Erkan Karacabey

Optimisation of pre‐drying and deep‐fat‐frying conditions for production of low‐fat fried carrot slices

BACKGROUND The main objective of the current study was to reduce the fat content of fried carrot slices with a hot air pre-drying step before frying. In this regard the effects of hot air drying and deep-fat-frying conditions on moisture and oil contents, breaking force and colour parameters of pre-dried and fried carrot slices were investigated. RESULTS Statistical analysis with response surface methodology showed that there was a significant correlation between investigated responses and process variables (P ≤ 0.05). Based on the optimal conditions (63.4 °C for drying temperature, 16% for weight loss, 152 °C for frying temperature, and 207 s for frying time) produced by the optimisation of process conditions, more than 50% reduction in fat content of fried carrot slices was achieved by hot air pre-drying before frying. CONCLUSION The results presented indicated that the proposed cooking method is useful to control final oil content of fried carrot slices, so indirectly limiting the daily calorie intake by consumers without spectacular losses in quality attributes.

Aroma transition from rosemary leaves during aromatization of olive oil

The aroma profile of aromatized olive oil was determined in this study. The primary objective was to investigate the transition of major aroma compounds from rosemary and olive fruit during the kneading step of olive oil production by response surface methodology. For this purpose, temperature, time, and amount of rosemary leaves were determined as independent variables. The results indicated that temperature and time did not affect the transition of target compounds, but rosemary leaves addition had a strong influence on transition, especially for characteristic aroma compounds of this herb. Adequacies of developed models were found to be high enough to predict each aromatic component of interest.

Modeling and Predicting the Drying Kinetics of Apple and Pear: Application of the Weibull Model

Drying data of apple and pear at 40, 50, 60, 70, and 80°C were described by the Weibull model and it was observed that the shape parameter of the Weibull model did not depend on temperature. Therefore the reduced Weibull model with fixed shape parameter was proposed as the primary model to describe drying data with a slight loss of goodness-of-fit. Temperature dependence of time-parameter (time necessary to reduce the initial moisture ratio by 90%) could be described by two ad hoc models as the secondary models. Predictions using the integrated models almost perfectly agreed with the experimental drying data of apple at 45 and 65°C and of pear at 55 and 75°C, respectively. Kinetic analyses with published data have shown that the reduced Weibull model can also successfully be used to describe the drying data of certain fruits. Time-parameters tabulated in this study can be useful for food manufacturers.