REDUCING FAT UPTAKE IN COATED FRIED FOOD BY USING MULTISCALE HYBRID MIXTURE THEORY BASED PREDICTIVE MODELING AND EXPERIMENTAL VALIDATION

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: NRI COMPETITIVE GRANT
• Reporting Frequency: Annual
• Accession No.: 0215346
• Grant No.: 2009-35503-05279
• Cumulative Award Amt.: $385,932.00
• Proposal No.: 2008-02213
• Project Start Date: Feb 1, 2009
• Project End Date: Jan 31, 2013
• Grant Year: 2009
• Program Code: [71.1]- Improving Food Quality and Value

Recipient Organization
TEXAS TECH UNIVERSITY
(N/A)
LUBBOCK,TX 79409

Performing Department
(N/A)

Non Technical Summary
Consumers demand tastier fried foods with reduced fat. This is difficult to achieve because the relation between transport mechanisms and food biopolymers, occurring over a hierarchy of spatial scales (from micro to macroscale), is not fully understood. Three-scale balance laws and the second law of thermodynamics will be exploited to develop multiscale fluid and heat transport equations for predicting moisture loss, and oil uptake coupled with physico-chemical changes in foods. The equations will be solved using numerical simulations. For validation, frying experiments with coated chicken nuggets will be performed. The experimental parameters are expected to be fluid permeabilities, thermal diffusivity, porosity and mechanical properties. The permeabilities will be measured gravimetrically; mechanical properties will be measured using static testing and porosity will be measured using solvent absorption method. Heat transfer will be accounted by developing a general three-scale heat transfer (Laplace) equation. Thermal diffusivity values will be calculated using temperature profiles. Color will be measured using colorimeter, and correlated to surface temperature and moisture. The average moisture and oil content will be measured using standard AOAC methods. Nuclear Magnetic Resonance imaging will used to image moisture and oil distribution in chicken nuggets. The developed predictive tool will aid in reducing oil uptake and improving quality of fried foods. The computer program will be made general to allow its use for other fried foods. The proposed research would fall under the CSREES priority areas 1 and 2-fundamental understanding of the basic transport mechanisms in the food matrix at different scales, their relation to biopolymers, and using an innovative engineering approach (multiscale simulations) for predicting food quality during frying.

Animal Health Component

30%

Research Effort Categories

Basic

70%

Applied

30%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
501	3260	2020	50%
502	3260	2020	50%

Knowledge Area
501 - New and Improved Food Processing Technologies; 502 - New and Improved Food Products;

Subject Of Investigation
3260 - Poultry meat;

Field Of Science
2020 - Engineering;

Keywords

frying of foods, fat uptake, fried foods, multiscale modeling,

transport processes, transport during frying, chicken nuggets, coated

fried foods, three-scale modeling, hybrid mixture theory

Goals / Objectives
It is expected that modeling based upon multiscale hybrid mixture theory applied to foods with edible coatings will provide improved insight into frying mechanisms, and allow processors to better optimize the frying parameters to make a lower fat product with desirable texture and taste. In order to achieve these outcomes, our objectives are as follows: 1. To develop the hybrid mixture theory based three-scale transport model for studying frying of food products. 2. To obtain the experimental parameters and solve the model using finite element method. 3. To validate the model by conducting frying and NMR imaging experiments. Objective 1 aims at developing a system of engineering equations that incorporate information from the food microstructure to macrostructure on frying mechanisms and associated quality changes in the food biopolymers. This will allow predicting fat uptake by foods during frying, and physico-chemical and structural changes in the food matrix. The information obtained from completing this objective will enhance information on the heat and fluid transport mechanisms of frying and will allow better optimization of the process parameters. Objective 2 involves measuring the experimental properties that are needed to solve the mathematical model and obtain the solution of equations using numerical simulations. This will provide improved understanding of the physics of oil and moisture transport processes involved during frying. A large amount of information will be generated using numerical simulations that may take significantly longer time using purely experimental approaches. Objective 3 is critical to validate the data of engineering model by making comparisons to the experimental frying data. The moisture and fat distribution in chicken nuggets predicted by the model will be compared to experimental profiles obtained using nuclear magnetic resonance (NMR) imaging. Conventional frying experiments will also be conducted to obtain average values of fat uptake and water loss in crust and core of the fried food. Comparison of water loss, oil uptake and physico-chemical changes between control samples and samples with an outer coating will be made to determine the effectiveness of coatings in reducing fat uptake and improving food quality attributes.

