نوع مقاله : مقالات پژوهشی
نویسندگان
1 گروه باغبانی، دانشکده کشاورزی، دانشگاه ارومیه،ارومیه،ایران
2 ندارد
چکیده
توت‌فرنگی میوه‌ای پرمصرف با ارزش تغذیه‌ای بالا می‌باشد که مصرف آن نقش مؤثری در کاهش بیماری‌های مزمن در انسان دارد. استفاده از محرک‌های سالم به‌منظور بهبود کیفیت و بازارپسندی این محصول می‌تواند در عین‌حال ارزش تغذیه‌ای این محصول را نیز بهبود ببخشد. تیمار پس از برداشت میوه‌های توت‌فرنگی با 24- اپی براسینولید در غلظت‌های 1 و 3 میکرومولار تأثیر مثبت در افزایش غلظت ترکیبات زیست فعال نظیر فنول کل به میزان 5/16 % و 5/19 %، فلاونوئید کل به میزان 5/5 % و 9 % و آنتوسیانین کل به میزان 12 % و 17 % در پایان دوره نگهداری (10 روز در دمای 1 ± 1 درجه سانتی‌گراد و سپس 24 ساعت در دمای اتاق) نسبت به شاهد داشت که این افزایش همبستگی مثبت و معنی‌داری با افزایش فعالیت آنتی‌اکسیدانی کل میوه‌های توت‌فرنگی نشان داد. فعالیت آنزیم‌های فنیل آلانین آمونیالیاز و تیروزین آمونیالیاز به‌عنوان آنزیم‌های مهم مسیر فنیل پروپانوئید در پاسخ به تیمار پس از برداشت 24- اپی براسینولید نیز افزایش پیدا کردند. 24- اپی براسینولید علاوه بر تأثیر مثبت در افزایش متابولیت‌های ثانویه و ترکیبات آنتی‌اکسیدانی که موجب بهبود ارزش تغذیه‌ای میوه توت فرنگی شد، همچنین بهبود خواص حسی و بازارپسندی محصول را نیز به‌همراه داشت. به‌طوریکه توت‌فرنگی‌های تیمار شده با 24- اپی براسینولید اسیدیته کم، مواد جامد محلول بیشتر، طعم و سفتی بهتری در مقایسه با نمونه شاهد داشتند. تأثیر مثبت 24- اپی براسینولید در افزایش میزان متابولیت‌های ثانویه با فعالیت آنتی‌اکسیدانی موجب شد که در پایان دوره نگهداری میوه‌های تیمار شده کیفیت، ماندگاری و بازارپسندی بهتری در مقایسه با میوه‌های شاهد داشته باشند.
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
Effect of 24-Epibrassinolide on nutritional value and marketability of strawberry fruit
نویسندگان [English]
- Mohammadreza Asghari 1
- Pari Zahedipour Sheshglani 2
- Safaa Mohammed Ali Kadhim Al-Janabi 2
1 Horticulture department, Agriculture faculty, Urmia University, Urmia, Iran
2 No
چکیده [English]
Introduction: Strawberry is a widely consumed fruit with high nutritional value, which the consumption plays an effective role in reducing human chronic diseases. Strawberry fruit is a source of secondary metabolites with antioxidant activity which influence nutritional value and quality attributes of this fruit. However, strawberry is a perishable fruit with a short shelf-life and high amount of this fruit is wasted during post-harvest periods which leads to economic, food and nutritional losses. In the last decade, the use of safe and natural elicitors in order to extend the shelf-life and improve the marketability of strawberry fruit has been increasing. Brassinosteroids (BRs) are plant growth regulators that modulate molecular, physiological, and biochemical responses in plant organs. Exogenous 24- Epibrassinolide (24-EBL) as a natural analog of BRs, has multiple effects on horticultural crops. Exogenous application of 24-EBL improves postharvest quality, antioxidant compounds and extends the shelf life of fruits and vegetables. Furthermore, 24-EBL has a significant effect on improving the sensory properties and marketability of stored crops. Therefore, this study was conducted to determine the effect of postharvest application of 24-EBL on bioactive compounds concentrations, antioxidant capacity and marketability of strawberry fruits.
Material and Methods: Strawberry fruits were harvested from a commercial greenhouse in the fully red color stage and immediately transferred to the laboratory. Healthy and uniform strawberries were selected and divided in three groups. Strawberry fruits were immersed in the 24-EBL solutions for 3 minutes. Strawberry fruits were dried completely at room condition and then were packed in polyethylene boxes (20×15×12 cm) and stored for 10 days at 1±1 °C. Control samples were treated with distilled water for same duration. After 10 d storage at low temperature, strawberry fruits were kept at room temperature for 24 hours to simulate the commercial situations, and then sampling was done to evaluate quality traits and marketability, biochemical compounds, phenylalanine ammonialyase and tyrosine ammonialyase enzymes activity and total antioxidant activity. In this study, the experiment was conducted completely randomized design with three replications.
Results and Discussion: Due to the high perishability and short shelf life of harvested strawberry fruits, it is necessary to investigate new methods. The use of safe and natural elicitors in order to improve the quality and marketability of the fruit may also result in an increase in the fruit nutritional value. The results showed that postharvest application of 24-EBL (1 and 3 µM) increased total phenolic content (16.5 % and 19.5 %), total flavonoids (5.5 % and 9 %) and total anthocyanins (12 % and 17 %) compared to control, respectively. Moreover, the activities of phenylalanine ammonialyase (PAL) and tyrosine ammonialyase (TAL), as important enzymes of the phenylpropanoid pathway increased in response to 24-EBL treatment. According to correlation coefficient analysis, there was a significant correlation among the phenolic compounds concentrations, PAL and TAL enzymes activity. Increaing the phenolic compounds, flavonoide and total anthocyanins content in response to 24-EBL treatment improved total antioxidant activity of strawberry fruits. Phenolics and flavonoids play important roles in increasing stress tolerance in crops and show a remarkably high scavenging activity toward reactive oxygen species. In addition to the positive effect of 24-EBL in enhancing secondary metabolites and antioxidant activity, which leads to improve the nutritional value of strawberry fruit, it also improved the sensory properties and marketability of the fruit. Treated berries with different concentrations of 24-EBL had lower titratable acidity, more total soluble solid, better taste and firmness compared to the control ones. These indices influenced the sensory properties and marketability of strawberries.These findings suggest that postharvest application of 24-EBL, especially at 3 μM, most effective to improve the postharvest quality and extend the shelf life of strawberry fruits. This research provided a new understanding regarding the impact of 24-EBL on increasing bioactive compounds and improving antioxidant activity of strawberry fruit and elucidated the effect of BRs on improving marketability of strawberry fruit.
Conclusion: The findings of this study indicate that postharvest application of 24- Epibrassinolide increse secondary metabolite content and nutritional value of stored strawberry fruits. Inceasing the secondary metabolite by antioxidant activity can also influence the sensory properties and marketability of strawberries. The mentioned results could be clear signs that 24- Epibrassinolide is a promising agent for extend the shelf life of strawberry fruits, as well as for improving their nutritional value.
کلیدواژه‌ها [English]
- Anthocyanins
- Correlation coefficient
- Marketability
- Phenylalanine ammonia-lyase
- Total antioxidant activity
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