اثر پاكت گذاري بر ارزش تغذيه اي، كلسيم (Ca) ، پتاسيم (K) آهن (Fe) و كيفيت ميوه انار رقم شيشه كب

Effect of pre-harvest bagging on the calcium, potassium, Iron contents and quality of pomegranate fruit cv. Shishe-Kab

جهت بررسي تاثير پاكت گذاري قبل از برداشت بر ميزان برخي عناصر معدني و همچنين انبارماني ميوه انار رقم شيشه كب آزمايشي در سال ‌1394 در دانشكده كشاورزي بيرجند و در قالب طرح بلوك كامل تصادفي با سه تيمار و چهار تكرار انجام شد. ارزيابي‌هاي شيميايي و عناصر معدني آريل و پوست ميوه پس از 10 هفته نگهداري در انبار سرد انجام شدند. پاكت گذاري اثر معني‌داري بر برخي شاخص‌هاي رنگ پوست داشت. بيشترين ميزان روشنايي رنگ (45/2)، زردي (19/3) و هيو (24/7) در ميوه‌هاي پوشانده شده با پاكت قهوه‌اي مشاهده شد. پاكت گذاري موجب كاهش ميزان آنتوسيانين شد، بيشترين ميزان در شاهد (16/7 ميلي گرم بر ليتر) و كمترين در پاكت قهوه اي روشن (4/04 ميلي گرم بر ليتر) مشاهده شد. پاكت گذاري ميوه با پاكت سفيد موجب افزايش حدود 68 درصد در ميزان پتاسيم پوست نسبت به شاهد شد. جالب اينكه پاكت سفيد همچنين موجب افزايش 23 درصدي در مقادير كلسيم پوست و 45 درصدي در آريل انار نسبت به شاهد شد. پاكت گذاري بر رنگ آريل، شاخص سرمازدگي، ميزان آهن پوست، آريل ميوه، ميزان فعاليت آنتي اكسيداني، اسيديته قابل تيتر و مواد جامد محلول اثر معني‌داري نداشت. بطور كلي، ميوه هاي پوشانده شده با پاكت سفيد در خصوصيات رنگ پوست بهتر از پاكت قهوه‌اي عمل كرد، بعلاوه با افزايش ميزان پتاسيم و كلسيم پوست ميوه نه تنها موجب بهبود ارزش تغذيه‌اي پوست شد بلكه احتمال افزايش دوره انبار سرد ميوه را به همراه خواهد شد.

Introduction: Pomegranate is a sub-tropical fruit which is sensitive to chilling injury during cold storage. Fruit elements play an important role in stress resistance. Among them, potassium is an important element which is involved in plant respiration and increases plant resistance to drought stress, pests and diseases, and chilling injury. Bagging is a simple and physical technique commonly used in the garden during fruit growth and may affect fruit composition. Some of the benefits of bagging such as reducing physical damage can be expected. In addition, this may have different effects on the quality of the red color of the fruit by reducing radiation. and increase the shelf life through reduction the physiological disorders. It is likely that pre-harvest bagging reducing the amount of calcium in the fruit. Therefore, the present study was conducted to investigate the effect of pre-harvest fruit bagging on the storage life and some of the important mineral elements of pomegranate fruit. Materials and Methods: The experiment was conducted on the Shishe-kab pomegranate cultivar at the Faculty of Agriculture, the University of Birjand during 2015. A randomized complete block design carried out with three treatments and four replicates and each replicate comprise five fruits. objectives were included the studying the effect of fruit bagging with cloth bags in two colors (white and light brown) and non-bagged fruit (control). The fruits were harvested at commercial maturity stage in early November and after disinfection with 1% Tybendazole for 1 minute were stored in a cool room at 5 °C for 10 weeks. Results and Discussion: The results showed that the bagging did not affect the components of aril color but showed a significant effect on some skin color characteristics so that the lightness, yellowing and the hue values in white bagged fruits significantly were increased in compared with non-bagged control. Bagging also had a significant effect on the amount of anthocyanin in fruit juice after 10 weeks of storage. The highest value was observed in nonbagged fruits (16.7 mg l-1) and the lowest in the light brown bag (4.04) mg l-1). Pre-harvest fruit bagging during fruit growth and development had a significant effect on the potassium content in the skin after 10 weeks of storage but did not significantly affect the amount of potassium in aril. Bagging fruit with white bag increased about 68% the potassium content in the skin compared to the control. The highest amount of calcium both in the skin and the aril was found in bagged fruit with white bag. Interestingly, white bag increased the calcium content of the skin and aril of pomegranate fruit 23% and 45%, respectively compared to the control. The results showed that bagging had no significant effect on redness and chroma values, ion leakage, chilling index, soluble solids, acidity, antioxidant activity, and the amount of iron in the skin and aril of pomegranate fruit cv. Shishe-kab. Conclusions: Bagging is a healthy and organic technique that plays an important role in improving the quality of the fruit. In general, fruit bagged with the white bag had better quality than the light brown bag on the skin color properties. In addition, enhancement the amount of potassium and calcium in the fruit skin not only improved its nutritional value but also likely it can be extended the fruit cold storage period with lower disorders and losses.