Effect of chitosan-based edible coating on antioxidants, antioxidant enzyme system, and postharvest fruit quality of strawberries (Fragaria x aranassa Duch.)

Abstract Background: Climate change in high-altitude areas causes tobacco (Nicotiana tabacum L.) in its mature period to be subjected to cold stress, which damages the yield and quality of tobacco leaves. We found that abrupt diurnal temperature difference (the daily temperature drops more than 20℃), along with rainfall occurred in the tobacco-growing areas at an altitude above 2450 m, which caused cold stress to tobacco in field. Results: The change process of the surface color of tobacco leaves was normal to dark green (within 1 to 2 d), to purple red (within 2 to 3 d), then dark red (within 3 to 4 d), and finally off-white (within 4 to 6 d), the final leaves appear obvious large areas browning, and the curing availability was extremely poor. Further research found the quality of fresh tobacco leaves, the content of key chemical components, and the quality of production are greatly reduced by cold stress. The reason was cold stress in high altitude environment destroyed the antioxidant enzyme system of mature flue-cured tobacco. Cold stress in high altitude environment destroyed the antioxidant enzyme system of mature flue-cured tobacco. The quality of fresh tobacco leaves, the content of key chemical components, and the quality of production are greatly reduced by cold stress.Conclusion: In conclusion, this study confirmed that the field cold stress in high-altitude tobacco areas was the main reason for the obvious browning tobacco leaves during the tobacco curing process. This adversity environment seriously damaged the quality of tobacco leaves.

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Effects of Polysaccharide-Based Edible Coatings on Quality and Antioxidant Enzyme System of Strawberry during Cold Storage

International Journal of Polymer Science ◽

10.1155/2017/9746174 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 9

Author(s):

Li Li ◽

Jian Sun ◽

Haiyan Gao ◽

Yingbin Shen ◽

Changbao Li ◽

...

Keyword(s):

Antioxidant Enzymes ◽

Antioxidant Enzyme ◽

Fruit Quality ◽

Cold Storage ◽

Enzyme System ◽

Total Phenolic ◽

Edible Coatings ◽

Strawberry Fruit ◽

Positive Effects ◽

Antioxidant Enzyme System

Strawberry is a nutritious, but highly perishable fruit. Three polysaccharide-based edible coatings (alginate, chitosan, and pullulan) were applied to postharvest strawberry fruit during cold storage (4°C), and their effects on fruit quality and antioxidant enzyme system were investigated in the present study. The results showed that polysaccharide coatings showed a significant delay in fruit softening and rot and reduced changes in total soluble solid and titratable acidity content during 16 d storage. Polysaccharide coatings also maintained higher ascorbic acid and total phenolic contents than control from day 2 and significantly inhibited fruit decay and respiration after 12 d storage (p<0.05). Polysaccharide treatments enhanced the activities of antioxidant enzymes (peroxidase, catalase, superoxide dismutase, and ascorbate peroxidase) so as to prevent lipid peroxidation and reduce membrane damage. Additionally, chitosan coating had the most positive effects on fruit quality amongst three polysaccharide-based edible coatings and presented the highest relative activities of antioxidant enzymes. These results indicated that polysaccharide-based edible coatings were helpful in postharvest quality maintenance of strawberry fruit.

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Changes in Antioxidative, Oxidoreductive and Detoxification Enzymes during Development of Aphids and Temperature Increase

Antioxidants ◽

10.3390/antiox10081181 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1181

Author(s):

Roma Durak ◽

Jan Dampc ◽

Monika Kula-Maximenko ◽

Mateusz Mołoń ◽

Tomasz Durak

Keyword(s):

