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|Title:||Interactions of Flavor Compounds With Food Solids and Their Application to Volatile Retention During Drying|
|Doctoral Committee Chair(s):||Villota, Ricardo|
|Department / Program:||Food Science|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Subject(s):||Agriculture, Food Science and Technology|
|Abstract:||Interactions of flavor compounds with food solids were studied by measuring air-liquid partition coefficients of volatiles, sorption capacities of solids in aqueous solutions and in dry forms, and changes in thermodynamic parameters upon adsorption. The information gathered from studies on the interactions was related to the data on flavor retention during air-drying for better understanding of mechanisms involved in flavor retention.
It has been demonstrated that the effect of solids on volatility of flavor compounds depends upon their ability to interact with water and volatiles. Silica and soy protein decrease volatility of alcohols by adsorbing them through hydrophobic association and/or hydrogen bonding. Denaturation of protein by heat may limit its ability to form hydrogen bonds with alcohols. Sodium silicoaluminate, xanthan gum and maltodextrin show little interaction with alcohols in the presence of water.
This investigation revealed that adsorption of water and ethanol vapors by a fumed silica is a surface phenomenon, while xanthan gum and soy protein adsorb the vapors to specific sites, both at the surface and in the interior of their molecules.
Heats of adsorption for volatiles on food solids measured by a gas-solid chromatographic method indicated that alcohols adsorb to xanthan gum and soy protein by forming two hydrogen bonds while carbonyls form one hydrogen bond. Hydrocarbons interact with the solids via nonspecific forces. Silica particles, air-dried and ground, showed somewhat different trends. Hydrocarbons adsorb to silica with higher heats of adsorption possibly due to multiple nonspecific interactions. Alcohols and aldehydes form only one hydrogen bond.
Studies on alcohol retention during air-drying of model solutions indicated that a high initial solids content favors retention, due to more binding sites available for alcohol-solid interactions and due to less time required to reach a critical moisture content at which point the volatiles are locked in. Viscosity effect on retention, however, is found to be relatively small. The time after which no further volatile losses occur during an air drying process can be estimated from sample temperature curves.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988.
|Date Available in IDEALS:||2014-12-15|
This item appears in the following Collection(s)
Dissertations and Theses - Food Science and Human Nutrition
Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois