Oil mobility

Projectname:
Improvement of the hazelnut oil yield and stability of hazelnut-based products by quantification of oil mobility and specific adaptation of process parameters

Workgroup: Chocolate technology

Research partner and scientific guidance:

  1. Fraunhofer Institut für Verfahrenstechnik und Verpackung IVV, Freising, Isabell Rothkopf
  2. Karlsruher Institut für Technologie KIT, Institut für Mechanische Verfahrenstechnik und Mechanik , Lena Trapp

IGF: 21785 N
Financing: BMWK
Duration: 2021 – 2024

Fats and oils are used as storage substances in almost all animal and vegetable organisms and their processed food. They influence not only the textural and structural behavior, but also the processing possibilities and shelf life of the fabricated foods from the raw materials. For example, the yield and process time in the extraction of edible oil from seeds depends on the oil binding capability in the plant fiber matrix. The raw material quality and the process parameters of nut-containing materials are also decisive for the oil mobility in the finished product. In the case of multi-layer products such as chocolates with whole hazelnuts or nougat fillings, oil migration from one layer to the other can occur depending on the type of binding. The migration of oil favors fat blooming, which is negatively associated with loss of shelf life and product quality by the consumer.

The aim of the research project is the optimal use of fat-based food raw materials, such as hazelnuts. For this purpose, a simple and robust measurement method to enable the determination of the oil mobility should be developed and established. The knowledge gained about the mobility of oil in raw materials and processed food will be used to optimize the raw material sorting porcess according to their intended use and to adapt further processing to the raw materials. At the same time, the influence of the raw material quality and processing on the shelf life of fatty foods, such as filled chocolates or sweet spreads, will be further investigated and utilized for higher quality products.

Initially, model systems that only have one type of oil immobilization, e.g. only physical or only chemical, are examined because of the complexity of the hazelnut, hereby reducing the number of influence factors. Measurement methods to determine the oil mobility that are used to this point, such as centrifugation or a simple oiling out on filter paper, have hardly provided comparable results and do not provide any further information about the type of oil binding in the products and their stability. NMR technology is used to investigate the oil binding capacity of the sample non-destructively and non-invasively. The model systems will initially be measured in high-field NMR in order to obtain information on the type of binding and its influence on the NMR signal, as well as to determine the most suitable measurement method. The results will then be used to investigate more complex, standardized food systems and to transfer the measurement method to TD-low-field NMR, which is more suitable for industry purposes and quality control.

The findings expand the current state of knowledge about the mechanisms of oil binding and oil migration. Furthermore, the findings will be used to optimize existing processes, e.g. to improve the ability to press oilseeds or the oil binding capability of nougat fillings. By expanding the state of knowledge, an improvement on the development of process technologies that influence the oil mobility can be specifically adapted. As a result, innovative products, such as filled chocolates can have a slower fat blooming tendency and therefore prolonged shelf life.

Report

The IGF project presented here by the Research Association of the Industrial Association for Food Technology and Packaging (IVLV e.V.) is funded by the Federal Ministry for Economic Affairs and Climate Action as part of the program for the promotion of industrial community research (IGF) based on a decision of the German Bundestag.