CHITOSAN COATING APPLICATION TO DELAY ‘PISANG TONGKAT LANGIT’ (Musa troglodytarum L.) RIPENING PROCESS AND REDUCE THE EXPRESSION LEVEL OF ACS1

• Main Author: Novianti, Cindy
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/36429
• Institution: Institut Teknologi Bandung

Pisang Tongkat Langit (Musa troglodytarum L.) is a banana cultivars which is originated from Eastern Indonesia and has high ?-caroten content, hence it can be explored as a nutritional food. Being a climateric fruit, banana has a relatively fast ripening process which can affect its quality. Application of chitosan coating to delay fruit ripening process is a promising postharvest technology due to its non toxic property, biocompatibility, and biodegradability. Therefore, the aim of this study was to analyze the effect of chitosan coating on M. troglodytarum fruit ripening process, based on physicochemical analysis, and the expression profile of ACS1, a gene that code 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS) as a key enzyme to regulate ethylene biosynthesis. The M. trgolodytarum fruits were divided into three groups of treatment, i.e. control (uncoated fruits), 1% acetic acid-coated fruits, and 1.25% chitosan-coated fruits. The analysis was conducted on physical, chemical, and sensory quality, and also gene expression profile analysis of ACS1 using Quantitative Polymerase Chain Reaction (qPCR) method. Results showed that the application of chitosan coating on M. troglodytarum fruits could delay the ripening process up to two days, by delaying their peel and pulp color alteration, starch relative content, total soluble solids (TSS), and pulp to peel ratio until the third day of storage. However, the weight loss of chitosan-coated fruits were not significantly different from control and 1% acetic acid-coated fruits. Sensory quality analysis showed that chitosan-coated fruit had lower aroma and taste quality compared to control at the seventh day of storage, however the overall fruit acceptability could be maintained. Gene expression analysis showed that ACS1 expression level was lower on chitosancoated fruits than control on the first day of storage, then increased and made the expression level higher than the control fruits on the last day (the seventh day) of the storage. In conclusion, chitosan coating delayed ripening process and delayed the increase of ACS1 gene expression at the early stage of M. troglodytarum fruits ripening.