Antioxidant Enzymes ◽

Enzymatic Activity ◽

Antioxidant Enzyme ◽

Temperature Increase ◽

Enzyme System ◽

Life Cycles ◽

Detoxification Enzymes ◽

Strong Positive Correlation ◽

Positive Correlation ◽

Antioxidant Enzyme System

Temperature, being the main factor that has an influence on insects, causes changes in their development, reproduction, winter survival, life cycles, migration timing, and population dynamics. The effects of stress caused by a temperature increase on insects may depend on many factors, such as the frequency, amplitude, duration of the stress, sex, or the developmental stage of the insect. The aim of the study was to determine the differences in the enzymatic activity of nymphs and adult aphids Aphis pomi, Macrosiphum rosae and Cinara cupressi, and changes in their response to a temperature increase from 20 to 28 °C. The activity of enzymatic markers (superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), β-glucosidase, polyphenol oxidase (PPO) and peroxidase (POD)) in aphid tissues was analysed for three constant temperatures. The results of our research showed that the enzymatic activity of aphids (measured as the activity of antioxidant, detoxifying and oxidoreductive enzymes) was mainly determined by the type of morph. We observed a strong positive correlation between the activity of the detoxifying and oxidoreductive enzymes and aphids’ development, and a negative correlation between the activity of the antioxidant enzymes and aphids’ development. Moreover, the study showed that an increase in temperature caused changes in enzyme activity (especially SOD, CAT and β-glucosidase), which was highest at 28 °C, in both nymphs and adults. Additionally, a strong positive correlation between metabolic activity (heat flow measured by microcalorimeter) and longevity was observed, which confirmed the relationship between these characteristics of aphids. The antioxidant enzyme system is more efficient in aphid nymphs, and during aphid development the activity of antioxidant enzymes decreases. The antioxidant enzyme system in aphids appears to deliver effective protection for nymphs and adults under stressful conditions, such as high temperatures.

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Increased Tolerance of Citrus (Citrus tangerina) Seedlings to Soil Water Deficit after Mycorrhizal Inoculation: Changes in Antioxidant Enzyme Defense System

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha4129218 ◽

2013 ◽

Vol 41 (2) ◽

pp. 524 ◽

Cited By ~ 5

Author(s):

Qiu-Dan NI ◽

Ying-Ning ZOU ◽

Qiang-Sheng WU ◽

Yong-Ming HUANG

Keyword(s):

Antioxidant Enzyme ◽

Soil Water ◽

Water Deficit ◽

Mycorrhizal Fungi ◽

Enzyme System ◽

Arbuscular Mycorrhizal ◽

Temporal Variations ◽

Soil Drying ◽

Soil Water Deficit ◽

Antioxidant Enzyme System

Arbuscular mycorrhizal fungi (AMF) can enhance tolerance of plants to soil water deficit, whereas morphological observations of reactive oxygen species and antioxidant enzyme system are poorly studied. The present study thereby evaluated temporal variations of the antioxidant enzyme system in citrus (Citrus tangerina) seedlings colonized by Glomus etunicatum and G. mosseae over a 12-day period of soil drying. Root colonization by G. etunicatum and G. mosseae decreased with soil drying days from 32.0 to 1.0% and 50.1 to 4.5% in 0-day to 12-day, respectively. Compared to the non-AM controls, the AMF colonized plants had significantly lower tissue (both leaves and roots) hydrogen peroxide (H2O2) and superoxide anion radical (O2â€¢â€“) concentrations during soil water deficit, whereas 1.03â€“1.92, 1.25â€“1.84 and 1.18â€“1.69 times higher enzyme activity in superoxide dismutase, peroxidase (POD) and catalase. In situ leaf H2O2 and root POD location also showed that AM seedlings had less leaf H2O2 but higher root POD accumulation. Furthermore, significantly higher root infection and antioxidant enzymatic activities in plants colonized with G. mosseae expressed than with G. etunicatum during the soil drying. These results demonstrated that the AMs could confer greater tolerance of citrus seedlings to soil water deficit through an enhancement in their antioxidant enzyme defence system whilst an decrease level in H2O2 and O2â€¢â€“.

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