From waste to a new sustainable ingredient in the kitchen: Red king crab abdominal flap (Paralithodescamtschaticus)

Abstract

Paralithodes camtschaticus (red king crab) is an introduced species in the Barents Sea. Nowadays it is considered invasive, representing a potential threat to the ecosystems. In Norway, the red king crab catch has increased from 50 tons to 1906 tons from 2004 to 2011. As it is almost exclusively the legs of the red king crab that are commercially used, around 32% of the crab is discarded. This means 351 tons of waste during this eight-year period, an amount that will only increase in the next few years. Taking this environmental problem into consideration, the king crab abdominal flap, a common waste product in the king crab industry, has been used as an example to analyze the nutritional value and heavy metal content. The results show that the content of lead (<0.01 mg/kg), cadmium (0.0986 mg/kg) and mercury (0.0163 mg/kg) is below the concentrations established by EFSA (0.5 mg/kg). Also, the concentration of macronutrients was compared to standard king crab legs where the protein accounts for 14.6 g per 100g, fat for 0.5 g and carbohydrates for 0.6 g. Mineral compounds such as potassium, phosphorus, and sodium have been found in high concentrations in comparison to king crab leg samples. According to a sensory analysis, there are significant differences between the abdominal flap and leg, but the abdominal flap has been accepted by consumers averaging 6 points on the hedonic scale. In addition, male testers appreciated the flavor more than female testers in all the samples, but without any preferences between samples (variances were the same). Finally, when comparing cooking methods, pan searing has been concluded to be the best method to cook the abdominal flap, as it enhances the texture, aroma, and flavor, followed by cooking it sous-vide and pan seared and lastly just sous vide. The differences in flavor are due to the compounds generated during each process. Our culinary application study shows that this product is completely acceptable as a new ingredient, even for fine dining restaurants.