بهبود خواص آنتي‌اكسيداني و آنتوسيانين ميوه توت‌فرنگي رقم آروماس با استفاده از لاكتات كلسيم و سوربات پتاسيم

Improvement of Anthocyanin and Antioxidant Properties of Strawberry (cv. Amaros) by Calcium Lactate and Potassium Sorbate Application

ﺑﻪ ﻣﻨﻈﻮر ﺑﺮرﺳﯽ ﺗﺄﺛﯿﺮ ﻻﮐﺘﺎت ﮐﻠﺴﯿﻢ و ﺳﻮرﺑﺎت ﭘﺘﺎﺳﯿﻢ ﺑﺮ ﺧﻮاص آﻧﺘﯽ اﮐﺴﯿﺪاﻧﯽ و ﺑﻌﻀـﯽ ﺻـﻔﺎت ﮐﯿﻔـﯽ ﻣﯿـﻮه ﺗﻮت ﻓﺮﻧﮕﯽ رﻗﻢ آروﻣﺎس، آزﻣﺎﯾﺸﯽ ﺑﻪ ﺻﻮرت ﻓﺎﮐﺘﻮرﯾﻞ در ﻗﺎﻟﺐ ﻃﺮح ﺑﻠﻮك ﻫﺎي ﮐﺎﻣـﻞ ﺗﺼـﺎدﻓﯽ ﺑـﺎ 9 ﺗﯿﻤـﺎر و 3 ﺗﮑﺮار، ﺑﺮ روي ﺑﻮﺗﻪ ﻫﺎي دو ﺳﺎﻟﻪ، در ﺳﺎل زراﻋﯽ 1395 در ﻣﺰرﻋﻪ ﺗﺤﻘﯿﻘﺎﺗﯽ ﺟﻬﺎد ﮐﺸﺎورزي ﺷﻬﺮﺳﺘﺎن ﻣﺮﯾﻮان، اﺟﺮا ﺷﺪ. ﺗﯿﻤﺎرﻫﺎي ﻣﻮرد اﺳﺘﻔﺎده ﺷﺎﻣﻞ ﺷﺎﻫﺪ )آب ﻣﻘﻄﺮ(، ﺳﻮرﺑﺎت ﭘﺘﺎﺳﯿﻢ ﺑﺎ ﻏﻠﻈﺖ ﻫﺎي )0/5 و 1 درﺻﺪ(، ﻻﮐﺘﺎت ﮐﻠﺴﯿﻢ ﺑﺎ ﻏﻠﻈﺖ ﻫﺎي )0/5 و 1 درﺻﺪ( و اﺛﺮ ﺗﺮﮐﯿﺒﯽ آن ﻫﺎ ﺑﻪ ﺻﻮرت ﻣﺤﻠﻮل ﭘﺎﺷﯽ در ﺳﻪ ﻣﺮﺣﻠﻪ، ﻣﺮﺣﻠﻪ اول ﺳﻪ ﻫﻔﺘﻪ ﻗﺒـﻞ از ﺑﺮداﺷﺖ ﺗﺠﺎري، ﻣﺮﺣﻠﻪ دوم دو ﻫﻔﺘﻪ ﻗﺒﻞ از ﺑﺮداﺷﺖ، ﻣﺮﺣﻠﻪ ﺳﻮم ﯾﮏ ﻫﻔﺘﻪ ﻗﺒـﻞ از ﺑﺮداﺷـﺖ اﻋﻤـﺎل ﮔﺮدﯾـﺪ ﻧﺘﺎﯾﺞ ﺣﺎﺻﻠﻪ ﺣﺎﮐﯽ از آن اﺳﺖ ﮐﻪ ﮐﺎرﺑﺮد ﺗﺮﮐﯿﺒﯽ ﻻﮐﺘﺎت ﮐﻠﺴﯿﻢ و ﺳـﻮرﺑﺎت ﭘﺘﺎﺳـﯿﻢ )ﻏﻠﻈـﺖ ﻫـﺎي 0/5 درﺻـﺪ ﻣﯿﺰان آﻧﺘﻮﺳﯿﺎﻧﯿﻦ ﮐﻞ ﻣﯿﻮه را ﺑﻪ ﻃﻮر ﻣﻌﻨﯽ دار )در ﺳﻄﺢ اﺣﺘﻤﺎل آﻣﺎري ﯾﮏ درﺻﺪ( اﻓـﺰاﯾﺶ داده، ﮐـﻪ اﯾـﻦ اﻣـﺮ ﺟﺬاﺑﯿﺖ رﻧﮓ و ﺑﺎزار ﭘﺴﻨﺪي ﻣﯿﻮه را ﻧﺴﺒﺖ ﺑﻪ ﺷﺎﻫﺪ ﺑﯿﺸﺘﺮ ﻧﻤﻮد، ﺑﻪ ﻃﺒﻊ آن ﺧﺎﺻﯿﺖ آﻧﺘـﯽ اﮐﺴـﯿﺪاﻧﯽ ﻧﯿـﺰ اﻓـﺰاﯾﺶ ﯾﺎﻓﺖ. از ﻃﺮف دﯾﮕﺮ اﺛﺮ اﯾﻦ ﺗﯿﻤﺎر )ﺗﺮﮐﯿﺐ ﻻﮐﺘﺎت ﮐﻠﺴﯿﻢ و ﺳﻮرﺑﺎت ﭘﺘﺎﺳﯿﻢ 0/5 درﺻﺪ( ﺑﺎﻋﺚ اﻓﺰاﯾﺶ ﻣﻌﻨـ ﯽ داري در ﺳﻄﺢ ﯾﮏ درﺻﺪ( ﻣﺤﺘﻮاي ﻓﻼوﻧﻮﺋﯿﺪ ﮐﻞ، ﮐﻞ ﻣﻮاد ﺟﺎﻣﺪ ﻣﺤﻠﻮل و ﺷﺎﺧﺺ ﻃﻌﻢ و ﺗﯿﻤﺎر ﺗﺮﮐﯿﺒﯽ )ﯾﮏ در ﯾﮏ درﺻﺪ( ﻻﮐﺘﺎت ﮐﻠﺴﯿﻢ و ﺳﻮرﺑﺎت ﭘﺘﺎﺳﯿﻢ ﺑﺎﻋﺚ اﻓﺰاﯾﺶ ﻣﻌﻨﯽ دار ﻓﻨﻞ ﮐﻞ )95/72 ﻣﯿﻠﯽ ﮔﺮم ﺑﺮ ﺻـﺪ ﮔـﺮم وزن ﺗـﺮ اﺳﯿﺪ ﮐﻞ و ﺳﻔﺘﯽ ﺑﺎﻓﺖ ﻣﯿﻮه ﻧﺴﺒﺖ ﺑﻪ ﺗﯿﻤﺎرﻫﺎي دﯾﮕﺮ ﺷﺪ (P  0.05)ﺑﻨﺎﺑﺮاﯾﻦ اﺳﺘﻔﺎده از اﯾﻦ دو ﻣﺎده در ﺳﻪ ﻣﺮﺣﻠﻪ و ﺑﻪ ﺻﻮرت ﺗﺮﮐﯿﺒﯽ ﺟﻬﺖ ﺑﻬﺒﻮد ﺧﻮاص ﮐﯿﻔﯽ و آﻧﺘﯽ اﮐﺴﯿﺪاﻧﯽ ﻣﯿﻮه ﺗﻮت ﻓﺮﻧﮕﯽ ﻗﺎﺑﻞ ﺗﻮﺻﯿﻪ ﻣﯽ ﺑﺎﺷﺪ

