Food models

Lievonen, S.M. and Roos, Y.H. 2002a. Nonenzymatic browning in amorphous food models Effect of glass transition and water. J. Food Sci. 67, 2100-2106. 

Bylaite, E., Adler-Nissen, J., and Meyer, A.S. Effect of xanthan on flavor release from thickened viscous food model systems, J. Agric. Food Chem., 53(9) 3577-3583, 2005. 

Monro, J. A., Mishra, S., Venn, B. J. (2008). Relative glycemic responses to foods modelled using in vitro digestive analysis of glycemic carbohydrate and a dose-sensitive baseline for glucose disposal (In preparation). 

Conde-Petit, B., Escher, F., Nuessli, J. (2006). Structural features of starch-flavor com-plexation in food model systems. Trends in Food Science and Technologys l s 227-235. 

The aim of this book is to assemble, for a handy reference, various emerging, state-of-the-art methodologies used for characterizing foods. Although the emphasis is placed on real foods, model food systems are also considered. The book contains invited chapters contributed by scientists actively involved in research, most of whom have made notable contributions to the advancement of knowledge in their field of expertise. 

Moore, W., Garden-Robinson, J., and Nelson, R. 1996. Characterization of flaxseed gum in food model systems. In Proceedings of the 56th Flax Institute of the United States , pp. 86-95. Fargo, ND. 

Among the other reported volatile TDP of B-carotene include B-cyclo-cltral, 5,6-epoxy-B-ionone and dihydroactinidiolide (25). These compounds were also found by Isoe et al. (30, 31), Wahlberg et al. (32) and Kawakami and Yamanishi (33) as photo-oxygenation products of B-carotene. Volatile thermal degradation of carotenoids has been extensively studied, mainly in nonfood systems. Hence, the objective of this study was to identify the volatile components of the TDP of B-carotene formed in a food model system. 

S. M. Lievonen, T. J. Laaksonen, and Y. H. Roos, Nonenzymatic browning in food models in the vicinity of the glass transition effects of fructose, glucose, and xylose as reducing sugar, J. Agric. Food Chem., 2002, 50, 7034-7041. 

Teixeira Neto, R.O., Karel, M., Saguy, I., Mizraki, S. 1981. Oxygen uptake and (3-carotene decoloration in a dehydrated food model. J. Food Sci. 46, 665-669, 676. 

The water present in foods may act as a plasticizer. Plasticizers increase plasticity and flexibility of food polymers as a result of weakening of the intermolecular forces existing between molecules. Increasing water content decreases Tg. Roos and Karel (1991a) studied the plasticizing effect of water on thermal behavior and crystallization of amorphous food models. They found that dried foods containing sugars behave like amorphous materials, and that small amounts of water decrease Tg to room temperature with... 

Figure 1-25 Modified State Diagram Showing Relationship Between Glass Transition Temperature (Tg), Water Activity (GAB isotherm), and Water Content for an Extruded Snack Food Model. Crispness is lost as water plasticization depresses Tg to below 24X2. Plasticization is indicated with critical values for water activity and water content. Source Reprinted with permission from Y.H. Roos, Glass Transition-Related Physico-Chemical Changes in Foods, Food Technology, Vol. 49, No. 10, p. 99, 1995, Institute of Food Technologists.

Roos, Y.H., and M.J. Himberg. 1994. Nonenzymatic browning behavior, as related to glass transition of a food model at chilling temperatures. J. Agr. Food Chem. 42 893-898. 

Roos, Y., and M. Karel. 1991d. Plasticizing effect of water on thermal behaviour and crystallization of amorphous food models. J. Food Sci. 56 38-43. 

Further research is needed if efficient labeling of both animal and plant food models with stable isotopes of zinc is to be achieved. This represents an Important challenge in the development of stable Isotope methodology for measurement of dietary zinc availability in human studies. 

Shimada, Y., Roos, Y., and Karel, M. (1991). Oxidation of methyl linoleate encapsulated in amorphous lactose-based food model. J. Agric. Food Chem. 39, 637-641. 

Miniati, E., Damiani, P, Mazza, G. (1992). Copigmentation and self-association of anthocyanins in food model systems. It. J. Food Sci., 4, 109-116. 

Bee, R., Clement, A., and Prins, A. Behaviour of an aerated food model, Food Emulsions and Foams, E. Dickson, ed., RSC, London, pp. 128-144,1987. Campbell, G.M. and Mougeot, E. Creation and characterization of aerated food products, Trends Food Sci. Technol., 10, 283,1999. 

Chanona-Perez, J.J., Alamilla-Beltran, L., Farrera, R.R.R., Quevedo, R., Aguilera, J.M., and Gutierrez-Lopez, G.F. Description of the convective air drying of a food model by means of the fractal theory. Food Sci. Technol. Int., 9, 207, 2003. 

Karmas, R. and Karel, M. The effect of glass transition on Maillard browning in food models, Maillard Reactions in Chemistry, Food, and Health, T.R Labuza, G.A. Reineccius, V.M. Monnier, J. O Brien and J.W. Baynes, eds.. The Royal Society of Chemistry, Cambridge, U.K., pp. 182-187, 1994. 

Three amorphous food model systems consisting of lactose, trehalose, and lactose/trehalose (1 1) as matrix materials, and L-lysine and D-xylose (1 1, 5% w/w) as reactants were prepared by freeze-drying. Aliquots (1 g) of the powdered freeze-dried model materials were transferred into 20-ml glass vials, which were stored in desiccators over four relative vapor pressures (RVP) of 33.2,44.1,54.5, and 65.6%. Triplicate samples were removed at 10- to 24-h intervals depending on the RVP, and the extent of browning was determined spectrophotometrically at 280 and 420 nm. 

Water plasticized the food models and caused a substantial decrease of the glass-transition temperature. The Gordon-Taylor equation was successfully fitted to experimental glass transition temperatures of the three model systems, as shown in Figure 53.2b. The constant, k, for the Gordon-Taylor equation was found to be 7.6 0.8 for lactose/reactant systems, 7.2 0.7 for lactose/trehalose/reactant systems, and 7.9 0.9 for trehalose/reactant systems. The three model systems had corresponding glass-transition behaviors, which were typical of lactose-based dairy products. The critical water contents at 23°C obtained from Tg data for lactose/reactant, lactose/trehalose/reactant, and trehalose/reactant systems were 7.0, 7.4, and 7.1 g/100 g of dry solids, respectively. 

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