Most imported marine products are distributed frozen in order to extend their storage period and reduce transportation cost. Because methods to increase the weight of the marine products, such as artificial injection of water or water-coating, are use...
Most imported marine products are distributed frozen in order to extend their storage period and reduce transportation cost. Because methods to increase the weight of the marine products, such as artificial injection of water or water-coating, are used in this process, consumer damage is increasing. Up to now, examination in general was difficult because the only ways to inspect such illegal deeds were a sensory test on site or using precise measurement instruments in laboratories. In this experiment, microwave technology was used to develop a method for prompt, accurate and nondestructive verification at the customs clearance process to determine whether water has been injected into the frozen octopus or not. In order to achieve this, 2.6-3.95 GHz and 7-11 GHz horn antennae were used to measure the reflection signals from frozen octopus samples, and a classification factor was developed to differentiate frozen octopuses with and without water injection based on these results. Accuracy of the classification factors developed for the 2.6-3.95 GHz horn antenna was at least over 90%, demonstrating higher accuracy than the classification factors developed for the 7-11 GHz antenna. A relatively accurate system with a simple structure allowing classification of frozen marine products can be developed based on two or three selected frequencies of a 2.6-3.95 GHz horn antenna. Plans for further research will focus on methods to identify not only the artificial injection of water, but also water glazing, a method of increasing the weight by making thick coatings of ice on the surface of marine products.