Thermal stability and in vitro digestion of alginate–starch–iron beads for oral delivery of iron

• Published in: Food hydrocolloids 2023-09, Vol.142, p.108808, Article 108808
• Main Authors: Mihaly Cozmuta, A., Purbayanto, M.A.K., Jastrzębska, A., Peter, A., Nicula, C., Uivarasan, A., Mihaly Cozmuta, L.
• Format: Article
• Language: English
• Subjects: Ferrous bisglycinate encapsulation; Ferrous bisglycinate thermal treatment; Ferrous ion thermal stability; In vitro digestion; Thermal treatment of beads
• ISSN: 0268-005X
• DOI: 10.1016/j.foodhyd.2023.108808

Ferrous bisglycinate can be used as an oral therapy for iron deficiency. However, the low thermal stability of ferrous bisglycinate powder to oxidation of ferrous ions hinders its application to fortification of foods that are heated before consumption. In this study, ferrous bisglycinate powder and beads prepared from alginate, starch, ferrous bisglycinate powder, and water in a ratio of 2:1:2:100 (w:w:w:v) were subjected to thermal treatment at 90 °C and 180 °C for 90 min. Heating changed the geometry of the beads. Large fractures appeared on the surface of the heated beads, while multiple pores formed in their cores. The beads increased the oxidative stability of Fe(II) at 180 °C, with 83.53% Fe(II) and 16.47% Fe(III) after heating, compared with 65.08% and 34.92% for ferrous bisglycinate powder alone. In a temperature-dependent manner, the amounts of bioaccessible Fe(II) and Fe(III) released from bisglycinate powder under in vitro gastric conditions ranged from 153.31 to 118.42 mg and 10.81–74.75 mg, respectively, compared to 32.90–42.49 mg and 7.94–14.51 mg released from the beads. At the end of the simulated oral-gastric-intestinal digestion, the beads heated to 180 °C released 1.22-fold more bioaccessible ferrous ions (147.85 mg) than were released from the corresponding bisglycinate powder (121.57 mg). These experimental results indicate that alginate–starch–ferrous bisglycinate beads thermally treated at 180 °C are promising carriers for oral delivery of iron. [Display omitted] •Alginate-starch-ferrous bisglycinate beads and ferrous bisglycinate powder were heated.•Heating affected shape parameters, core and surface morphology of beads.•Fe(II) ions in beads were better protected against oxidation to Fe(III).•The beads massively released the Fe(II) ions during the intestinal digestion.•Ferrous bisglycinate powder released the largest amount of Fe(II) at gastric level.