Nuts, used in the manufacture of beverages contamination of mycotoxins

The master's thesis was prepared at the Veterinary Academy of the Lithuanian University of Health Sciences, Faculty of Veterinary Medicine, Department of Food Safety and Quality. Topic of the Master’s thesis: Nuts, used in the manufacture of beverages contamination of mycotoxins. Author: Justė Jakelaitytė. Supervisor: doc. dr. Violeta Baliukonienė. Thesis consists of: 39 pages, 7 tables, 5 figures. The study was started in January 2018 and completed in September 2019. The aim of the study was to determine the contamination of nuts used in the production of beverages with aflatoxin B1 and ochratoxin A and to estimate the proportion of mycotoxins tested in beverages. For this purpose, a sample of 21 nuts was collected, consisting of selected nut species: hazelnut, almond, coconut and coconut chips. Samples were collected from nuts sold in Lithuania and abroad. Concentrations of aflatoxin B1 and ochratoxin A were determined by thin layer chromatography. The concentration of AFB1 was 33.3 % in the tested nuts, in which the concentration ranged from 0.7 to 3 μg/kg. OTA concentrations were found in 55.5 % of the tested samples, which ranged from 1.8 to 5 μg/kg. Homemade nut drinks were contaminated with mycotoxins: AFB1 was detected in 33.3 % (p> 0.05), OTA - in 55.5 % (p> 0.05). In nuts and home-made nut beverages, AFB1 concentrations decreased from 50 to 100 % during beverage production. Looking at the change in AFB1 concentration between nuts and nut drinks, a very weak correlation was found r = - 0.12944, statistically insignificant (p> 0.05). During the study, OTA concentrations in nuts during beverage production decreased from 33.3 % up to 100 % nut drinks or was not detected. However, 22.2 % OTA levels in home-made nut drinks were found to be 0.5 μg/kg, although they had not previously been detected in nut samples. Looking at the change in OTA concentration between nuts and nut drinks, a very weak correlation was found r = 0.291626, statistically insignificant (p> 0.05)