Application of infrared spectroscopy for rapid an non-invasive quality determination of free fatty acids in nuts for quality assessment

Workgroup: Preservation of food quality

Scientific Partners and Guidance:

  • Fraunhofer-Institut für Verfahrenstechnik und Verpackung IVV Freising, Thorsten Tybussek

IGF: 20715 N
Financing: BMWi
Duration: 2019 – 2021

Nuts are an essential part in many foods. In season 2017/2018 45.2 million tons peanuts and 4.3 million tons of nuts were harvested worldwide. Since the nut harvest is predominantly seasonal, the nuts are stored for a long time. During storage the formation of free fatty acids occurs, which enforces a loss of quality of the nuts. The formation of free fatty acids has two different causes, the natural metabolism of the nuts and spoilage of the nuts by molds. Especially mold infestation of nuts is problematic due to the occurrence of mycotoxins formed by the molds. These mycotoxins are a major health risk for the consumer.

The state-of-the-art analysis for determination of free fatty acids is a random sampling and destruc-tive procedure. Considering that the content of free fatty acids in a batch of nuts is not distributed equally and mold infestation usually occurs locally or even only on individual nuts, random sampling cannot be a sufficient procedure for determination of free fatty acids in nuts.

The aim of the research project is the application of infrared spectroscopy (NIR, FTIR) for a rapid and non-invasive quality assessment of single nuts (hazelnuts, almonds, peanuts) due to the con-tent of free fatty acids. This application is intended to enable the identification and removal of sin-gle bad quality and molded nuts. The removal of these bad quality and molded nuts from a batch shall improve the product quality and product safety of a large batch of nuts.


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.