Cryoprotective Potential of Cellulose Nanofibers and Gelatin Hydrolysate in Frozen Potatoes

In this study, the combined effect of gelatin hydrolysate (GH) and cellulose nanofibers (CNF) on the quality parameters of frozen potatoes with and without temperature fluctuation was evaluated. Potatoes were cut, blanched, impregnated with different concentrations of GH (0.08 to 4.32% w/w) and CNF (0.08 to 4.32% w/w) combined in a central composite rotational design and frozen with and without temperature fluctuation. Bleached samples without impregnation were used as controls. Electrophoresis and FTIR analyses indicated the presence of polypeptides in the gelatin hydrolysate, and electron microscopy indicated that cellulose nanofibers have nanometric diameters (20 to 90 nm); these characteristics influence the freezing of water. The solution containing 2.20% w/w GH and 2.20% w/w CNF showed a lower freezable water content by DSC analysis (92.49 ± 0.42%), indicating greater interaction of the compounds with water in this condition. When impregnated in potato cuts, this solution promoted lower losses of fluid (19.06 ± 0.51% and 28.71 ± 0.21%, respectively) and texture (23.30 ± 0.54% and 41.95 ± 0.55%, respectively) when subjected to storage without and with temperature fluctuations, thus delaying the recrystallization of the ice. Furthermore, smaller losses in the microstructure and color of the plant tissue were observed when using this treatment. A reduction in the freezing temperature of the impregnated samples was also observed (temperatures lower than the control − 0.615 °C). The results indicated that GH and CNF have effective cryopreservation potential.