Identificazione su base molecolare di insetti utilizzati come di ingredienti in cibo e mangimi.

The use of insects as ingredients for animal feeds production or as processed products for human consumption has increased significantly in recent years. At the same time, the lack of methods for the detection of these compounds requires the adaptation and improvement of some technologies for their detection. My PhD thesis was mainly aimed to give a contribution towards this objective. Indeed, with suitably designed primers, it was possible to detect the presence of target DNA in complex matrices such as feeds, bars and other mixtures by RT-PCR technology. Specifically, it was possible to accurately discriminate the presence of Gryllodes sigillatus within detecting up to 0.02 ng / μl of target DNA in compounds subjected to different technological processing treatments and with the possible presence of inhibitors. Therefore, the combination of a specific pair of primers is able to certify the unique identification of the target species. However, if the method has to be applied for relative quantification, specific calibration curves need to be developed and validated for the different technological processes as they affect DNA integrity. Subsequently based on the results of PCR, an innovative OLED-based biosensor based on target DNA recognition was developed. After several investigations on the more appropriate chemical deposition reaction of primers PCR-derived DNA probes, the presence of Hermetia illucens has been detected in several commercial feeds. The technology was able to detect target DNA with a detection limit of 0.75 ng / μl; without false-positive results and avoiding the need for amplification as occurs in the PCR approach. Data obtained by the biosensor system were validated by RT-PCR analyzes, which confirmed the reliability of the new system for future applications in the food and feed control area. The positive results support the implementation needed to make this system a Point of Care. Another subject considered in my thesis work was the evaluation of the effect of the dietary inclusion of Hermetia illucens (HI) meal on the activation of specific metabolic pathways in the gastrointestinal tract of gilthead sea bream within the EU AQUAEXCEL project carried out at the HCMR (GR) laboratories. Results underlined that it is possible to partially replace the traditional ingredients with HI meal resulting in positive effects on the gastrointestinal tract. In particular, the presence of this new ingredient resulted in a mitigation of the tissue damage of the gastric mucosa due to the use of vegetable-based diets. In addition, animal growth performance was not hampered by the dietary composition and the overexpression of hepatic SOD suggests an increase in antioxidative capacity. In any case, a dose-response effect of the enzymes for the hydrolysis of chitin was not detected although the expression of these genes was analysed.