en Nutrition Nutrition پژوهشي Research <p><strong>Background and Objectives: </strong>Zedo gum is exuded in three colours (white, yellow, and red) from <em>Amygdalus scoparia</em>. It is used in both food and non-food industries, as well as in traditional medicine. This study aimed to determine the physicochemical and rheological properties of Zedo gum.</p> <p><strong>Materials and Methods: </strong>Zedo gum was collected in Sirjan and classified into three groups, based on colour (samples W, Y, and R). Their soluble parts were separated by centrifuging the dispersions and freeze-drying the supernatants. Surface tension was determined using Du Nouy ring method and NMR spectroscopy was carried out using a Varian Inova-500 MHz spectrometer. Gel Permeation chromatography was used for determining molecular weight and rheological data were obtained with a Physica MCR 301 rheometer.</p> <p><strong>Results: </strong>Surface tension decreased as the concentration decreased, except for sample R that had a maximum point at 1 %. The molecular weight of sample W was the highest, while its dispersity was the lowest. NMR spectroscopy indicated that Ara residues variously were&nbsp; linked to &alpha;-Araf residues, and Gal residues were determined as terminal &alpha;-Gal residues. Intrinsic viscosity values for samples W, Y, and R were 7.14&plusmn;0.13, 6.45&plusmn;0.11 and 5.40&plusmn;0.15dl/gr, respectively. Rheological results showed that viscosity was inversely proportional to temperature and directly to concentration.</p> <p><strong>Conclusions: </strong>As three samples of Zedo gum had different characteristics, colour can be a good tool in trade.</p> <p><strong>Keywords: </strong>Zedo, Dispersity, GPC, <em>Amygdalus Scoparia, </em>NMR</p> Zedo, Dispersity, GPC, Amygdalus Scoparia, NMR 33 40 http://nfsr.sbmu.ac.ir/browse.php?a_code=A-10-48-1&slc_lang=en&sid=1 Ghasem Fadavi 10031947532846001944 10031947532846001944 No Dept. of Food and Agricultural Products, Standard Research Institute, Karaj, Iran Mina Ghiasi 10031947532846001945 10031947532846001945 No Dept. of Chemistry, Faculty of Physics & Chemistry, Alzahra University, Vanak, Tehran, Iran Azizollah Zargarran 10031947532846001946 10031947532846001946 No Dept. of Food Science and Technology, National Nutrition and Food Technology Research Institute, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mohammad Amin Mohammadifar 10031947532846001947 10031947532846001947 Yes Dept. of Food Science and Technology, National Nutrition and Food Technology Research Institute, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran