Development and characterisation of fish nuggets obtained from mechanically separated meat of Nile tilapia (Oreochromis niloticus), with and without edible coatings

The production of fish nuggets is an example of the valorisation of mechanically separated fish meat (MSM) with its high nutritional value. However, the consumption of breaded food is often avoided due to the large amount of fat absorbed during deep frying in oil. Therefore, the aim of the present work was to develop Nile tilapia (Oreochromis niloticus) MSM nuggets coated with an edible coating to reduce the fat absorption during frying, preserving the flavour. Different combinations of corn starch, gelatine, and plasticiser (glycerol or sorbitol) were evaluated for their lipid absorption, with the coating containing 5% corn starch and 20% sorbitol (Treatment 4; T4) being chosen for further studies. Subsequently, T2 (Treatment 2; control, without coating) and T4 were evaluated through chemical (proximate composition), physical (breading yield, shear force, instrumental colour), microbiological, and sensorial analyses. Proximate composition differed only due to the carbohydrates present in the coating, resulting in a breading yield of 23.80% (T4). A higher shear force (24.83 N) was observed for T4. Both T2 and T4 had acceptance indexes greater than 70%, except for the colour attribute. The instrumental colour analysis revealed that the coating and frying processes affected the colour parameters a* and b*. Despite the purchase intention had been probably limited by the acceptance rate obtained for the attribute colour, 58% of panellists certainly or probably would purchase T4.