CHANGES ON PHYSICOCHEMICAL, LIPOLYSIS AND PROTEOLYSIS OF VACUUMPACKED TURKISH KASHAR CHEESE DURING RIPENING

The vacuum-packed Turkish Kashar cheese ripening was evaluated in the medium and internal zones of cheese throughout a 90 day storage period. The parameters analyzed were; lipolysis level, water soluble nitrogen (WSN), total nitrogen, ripening index (RI), trichloroacetic acid-soluble nitrogen (TCA-SN), moisture, salt and salt in moisture, fat values and sensorial properties. The moisture values, acidity, salt and salt in moisture was less internal section. The lipolysis level, RI, TCA-SN ratios of internal section of cheese was less than medium section. Lipolysis level, RI, TCA-SN values, salt content and salt in moisture of the cheese samples increased continuously until end of the ripening but total nitrogen and fat content shown no signifi cant changes with ripening, as moisture values decreased slightly. The ripening period was the main factor affecting sensory properties of cheese in medium and internal zones

Probabilistic-Mechanistic Evaluation of a Hybrid Drying System Using <i>l</i>₁ Norm Regularisation:Simultaneous Ohmic Heating and Convection Drying

Ohmic-assisted drying (OAD) is a novel drying system that combines ohmic heating and convection drying simultaneously. The present study is aimed at evaluating the mechanism of OAD system behaviours against the combined impact of operational and model uncertainties. Moreover, the dynamic (time-dependent), as well as static (end-of-drying) spatial homogeneity of the model predictions, was quantitatively described for the first time in the literature using Buzas and Gibson’s evenness value (an α-diversity index). The Monte Carlo simulation approach was used to propagate the uncertainty of randomly selected input variables using the Halton sequence sampling method. Mechanistic models include input uncertainties that lead to deviations in model estimations. Both time-dependent and independent global sensitivity of moisture, sample temperature, sample’s internal pressure, their spatial homogeneity, and drying time were assessed using Lasso regression (a variable selection method that penalises the coefficients using l1 norm). The stochastic results of the mechanistic investigation showed that the effects of the input variables are almost identical both as static and time-dependent variables. Lasso regression results indicated that operational and model uncertainties cause varying changes in the magnitude and direction of the stochastic model predictions throughout the process. By contrast, the homogeneity properties of the dry product are not caused by these variations and heterogeneous distribution of the electric field. Additionally, electrical conductivity, oven temperature, applied voltage, and initial moisture were found to be the variables which have the most significant effect on all the variables which were examined in terms of operational and model uncertainties. Practical Applications. The present study investigates the stochastic behaviour of the OAD system through the mechanistic model and using a probabilistic modelling approach. To the best of our knowledge, in addition to being the first study to probabilistically evaluate the OAD system, we are introducing Buzas and Gibson’s evenness value for the first time in the food science/technology literature. This measure serves as a numerical indicator of the spatial distribution homogeneity of the physical properties of the sample. The study’s findings and proposed methodologies will have further applications not only for researchers but also for manufacturers, particularly for those involved in the design and analysis of new drying and food systems in general. Moreover, the presented methods and novel homogeneity measures are generic tools; they can be easily adapted to other process improvement practices involving input/output uncertainty/variability

Optimization of Microwave-Assisted Predrying and Deep-Fat-Frying Conditions to Produce Fried Carrot Slices

WOS: 000399308000033Main objective of the current study was to reduce the fat content of fried carrot slices by applying a microwave assisted drying (MAD) step before frying. The effects of MAD and deep-fat-frying conditions on moisture and oil contents, breaking force, and color parameters of predried and fried carrot slices were investigated. The results of data analysis using response surface methodology showed that there was a significant correlation between investigated responses and process variables (P0.05). Based on the optimal conditions (12% for weight loss, 140 degrees C for frying temperature, and 227 s for frying time), more than 18% reduction in fat content of fried carrot slices was achieved by MAD applied before frying. SEM analysis was performed to determine the relationship between fat absorption and structural changes under effects of conditions of the proposed MAD and frying. Practical ApplicationsDeep-fat-frying is one of the most common cooking methods for foods. There are plenty number of studies devoted to manufacturing of fried foods with reduced fat content, since concerns about high fat content rise for food manufacturers from an economic point of view and also for the consumers from the health angle. The information presented in this work will be useful in manufacturing of fried carrot slices of acceptable quality attributes by optimizing the MAD and frying processes. The result is very useful for manufacturer and consumers in considering different processing variables and responses at the same time, which have been commonly studied with single factor experiment in literature and none of them has included MAD combined frying for cooking of carrot slices in terms of fat content and quality assurance.Scientific and Technological Research Council of Turkey [113R015]The authors appreciate the financial support received through The Scientific and Technological Research Council of Turkey Project no. 113R015

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

WOS: 000382838100038PubMed ID: 26916385BACKGROUND: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 o52 degrees C for frying temperature, and 207 s for frying time) produced by the optimal conditions (63.4 degrees C for drying temperature, 16% for weight loss, 1ptimisation 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. (C) 2016 Society of Chemical IndustryScientific and Technological Research Council of Turkey [113R015]The authors appreciate the financial support received through The Scientific and Technological Research Council of Turkey, Project no. 113R015