Chapter 5. Nutritional Aspects

  1. Deutsche Forschungsgemeinschaft (DFG)
  1. Prof. Dr. Dr. Gerhard Rechkemmer1,2

Published Online: 19 JUN 2007

DOI: 10.1002/9783527611492.ch5

Thermal Processing of Food: Potential Health Benefits and Risks

Thermal Processing of Food: Potential Health Benefits and Risks

How to Cite

Rechkemmer, G. (2007) Nutritional Aspects, in Thermal Processing of Food: Potential Health Benefits and Risks (ed Deutsche Forschungsgemeinschaft (DFG)), Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany. doi: 10.1002/9783527611492.ch5

Author Information

  1. 1

    Lehrstuhl für Biofunktionalität der Lebensmittel, Technische Universität München, Hochfeldweg 1, 85350 Freising, Germany

  2. 2

    Unit Biofunctionality of Food, Life and Food Sciences Center Weihenstephan, Technical University of Munich, Hochfeldweg 1, 85350 Freising, Germany

Publication History

  1. Published Online: 19 JUN 2007
  2. Published Print: 23 FEB 2007

ISBN Information

Print ISBN: 9783527319091

Online ISBN: 9783527611492

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Keywords:

  • thermal processing of food;
  • health benefits;
  • health risks;
  • nutritional aspects;
  • inactivation of enzyme activities;
  • elimination/reduction of microbial contamination;
  • elimination/reduction of microbial toxins;
  • inactivation of microbial contamination;
  • inactivation of microbial toxins;
  • some water-soluble vitamins are heat-sensitive;
  • vitamins C, B1, B2, B6, and folic acid;
  • β-carotene, lycopene, and lutein;
  • isoflavonoids;
  • act as radical scavengers;
  • antioxidants;
  • antimicrobials;
  • phytoestrogens;
  • anticarcinogenic activity;
  • act as signalling molecules;
  • heat treatment increase in bioavailability;
  • biological activity;
  • nutritional quality of foods;
  • not all allergens can be inactivated by heat treatment

Summary

Important nutritional aspects of the thermal treatment of food are the inactivation of enzyme activities and the elimination/reduction and inactivation of microbial contamination and microbial toxins. These changes in general lead to an increase in the ability to store and use food. Thermal treatment also changes the physico-chemical structure of macronutrients, e.g. starches and proteins, with the generalised effect of a better gastro- intestinal digestion. Regarding the nutritional quality of heat-treated food one should discriminate between the effects on essential nutrients and non-nutrient bioactive components. While some water-soluble vitamins are heat-sensitive, e.g. vitamins C, B1, B2, B6, and folic acid, the lipid-soluble vitamins are not. A decrease in essential nutrients by heat treatment thus reduces the nutritional value of certain foods. Thermal treatment also causes changes in plant cell wall structure and thus modifications of the food matrix. These changes may lead to a marked increase in the bioavailability of bioactive food components, e.g. secondary plant metabolites (phytochemicals). Such effects have been demonstrated for carotenoids, e.g. β-carotene, lycopene, and lutein, but also for other substances like the isoflavonoids. These non-nutrient bioactive compounds have various biological functions. They act for example as radical scavengers, antioxidants, antimicrobials, phytoestrogens or have even anticarcinogenic activity and act as signalling molecules. The increase in bioavailability thus is relevant for the biological activity and the nutritional quality of these foods. By changing the tertiary structure of proteins thermal treatment may also lead to a change in epitopes responsible for allergenicity of certain foods. However, not all allergens can be inactivated by heat treatment. The examples discussed relate to changes of components already present naturally in food before thermal treatment. However, during thermal treatment new compounds are formed and these compounds may have nutritional relevance. The Maillard reaction products are important for the colour and sensory properties of foods. The biological activities of these compounds are discussed in the following.