Postharvest Biology and Technology
Samane Mollaei; Seyed Hossein Mirdehghan; Mahdi Shariat; Fatemeh Nazoori
Abstract
Purpose: This study evaluated the effects of cold plasma (CP) treatment using argon (Ar), nitrogen (N₂), and oxygen (O₂) gases at two voltages (5 and 8 kV) on the postharvest quality and shelf life of fresh in-hull pistachio (Pistacia vera L.) during cold storage. Research Method: Treatments were ...
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Purpose: This study evaluated the effects of cold plasma (CP) treatment using argon (Ar), nitrogen (N₂), and oxygen (O₂) gases at two voltages (5 and 8 kV) on the postharvest quality and shelf life of fresh in-hull pistachio (Pistacia vera L.) during cold storage. Research Method: Treatments were applied, and the samples were stored at 4°C for 25 and 50 days. Key parameters, including decay index (DI), water activity, total phenolic content (TPC), total flavonoid content (TFC), total chlorophyll content, electrolyte leakage (EL), and sensory attributes, were assessed. Findings: Decay index (DI) measurements demonstrated that CP treatments significantly inhibited microbial spoilage, and argon-CP reduced decay by up to 40% compared to untreated controls. Water activity declined from 0.957 in the controls to as low as 0.952 in the argon-treated samples, indicating reduced free water available for microbial growth. Biochemical analyses revealed that total phenolic content (TPC) increased the most under nitrogen-CP (0.485 mg GAE/100 g at 50 days vs. 0.350 mg in controls). Total chlorophyll content was highest in N₂-treated pistachios (2.96 g kg⁻¹), and electrolyte leakage (EL), an indicator of membrane integrity, was lowest in argon-CP samples (74.82% vs. 88.67% in controls), reflecting reduced cellular damage. Sensory analysis confirmed that CP-treated samples, particularly those treated with Ar, improved texture, taste, color, and aroma. Research limitations: This study was limited to laboratory-scale conditions and storage durations. Originality/Value: This research provides new insights into non-thermal postharvest preservation of pistachios and highlights cold plasma, particularly Ar-treatment, as a practical, chemical-free method to enhance quality and extend shelf life.
Plant Physiology
Mozhdeh Yousefi; Seyed Hossein Mirdehghan; Majid Esmaeilizadeh; Fatemeh Nazoori; Seyyed Rasoul Sahhafi
Abstract
Purpose: The pistachio nut is an important product primarily traded as dry nut in-shell kernels. Any damage to the shell during growth and development can cause shell staining and kernel decay in pistachios, rendering them unsuitable for sale. This study aimed to mitigate these issues by evaluating the ...
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Purpose: The pistachio nut is an important product primarily traded as dry nut in-shell kernels. Any damage to the shell during growth and development can cause shell staining and kernel decay in pistachios, rendering them unsuitable for sale. This study aimed to mitigate these issues by evaluating the effects of various calcium nitrate solutions. Research method: Fruit samples from two pistachio cultivars, 'Akbari' and 'Kaleh-Ghoochi,' were collected from 18-year-old trees with moderate tree vigor in a commercial orchard. The calcium nitrate solutions included a control sample (distilled water), 0.4% calcium nitrate, and 0.2% calcium nitrate enriched with lecithin, foliar applied two weeks after full bloom. Findings: Calcium nitrate treatments, both alone and enriched with lecithin, significantly reduced physiological disorders such as endocarp lesions and fruit abscission. In 'Akbari,' calcium nitrate treatments reduced issues such as nut ounce, shell staining, deformed nuts, blank nuts, endocarp lesions, early-split nuts, hull decay, and hull cracking. In contrast, Kaleh-Ghoochi also benefited from reduced occurrences of deformed nuts, early-split nuts, hull decay, and hull cracking. However, when treated with calcium nitrate enriched with lecithin, there was a notable reduction in blank nuts in Kaleh-Ghoochi, whereas calcium nitrate alone led to an increase in blank nuts. These calcium nitrate treatments resulted in positive outcomes and reduced fruit defects, thereby enhancing the overall quality and marketability of pistachios. Notably, the combination of calcium nitrate and lecithin had a more pronounced impact on Akbari, improving the pistachio nut's hull appearance, firmness, and reducing water activity. Research limitations: There were no limitations. Originality/Value: These findings suggest that calcium plays a significant role in enhancing the yield, quality, and marketability of pistachio fruit, providing practical insights for farmers aiming to improve their pistachio production practices.
