roghayyeh ashrafiyourghanloo

White cheese contains a lot of saturated fat and cholesterol, which is undesirable from a nutritional point. In this regard, the aim of this study was to reduce of cholesterol in white brine cheese using Betacyclodextrin (β.CD) and determine of physicochemical, texture and sensory properties of the product. After separating milk fat, Cholesterol isolated from cream with β.CD in concentration of 10% at 35 °C and stirring at rate of 800 rpm for 0.5 hours on a laboratory scale, then, by adding to the skim milk, the preparation of samples were performed. The results of cholesterol measurement showed that the treatment of cheese with β.CD could reduce the cholesterol content about 63%. During storage of cheese, samples treated with β.CD showed significant differences in terms of pH, acidity, proteolysis and lipolysis compared to the control. By addition of β.CD hardness and gumminess of treated cheese decreased and cohesiveness increased, but β.CD not had a significant effect on chewiness and elasticity of white cheese (p>0.05). Sensory evaluation also showed that β.CD while reducing cholesterol and improving the texture of the cheese, but had no significant effect on the sensory properties of the final product compared to the control sample. Thus, according to the obtained results, β.CD to reduce cholesterol of white cheese is appropriate.

In recent years, synthetic and biologically active antioxidant films contain a variety of natural and synthetic antioxidants have been designed and their effect on the oxidative stability of various food products has been proven. The aim of this study was to investigate some physicochemical and antioxidant properties of biodegradable film prepared from hydroxy propyl methyl cellulose containing Acanthophyllum alginate and its effect on oxidative resistance of local butter oil. For this purpose, bionanocomposite films containhydroxy propyl methyl cellulose at levels (0,1 and 1.5%,) and essential oil(1,3 and 5%) were prepared. In general, the results indicated that alginate gum was more effective than Hawk's Essence on the physical and mechanical properties of films. By adding alginates, water solubility and water vapor permeability (WVP) decreased significantly compared to pure HPMC film (p <0.05), with the lowest WVP content belonging to HPMC-AL1.5% -EO5% composite film Which was equal to g / mhPa of 10.3 × 10.3 / 3. Adding the alginate increased the thickness and opacity of the films . Also, with increasing essential oil concentration, the antioxidant properties of the films increased, so that the films containing 1, 3 and 5% essential oil of lemon balm had 40, 53 and 74 percent antioxidant properties respectively. But ginger alginate did not have a significant effect on this property of the films. Results of the stability test against the oxidation of virgin olive oil were analyzed based on the Rensmet test. Results showed does not exist a significant difference of 5% (P <0.05) between HPMC film containing essential oil at 1% concentration and synthetic antioxidant TBHQ . Due to its antioxidant activity, film samples containing Chojbak essential oil have a positive effect on reducing the process of oxidation of local butter oil and can be a good alternative to the use of synthetic antioxidants.