Determination of in-vitro bioaccessibility of vitamin b1 in baby biscuits prepared with or without UHT cow's milk

Thiamine is an important nutrient in infant nutrition due to its role and functions in both neurological development and energy metabolism. For this reason, it is important to know the thiamine bioavailability of baby biscuits and follow-on milk in infant nutrition to ensure that the requirement is met. For estimation of bioavailability, in-vitro bioaccesibility can be used and is a more advantageous method in terms of cost, ethics and time. The aim of this thesis study is to determine the thiamine bioaccessibility of baby biscuits and follow-on milks in infant nutrition by in-vitro digestive system model. Since baby biscuits can be prepared with milk, the effect on bioaccessibility was also studied. The in-vitro digestive system model was carried out at two different pH values, 1.5 and 4 pH, taking into account the stomach pH of my babies. The thiamine amount of the samples was determined using HPLC. When the analysis results and the amount of thiamine declared on the label of the samples were compared, it was determined that the thiamine content of baby biscuits changed by 94.2% and the follow-on milk by 246.6%. While gastric acidity was pH 1.5, the average of bioaccessibility for baby biscuit samples with and without added UHT milk were 107% and 43%. While gastric acidity was pH 4, the average of bioaccessibility for baby biscuit samples with and without added UHT milk were; It is 104% and 96%. The average bioaccesibility of follow-on milk samples is 47% when the stomach pH is 1.5, and 80% when the stomach pH is 4. When the data obtained as a result of the study are examined, it has been determined that bioaccessibility may decrease depending on the dietary fiber content of the product, the temperature it is exposed to during the production process, the polysaccharides and peptides in the product, and the pH of the stomach. In addition, it was concluded that adding UHT milk to baby biscuits could increase bioaccessibility and follow-on milks were higher at infant stomach pH of 4. Keywords: Baby b%scu%ts, B%oaccess%b%l%ty, Follow-on m%lk, Th%am%n.