نوع مقاله : مقاله پژوهشی

نویسندگان

• مهنوش هاشمی ¹
• محمد سیاری ²
• مرتضی سلیمانی اقدم ³
• علی عزیزی ¹
• وحیده مهدوی ⁴

¹ گروه علوم باغبانی،دانشکده کشاورزی، دانشگاه بوعلی سینا، همدان، ایران

² گروه علوم باغبانی، دانشکده کشاورزی، دانشگاه بوعلی سینا، همدان، ایران.

³ گروه علوم باغبانی دانشکده کشاورزی، دانشگاه بین المللی امام خمینی، قزوین، ایران

⁴ بخش تحقیقات آفتکش ها، موسسه تحقیقات گیاهپزشکی کشور، سازمان تحقیقات،آموزش و ترویج کشاورزی،تهران، ایران

چکیده

کلیدواژه‌ها

• آنتوسیانین
• انبارمانی
• پوسیدگی
• سفتی
• فنل کل

موضوعات

• علوم میوه

عنوان مقاله [English]

The effect of staged ultraviolet C radiation on some qualitative parameters and antioxidant activity of strawberry fruits cv. Paros during storage period

نویسندگان [English]

• Mehnoosh Hashemi ¹
• Mohammad Sayyari ²
• Morteza Soleimani Aghdam ³
• Ali Azizi ¹
• Vahideh Mahdavi ⁴

کلیدواژه‌ها [English]

• Anthocyanin
• Decay
• Firmness
• Storage life
• Total phenol

Extended Abstract

Introduction

     Strawberry (Fragaria × ananassa) is widely consumed because of its outstanding organoleptic characteristics, bioactive compound, and antioxidant activity. However, its postharvest life is short due to some factors such as relatively high metabolic activity, sensitivity to fungal decay, and susceptibility to water loss. In addition, it is susceptible to mechanical injuries, resulted from its soft texture and lack of a protective rind. Ultraviolet-C radiation (UV-CR) is generally considered as a safe, effective, and economical method to maintain the postharvest’s quality of fruit and vegetables during cold storage and shelf life. The low-dose of UV-CR has been previously reported to be effective on delaying senescence, inducing resistance to pathogens, maintaining fruit flavor, and prolonging the length of time at which fruit can be qualitatively stored. The aim of this study was to investigate the effect of staged application of UV-CR on: 1) evaluating antioxidants’ activity, 2) controlling fruit’s decay, and 3) maintaining quality of strawberry’s fruit at a 14- day storage period. 

Materials and Methods   

    First, strawberry (Fragaria × ananassa cv. Paros) was harvested at a commercial ripeness time (the time at which 80% of the fruit surface turning into red), from an organic farm in Kurdistan Province and transported to the Horticultural Science Laboratory of Bu Ali Sina University. Afterwards, the fruit of same size and weight, without any defect, was selected and subjected to different applications of UV-CR treatments. The fruit, as control, didn't receive any light radiation. Fruit was then packed in a polyethylene box and stored at 4°C and 85–90% relative humidity for a 14-day storage period. The single stage of UV-CR (4kJ/m²) was applied at the beginning of the experiment, the double stage of UV-CR (2 kJ/m²) on 0 and fourth day of storage, and the multiple stages of UV-CR (1 kJ/m²) on 0, second, fourth, and sixth day of storage. The content of some bioactive compounds was measured on 0, seventh, and 14th day of storage. Furthermore, to evaluate precisely the effect of staged application of UV-CR on the qualitative characteristics and bioactive compounds of strawberry, the fruit was retained inside a morgue until the 14th day of the storage. The qualitative and phytochemical traits were measured on 0, seventh, and 14th day of storage. 

Results and Discussion   

    The results of this study showed that the multiple stages of UV-CR had the remarkable effect on maintaining the quality of strawberry at the end of the 14-day storage period, as compared to other UV-CR treatments. Furthermore, the multiple stages of UV-CR not only reduced fruitweight (55.17%) and decay (72.73%), but also maintained fruit firmness (148%) and titratable acidity (64%). Although no significant difference was found between UV-CR treatments in terms of fruit’s pH level toward the end of storage, the pH value of all treated fruit was higher than that in the control. Toward to the end of the storage period, the multiple stages of UV-CR remarkably increased the content of bioactive compounds. Moreover, the multiple stages of UV-CR also raised vitamin C (by 61.65%), total phenol (by 49.44%), and antioxidant activity (by 22.92%). The single stage of UV-CR also was effective on enhancing the content of specific phytochemicals. For example, on the 14th day of storage, it increased the total flavonoid (51%) and anthocyanin (111%). In conclusion, the multiple stages of UV-CR had the most effect on improving bioactive compounds and preserving the quality of strawberry fruit during storage. Additionally, the double stage of UV-CR acted better than single stage of UV-CR during this experiment.  

Conclusion

     Our results showed that the fruit treated with different stages of UV-CR had the highest titratable acidity, vitamin C, total phenol, and fruit firmness, but the lowest weight loss, total soluble solids, TSS/TA, and decay, as compared to the control. Taken together, our findings proved the efficiency of multiple stage of UV-CR on maintaining the quality of strawberry during storage. Moreover, considering the hormetic property of UV-C radiation during storage time, and its beneficial effects on horticultural products, multiple stage application of UV-C radiation throughout the storage period can amplify its effects. However, additional research is necessary to identify the molecular and enzymatic mechanisms that are involved in this process.