Iron fortification: Chitosan encapsulation strengthens stability and boosts bioavailability

By Gary Scattergood

- Last updated on GMT

The chitosan-coated layer delayed the release profile of iron. ©iStock
The chitosan-coated layer delayed the release profile of iron. ©iStock

Related tags Fatty acid

Coating iron with chitosan nanostructured lipid carriers is a superior protection method when fortifying milk, with researchers also predicting its suitability for fruit juices, yogurts and traditional drinks.

Scientists said chitosan had been used for several encapsulation process, but they wanted to assess its suitability in milk products under simulated gastric and intestinal conditions.

“Iron-loaded nanostructured lipid carriers (NLCs) and iron-loaded chitosan nanostructured lipid carriers (CH-NLCs) were characterised by measuring their mean particle size, size distribution, potential, and encapsulation efficiency.

“Furthermore, in vitro release properties, in vitro lipid digestion, and changes in thiobarbituric acid (TBA) absorbance were investigated,”​ academics from Korea wrote in the Journal of Food Science.

Found that CH-NLCs improved the stability and oral bioavailability of iron, with results showing that chitosan coating created more stable NLCs with high encapsulation efficiency.

“The encapsulation efficiency of CH-NLCs (83.9%) was significantly higher compared to that of NLCs (73.6%),”​ they wrote.

“This result might be explained by the interaction between lecithin in the lipid particles and chitosan.

"Lecithin in NLCs plays a fundamental role in the lipid matrix, because the hydrophilic group of lecithin can offer some spaces where the iron can be localized and reduced the release of iron into the outside,”​ they stated.

Delayed release

The in vitro tests revealed that the release of iron was also significantly slower in both gastric and intestinal conditions.

“Under the gastric condition (pH 1.2), iron release from NLCs was greatly increased from 2.1% in one hour to 10.6% in three hours. However, iron release from CH-NLCs was only slightly increased from 1.65% in one hour to 5.6% three hours.

“The chitosan-coated layer delayed the release profile of iron.”

Further tests showed the enhanced benefits of CH-NLC in milk when it was stored for up to 10 days, and in terms of free fatty acids that were released.

“Stable iron containing NLCs were successfully prepared using melt dispersion method and chitosan coating process showed the formation of stable CH-NLCs with high encapsulation efficiency,” ​the study concluded.

Based on our results, iron CH-NLCs can be applied to other food products with low iron content, such as fruit juice, yogurts, and traditional drinks. Therefore, CH-NLCs show potential for use as a superior and convenient iron carrier for food fortification.”


Source: Journal of Food Science

doi: 10.1111/1750-3841.13655

“Preparation of Chitosan-Coated Nanostructured Lipid Carriers (CH-NLCs) to Control Iron Delivery and Their Potential Application to Food Beverage System”.

Authors: Sun Ah Lee, et al

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