• Universitat de València

• Majid Dowlati

Freshness is the most important indicator of fish quality. Freshness is a complex concept but can be estimated from storage time at zero degrees Celsius as a combination of various sensory properties, such as appearance, odour, taste and texture, using the scheme defined by the Quality Index Method (QIM) applied by a trained panel of people. However, such panels are expensive, panel training is critical and the panel is not always accessible. There are also instrumental methods for the determination of fish freshness based on chemical, biochemical or microbiological analysis. However, in order to satisfy the need for simple and low-cost quality measurements in the industry, as well as for determinations by a non-experienced user in the trade or by the consumer himself, new methods for determining the freshness of fish are needed.

Researchers at the Universitat de València have developed a procedure that allows the rapid determination of the freshness of fish without using a trained panel of tasters and without damaging the samples or requiring expensive instruments, i.e. without smelling, touching, dissolving or handling the fish. The technology allows the determination of the freshness of a fish based solely on the mathematical processing of images of the fish taken with any digital camera, including mobile phones, and their comparison with a library of images and data obtained for specimens of the same type of fish to be evaluated. In addition, the method makes it possible to check whether the fish has been kept correctly, without breaking the cold chain, by comparing the freshness value determined by the developed procedure with the freshness value appearing on its traceability label.

The main application of the technology is in the food sector, for the determination of the freshness of fish or the verification of the proper preservation of fish.

The main advantages provided by the invention are:

• The absence of manipulation of the sample to carry out the determination.
• Simplicity and speed, as it is only necessary to use a smartphone and suitable lighting conditions and does not require specialised personnel.
• Universality, as the procedure is applicable to any type of fish for which a calibration obtained from data for that species is available.

• Patent granted