Preparation and Characterization of Licorice-Chitosan Coatings for Postharvest Treatment of Fresh Strawberries

Abstract

Several plant extracts are being investigated to produce edible coatings, mainly due to their antioxidant and antimicrobial activities. In this study, licorice root extracts were produced by ultrasound-assisted extraction and were combined with chitosan to elaborate edible coatings. Different solvents and temperatures were used in the extraction process, and the antioxidant and antimicrobial activity of the extracts were assessed. The most bioactive extracts were selected for the development of the edible coatings. The rheological properties of the coatings were studied, and they were applied on strawberry to evaluate their physicochemical and microbiological properties. The addition of licorice extract to chitosan resulted in positive effects on the rheological properties of the coatings: the incorporation of phytochemicals to chitosan decreased the shear stress and improved the restructuring ability of the coating solutions. The films presented a reduction of the Burger model parameter, indicating a reduction of rigidity. Furthermore, the strawberry coated with chitosan and licorice extract maintained good quality parameters during storage and showed the best microbiological preservation in comparison with controls. Hence, the use of chitosan with licorice extract is a potential strategy to produce edible coating for improving the postharvest quality of fruits.

Rheological and Microstructural Properties of Oil-in-Water Emulsion Gels Containing Natural Plant Extracts Stabilized with Carboxymethyl Cellulose/Mango (Mangiferaindica) Starch

“…Ultrasound-assisted extraction (UAE) was carried out following the procedure described by Lastra-Ripoll et al [23] and Quintana et al [7], using an ultrasonic bath with an operating frequency of 25 kHz and an input power of 200 W. The extractions were carried out for 30 min with a plant/ethanol ratio of 1:10 w/v, at 25 • C. The mixture was separated by filtration and dryed by rotary evaporation (IKA RV 8-V) to obtain mango peel extracts.…”

“…The development of food products with bioactive compounds represents an opportunity to improve the shelf life and health condition of the products [7,8]. Mango, and mainly its peel, is a rich source of phenolic compounds, such as gallotanins, gallic acid and mangiferin [9,10]; these compounds have been associated with solid antioxidant effects and benefits for therapeutic properties [11].…”

Bioactive compounds of mango (Mangifera indica): a review of extraction technologies and chemical constituents

“…2 These beneficial health effects are due to the presence of various bioactive compounds that are present in fruits and vegetables; [12][13][14] the presence of phenolic compounds in the human diet is associated with protective effects against some chronicdegenerative diseases related to oxidative stress, 15 with phenolic compounds and carotenoids showing antioxidant, antiatherogenic, anti-inflammatory, antiallergenic, and antimicrobial effects. [16][17][18][19] Therefore, the revalorization of the phenolic compounds from mango and their by-products represents a great challenge to obtain value-added products with health-promoting activities, improving the economic feasibility of the main process in a sustainable framework of the circular economy. Therefore, all these activities are of great interest to consumer health.…”

Rheological and Microstructural Properties of Xanthan Gum-Based Coating Solutions Enriched with Phenolic Mango (Mangifera indica) Peel Extracts

“…Various phenolic extracts have been reported in the literature, such as essential oils, ultrasound-assisted extracts, or supercritical phenolic-rich extracts, that are added into gumbased coating materials, which enhances the antioxidant and/ or antimicrobial activity in films and coatings. 7,8 Nevertheless, it is estimated that most of the compounds currently in development are prone to dissolution problems and can easily be degraded under high temperatures, low pH, light, and reactive oxygen species, 9 making their application in food products challenging. Moreover, their use is limited because they give flavor to food, contributing to negative organoleptic characteristics, 10 and they can change film properties, making it necessary to characterize the material to observe if both components presented synergistic or antagonistic properties of the films.…”