Development of Vitamin-fortified rice analogs with a focus on extrusion and cooking stability and retention

Rice, a global staple, often lacks essential nutrients due to milling, leading to micronutrient deficiencies or "hidden hunger." This study aimed to optimize the fortification of rice analogues with essential vitamins, focusing on nutrient retention during cooking. Using cold extrusion technology, rice analogues were produced from a mixture of rice flour, sodium alginate (1%), water (30%), and a nutrient ready mix (NRM) in varying proportions: low-dose (100%), intermediate-dose (125%), and High-dose (150%) of recommended levels. The fortification level was statistically optimized using Design Expert software, with high-dose fortification (150% NRM) yielding the highest cooking retention, achieving a desirability value of 0.961. Post-cooking, the fortified rice analogues retained significant levels of key vitamins, including vitamin A (4713.76 ± 64.65 µg RE/kg), thiamine (6.67 ± 0.01 mg/kg), riboflavin (84.03 ± 0.54 mg/kg), niacin (447.18 ± 0.01 mg/kg), pyridoxine (33.21 ± 1.12 mg/kg), and folic acid (4.52 ± 0.04 mg/kg). Retention rates varied across vitamins, with thiamine showing lowest retention (6.7-7.1% after extrusion and cooking), while riboflavin exhibited the highest stability (64.3-74.7% retention after extrusion and cooking) demonstrating its relative heat stability. Other vitamins showed intermediate retention rates: vitamin A (10.1-12.4%), niacin (28.6-36.7%), pyridoxine (15.5-22.1%) and folic acid (44.2-60.4%). By blending these fortified analogues with raw rice at a 1:50 ratio produced vitamin-fortified rice that meets nutritional standards. This optimized fortification process offers a viable solution to combat hidden hunger by enhancing the nutritional value of rice without altering traditional dietary habits.

The online version contains supplementary material available at 10.1007/s13197-025-06337-5.