apparent yield stress of emulsion, but increased that of emulsion gel. Chicken and turkey had higher apparent yield stress of emulsion gel than beef. Between the levels of WP and SNIP, 0.25% WP and 0.50% SMP increased apparent yield stress of emulsion gel. The results suggested that WP and SMP were important to improve apparent yield stress of emulsion gel, and there was a significant (p < 0.01) negative correlation between ED and apparent yield stress of emulsion gel. (C) 2004 Elsevier Ltd. All rights reserved.
The Effects of Enzymatic Hydrolysis of Casein on Apparent Yield Stress and Some Emulsion Properties
(Elsevier Sci Ltd, 2006) Tunçtürk, Y; Zorba, Ö
In this investigation, casein was proteolysed at different levels using a neutral proteinase (Neutrase) and the effects of proteolysis on emulsion capacity (EC) of casein, emulsion stability (ES), emulsion density (ED), and apparent yield stress (AYS) values of emulsions have been investigated. In order to clarify the effect of proteolysis on proteins, the proteolysis-applied proteins at different levels went through urea-PAGE and SDS-PAGE analysis. The proteolysis level exerted a statistically very significant difference on proteolysis degree, EC, ES, ED, AYS values (p < 0.01). In the trial, no significant effect of enzyme and enzyme inhibitor (ethylenediaminetetraacetic acid, EDTA) on parameters was determined (P > 0.05); the difference was found to be associated with an outcome from proteolysis. While proteolysis increased rapidly up to 20th minute, it increased slowly from 80 min. It was also observed that urea-PAGE and SDS-PAGE patterns belonging to casein fractions were quite in perfect harmony with proteolysis degrees, whereas a remarkable weakening in main protein bands due to the period was seen. A constitution of new peptide bands was observed up to 80 min, but these bands vanished after this period. Another finding, which became the chief focus of our concern throughout our experimental trials was that EC, ES, ED and AYS values generally improved up to 5 min; however, it did not change from that period up to 20 min. From that period, these values were negatively affected, whereas from 80 min (0.136 AN/TN) a remarkable deterioration was observed in emulsion properties. (c) 2005 Elsevier Ltd. All rights reserved.
The Effects of the Amount of Emulsified Oil on the Emulsion Stability and Viscosity of Myofibrillar Proteins
(Elsevier Sci Ltd, 2006) Zorba, Ö
In this study Bovine M. longissimus dorsi samples at post-rigor stage were used. Myofibrils were isolated, glycerated, and frozen at -20 degrees C until needed. After emulsion capacity of the samples was determined, emulsion was prepared with addition of oil at rates of 25, 40, 50, 60, 70, 80, 90 and 95%. Emulsion stability (ES) and emulsion viscosity (EV) were determined in these emulsions. It was seen that the emulsified-oil ratios had significant effect (P < 0.01) on the emulsion stability and viscosity of myofibrillar proteins. According to the multiple comparison tests, while the oil emulsified until 70% increased the emulsion stability, but no effect on emulsion stability was observed after 70%. As the oil ratio increased, the emulsion viscosity of myofibrillar proteins increased significantly (P < 0.05). (c) 2005 Elsevier Ltd. All rights reserved.