Chitosan–citric acid edible coating to control Colletotrichum gloeosporioides and maintain quality parameters of fresh-cut guava

• Published in: International journal of biological macromolecules 2020-11, Vol.163, p.1127-1135
• Main Authors: Nascimento, Julia Idalice Gois, Stamford, Thayza Christina Montenegro, Melo, Natalia Ferrão Castelo Branco, Nunes, Ihasmyn dos Santos, Lima, Marcos Antônio Barbosa, Pintado, Maria Manuela Estevez, Stamford-Arnaud, Thatiana Montenegro, Stamford, Newton Pereira, Stamford, Tânia Lúcia Montenegro
• Format: Article
• Language: English
• Subjects: Anthracnose; Biocompatible Materials - chemistry; Biocompatible Materials - pharmacology; Biopolymer; Chitosan - chemistry; Citric Acid - chemistry; Coated Materials, Biocompatible - chemistry; Colletotrichum - drug effects; Colletotrichum - ultrastructure; Food Preservation; Food Quality; Fruit; Magnetic Resonance Spectroscopy; Minimally processed fruit; Psidium; Sensory attributes; Spores, Fungal - drug effects; Spores, Fungal - ultrastructure
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2020.07.067

This study aimed to verify the action of edible chitosan–citric acid (CHI–CA) coating to control Colletotrichum gloeosporioides and maintain quality parameters of fresh-cut guava. Chitosan was obtained from Litopenaeus vannamei shells using high temperature and short exposure times. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of CHI–CA against C. gloeosporioides were determined by macrodilutions at 28 °C/120 h in the absence/presence of CHI–CA (0–10 mg/mL). Scanning electron microscopy was used to evaluate morphological changes in the fungus. Guava slices were coated with CHI–CA (MIC) or 5 mg/mL glycerol (control). Rot incidence and physicochemical, physical, and microbiological factors were determined at 0, 3, 7, and 14 days at 24 °C and 4 °C. Chitosan presented typical structural characterization, 64% deacetylation, and a molecular weight of 1.6 × 104 g/mol. CHI–CA exhibited MIC and MFC values of 5 mg/mL and 10 mg/mL, respectively, and promoted changes in the morphology and cell surface of fungal spores. The fresh-cut guava coated with CHI–CA maintained quality parameters during storage and preserved their sensorial characteristics. Therefore, the use of CHI–CA as a coating is a promising strategy for improving postharvest quality of fresh-cut fruits. •Chitosan obtained (L. vannamei) for new method: high temperatures/very short times•Low molecular weight chitosan formed gel in 1% citric acid•Chitosan-citric acid promoted changes in the ultrastructure of C. gloeosporioides•Chitosan-citric acid coating improved the quality of fresh-cut guava along storage.•Chitosan-citric acid did not affect the sensory attributes of the fresh-cut guava.