Effects of different processing methods on the chlorophyll structure in kiwifruit

Area of Science:

• Food Science
• Analytical Chemistry
• Biochemistry

Background:

• Chlorophyll degradation impacts the visual appeal and nutritional value of processed fruit products.
• Understanding the structural transformations of pigments under processing conditions is crucial for maintaining product quality.
• Kiwifruit contains unique chlorophyll derivatives that may undergo specific changes during thermal and pressure treatments.

Purpose of the Study:

• To investigate the structural alterations of chlorophyll derivatives in kiwifruit puree subjected to varying temperature and pressure conditions.
• To identify and characterize the main pigment compounds formed after processing.
• To elucidate the degradation pathway of red chlorophyll catabolite (RCC) in kiwifruit.

Main Methods:

• Kiwifruit puree was processed using high and normal temperatures and pressures as independent variables.
• High Performance Liquid Chromatography (HPLC) was employed to separate and identify colored elution samples.
• High Resolution Mass Spectrometry (HRMS) and Nuclear Magnetic Resonance (NMR) were utilized for structural elucidation of the isolated compounds.

Main Results:

• Two distinct colored compounds were isolated and identified as hydroxymethylbilane (HMB) and red chlorophyll catabolite (RCC).
• HRMS and NMR analyses confirmed HMB and RCC as the predominant pigments following high temperature and pressure treatments.
• The study provides evidence for the cleavage pathway of RCC in kiwifruit puree.

Conclusions:

• High temperature and pressure treatments induce structural changes in kiwifruit chlorophyll derivatives, leading to the formation of HMB and RCC.
• HMB and RCC are key pigments resulting from chlorophyll degradation in processed kiwifruit.
• The identified RCC cleavage pathway offers a theoretical foundation for developing strategies to preserve the color of kiwifruit products during food processing.