Application of Pullulan and Chitosan Multilayer Coatings in Fresh Papayas

Linyun Zhang,Chongxing Huang,Hui Zhao

doi:10.3390/coatings9110745

Abstract

In this work, some multilayer coatings (two-layer, four-layer or six-layer) based on pullulan and chitosan for protecting papayas were prepared by the layer-by-layer technique. The papayas were coated by immersion and stored at 25 °C, 50% relative humidity or up to 14 days. Uncoated and monolayer-coated papayas were used as controls. The pullulan/chitosan coatings decreased the papaya weight loss, softening, color change (b*, ΔE), and pH, retarded the fall of titratable acidity and vitamin C, and maintained respiratory rate and soluble solid contents. Sensory quality evaluation demonstrated that pullulan/chitosan coatings effectively preserved papaya flavor and overall acceptance. In general, the four-layer coatings provided the best fruit preservation. In conclusion, multilayer pullulan/chitosan coatings are efficient in maintaining the post-harvest quality and prolonging the shelf life of fresh papaya.

Highlights

Papaya is a rich resource of many active components with nutritional value such as vitamin C, carotene, and protease [1]
The results showed that chitosan/pectin coating reduced the losses of vitamin C and total carotenoid content, and extended the shelf life of fresh-cut papaya stored at 4 ◦ C for up to 15 d
Pullulan/chitosan multilayer coatings maintained the physiological and nutritional attributes of papayas stored at 25 ◦ C and 50% relative humidity (RH), and extended the fruit shelf life if compared with uncoated and single-coated fruits

Summary

Introduction

Papaya is a rich resource of many active components with nutritional value such as vitamin C, carotene, and protease [1]. The papain found in papaya can be used to treat gastritis and indigestion, improve the nutritional value and functional properties of protein, and to produce shampoo, toothpaste, and beverages. Papayas have high medicinal and industrial value [2]. Papayas are susceptible to fungal infections, such as anthracnose and stem-end rot, which are the major causes of papaya decay [3]. Papayas ripen at room temperature after harvest and quickly enter the senescence stage, with browning of the skin accompanied by dark spots and soft flesh [3]. The development of an environmental and low-cost method for papaya preservation is necessary

Objectives

Methods

Results

Conclusion