Enzymatically crosslinked gelatin coating added of bioactive nanoparticles and antifungal agent: Effect on the quality of Benitaka grapes

Abstract

Edible coatings have been studied as an alternative to incorporate bioactive substances on foodstuff surface. In this work, gelatin hydrogels were obtained by enzymatic crosslinking using transglutaminase (TGase) and added with curcumin-loaded zein nanoparticles or calcium propionate. The coatings were applied to Benitaka grapes and analyzed during 7 days of storage at 25 °C and 50% relative humidity. First, curcumin-loaded nanoparticles where characterized presenting spherical morphology with large size distribution and average diameter of 585 nm. Curcumin encapsulation was confirmed by FTIR and DSC results. Rheology analyses showed that TGase action increased the pseudoplastic behavior of the gelatin hydrogels with increasing temperatures which was confirmed by fitting the experimental curves to the Power Law model. When applied to Benitaka grapes the edible coatings did not contribute to an increase in microorganisms growth after 7 days of storage and did not altered titratable acidity. A better control of fruit ripening was obtained with the hydrogel added of calcium propionate. Overall results of texture profile analysis demonstrated that the presence of the edible coating did not affect the texture properties of the grape and color intensity of the grapes increased when curcumin-loaded nanoparticles were applied to the coating.