Postharvest physiology
L. Taghipour; P. Hayati; M. Hosseinifarahi; P. Assar
Abstract
Introduction
Physalis (Physalis peruviana L.), commonly known as Cape gooseberry or ground cherry, is a valuable member of the Solanaceae family. It is cultivated as a perennial crop in tropical regions and as an annual in temperate climates. The fruit is a spherical berry that can be consumed fresh, ...
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Introduction
Physalis (Physalis peruviana L.), commonly known as Cape gooseberry or ground cherry, is a valuable member of the Solanaceae family. It is cultivated as a perennial crop in tropical regions and as an annual in temperate climates. The fruit is a spherical berry that can be consumed fresh, dried, or processed into jams and desserts. Physalis fruits are rich in minerals, vitamins, and phytochemicals known for their anti-tumor and anti-inflammatory properties, contributing to their reputation as a "superfood." Globally, demand for this crop is increasing due to its health benefits, including in Iran, although comprehensive data on its cultivation within the country remains limited. As a climacteric fruit, Physalis has a very short postharvest shelf life—typically no more than five days—highlighting the need for safe and effective postharvest treatments to preserve quality and extend its marketability. To improve the storability and maintain the postharvest quality of physalis, researchers are exploring natural and safe treatment options. One such promising compound is melatonin, a pleiotropic molecule derived from tryptophan and endogenously synthesized in plant, animal, fungal, and prokaryotic cells. In plants, melatonin functions as a regulatory agent involved in numerous physiological processes, particularly in response to stress. It interacts with plant hormones and reactive species like hydrogen peroxide (H₂O₂), nitric oxide (NO), and hydrogen sulfide (H₂S), contributing to improved antioxidant activity, delayed senescence, and better stress tolerance. Thus, melatonin represents a promising and eco-friendly strategy to improve the shelf life, sensory quality, and marketability of physalis fruit. The aim of the present study was to improve the shelf life and postharvest quality of physalis fruits through melatonin treatment for distribution in local markets.
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. The experimental design was a factorial arrangement based on a completely randomized design (CRD), consisting of 12 treatments with three replicates per treatment (20 fruits per replicate). The experimental factors included fruit immersion in four levels of melatonin solution concentration (100, 200, and 300 µM, with distilled water as the control) and sampling time at three levels (7, 14, and 21 days of storage). Following the preparation of melatonin solutions at different concentrations, sixty fruits were immersed in each solution for five minutes. The treated fruits were air-dried for 30 minutes, then packaged in polyethylene bags with 3% perforation and stored at 10 °C under 90 ± 5% relative humidity for 21 days. Assessments were carried out at weekly intervals.
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.
Conclusions
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.
Postharvest physiology
P. Hayati; S. M. Hosseinifarahi; Gh. Abdi; M. Radi; L. Taghipour; P. Assar
Abstract
IntroductionThe Peruvian Groundcherry (Physalis peruviana L.) is a perennial plant that is native to the South American regions and belongs to the Solanaceae family. The harvested fruits are vulnerable to both biotic and abiotic stresses, which can trigger unfavorable physiological and biochemical changes. ...
