Process-Induced Chemical Changes in Food

Chemical changes that occur in foods during processing and storage are manifold and might be both desirable and undesirable in nature. While many of the processes are carried out intentionally, there are also certain unwanted changes that naturally occur in food and might have to be controlled. Therefore, efforts are made to devise processing technologies in which desirable attributes of foods are retained and their deleterious ef fects are minimized. While proteins, lipids and carbohydrates are the main nutrients of food that are affected by processing, it is their interaction with one another, as well as in volvement oflow-molecular-weight constituents that affects their flavor, color and overall acceptability. Thus, generation of aroma via thermal processing and bioconversion is of utmost importance in food preparation. Furthermore, processing operations must be opti mized in order to eliminate or reduce the content of antinutrients that are present in foods and retain their bioactive components. Therefore, while novel processing technologies such as freezing, irradiation, microwaving, high pressure treatment and fermentation might be employed, control process conditions in a manner that both the desirable sensory attributes and wholesomeness of foods are safeguarded is essential. Obviously, method ologies should also be established to quantitate the changes that occur in foods as a result of processing. This volume was developed from contributions provided by a group of internation ally-recognized lead scientists.

Zusammenfassung
Based in part, on Proceedings of Pacifichem 95 held in Honolulu, Hawaii, December 18-22, 1995

Inhalt

1. Process-Induced Chemical Changes in Foods: An Overview.- 2. Methods to Monitor Process-Induced Changes in Food Proteins: An Overview.- 3. Proteolysis and Gelation of Fish Proteins under Ohmic Heating.- 4. Effect of Maturity and Curing on Peanut Proteins: Changes in Protein Surface Hydrophobicity.- 5. High Pressure Processing Effects on Fish Proteins.- 6. Effect of High Hydrostatic Pressure on Pacific Whiting Surimi.- 7. High Pressure Processing of Fresh Seafoods.- 8. High Pressure and Heat Treatments Effects on Pectic Substances in Guava Juice.- 9. Chemometric Applications of Thermally Produced Compounds as Time-Temperature Integrators in Aseptic Processing of Particulate Foods.- 10. Heating Rate of Egg Albumin Solution and Its Change during Ohmic Heating.- 11. Chemical Changes during Extrusion Cooking: Recent Advances.- 12. Sucrose Loss and Color Formation in Sugar Manufacture.- 13. Process-Induced Changes in Edible Oils.- 14. Effects of Processing Steps on the Contents of Minor Compounds and Oxidation of Soybean Oil.- 15. Antioxidizing Potentials of BHA, BHT, TBHQ, Tocopherol, and Oxygen Absorber Incorporated in a Ghanaian Fermented Fish Product.- 16. Minimizing Process Induced Prooxidant Stresses.- 17. Antioxidative Properties of Products from Amino Acids or Peptides in the Reaction with Glucose.- 18. Maillard Reaction and Food Processing: Application Aspects.- 19. Generation and the Fate of C2, C3, and C4 Reactive Fragments Formed in Maillard Model Systems of [13C]Glucose and [13C]Glycine or Proline.- 20. Metal Chelating and Antioxidant Activity of Model Maillard Reaction Products.- 21. Volatile Components Formed from Reaction of Sugar and ?-Alanine as a Model System of Cookie Processing.- 22. Amino-Reductones: Formation Mechanisms and StructuralCharacteristics.- 23. Effects of Gamma Irradiation on the Flavor Composition of Food Commodities.- 24. Flavor Deterioration in Yogurt.- 25. Flavor Generation during Extrusion Cooking.- 26. Process-Induced Compositional Changes of Flaxseed.- 27. Effect of Processing on Phenolics of Wines.- 28. Photochemical Reactions of Flavor Compounds.