Automatic and precise quality assessment
In retail, the freshness and safety of fresh food must be continuously guaranteed. Fruit and vegetables in particular have a short shelf life that varies and depends on a number of factors. If impending spoilage is not detected in time, the products often end up in the trash. In the EU alone, around 58 million tons of food end up as waste every year – worth around 132 billion euros.
To counteract this, forward-looking strategies regarding the timing of sales and pricing are essential. Continuous quality controls along the supply chain are therefore indispensable. Traditionally, destructive laboratory methods are usually used for this purpose, but these are costly and time-consuming. As a result, quality control approaches using spectral sensor technology are becoming increasingly important.
AI-supported quality inspection with hyperspectral imaging
As part of a research project, Fraunhofer IOSB is developing a scanner that uses spectral imaging to capture entire crates of fruit and vegetables and derive AI-supported quality assessments. The aim is to transfer near-infrared spectroscopy, which is well established in research, into robust, practical applications.
The system is designed to enable fast, non-destructive analysis of various quality parameters of fruit and vegetables, thus providing a basis for:
- Objective, automated quality control in goods receipt,
- Predictions of remaining shelf life,
- Data-supported control of sales and logistics,
- Digital data acquisition,
- Rapid determination of non-visible quality characteristics.
Using physics instead of gut feeling
Unlike conventional RGB cameras, hyperspectral imaging captures not only three color channels, but also many closely adjacent wavelength ranges. Each pixel thus contains a spectrum of reflected light that serves as a characteristic fingerprint of the material. Since many properties relevant to food (e.g., water, sugar, and dry matter content) exhibit specific absorption patterns in the near-infrared range, quality characteristics such as incipient spoilage or internal damage can be derived from this.
Spectral imaging offers the following advantages over conventional methods for quality control of fruit and vegetables:
- Non-destructive: The goods remain intact.
- Comprehensive: Not only individual samples, but entire crates are scanned.
- Fast: Measurement in seconds.
- Contactless: Hygienic analysis without complex mechanics.
Spectral sensors reveal differences in quality that are not visible to the human eye. This enables a reliable assessment of the degree of ripeness, remaining shelf life, and homogeneity of the goods.
Fraunhofer Institute of Optronics, System Technologies and Image Exploitation IOSB