Development of a sensitivity-enhanced chlorophyll fluorescence lifetime spectroscopic method for nondestructive monitoring of fruit ripening and postharvest decay

• Published in: Postharvest biology and technology Vol. 198; p. 112231
• Main Authors: Ma, Te, Inagaki, Tetsuya, Tsuchikawa, Satoru
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2023
• Subjects: Climacteric and non-climacteric fruit; Fluorescence lifetime; Nondestructive method; Postharvest decay; Storage time; Time-resolved fluorescence spectroscopy; Climacteric and non-climacteric fruit; Storage time; Fluorescence lifetime; Nondestructive method; Time-resolved fluorescence spectroscopy; Postharvest decay
• ISSN: 0925-5214; 1873-2356
• DOI: 10.1016/j.postharvbio.2022.112231

Nondestructive monitoring of the environmental changes around fluorescent molecules in postharvest fruit is highly informative for monitoring their ripening and early decay process. In this study, a time-resolved laser-induced fluorescence (TRLIF) spectroscopic system, including a streak camera, spectrometer, and 403 nm picosecond-pulsed laser, was first developed. Then, representative pigments in photosynthesis (chlorophyll a, chlorophyll b, and carotenoids liquid samples) were initially measured and studied to determine whether the developed TRLIF spectroscopic system could produce the characteristics of chlorophyll fluorescence decay traces. Finally, the same approach was tested to monitor the ripening and early decay processes of each three samples of avocado and strawberry. The overall findings demonstrated that the fluorescence lifetime (FLT) of the fruit samples declined steadily during the shelf-life storage. For the avocados samples, the average FLT loss at the wavelength range of 706–749 nm decreased by approximately 23 % and 31 % at 1 and 2 d under shelf-life storage, respectively. For the strawberry samples, the average FLT loss at the wavelength range of 631–706 nm decreased by approximately 22 %, 46 %, 68 %, and 73 % at 0.5, 1, 1.5, and 2 d under the same shelf-life storage condition. This study indicates that the developed TRLIF spectroscopic method is potentially robust and accurate for assessing the ripening and early decay process of various climacteric and non-climacteric fruit. •A time-resolved fluorescence spectroscopic (TRFS) system was developed.•Fluorescence intensity and lifetime (FLT) can be deduced simultaneously.•TRFS data of chlorophylls, carotenoids, and their mixtures in liquid were compared.•Chlorophyll FLT was calculated using a multicomponent exponential decay model.•The chlorophyll FLT of avocado and strawberry decreased steadily during storage.