Susceptibility of 5-methyltetrahydrofolic acid to heat and microencapsulation to enhance its stability during extrusion processing

Thermal protection and pH-gated release of folic acid in microparticles and nanoparticles for food fortification

Dispersed folic acid was successfully encapsulated in alginate–pectin hydrogels, proliposomes, and combinations thereof, providing an efficient pH-responsive delivery system.

Protection of folic acid through encapsulation in mesoporous silica particles included in fruit juices

Folic acid (FA) is a synthetic vitamin commonly used for food fortification. However, its vulnerability to processing and storage implies loss of efficiency, which would induce over-fortification by processors to obtain a minimum dose upon consumption. Recent studies have indicated potential adverse effects of FA overdoses, and FA protection during processing and storage could lead to more accurate fortification. In addition, sustained vitamin release after consumption would help improve its metabolism. The objective of this work was to study controlled FA delivery and stability in fruit juices to reduce potential over-fortification risks by using gated mesoporous silica particles (MSPs). The obtained results indicated that FA encapsulation in MSPs significantly improved its stability and contributed to controlled release after consumption by modifying vitamin bioaccessibility. These results confirmed the suitability of MSPs as support for controlled release and protection of bioactive molecules in food matrices in different food production and storage stages.

Folates: Chemistry, analysis, occurrence, biofortification and bioavailability

Folates (Vitamin B₉) include both naturally occurring folates and synthetic folic acid used in fortified foods and dietary supplements. Folate deficiency causes severe abnormalities in one-carbon metabolism can result chronic diseases and developmental disorders, including neural tube defects. Mammalian cells cannot synthesize folates de novo; therefore, diet and dietary supplements are the only way to attain daily folate requirements. In the last decade, significant advancements have been made to enhance the folate content of rice, tomato, common bean and lettuce by using genetic engineering approaches. Strategies have been developed to improve the stability of folate pool in plants. Folate deglutamylation through food processing and thermal treatment has the potential to enhance the bioavailability of folate. This review highlights the recent developments in biosynthesis, composition, bioavailability, enhanced production by elicitation and metabolic engineering, and methods of analysis of folate in food. Additionally, future perspectives in this context are identified. Detailed knowledge of folate biosynthesis, degradation and salvage are the prime requirements to efficiently engineer the plants for the enhancement of overall folate content. Similarly, consumption of a folate-rich diet with enhanced bioavailability is the best way to maintain optimum folate levels in the body.

Optimization of folic acid nano-emulsification and encapsulation by maltodextrin-whey protein double emulsions

Due to susceptibility of folic acid like many other vitamins to environmental and processing conditions, it is necessary to protect it by highly efficient methods such as micro/nano-encapsulation. Our aim was to prepare and optimize real water in oil nano-emulsions containing folic acid by a low energy (spontaneous) emulsification technique so that the final product could be encapsulated within maltodextrin-whey protein double emulsions. A non ionic surfactant (Span 80) was used for making nano-emulsions at three dispersed phase/surfactant ratios of 0.2, 0.6, and 1.0. Folic acid content was 1.0, 2.0, and 3.0mg/mL of dispersed phase by a volume fraction of 5.0, 8.5, and 12%. The final optimum nano-emulsion formulation with 12% dispersed phase, a water to surfactant ratio of 0.9 and folic acid content of 3mg/mL in dispersed phase was encapsulated within maltodextrin-whey protein double emulsions. It was found that the emulsification time for preparing nano-emulsions was between 4 to 16 h based on formulation variables. Droplet size decreased at higher surfactant contents and final nano-emulsions had a droplet size<100 nm. Shear viscosity was higher for those formulations containing more surfactant. Our results revealed that spontaneous method could be used successfully for preparing stable W/O nano-emulsions containing folic acid.

Studies on the retention of microencapsulated l-5-methyltetrahydrofolic acid in baked bread using skim milk powder

Our aim was to protect l-5-methyltetrahydrofolic acid (L-5-MTHF) from degradation throughout the baking and storage of a fortified white bread using microencapsulation. L-5-MTHF, with or without sodium ascorbate (ASC), was microencapsulated using skim milk powder (SMP) as the coating agent. Recoveries of L-5-MTHF in spray-dried materials were greater than 95 ± 5%. Microencapsulated L-5-MTHF was completely released from the skim milk coating material in simulated gastric fluid within the first 10 min at 37°C. Incorporation of SMP-L-5-MTHF or SMP-L-5-MTHF+ASC into bread gave recoveries of 81.3 ± 1.3% and 87.1 ± 1.2% (n=3), respectively, for L-5-MTHF immediately after bread baking. These treatments also showed significantly (p<0.05) greater L-5-MTHF stability during room temperature storage, compared to the free L-5-MTHF. This study has shown that SMP is an effective microencapsulating agent and in the presence of ASC will produce excellent conditions for stabilising L-5-MTHF in baked bread.