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IntroductionThe Peruvian Groundcherry (Physalis peruviana L.) is a perennial plant that is native to the South American regions and belongs to the Solanaceae family. The harvested fruits are vulnerable to both biotic and abiotic stresses, which can trigger unfavorable physiological and biochemical changes. As a result, the quality and marketability of the product may decrease by the time it reaches the consumer. The fruit of the Peruvian Groundcherry has a high water content and is sensitive to ethylene, causing rapid ripening with a high respiration rate, making it highly perishable. To ensure quality maintenance after harvest, various postharvest treatments are being studied; however, some methods may not be practical due to low customer preference or lack of effectiveness verification. Therefore, alternative treatments need to be found to prolong shelf life and reduce postharvest losses. Currently, environmentally friendly technologies and treatments are recommended. The aim of this study was to investigate the effects of γ-Aminobutyric acid (GABA) postharvest treatment on the respiration rate, antioxidant activities, and fruit quality of the Peruvian Groundcherry during 21 days of storage, addressing a research gap in this area.Materials and MethodsHandpicked Peruvian Groundcherry fruits were taken from a commercial greenhouse located in Fars province, Iran. The fruits were picked at two stages of maturity based on their color, which was either yellowish green or orange. Following the harvest, the fruits were taken to a horticulture laboratory where they were assessed for appearance, size, color, and any damages. The experimental design was factorial based on a completely randomized design with three replications, each containing 25 fruits. Experimental factors included the GABA concentration (0, 5, 10 and 15 mM), storage time (7, 14 and 21 days) and fruit maturity stage based on color at harvest (yellowish green and orange). Following dip treatments in GABA solutions, fruits were packed in plastic clamshells measuring 20×5×10 cm3 and with a hole ratio of 3%. Fruits were stored at a temperature of 15 ◦C for 21 days, and their quality characteristics and respiration rate were evaluated on a weekly basis.Results and DiscussionThe findings indicated that both groups of treated fruits had a slower increase in respiration rate and lower final respiration rate compared to the control group. The effect of different concentrations of GABA on the final respiration rate of fruits was similar for each stage of fruit maturity. During the storage period, the changes in total soluble solids and total acids of the treated fruits were less than the control group. At the end of the storage period, yellowish green fruits treated with 10 and 15 mM GABA had the lowest amount of total soluble solids; orange fruits had the lowest amount with 15 mM GABA treatment. GABA concentrations had a similar effect on total acids retention of yellowish green fruits, but 15 mM GABA treatment was more effective for orange fruits. Ascorbic acid content and phenylalanine ammonia-lyase enzyme activity were consistently higher in treated fruits than in the control group. In green fruits treated with GABA concentrations, the amount of ascorbic acid increased significantly and continuously, with no significant difference between treatments at the end of storage period. Orange fruits showed a significant increase until the second week of storage, followed by a non-significant decrease. Higher amounts of ascorbic acid in orange fruits were detected by applying higher GABA concentrations. Both groups of fruits had significantly higher amounts of total phenol, carotenoid, and antioxidant capacity in response to increasing GABA concentration, while the minimum amount of these compounds during the storage period was related to the control group. However, orange-colored fruits were more sensitive to treatments compared to yellowish green fruits.ConclusionsThe results of the present study indicate a positive effect of postharvest GABA treatment on reducing respiration rate, improving antioxidant activities, and maintaining the quality and nutritional value of Peruvian groundcherry fruit during a 21-day storage period. Considering the global preference and demand among governments and consumers to use environmentally-friendly treatments of biological origin that pose no risk to human health, we recommend the use of GABA treatment for optimal storage of Peruvian groundcherry fruit. Finally, it is recommended to assess the efficacy of GABA or other safe and environmentally-friendly postharvest treatments on the quality and shelf life of other valuable horticultural commodities.
Leila Taghipour; Majid Rahemi
Abstract
Abstract
To evaluate the effects of some chemical agents on fruit thinning percent and fruit quality of apricot cv ‘Khiary’ an experiment were carried out in the commercial orchard at Neyriz, Fars province, Iran. Naphthaleneacetic acid (NAA)( 10, 20 and 40 mg l-1 ), naphthaleneacetamide (NAD) ( ...
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Abstract
To evaluate the effects of some chemical agents on fruit thinning percent and fruit quality of apricot cv ‘Khiary’ an experiment were carried out in the commercial orchard at Neyriz, Fars province, Iran. Naphthaleneacetic acid (NAA)( 10, 20 and 40 mg l-1 ), naphthaleneacetamide (NAD) ( 20, 40 and 80 mg l-1 ), ethephon ( 50, 100 and 200 mg l-1 ) and urea( 0.2, 0.4 and 0.6%) were sprayed on selected branch units 2 weeks after full bloom (AFB) in 2006. Results showed that all treatments except urea at 0.6% significantly increased fruit drop in comparison with control (P=0.05). Chemical agents increased fruit volume, length, diameter, total soluble solids (TSS), Tss/total acid ratio, nut weight and flesh/nut ratio. Between control and other treatments had no significant effect on total acidity (TA) of fruits.
Key words: Ethephon, Naphthaleneacetic acid (NAA), Naphthaleneacetamide (NAD), Urea
