Flow field–flow fractionation–inductively coupled optical emission spectrometric investigation of the size-based distribution of iron complexed to phytic and tannic acids in a food suspension: implications for iron availability

  • Sopon Purawatt
  • Atitaya Siripinyanond
  • Juwadee Shiowatana
Original Paper

Abstract

Flow field–flow fractionation–inductively coupled plasma optical emission spectrometry (FlFFF–ICP–OES) was applied to achieve the size-based fractionation of iron in a food suspension in order to gain insights into iron availability. The binding of iron with phytic and tannic acids, employed as model inhibitors of iron availability in foods, was investigated at pH 2.0 (representing stomach fluid), pH 5.0 (the transition stage in the upper part of the duodenum), and pH 7.0 (the small intestine). In the presence of phytic acid, iron was found as a free ion or it was associated with molecules smaller than 1 kDa at pH 2.0. Iron associated with molecules larger than 1 kDa when the pH of the mixture was raised to 5.0 and 7.0. In the presence of tannic acid, iron was again mostly associated with molecules smaller than 1 kDa at pH 2.0. However, at pH 5.0, iron and tannic acid associated in large molecules (∼25 kDa), while at pH 7.0, most of the iron was associated with macromolecules larger than 500 kDa. Iron size-based distributions of kale extract and tea infusion containing phytic and tannic acids, respectively, were also examined at the three pH values, with and without enzymatic digestion. Without enzymatic digestion of the kale extract and the tea infusion at pH 2.0, most of the iron was released as free ions or associated with molecules smaller than 1 kDa. At other pH values, most of the iron in the kale extract and the tea infusion was found to bind with ~2 kDa and >500 kDa macromolecules, respectively. Upon enzymatic gastrointestinal digestion, the iron was not observed to bind to macromolecules >1 kDa but <500 kDa, due to the enzymatic breakdown of large molecules to smaller ones (<1 kDa).

Figure

Flow field–flow fractionation was exploited in order to achieve size-based iron fractionation and thus investigate iron-binding behavior under gastrointestinal conditions

Keywords

Iron FlFFF ICP–OES Size-based elemental fractionation 

References

  1. 1.
    Martinez-Navarrete N, Camacho MM, Martinez-Lahuerta J, Martinez-Monzo J, Fito P (2002) Food Res Int 35:225–231CrossRefGoogle Scholar
  2. 2.
    Lopez HW, Leenhardt F, Coudray C, Remesy C (2002) Int J Food Sci Technol 37:727–739CrossRefGoogle Scholar
  3. 3.
    Glahn RP, Wortley GM, South PK, Miller DD (2002) J Agric Food Chem 50:390–395CrossRefGoogle Scholar
  4. 4.
    Brigide P, Canniatti-Brazaca SG (2006) Food Chem 98:85–89CrossRefGoogle Scholar
  5. 5.
    Graf E, Mahoney JR, Bryant RG, Eaton JW (1984) J Biol Chem 259:3620–3624Google Scholar
  6. 6.
    Graf E, Empson K, Eaton J (1987) J Biol Chem 262:11647–11650Google Scholar
  7. 7.
    Graf E, Eaton JW (1990) Free Rad Biol Med 8:61–69Google Scholar
  8. 8.
    Vasca E, Materazzi S, Caruso T, Milano O, Fontanella C, Manfredi C (2002) Anal Bioanal Chem 374:173–178CrossRefGoogle Scholar
  9. 9.
    Sandberg AS, Svanberg U (1991) J Food Sci 56:1330–1333CrossRefGoogle Scholar
  10. 10.
    Engle-Stone R, Yeung A, Welch R, Glahn R (2005) J Agric Food Chem 53:10276–10284CrossRefGoogle Scholar
  11. 11.
    South PK, Miller DD (1998) Food Chem 63:167–172CrossRefGoogle Scholar
  12. 12.
    King A, Young G (1999) J Am Diet Assoc 99:213–218CrossRefGoogle Scholar
  13. 13.
    Chung K-T, Wong TY, Wei C-I, Huang Y-W, Lin Y (1998) Crit Rev Food Sci Nutr 38:421–464CrossRefGoogle Scholar
  14. 14.
    Brune M, Hallberg L, Skaanberg AB (1991) J Food Sci 56:128–167CrossRefGoogle Scholar
  15. 15.
    Chou CL, Uthe JF, Guy RD (1993) J AOAC Int 76:794–798Google Scholar
  16. 16.
    Sadi BBM, Vonderheide AP, Becker JS, Caruso JA (2005) ACS Symp Ser 893:168–183CrossRefGoogle Scholar
  17. 17.
    Wuilloud RG, Kannamkumarath SS, Caruso JA (2004) J Agri Food Chem 52:1315–1322CrossRefGoogle Scholar
  18. 18.
    Siripinyanond A, Barnes RM (1999) J Anal Atom Spectrom 14:1527–1531Google Scholar
  19. 19.
    Stolpe B, Hassellov M, Andersson K, Turner DR (2005) Anal Chim Acta 535:109–121CrossRefGoogle Scholar
  20. 20.
    Gimbert LJ, Andrew KN, Haygarth PM, Worsfold PJ (2003) Trends Anal Chem 22:615–633Google Scholar
  21. 21.
    Contado C, Blo G, Fagioli F, Dondi F, Beckett R (1997) Colloids Surf A 120:47–59CrossRefGoogle Scholar
  22. 22.
    Bolea E, Gorriz MP, Bouby M, Laborda F, Castillo JR, Geckeis H (2006) J Chromatogr A 1129:236–246CrossRefGoogle Scholar
  23. 23.
    Jackson BP, Ranville JF, Neal AL (2005) Anal Chem 77:1393–1397CrossRefGoogle Scholar
  24. 24.
    Hurrell Richard F (2003) J Nutr 133:2973S–2977SGoogle Scholar
  25. 25.
    Evans WJ, Martin CJ (1991) J Inorg Biochem 41:245–252CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Sopon Purawatt
    • 1
  • Atitaya Siripinyanond
    • 1
  • Juwadee Shiowatana
    • 1
  1. 1.Department of Chemistry, Faculty of ScienceMahidol UniversityBangkokThailand

Personalised recommendations