Structural characteristics and physicochemical properties of freeze-dried snail meat

Snails although considered a delicacy in several parts of the world, still many people are reluctant in consuming them. Moreover, little is known about their meat protein properties, thus limiting their further exploitation in the food industry. In this work, a land snail meat material with increased protein content was prepared by removing mucus, ash, and lipids, through successive steps of extraction with suitable aqueous media. The final extraction residue was then freeze-dried to obtain a snail meat concentrate powder (SMC) and its structure was compared with those of the freeze-dried whole snail meat powder (SM) as well as with the freeze-dried intermediate snail meat powder preparation without the mucus (SM-WM), through confocal laser scanning and scanning electron microscopy. The preparation of SMC affected the physicochemical properties of the snail meat protein fraction. The SMC exhibited enhanced protein solubility and negative charge, and almost double values of water- and oil-binding capacity compared to the SM. The secondary protein structure as unveiled by Fourier Transform Infrared spectroscopy was dominated by p-structures in all samples. These findings would be useful for the potential technological exploitation of SMC enhanced solvent-binding properties in the preparation of complex and more attractive food formulas.