ABSTRACT
Abstract .................................................................................................................................................... 26 2.1 Introduction .................................................................................................................................... 26 2.2 Edible Coatings to Control Oil Uptake in Fried Foods ................................................................. 27
2.2.1 Case Study: Heat and Mass Transfer in Frying Processes ................................................ 27 2.2.2 Mathematical Modeling of Heat and Mass Transfer during Frying Process .................... 28 2.2.3 Numerical Solution ............................................................................................................ 32 2.2.4 Validation of the Mathematical Model: Frying Process of a Coated Dough Disc ........... 32
2.2.4.1 Description of the Food System and Selection of the Frying Conditions ......... 32 2.2.4.2 Application of a Hydrocolloid Coating to Reduce Oil Uptake during Frying ....... 33 2.2.4.3 Heat Transfer Validation: Thermal Histories of Coated and Uncoated
Samples during the Frying Process ................................................................... 33 2.2.4.4 Water Transfer .................................................................................................... 33 2.2.4.5 Temperature and Water Content Predictions Using the
Mathematical Model ......................................................................................... 35 2.2.5 Oil Uptake of Coated and Uncoated Products .................................................................. 35 2.2.6 Quality Attributes of Coated and Uncoated Fried Samples .............................................. 37 2.2.7 Microstructure Analysis of the Fried Product ................................................................... 39 2.2.8 Relationship between Oil Uptake and Microstructure Changes during
the Frying Process ............................................................................................................. 40 2.2.9 Final Considerations about the Modeling of Coated Fried Food ...................................... 42
2.3 Case Study: Release of an Antimicrobial Agent from a Biodegradable Active Film to a Food System ........................................................................................................ 42 2.3.1 Active Film Preparation and Characterization .................................................................. 43 2.3.2 Effect of PS on Optical and Barrier Properties of the Active Films ................................. 43 2.3.3 Experiments to Determine PS Release from the Active Film
to a Model Food System ................................................................................................... 44 2.3.4 Mathematical Modeling of PS Diffusion Process ............................................................. 44 2.3.5 Diffusion Coefcients Determination ............................................................................... 45 2.3.6 Application of Active Films in Dairy Products: PS Minimum
Inhibitory Concentration ................................................................................................... 47 2.3.7 Antimicrobial Performance of the Active Film on a Dairy Product ................................. 47 2.3.8 Final Considerations about the Modeling of the Preservative
Release in Active Films .................................................................................................... 48 References ................................................................................................................................................ 49
In the present chapter, two examples related to transport phenomena in lms and coatings are discussed. One of them represents the heat and mass transfer process in fried foods that were covered with an
edible coating based on methylcellulose (MC). This is an alternative to reduce oil uptake (OU) in fried foods due to its lipid-barrier properties. The following aspects are discussed: (1) mathematical modeling of heat and moisture transfer during the deep-fat frying of food, (2) experimental validation of the mathematical model with regard to the temperature proles and the water losses from the food product, (3) analysis of the relationship between the OU measurements and microstructural changes developed, and (4) performance of applying an edible coating based on MC on a food model dough system.
