Chitosan Coating to Preserve the Qualitative Traits and Improve Antioxidant System in Fresh Figs (Ficus carica L.)

Giuseppina Adiletta,Caterina Coletta,Milena Petriccione,Luigi Zampella

doi:10.3390/agriculture9040084

Abstract

Chitosan-based coatings are used as a postharvest treatment to extend the shelf-life of several fruits. In this study, the effectiveness of chitosan-based coating to preserve the physico-chemical (weight loss, soluble solid content, and titratable acidity) and nutraceutical traits (total polyphenol, anthocyanin, flavonoid, ascorbic acid content, antioxidant capacity) in fresh fig “Troiano” has been evaluated. Furthermore, antioxidant enzyme activities, such as catalase (CAT) and ascorbate peroxidase (APX), were evaluated as well as the enzymes activities involved in fruit browning (polyphenol oxidase (PPO), guaiacol peroxidase (GPX)). Fruits were treated with 1% chitosan and 1% ascorbic acid coating, stored at 4 °C for nine days, and sampled every three days. Chitosan-based coating significantly reduced the weight loss and the qualitative changes, improving the total polyphenol, anthocyanin, and flavonoid contents and the antioxidant activity in stored figs. The higher activity of antioxidant enzymes allowed to reduce oxidative stress and prevent the browning reactions in chitosan-coated figs. The principal component analysis allowed to distinguish different behaviors among uncoated and chitosan-coated figs, indicating that the combined effects of chitosan-based treatment and storage time influenced the physico-chemical, nutraceutical and antioxidant system of figs during storage.

Highlights

Fig (Ficus carica L.) belongs to the Moraceae family and it is one of the earliest cultivated fruit trees in the world, being the first domesticated one [1,2,3]
Our results are in agreement with previous studies that demonstrated that chitosan coating retarded fruit weight loss in different fruit crops, such as strawberry, sweet cherry, loquat, and plum [22,39]
Alginate-chitosan bilayer coating had a significant effect on the weight loss of fresh figs since weight loss for coated and uncoated figs reached up to

Summary

Introduction

Fig (Ficus carica L.) belongs to the Moraceae family and it is one of the earliest cultivated fruit trees in the world, being the first domesticated one [1,2,3]. The fig tree is cultivated in most warm and temperate Mediterranean climates with fifty percent of the world’s fig production concentrated in the Mediterranean area [4]. In the global world market, consumer demand increases for fresh figs but is stable for dried ones [6]. The short postharvest life of fresh fruits is a critical point for the marketability in respect to dried fruits. Most dried fruit producers must compete with lower production costs of other countries [7]

Methods

Results

Conclusion