Strawberry (Fragaria × ananassa Duch.) is one of the most popular soft fruits worldwide. It is a rich source of health promoting compounds such as essential macro/micro-nutrients, polyphenols, anthocyanin, vitamins and amino acids, while showing a high antioxidant capacity. Preharvest applications of calcium lactate and potassium sorbate have shown to be promising as a tool to improve the quality and extend the shelf life of various fruits. To our knowledge, however, little information is available regarding the effect of calcium lactate and potassium sorbate on strawberry fruits. Thus, the objective of the present study was to determine the effect of foliar application of calcium lactate and potassium sorbate on important quality characteristics and antioxidant properties of ‘Armas’ strawberries. Materials and Methods This research was performed at a commercial orchard on 2-year old strawberries in Marivan, Iran in 2015. The experiment was arranged as factorial based on randomized complete block design with two factors and four replications. The first factor included different levels of calcium lactate (0, 0.5 and 1%) and the second factor included different levels of potassium sorbate (0, 0.5 and 1%). Foliar spraying was performed in three stages: three weeks before commercial harvesting, at initial coloring, and one week before harvest. Fruit were harvested at commercial maturity and immediately transported to the laboratory at University of Zanjan and subjected to physicochemical analysis. Differences among means of data were analyzed by Duncan’s test at p ≤ 0.05 (n = 3). All statistical analyses were performed with SAS version 9.4. Results The results showed that the combination of calcium lactate and potassium sorbate (0.5 Percent concentration) treatment significantly (P £ 0.01) increased the total anthocyanin content of the whole fruit, reuslting into further attractive fruit color and market than the control. It also increased antioxidant properties up to a level of 57.07%. On the other hand, the application of this treatment (calcium lactate and potassium sorbate 0.5 Percent) significantly increased the total flavonoid content, total soluble solids, flavor index (1.1 Percent) and calcium lactate (1 Percent). Potassium sorbate increased total phenol, total acidity, and fruit acidity significantly compared to other treatments and control (P £ 0.05). Discussion In general, the results of the present study showed that a preharvest application of calcium lactate and potassium sorbate increased firmness, nutritional quality, and antioxidant potential of strawberry fruits. Thus, the use of these two materials is recommended to improve the qualitative and antioxidant properties of strawberry fruit.