Rheological Properties of Iranian Yoghurt Drink, Doogh

Fabrication and characterisation of bioglass and hydroxyapatite-filled scaffolds

Tissue engineering is a continuously evolving field. One of the main lines of research in this field focuses on the replacement of bone defects with materials designed to interact with the cells of a living organism in order to provide the body with a structure on which new tissues can easily grow. Among the most commonly used materials are bioglasses, which are frequently used due to their versatility and good properties. This article discusses the results of the production of an injectable paste of Bioglass® 45S5 and hydroxyapatite on a 3D printed porous structure by additive manufacturing, using a thermoplastic (PLA). The results were evaluated in a specific application of the paste, so the mechanical and bioactive properties were studied to show the multiple possibilities of using this combination for its application in regenerative medicine and more specifically in bone implants.

A study on rheological properties, sensory evaluation and shelf life of ayran-shalgam mixtures

Ayran, a dairy-based fermented beverage, and shalgam, a plant-based fermented beverage were mixed [25% ayran + 75% shalgam (v/v), 50% ayran + 50% shalgam (v/v) and 75% ayran + 25% shalgam (v/v)] and rheological data were obtained at different temperature levels (4-12 °C). Power law model was used to describe the data. Temperature had no effect on the flow behavior index, but it affected the consistency index of the mixtures. Ayran-shalgam mixtures had similar flow behavior index with that of shalgam irrespective of the levels of ayran or shalgam. However, consistency index increased as the amount of ayran increased in the mixtures at a constant temperature. Mixture with the higher amount of ayran [75% ayran + 25% shalgam] had the highest scores in sensory evaluation. Shelf life analyses up to 4 weeks at 4 °C indicated that serum separation increased till the second week and then stabilized for all mixtures. Slight increase (0.05-0.1 unit) in pH was observed during the first week then pH values were stabilized just like the serum separation. Microbiological analyses revealed that mixtures had a similar shelf life with that of ayran. Consequently, mixture of two different fermented beverages could be possible with similar flow behavior and shelf-life, and ayran-shalgam mixture has a huge potential for commercial production. This study may be a basis for designing new products to fulfill the healthy diet demands.

Effect of thermosonication on physicochemical, microbiological and sensorial characteristics of ayran during storage

The aim of the study was to determine whether thermosonication extends the shelf life of ayran, an acidic milk drink. The effect of thermosonication at different temperatures (60, 70 and 80 °C) and times (1, 3 and 5 min) on the physicochemical and microbiological characteristics, and sensorial properties of ayran during storage were investigated. According to the results, thermosonication applied at 60 °C decreased lower the bacteria counts, although the Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus counts decreased as the temperature and time increased. The yeast and mold levels in samples treated with thermosonication were <1 log CFU mL(-1) during storage period. The ayran samples had non-Newtonian behavior, and the consistency coefficients of the thermosonicated samples were significantly higher than that of the heat-treated samples. Regarding serum separation, the most effective thermosonication treatment was applied at 70 °C for 3 min. The sensory properties of the thermosonicated samples were better than the thermal-treated samples after storage.

An introduction to the traditional fermented foods and beverages of Turkey

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.

Particle Stability in Dilute Fermented Dairy Drinks: Formation of Fluid Gel and Impact on Rheological Properties

Fluid gels are known to be very shear-thinning materials with yield stress. In this study, the rheological properties of gellan and gellan—pectin fluid gels in fermented dairy drinks were evaluated using viscometric measurements. Both gellan- and gellan—pectin-containing solutions showed the rheological properties of fluid gels resulting in stabilization of particles; but no evidence of a fluid gel was observed for those with pectin alone and those with no hydrocolloid content. Unlike pectin, gellan gum was capable of creating significant values of yield stress and accordingly stabilized colloidal particles and extrinsic added solid particles in the fermented dairy drink. However, pectin improved the stability in combination with gellan. The origin of fluid gel formation was assumed to be both permanent interactions occurring between gellan and proteins, forming hairy particle gels and transient interactions between the particle gels. The significance of yield stress values for particle stability was demonstrated and two methods, including a noteworthy infinite apparent viscosity method and a conventional Bingham approach, were employed to calculate the values of yield stress. Both the methods showed a good application potential due to their simplicity, reasonable results and also wide availability of the instrument applied.