en Aquaculture and Health management Aquaculture and Health management پژوهشي Original research papers <div style="text-align: justify;">The aim of the present study was to evaluate the physico-chemical criteria of yogurt fortified with fish protein hydrolysate (FPH) obtained from Fresh Abu mullet (<em>Planiliza abu</em>) fish weighing 40 g during 21-day refrigeration. A hundred milliliters of final milk were inoculated with starter culture, and fermented for 4-5 hours until the pH reached to 4.6. The yogurts were divided in two groups in triplicate and each group was prepared in triplicate. Yogurts supplemented with nanoencapsulated hydrolysates exhibited a slight reduction in pH and augmented acidity particularly up to three weeks of refrigeration. The pH of nanoemulsion-FPH yogurt was initially 4.52 and reached 4.01 in third week with a significant difference (<em>p<0.05</em>) compared with that of the control at the same time (3.80). The pH value of the fortified yogurt showed acceptable limit on day 7 (4.35) but it was remarkably decreased on day 14 (4.19, <em>p<0.5</em>). The upmost and the least values of viscosity of nano-FPH yogurt samples were respectively 4187.3 and 4046.6 (cps) on days 1 and 21. The viscosity values of control were ranged from 3716.0 to 4042.0, respectively in 21 and 1 days of refrigeration. Moreover, the maximum and minimum water holding capacity (WHC) value of nano-FPH yogurt samples 92.5% and 86.2%, respectively on days 1 and 21. It is concluded that the incorporation of the FPH in the form of nanoencapsulation offered superior physico-chemical advantages than those of control yogurt samples.</div> <div style="text-align: justify;"></div> Yogurt, Nanoemulsion, Fish protein hydrolysate, Physico-Chemical parameters 66 76 http://ijaah.ir/browse.php?a_code=A-10-395-1&slc_lang=en&sid=1 N Vakili drvakililaboratory@gmail.com 10031947532846003015 10031947532846003015 No Department of food hygiene, Science and Research Branch, Islamic Azad University, Tehran, Iran M Ataee drmaryat@gmail.com 10031947532846003016 10031947532846003016 Yes Department of food hygiene, Science and Research Branch, Islamic Azad University, Tehran, Iran S Kakoolaki bsh443@gmil.com 10031947532846003017 10031947532846003017 No Iranian Fisheries Science Research Institute, Agriculture Research Education and Extension Organization (AREEO), Tehran, Iran H Ahari Dr.h.Ahari@gmil.com 10031947532846003018 10031947532846003018 No Department of Food Science and Technology, Science and Research Branch, Islamic Azad University, Tehran, Iran A Ghorbanzadeh armangho@gmail.com 10031947532846003019 10031947532846003019 No Department of Aquatic Health and Disease, Veterinary Science Faculty, Islamic Azad University, Tehran, Iran