Pomegranate juice powder is easier to handle and has more potential applications than the concentrate. In this study, the response surface, 3-level factorial design was used to evaluate the influence of spray-drying conditions on the physicochemical properties of a powdered product obtained by drying pomegranate juice concentrate (PJC). It was spray-dried with a lab-scale spray-dryer using 18 and 7 dextrose equivalent (DE) maltodextrins (MD) as drying-aid agents. Adding MD significantly reduced the hygroscopicity and stickiness of the pomegranate juice powder, and thus yielded higher recovery. The maximum achieved ratio of PJC ⁄ MD was 1 ⁄ 1, and it was obtained with the use of DE7 MD. However, graphical optimisation studies resulted in 125-145°C and 0.6-0.8 PJC ⁄ MD ratio as optimum variables to produce acceptable dried powder. The results indicated that increasing inlet air temperature increases solubility time and loss of anthocyanins and decreases bulk density and moisture content of the powder.

No abstract

No abstract

No abstract

In this study, it was aimed to investigate the perceptions and competences of prospective science teachers about formative assessment approaches. Qualitative case study methodology was used in the study. Research group consisted of 17 senior students of science education. As a data collection tool, a semi-structured "Formative Assessment Perception Interview Form" was used which was developed by the researcher. The data were collected by conducting a total of ten in-depth interviews, 8 with focus groups and another 2 as face -to-face. Collected data were subjected to content analysis. Study findings revealed that perceptions and competences of prospective science teachers on formative assessment approaches are very low and not sufficient. In particular, it was found out in this study that prospective science teachers are familiar with the definition and function of formative assessment approaches (12%) at a low extent albeit; however, they are seriously deficient about for what purpose (7% competence) they will use and choose them, how to prepare such approaches (3% competence), how to interpret and score effects of the results for the learning-teaching process (2% competence). Science teacher training curricula need to be revised in a way to give prospective teachers a training and preparation in practical, long-term and real learning-teaching environments for formative assessment approaches.