Application of food-grade microorganisms for addressing deterioration associated with fortification of food with trace metals

ABSTRACT

Malnutrition caused by iron deficiency can be overcome by fortification of food with iron. For the first time, metal (iron) bound/uptake food-grade microorganisms were used as fortificants in order to prevent deteriorative changes and to preserve the organoleptic acceptability of the fortified food. In the present study, biosorption capacity of Bacillus subtilis and uptake capacity of Saccharomyces cerevisiae for iron ions was determined by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and found to be 7.1 ± 0.2 and 3.2 ± 0.2 mg per gram of the biosorbent respectively. Chocolate was fortified with various concentrations of biosorbed/uptaken iron, inorganic (free) iron and free biomass. Appearance, chemical and microbiological changes associated with fortification was monitored for 28 and 30 days of storage at 30°C respectively. Chocolate fortified with free (inorganic) iron showed significant increase in thiobarbituric acid (TBA) values when compared with the biosorbed/uptaken iron-fortified or free biomass-fortified chocolate samples. Black discoloration was observed in free iron-fortified samples when compared with samples fortified with metal enriched biomass or free biomass.

KEYWORDS:

• Biosorption
• iron
• fortification
• uptake
• Bacillus subtilis

Acknowledgments

The authors would like to thank NCCCM, Hyderabad for their support in ICP-OES analysis.