Triple Fortification of Rice: Feasibility, Consumer Acceptance and In-Vitro (Caco 2-Cell) Absorption Studies

Rice fortification with multiple micronutrients (folic acid, iron and β-carotene) by utilizing two different processes: parboiling- an ancient process and High Pressure processing (HPP) a novel process has been examined in this thesis. The fortification process was addressed through four vital phases: optimisation of parboiling process and use of HPP for fortification with multiple micronutrients, physico-chemical properties of the fortified rice, consumer acceptance study and bio-accessibility and transport studies.Parboiling process was optimised for fortifying rice with three micronutrients using the following condition: soaking the brown rice at 70°C for 2 hours with the fortificant solution(FA- 150 mg; BC- 62.5 mg; Fe- 25 mg) followed by steaming at 100°C for 1 hour and then air drying the rice at room temperature until the moisture content dropped to 10-12%.Folic acid showed highest uptake during parboiling. After cooking folic acid was retained the highest (98%) followed by iron (90%) and then β-carotene (35%).For HPP, thebest condition for fortification was selected: treating milled white rice with the fortificant solution at 200 MPa for 1 hour (non-thermal) and then air-drying the processed rice (10-12% final moisture content). Folic acid showed highest uptake after HPP (41%) followed by β-carotene and iron (20% each). Retention in cooked HPP rice followed the same trend as parboiled rice- Folic acid (98%)> Iron (64%)>β-carotene (18%). Rice fortified by the twotechniques was assessed for physico-chemical properties to understand changes in starch during fortification. The process of adding nutrients did not have an impact on starch properties in the fortified rice. Parboiled rice was completely gelatinised while HPP rice showed partial gelatinization which affected hydrolysis of starch by α-amylase which in turn influenced the release of vitamins from the rice matrix during extraction and in vitro digestion.Fortified parboiled rice was diluted with white rice and assessed for colour variation instrumentally in comparison to white rice, which showed no significant difference betweenthem. The diluted fortified rice was presented to consumers for visual and taste acceptance. Fortified diluted rice (uncooked) was not as acceptable as uncooked white rice (coomercial) to consumers due to non-uniformity in appearance. Initially the purchase intent was low (28%) for the diluted fortified rice. Howeverafter informing consumers about fortification and the additional nutritional value, purchase intent for fortified rice increased to 51% implying that at least half of the consumers were willing to buy the rice. 76% of consumers preferred cooked fortified rice mixed with white rice particularly when mentioned about fortification. The bio-accessibility of fortified micronutrients using both techniquesviiiwere higher for fortified parboiled rice ( FA- 96% BC- 12%) followed by HPP ( FA- 46%; BC- 2%) compared to the fortificant solution (FA- 80%; BC- 0.1%) containing the same concentration of nutrients except for iron (parboiled rice- 31%, HPP rice 42% and fortificant- 38%). Fortification with multiple micronutrients using parboiling process showed better transport (FA- 33%; BC- 23% and Ferritin 26 ng/mL) after in vitro digestionand would be easier for implementation