Quality of postharvest strawberries: comparative effect of fungal chitosan gel, nanoparticles and gel enriched with edible nanoparticles coatings

Natália Ferrão Castelo Branco Melo,Margarida Angélica Da Silva Vasconcelos,Miguel Angel Pelágio Flores,Thatiana Montenegro Stamford–Arnaud,Tânia Lucia Montenegro Stamford,Viviane Lansky Xavier,Marcos Antônio Barbosa De Lima,Thayza Christina Montenegro Stamford,Maria Manuela Estevez Pintado,André Galembeck,José Alberto Da Costa Medeiros

doi:10.7455/ijfs/9.2.2020.a9

Natália Ferrão Castelo Branco Melo, Margarida Angélica Da Silva Vasconcelos + Show 9 more

Open Access

https://doi.org/10.7455/ijfs/9.2.2020.a9

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Abstract

This study compared, for the first time, the postharvest conservative action of edible fungal chitosan coatings (gel, nanoparticles and gel-nanoparticle) on the physico-chemical, sensorial and microbiological characteristics of strawberries. The nanoparticles were prepared by an ionic gelation method and characterized by dynamic light scattering and scanning electron microscopy. The antioxidant (DPPH* and ABTS*) activity of the edible coatings and the antimicrobial (macrodilution method) action against phytopathogenic fungi were verified. The nanoparticles had a size of 331.1 nm and a zeta potential of+ 34 mV. The gel, nanoparticles and gel+nanoparticles exhibited minimum inhibitory concentration values ranging from 4 to 5, 1.5 to 2.5 and 1.0 + 0.5 to 2.0 + 1.5 g.L-1, respectively. All the edible coatings exhibited antifungal action. All the coatings had high scavenging activity, especially the gel edible coating. The coatings, especially the gel+nanoparticles, decreased the weight loss, microbiological growth, soluble solids, maturity index and moisture loss of the strawberry and preserved the pH values, anthocyanin content, titratable acidity and sensory characteristics. Therefore, the use of chitosan edible coating containing nanoparticles can be a promising strategy to improve the post-harvest quality of strawberries.

Highlights

Strawberry (Fragaria × ananassa Duch.) is a non-climateric fruit cultivated worldwide and characterized by an attractive taste, flavour and important nutritional compounds
The particles produced in the present research exhibited an average size which contributed to the antifungal activity and to the ability of these particles to preserve the quality of postharvest fruit as an edible coating
The fungal chitosan nanoparticles (FCN) observed by scanning electron microscopy (SEM) exhibited a smaller size than the size of FCN analyzed by dynamic light scattering

Summary

Introduction

Strawberry (Fragaria × ananassa Duch.) is a non-climateric fruit cultivated worldwide and characterized by an attractive taste, flavour and important nutritional compounds. The application of edible coating has been considered as an alternative method to prevent fruit postharvest decay and to extend the storage life, while retaining the overall quality of different fresh commodities (Yousuf, Qadri, & Srivastava, 2018). Due to the interaction between nanoparticles and chitosan gel, the chitosan edible composite coatings are supposed to show enhanced antimicrobial activity and barrier properties to the internal gas atmosphere of the fruit, which gives better maintenance of the physicochemical and microbiological characteristics of fresh strawberry (Eshghi et al, 2014). The aim of this research was to compare, for the first time, the preservative action of three different fungal chitosan edible coatings (gel, nanoparticles and gel enriched with nanoparticles) on the quality of postharvest strawberries during storage time

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