Fructo-oligosaccharides in table grapes and response to storage

Area of Science:

• Plant physiology
• Food science
• Biochemistry

Background:

• Fructo-oligosaccharides (FOS) are known plant protectants against environmental stress.
• Individual FOS profiles in Cardinal table grapes were previously uncharacterized.

Purpose of the Study:

• To identify and quantify individual FOS in Cardinal table grapes.
• To investigate the impact of low temperature and high CO2 on FOS levels.

Main Methods:

• High-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) for FOS analysis.
• Measurement of glucose, fructose, and sucrose content.
• Storage of grapes at 0°C with and without 20% CO2 exposure.

Main Results:

• Five FOS were identified: 1-kestose, neokestose, nystose, nystose b, and kestopentaose.
• Low temperature storage (0°C) alone did not alter endogenous FOS levels.
• Exposure to 20% CO2 for 3 days significantly increased 1-kestose and kestopentaose (inulin series).

Conclusions:

• CO2 treatment induces accumulation of specific FOS in table grapes.
• This FOS increase may confer protection against cold storage-induced damage.
• Findings suggest a potential strategy for improving grape post-harvest quality and shelf-life.