the effect of climatic conditions on the concentration of stevioside in stevia production in different regions of iran and optimization of stevioside extraction

background & aim: according to the increase in diseases such as diabetes and obesity, using of saccharose alternatives for producing of low-calorie and sugar-free alternatives, are taken into consideration of researchers and industrialists. among them, steviosidewith the 300 times more sweetness than saccharose has special place, due to is a natural. the aim of this study is optimizing of stevioside extraction conditions from leaves of stevia (the solvent, temperature and time) and evaluation the effect of different climates on the stevioside concentration. experimental: at first, optimizing extraction of stevioside (the solvent, temperature and time) was done. then, obtained results on the plants in five regions with different climates (tehran: dry and semi-dry, kashan: warm and dryisfahan: temperate and mountainous, shahrekord : cold and mountainous shiraz: warm and mountainous) was applied, and finally concentration steviosidewas investigated using high performance liquid chromatography. results and discussion: according to the results, the best extraction conditions is at the time of 120 minutes, 50 ° c and 160 ml of solvent (ethanol). after that, by applying the results on the cultured plants in five cities: tehran, isfahan and shiraz, kashan and shahrekord, results showed climate conditions have effect on product. so that, among them, the cultured plants in isfahan have the highest level of production efficiency (tons per hectare); although, have the most impurities. recommended applications/industries: according to rise in consumtion of stevioside sweetener and increase in price of mentioned sweetener, its cultivation is very important in iran. the survey results indicate that application of it in country can be achieved by solvent. however, more research on the other extraction methods is necessary and important.