PhD DBOF Scholarships

Страна: Бельгия;

Дедлайн: 31.01.2011


Адрес: Katholieke Universiteit Leuven


PhD DBOF Scholarships

High pressure high temperature (HPHT) processing of foods is a recent processing technology combining high hydrostatic pressure (600-900 MPa) and high temperature (80-120°C) allowing the use of shorter processing times and reduced maximal processing temperatures as compared to conventional thermal sterilization processing, potentially resulting in better retention of color, flavor, texture and nutrients for a preset microbial safety.
It is however unclear to what extent and how HPHT processes influence chemical changes of food quality indices, in particular Maillard reaction related product characteristics including health risk components as well as other types of reactions (e.g. oxidation reactions) influencing the health related aspects of food materials.

Research objectives:   Given the possible effects of high pressure high temperature processing conditions on chemical changes, in particular the Maillard reaction and oxidation reactions, this proposal aims at answering the following key questions (i) what is the effect of the key processing variables (pressure, temperature, time) on the different stages of these reactions in terms of relevant indicators and are indicators, currently in use to evaluate the impact of conventional thermal processing, transferable to high pressure high temperature conditions, (ii) what is the effect of combined high pressure high temperature processes on the generation (and reduction) of health related risk compounds (e.g. acrylamide and furan), (iii) to what extent is the rate of the reactions of the different stages influenced by HP and HT.

Research approach:  The research approach will include:
- Studies will focus on systems with different levels of complexity, from simplified model systems to complex plant based food systems, with focus on low acid food systems.
- A study on the identification of relevant targeted components and profiling using GC-MS and LC-MS.
- A sutdy on targeted components representing different stages of e.g. the Maillard reaction such as Amadori reaction products, hydroxymethylfurfural and melanoidins and specific risk components such as acrylamide and/or furan including the kinetics.
- A study on targeted components including precursors e.g. for the Maillard reaction (sugars and amino acids, sugar isomerisation and degradation products and amino acid-derived products) including the kinetics.