Screening of antioxidants present in unripe Manilkara zapota fruit of Indian origin using LC-MS/MS

Importance of the topic

Natural antioxidants play a critical role in preventing oxidative damage in food, nutraceutical and pharmaceutical products by scavenging free radicals and slowing lipid peroxidation. Screening plant sources for potent antioxidants supports the development of healthier foods and supplements and contributes to quality control in industrial applications.

Objectives and Study Overview

This study aimed to screen and identify polyphenolic antioxidants present in unripe fruit of Manilkara zapota of Indian origin. Using advanced LC MS MS techniques, the work evaluated the fruit extract for known catechin derivatives and explored its potential as a novel antioxidant source.

Methodology and Instrumentation

Fruit pulp was extracted in methanol and water with heat treatment, followed by filtration. Extracts underwent centrifugation and solid phase extraction on C18 cartridges. Sequential elution steps with water, ethyl acetate, diethyl ether and isopropanol separated catechins and oligomeric proanthocyanidins. Dried fractions were reconstituted in HPLC grade water for analysis.

Instrumentation Used

LC MS MS analysis was performed on a Shimadzu LCMS 8030 triple quadrupole system with electrospray ionization in positive and negative modes. Desolvation line temperature was set to 250 C and heat block to 400 C. Nitrogen nebulizing and drying gas flows were 3 L per minute and 15 L per minute respectively.

Main Results and Discussion

Product ion scans confirmed the presence of key antioxidants including catechin, epicatechin, gallocatechin gallate, epigallocatechin gallate and epicatechin gallate. Observed m/z values matched literature data and characteristic fragment ions provided further confirmation. The study demonstrated a clear antioxidant profile in the unripe fruit extract.

Benefits and Practical Applications

Identification of multiple potent polyphenols in Manilkara zapota supports its use as a natural antioxidant additive in food preservation and as a nutraceutical ingredient. The developed LC MS MS method offers reliable screening for quality control in industrial settings.

Future Trends and Opportunities

Further work may include quantitative analysis, assessment of antioxidant capacity, exploration of other fruit maturation stages and scale up of extraction protocols. Integration with metabolomics could reveal additional bioactive compounds.

Conclusion

The study established an efficient extraction and LC MS MS screening method for polyphenolic antioxidants in unripe Manilkara zapota fruit and identified several catechin derivatives. These findings highlight the fruit as a promising new source of natural antioxidants for various industries.

Reference

1 Shui G Wong SP Leong LP Characterization of antioxidants and change of antioxidant levels during storage of Manilkara zapota J Agric Food Chem 2004 52 7834 7841
2 Giusti M Griffin D Wrolstad RE Electrospray and tandem mass spectroscopy as tools for anthocyanin characterization J Agric Food Chem 1999 47 4657 4664