Gellan-based coatings incorporated with natural antimicrobials in fresh-cut strawberries: Microbiological and sensory evaluation through refrigerated storage

Abstract

Gellan (Gel) coatings (0.5% w/v) were tested on quality parameters of fresh-cut strawberries through storage. Geraniol (G) and Pomegranate extract (PE) were incorporated at different concentrations according to their solubility and stability on the film forming solutions: 1.2 and 2.4 μL/mL of G (Gel + G1 and Gel + G2, respectively), and 360 and 720 μg/mL of PE (Gel + PE1 and Gel + PE2, respectively). Fresh-cut strawberries were immersed in the different solutions and were stored (7 days, 5 °C) in order to assess the evolution of mesophilic bacteria (MES), yeast and molds (YM) and psychrophilic bacteria (PSY). Furthermore, at days 0 and 7, a sensory evaluation was performed. Gel coatings (without bioactive compounds) had no significant effect on native microflora compared to control. Gel + G coatings at both concentrations tested significantly reduced microbial counts, compared to untreated sample, improving the microbiological stability with respect to control. On the other hand, the incorporation of PE was not able to control the microbial growth of the product. With regards to sensory quality, the texture of the fresh-cut strawberries was significantly affected by storage time, and the tested treatments were not able to improve this attribute. In fact, samples with coatings incorporated with geraniol showed a bigger firmness loss than control.