Project Methods
Hybrid Mixture Theory (HMT) based transport model will be developed by using three-scale equations of conservation of mass, momentum, energy and entropy balance, incorporating the physico-chemical nature of foods during frying and exploiting the second law of thermodynamics to obtain simplified relations. In the past research, three-scales approaches have not been used for studying frying. Thus, he use of HMT for studying frying will be a novel contribution that will provide information on not only how oil uptake and water loss occur but also what quality changes are caused in the food matrix. In the past approaches, the quality changes in food could not be coupled with transport equations. The developed three-scale equations will be useful not only for studying frying of foods, but also other unsaturated transport processes in food engineering. Several decades of research in continuum mechanics (the field to which HMT belongs) has demonstrated that the methods used to develop engineering models using continuum mechanics framework are better able to describe the complex processes involving multiphases (oil, water and vapor in the case of frying). The solution of these equations using numerical simulations (finite element method) will involve solving the water, vapor, oil and heat transfer equations coupled with volume and mechanical properties changes in the solid matrix. This is related to the quality changes in foods during frying because the volume and mechanical properties help to predict the formation of crunchy crust and soft interior of foods. Thus, using information from solution of equations, one can predict the process parameters that lead to desirable texture of foods with minimum oil uptake. The model will provide information on moisture distribution, oil distribution, temperature profile, amount of shrinkage and texture (related to oil and water content, cellular matrix formed by growing bubbles, glassy surface etc.). The surface temperature of the nuggets will also be correlated to the color of nuggets. These predictions will be compared to the data obtained from frying experiments measuring water, oil and thermal diffusivities etc. In order to quantify the levels of oil and water within the chicken nuggets a series of NMR micro imaging and NMR spectroscopic studies will be performed. NMR techniques allow the non-destructive observation of the distribution of water and fat (lipids) within a food material. In addition to the distribution, the imaging techniques allow one to localize the respective proton densities as well as probe the mobility of the moisture or lipid as a function of location within the food. The spectrometer that will be used to obtain NMR spectroscopic and micro imaging data is a Varian Inova high-resolution spectrometer with a narrow bore 11.75 T magnet operating at 499.843 MHz for 1H observation. The probe that will be used is a high sensitivity, 1H observe probe with a 5mm diameter x 16 mm length coil and shielded X,Y,Z axis pulsed field gradients.

Progress 02/01/09 to 01/31/10

Outputs
Target Audience: The project aims at solving the multiscale fluid transport equations for understanding the frying mechanisms and making comparisons to the experimental data. Most of the experimental work on measuring frying profiles in chicken nuggets, viscoelastic properties measurement and NMR imaging of moisture and oil distribution during frying has been completed. The work on mathematical modeling of transport processes during frying and the comparison of model predictions with experimental data is currently under progress. The graduate student has solved the frying model for a simpler food material (rice crackers). Since, chicken nuggets are more heterogeneous than rice crackers, in the current stage the model is being applied to them. After completion of the remaining work, a modeling tool will be available using which the suggestions for reducing fat uptake in chicken nuggets will be made. Three peer-reviewed papers on the experimental measurements in fried nuggets have already been published/submitted. Additional publications and conference presentations on the remaining work are expected to be made as part of the remaining work. This will provide useful information to the food industry to develop healthier fried food products. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? The project has trained one graduate student in solving the multiscale modeling equations for studying transport mechanisms during frying and a second doctoral student in peforming the NMR imaging experiments on fried food products. One graduate student was trained in conducting the frying experiments and measuring the mechanical properties of foods using dynamic mechanical analysis. How have the results been disseminated to communities of interest? The results have been disseminated through journal publications listed on previous page and via following conference presentations: 1. Yalamanchili, T., P. S. Takhar and C. Alvarado (2011). Creep compliance of chicken nuggets at different frying temperatures. 2011 International Poultry Expo, Jan 24-26, Atlanta, GA. 2. Yalamanchili, T., P. S. Takhar and C. Alvarado (2011). Texture of chicken nuggets with methylcellulose added as a pre-dust coating. 2011 International Poultry Expo, Jan 24-26, Atlanta, GA. 3. Takhar, P. S., Thompson, L.D. and Alvarado, C. (2011). Transport mechanisms during deep fat frying of chicken nuggets. Presented at USDA-PD meeting held as part of IFT Annual meeting. June 11-15, New Orleans, LA. 4. Lalam, S., P. S. Takhar, C. Alvarado and L. Thompson (2010). Pressure measurement and fluid transport imaging during deep fat frying of chicken nuggets. Institute of Food Technologists (IFT) Annual International Meeting, July 18-20, Chicago, IL. What do you plan to do during the next reporting period to accomplish the goals? In the next reporting period the work on objectives 2 and 3 will be completed.

Impacts
What was accomplished under these goals? Objective 1 on developing the multiscale model has been completed. Objective 2 on obtaining the experimental parameters and solving the model has been partially completed. Objective 3 has also been partially completed. The NMR imaging experiments have been completed (a publication currently in review on NMR experiments). The work on comparison of the data to the model is currently in progress.

Publications

• Type: Journal Articles Status: Published Year Published: 2013 Citation: Lalam, S., J. Sandhu, P. S. Takhar, L. Thompson and C. Alvarado (2013). "Experimental study on transport mechanisms during deep fat frying of chicken nuggets." LWT-Food Science and Technology 50(1): 110-119.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Sandhu, J., H. Bansal and P. S. Takhar (2013). "Experimental Measurement of Physical Pressure in Foods During Frying." Journal of Food Engineering 115(2): 272-277.
• Type: Journal Articles Status: Under Review Year Published: 2013 Citation: Oztop, M., H. Bansal, P. S. Takhar, M. J. McCarthy and K. L. McCarthy (2012). "Using Multi-Slice-Multi-Echo images with NMR Relaxometry to access water and fat distribution in coated chicken nuggets." Journal of Food Engineering (submitted).