Physical and chemical stability of Refractance Window®–dried mango (Philippine ‘Carabao’ var.) powder during storage

ABSTRACT

The effect of packaging atmosphere, storage temperature, and time on the physical and chemical stability of Refractance Window® (RW)-dried mango powder was evaluated over a period of 12 months. RW-dried mango powder with a moisture content of 0.037 ± 0.001 kg water/kg dry solids was stored at 5, 22 and 45°C for 12 months using air or nitrogen flush packaging. Headspace gas composition in the package, moisture content, color, ascorbic acid (AA), β-carotene, and microstructures of powder was measured at months 0, 6, and 12. The mango powder stored at 45°C suffered discoloration and ascorbic acid and β-carotene degradation after 6 and 12 months of storage in both air packaging and nitrogen flush packaging, while powder stored at 5 and 22°C had reduced nutrient degradation and preserved color of mango powder for both packaging conditions. Replacing the air inside the package with nitrogen was effective in preserving AA in mango powder stored at 22 and 5°C. Nitrogen flushing also reduced the percentage loss of β-carotene after 6 months, but no significant difference was found after 12 months. The microstructure of mango powder stored at 5 and 22°C was preserved after 6 and 12 months. Regardless of the packaging technique applied, the powder particles inside the package formed a single lump when stored at 45°C. The microstructures of mango powder at different storage conditions confirmed these results. Nitrogen flush packaging of mango powder is recommended to minimize degradation during long-term storage.

KEYWORDS:

• Air packaging
• ascorbic acid
• β-carotene
• glass transition temperature
• mango powder
• microstructure
• nitrogen flushing
• storage

Acknowledgments

We thank the Philippine Center for Postharvest Development and Mechanization (PhilMech) for granting study leave to the first author. We also thank Richard E. Magoon and Karin M. Bolland of MCD Technologies, Inc. for granting our request to use the RW drying facilities and for assisting with drying experiments; Mr. Clifton Oy of KSM Enterprises for supplying the packaging material; and Ms. Galina Mikhaylenko, Dr. Roopesh Syamaladevi, Scott Mattinson, and Dr. Valerie Lynch-Holm for assisting with various laboratory analyses.