Preservation of Xinyu Tangerines with an Edible Coating Using Ficus hirta Vahl. Fruits Extract-Incorporated Chitosan

Abstract

Xinyu tangerine is a citrus fruit that has enjoyed great popularity in China for its fewer dregs and abundant nutrients. However, it is considered an easily perishable fruit that is vulnerable to various pathogenic fungal infections, especially by Penicillium italicum, which reduces its storage life and commercial value. Normally, to reduce the losses caused by fungal deterioration of harvested fruit, polysaccharide-based edible coating, containing natural antimicrobial agents (e.g. plant extracts), have been applied. In current study, we evaluated the effects of Ficus hirta Vahl. fruits extract (FFE)–incorporated chitosan (CS) edible coating on Xinyu tangerines during cold storage at 5 °C. The results showed FFE has efficacy as an antifungal against P. italicum in a dose-dependent manner in vivo, with an EC50 value of 12.543 mg·mL−1. It was found that the edible coating of FFE–CS exhibited a higher reduction of total soluble solid (TSS), titrable acid (TA), and ascorbic acid (AsA) content by reducing the fruit decay rate, weight loss, respiration rate, and malondialdehyde (MDA) content during cold storage at 5 °C. Moreover, the activities of protective enzyme such as superoxide dismutase (SOD), peroxidase (POD), and phenylalanine ammonia-lyase (PAL), which have been linked with reactive oxygen species (ROS) and the phenylpropanoid pathway, were higher in the FFE–CS-coated fruits. On the basis of these study results, the FFE–CS edible coating could reduce postharvest loss and enhance the storability of Xinyu tangerines due to the in vivo antifungal activity of FFE.

Antioxidant, Antifungal Activities of Ethnobotanical Ficus hirta Vahl. and Analysis of Main Constituents by HPLC-MS

“…The MICs of six HFF extracts on the mycelial growth of the tested fungal strains were determined using the agar dilution method described previously [21]. Different concentrations of HFF extracts were mixed with PDA in a proportion of 1:9 for obtaining the final concentrations of 0, 62.5, 125, 250, 500, 1000, and 2000 µg/mL.…”

“…The healthy fruits having a consistent size (240-280 g), uniform color (citrus color index, 4.8-6.0), and free of bruises or disease were chosen as experimental material. The in vivo antifungal efficacy of HFF extracts to control citrus blue mold (P. italicum) was carried out according to our previous study [21]. All selected fruits were dipped in 1.0% (v/v) sodium hypochlorite solution for 1 min, washed with running tap H 2 O to remove the residual disinfectant, and air-dried on a sterilized bench top before wounding.…”

Recent Applications of Chitin- and Chitosan-Based Polymers in Plants

“…Reduction postharvest loss and enhancement of fruits storability [43] Fragaria × ananassa Duch. CHT + photoactivated chlorophyllin Extension of fruit shelf life and inhibition of pathogens growth [44] Zizyphus jujuba Mill.…”

“…Coating with Ficus hirta Vahl. fruits extract-incorporated CHT reduced postharvest loss and enhanced the storability of Xinyu tangerines during cold storage by antimicrobial activity [43]. Coating with a photoactivated chlorophyllin-CHT conjugate diminished microbial contamination thus prolonging the shelf life of strawberries without any negative impact on commodities aspect and quality [44].…”

Vegetable Additives in Food Packaging Polymeric Materials

“…The low antioxidant ability of chitosan [182] is usually improved by mixing chitosan with high antioxidant natural extracts (for example, tomato plant extract [183,184], leaf and seed extracts of Pistacia terebinthus [185], Ficus hirta fruits extract [186], flax seed mucilage extract [187], and Laurus nobilis extract [188]). Alginate and chitosan coatings containing olive leave extract were also found to improve the TP content and antioxidant activity of Sweet Cherries (Prunus avium L.).…”