Haikou: Researchers have found that storing mangoes at 12 degrees Celsius can significantly extend the fruit's freshness while preventing cold damage, offering a potential breakthrough for mango transportation and storage systems.
According to United News of Bangladesh, a study by scientists from Hainan University revealed that mangoes stored at 12°C ripened more slowly, retained their firmness and flavor longer, and activated stronger natural antioxidant defenses compared to fruit stored at warmer temperatures. The findings, published in Tropical Plants, could reduce spoilage and improve cold-chain transport for tropical fruits.
Mangoes, appreciated worldwide for their sweet taste and nutritional value, are prone to quick spoilage after harvesting due to ongoing ripening during storage and transport. In many tropical regions, the standard transportation temperatures range from 26°C to 30°C. However, these warm conditions accelerate ripening and moisture loss, leading to faster deterioration.
While colder storage conditions are known to slow the ripening process, mangoes are sensitive to extremely low temperatures, which can cause chilling injuries. Prior research suggested that 12°C might be an effective storage temperature for 'Tainong No.1' mangoes, but the underlying reasons were not fully understood.
To delve deeper into this, scientists conducted a comparative study on mangoes stored at 12°C and 30°C over a 24-day period. They monitored factors such as fruit color, firmness, weight loss, sugar content, acidity, respiration rate, and levels of harmful molecules linked to cell damage.
The study revealed that mangoes stored at 12°C remained fresh for much longer than those kept at 30°C. By the 16th day, mangoes stored at warmer temperatures had turned yellow quickly, whereas those stored at 12°C retained their green color for a longer duration. Those kept at 30°C also experienced faster acidity loss and fluctuating sugar content, while mangoes stored at 12°C exhibited slower and steadier ripening.
Physically, the difference was stark. Mangoes stored at 30°C lost over 17% of their weight, while those at 12°C lost less than 4%. The cooler storage also helped maintain the fruit's firmness over longer periods.
Microscopic analysis indicated that mangoes stored at 12°C retained stronger cell walls and starch structures even after 24 days, unlike those at 30°C which showed early cell damage and collapse. Cooler temperatures also reduced oxidative stress by limiting the buildup of harmful molecules linked to spoilage. Furthermore, mangoes stored at 12°C maintained higher levels of vitamin C and other antioxidant compounds, with protective enzymes remaining active longer.
Gene analysis indicated increased activity in several antioxidant-related genes, bolstering the fruit's natural defense system and reducing cellular damage during storage.
Scientists believe these findings could offer practical guidance for the mango industry, enabling earlier harvesting, extended transportation distances, and ripening closer to consumer markets with minimized waste and quality loss. The research was supported by several Chinese agricultural and research programs, including the Hainan Province Agricultural Reclamation Team Joint Innovation Project and China's National Key Research and Development Programme.