Effect of gamma irradiation on quantification of crocin, kaempferol and safranal components of saffron (Crocus sativus L.) in Ghaen, Torbat heydarieh and Kalat regions

Background and objectives: Saffron (red gold), the world's most expensive spice, is dried stigmas of Crocus sativus L. Edible additives, colors and flavors for foods, spices and medicinal applications in traditional medicine are included usage of saffron. Due to the disadvantages of thermal methods such as loss of sensory properties, nutritional and high cost of foods, tend to use non-thermal methods such as irradiation is increased in recent decades. Irradiation alone or in combination with other processes can while maintaining the taste, color and texture, and guaranteed the safety and consumers of products and increased product shelf-life. In this study, the effect of gamma irradiation on three main pigments compounds of saffron (Crocus sativus L.) as crocin (factor in saffron color), kaempferol (of bioactive polyphenol compounds) and safranal (the main compound of volatile aromatic saffron), was investigated.
Materials and Methods: In this study, 189 samples from three regions in Khorasan province in terms of saffron crocin, kaempferol, safranal was investigated. The quantities analysis according to International Standard Organization by statistical results using SPSS version 17 and Minitab version 16 was conducted. The data was compared by LSD test in 99% confidence level.
Results: The results obtained from saffron control (non-irradiated) sample, amount of crocin, kaempferol and safranal were 0.03, 0.01 and 0.04 mg per gram sample in Ghaen regions. After irradiation, these amounts were increased 0.71, 0.03 and 0.79 mg per gram sample, respectively. Crocin and safranal amounts were increased and kaempferol amount was slightly decreased after thirty and sixty days. Due to results obtained from saffron control (non-irradiated) sample amount of crocin, kaempferol and safranal were 0.31, 0.35 and 0.55 mg per gram sample in Torbat heydareh region. After irradiation, these amounts were 0.40, 0.35 and 0.35 mg per gram, respectively. The crocin amount was increased, kaempferol was steady and safranal was decreased. These amounts crocin, kaempferol and safranal were increased in Torbat hydareh region samples after thirty and sixty days. Based on the results of control (non-irradiated) samples, amounts of crocin, safranal and kaempferol were 0.50, and 0.55 and 0.67mg per gram in Kalat regions. These amounts were 0.60, 0.29 and 0.67 mg per gram, respectively where crocin was increased, and safranal were decreased and kaempferol was remained stable after irradiating. The amount of crocin was decreased; safranal and kaempferol were increased, after thirty days. The amount of crocin, safranal and kaempferol were increased in Kalat region, after sixty days.
Conclusion: The results of this study were confirmed that irradiation from minimum dose of 4 kilo Gray (kGy) to Maximum dose of 6 kGy, has no unfavorable changes on effective components of saffron.