Quality Characteristics and Lutein Bioavailability From Maize and Vegetable-Based Health Food

Oxidative stability of lutein on exposure to varied extrinsic factors

Pre-processing treatments performed on lutein sources can cause it to degrade, generating superfluous metabolites and lowering lutein's bioactivity. However, evidences suggesting extent of reduction in functional stability of lutein on exposure to such treatment conditions are nil. This study is first of its kind, where we attempted to gain clarity on the extent of degradation caused by the changes in temperature (40-100 °C), pH (2-8) and duration of such treatments. Increase (3.9 folds) in lutein loss within an hour at 40 °C occurred when pH was lowered from 8 to 2. Increase (1.7 folds) in lutein loss at neutral pH and 40 °C occurred when duration of exposure was increased from 1 to 4 h. Besides, lutein loss significantly increased on rising the temperature by every 10 °C. The functional stability of lutein in relation to its degradation was also studied by monitoring its radical scavenging activity. While lutein is highly unstable, lutein structure and its respective bioactivity can be significantly (p < 0.05) retained (< 12.44% and > 54.87% respectively) by maintaining the operating conditions at higher pH (7-8) and lower temperatures (40-50 °C) for a short period of time (< 1 h).

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05430-3.

Development and evaluation of lutein-loaded alginate microspheres with improved stability and antioxidant

BACKGROUND

Lutein has been of great interest to the food processing and pharmaconutrient industries owing to its beneficial effects on human health. However, lutein is very sensitive to heat, light, pH and oxidative conditions, which limits its application in food systems. The present study aimed to prepare lutein-alginate microspheres by a calcium chloride gelation method with the purpose of improving the stability and antioxidant abilities of lutein.

RESULTS

The loading capacity of lutein in the microspheres was approximately 5.3% (w/w) and the entrapment efficiency was about 63%. The loaded microspheres were nearly spherical with an average size of 150 μm. They exhibited a crimped surface by scanning electron microscopy. The lutein was in amorphous state by X-ray powder diffraction. Analysis by Fourier transform infrared spectroscopy and molecular docking revealed an intermolecular hydrogen bond interaction between lutein and sodium alginate. In vitro release experiments showed that the microspheres presented slower release at acidic conditions than at neutral intestinal conditions. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of the microencapsulated lutein was higher than that of free lutein. The stability of lutein in the microspheres was improved significantly when compared with that of free lutein at various temperatures.

CONCLUSION

The present work successfully developed well-protected lutein-alginate microspheres. This indicates that it is feasible to use microspheres loaded with lutein as antioxidant functional ingredients in food products. © 2019 Society of Chemical Industry.

Lutein has a protective effect on hepatotoxicity induced by arsenic via Nrf2 signaling

Arsenic produces liver disease through the oxidative stress. While lutein can alleviate cytotoxic and oxidative injury, nuclear factor erythroid 2-related factor 2 (Nrf2) pathway plays a critical role in defending oxidative species. However, the mechanisms by which lutein protects the liver against the effect of arsenic are not known. Therefore, this study aims to investigate the mechanisms involved in the action of lutein using mice model in which hepatotoxicity was induced by arsenic. We found that mice treatment with lutein could reverse changes in morphological and liver indexes and result in a significant improvement in hepatic function comparing with arsenic trioxide group. Lutein treatment improved the activities of antioxidant enzymes and attenuated increasing of ROS and MDA induced by arsenic trioxide. Lutein could increase the mRNA and protein expression of Nrf2 signaling related genes (Nrf2, Nqo1, Ho-1, and Gst). These findings provide additional evidence that lutein may be useful for reducing reproductive injury associated with oxidative stress by the activation of Nrf2 signaling. Our findings suggest a possible mechanism of antioxidant lutein in preventing the hepatotoxicity, which implicate that a dietary lutein may be a potential treatment for liver diseases, especially for arsenicosis therapy.