Document Type : Research Article
Authors
1 Department of Horticultural Science-, College of Agriculture,- Jahrom University, PO BOX: 74135-111, Jahrom, Iran
2 Associate Professor, Department of Horticultural Science, Yasuj Branch, Islamic Azad University, Yasuj, Iran, respectively
3 Former student, Department of Horticultural Science, Yasuj Branch, Islamic Azad University, Yasuj, Iran, respectively
4 Department of Horticultural Science- College of Agriculture,- Jahrom University, PO BOX: 74135-111, Jahrom, Iran
Abstract
Extended Abstract
Introduction
The physalis (Physalis peruviana L.) is one of the most important members of the Solanaceae family. It is cultivated as a perennial in tropical regions and as an annual in temperate regions. The fruit is a round berry that can be consumed fresh, dried, or used in desserts and jams. Physalis fruits are rich in minerals, vitamins, and phytochemicals with anti-tumor and anti-inflammatory properties, making them a popular "superfood." Globally, there is increasing demand for this crop as a healthy and beneficial food, including in Iran, although detailed statistics on its cultivation in Iran are lacking. Physalis is a climacteric fruit with a very short postharvest life, typically lasting a maximum of 5 days. Therefore, there is a need for safe postharvest treatments to maintain high quality and extend its shelf life.
Materials and Methods
Fully orange-colored physalis fruits with completely yellow calyxes were harvested from a commercial greenhouse in Pasargad, Fars province. The fruits were quickly transported to the lab, visually evaluated, washed with deionized water, and air-dried. Melatonin solutions at concentrations of 100, 200, and 300 μM were prepared. Sixty fruits were dipped in each melatonin solution for 5 minutes, with distilled water used as the control. The treated fruits were then air-dried for 30 minutes, packaged in polyethylene bags with 3% perforation, and stored at 10 °C with 90 ± 5% relative humidity for 21 days. Evaluations were conducted weekly.
Results and Discussion
Overall, postharvest treatment with melatonin led to a reduction in respiration rate and polyphenol oxidase (PPO) activity in the juice, as well as an improvement or maintenance of skin carotenoid content, total soluble solids (TSS), titratable acidity (TA), ascorbic acid, total phenols, phenylalanine ammonia-lyase (PAL) enzyme activity, and total antioxidant activity in the juice. After 21 days of storage and at the end of the experiment, the assessment of all these attributes revealed that fruits treated with 300 μM melatonin were superior in terms of nutritional value, appearance, and postharvest oxidative stress response mechanisms compared to the other experimental groups. There was no significant difference in total soluble solids and titratable acidity among the fruits treated with different concentrations of melatonin; however, fruits treated with the two higher concentrations of melatonin showed the lowest respiration rate and the highest ascorbic acid content in the juice. Furthermore, fruits treated with 300 μM melatonin exhibited higher levels of total phenols, PAL enzyme activity, total antioxidant activity, and skin carotenoids compared to all other experimental groups, while also showing the lowest PPO enzyme activity.
Conclusion
Treating physalis fruits with exogenous melatonin, especially at concentration of 300 μM, can significantly enhance their postharvest quality and storability by modulating various physiological and biochemical processes. This approach has the potential to improve the marketability and economic value of harvested physalis as a high-value horticultural crop.
Extended Abstract
Introduction
The physalis (Physalis peruviana L.) is one of the most important members of the Solanaceae family. It is cultivated as a perennial in tropical regions and as an annual in temperate regions. The fruit is a round berry that can be consumed fresh, dried, or used in desserts and jams. Physalis fruits are rich in minerals, vitamins, and phytochemicals with anti-tumor and anti-inflammatory properties, making them a popular "superfood." Globally, there is increasing demand for this crop as a healthy and beneficial food, including in Iran, although detailed statistics on its cultivation in Iran are lacking. Physalis is a climacteric fruit with a very short postharvest life, typically lasting a maximum of 5 days. Therefore, there is a need for safe postharvest treatments to maintain high quality and extend its shelf life.
Materials and Methods
Fully orange-colored physalis fruits with completely yellow calyxes were harvested from a commercial greenhouse in Pasargad, Fars province. The fruits were quickly transported to the lab, visually evaluated, washed with deionized water, and air-dried. Melatonin solutions at concentrations of 100, 200, and 300 μM were prepared. Sixty fruits were dipped in each melatonin solution for 5 minutes, with distilled water used as the control. The treated fruits were then air-dried for 30 minutes, packaged in polyethylene bags with 3% perforation, and stored at 10 °C with 90 ± 5% relative humidity for 21 days. Evaluations were conducted weekly.
Results and Discussion
Overall, postharvest treatment with melatonin led to a reduction in respiration rate and polyphenol oxidase (PPO) activity in the juice, as well as an improvement or maintenance of skin carotenoid content, total soluble solids (TSS), titratable acidity (TA), ascorbic acid, total phenols, phenylalanine ammonia-lyase (PAL) enzyme activity, and total antioxidant activity in the juice. After 21 days of storage and at the end of the experiment, the assessment of all these attributes revealed that fruits treated with 300 μM melatonin were superior in terms of nutritional value, appearance, and postharvest oxidative stress response mechanisms compared to the other experimental groups. There was no significant difference in total soluble solids and titratable acidity among the fruits treated with different concentrations of melatonin; however, fruits treated with the two higher concentrations of melatonin showed the lowest respiration rate and the highest ascorbic acid content in the juice. Furthermore, fruits treated with 300 μM melatonin exhibited higher levels of total phenols, PAL enzyme activity, total antioxidant activity, and skin carotenoids compared to all other experimental groups, while also showing the lowest PPO enzyme activity.
Conclusion
Treating physalis fruits with exogenous melatonin, especially at concentration of 300 μM, can significantly enhance their postharvest quality and storability by modulating various physiological and biochemical processes. This approach has the potential to improve the marketability and economic value of harvested physalis as a high-value horticultural crop.
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