Evaluation of Climate Effect on Saffron's Metabolites (Crocin, Picrocrocin and Safranal) in Bonab Region of Marand

Nowadays, due to the decrease in rainfall and groundwater level, the cultivation of crops with low water requirements should be given priority. Different regions of Iran, especially the region of East and West Azerbaijan, have faced a decrease in rainfall in recent years, compared to previous years. Saffron could have relatively stable production in these areas due to low water demand and suitable economic efficiency. Special properties of saffron such as low water requirement, irrigation in non-critical times, water requirement of other plants, possible operation of farms for several years after one planting, ease of transportation and storage of the product, possibility of high employment, possibility of cultivation in areas that lack industrial talents and limited agricultural water, having medicinal properties and also, suitable domestic and foreign sales market has made this plant for cultivation. On the other hand, saffron cultivation in the Iran could increase employment and non-oil exports.If we pay attention to its production and processing processes, it could provide a significant currency to the country. Today the cultivation of saffron is under development in areas such as Azerbaijan. On the other hand, due to the harmful effects of the using synthetic antioxidants in the food and pharmaceutical industries, special attention has been paid for using of natural antioxidants. Considering the importance of compounds in saffron quality and the effect of climatic conditions in different years on the amount of secondary metabolites and antioxidant properties of this valuable plant, the present experiment were evaluated the yield and quality of saffron and compared antioxidant activity of different parts of saffron during two cropping years.

The effect of climate of Marand city of East Azarbaijan province in different years on quality and antioxidant characteristics of different parts of saffron was investigated in this region. So, the climatic factors governing this region during two consecutive years of 2014 and 2015 in terms of temperature, rainfall and humidity were studied using meteorological data. Saffron yield in the region were obtained by using a questionnaire from saffron producers in the region. Meanwhile, the amount of crocin, picocrocin and safranal and the antioxidant activity of different parts of saffron, including stigma, style, stamen and petals, were examined.

The results showed that the Marand city was classified as semi-arid in accordance the amount of crocin metabolites in 2014 (maximum: 306 mg/g in the stigma), picocrocin in 2015 (102.15 mg/g in the stigma), and Safranal in 2015 (highest: 49.95 mg/g in saffron petals) and the antioxidant activity of saffron and saffron petals were the highest in 2014 (30.43% and 88.32%, respectively). The results showed that the quality of different parts of saffron varied in different years. Due to the quality of different parts of saffron in different years, different parts could be used for exploitation.

The amount of active ingredients in the plant were not constant at all and varied according to the growth and climatic conditions and harvest time. Changes in the amount of active ingredients in the plant over consecutive years or even hours a day emphasized the importance of collecting the medicinal plant when the plant contained the maximum amount of active ingredient. The quality of saffron depended on the amount of crocin, picrocrocin and safranal compounds and antioxidant activity. These compounds varied in different organs of saffron (stigma, style, stamen‎ and petals) and over consecutive years. Bonab of Marand ‎region of East Azerbaijan is suitable for saffron cultivation due to the climate change. The quality of different saffron organs were different in consecutive years of multi-year cultivation. The highest amount of crocin in the first year of cultivation in the stigma and its antioxidant activity in the stigma and petals were the highest and in the following year the amount of picrocrocin in the stigma and safranal in the petals were the highest. Therefore, different metabolites could be harvested according to the need in the maximum number of years.