Observations from the study demonstrated that the nanostructured lipid carriers (R-NLCs) did not affect the appearance of enriched food beverages when applied as the nutrient carriers.
The R-NLCs also proved stable against degradation during processing and storage time and were made of safe and food grade components.
These findings come at a time where consumers are shifting towards foods that contain more multifunctional ingredients and less of those deemed unhealthy.
However, in catering to this consumer demand for low-fat products for example, dietary deficiencies in fat-soluble nutraceuticals such as vitamins, carotenoids and phytosterols may arise.
Using nanodelivery systems such as food grade R-NLCs can potentially provide foods with these health-beneficial compounds. However, some of these compounds suffer from low solubility in aqueous media and weak stability during the processing and storage period.
The direct addition of flavonoids, such as rutin, into foods or beverages suffers from such a problem. Hence, using nanotechnology to effectively deliver the phyto-constituent goodness of rutin could lead to new methods for creating novel functional foods.
Testing R-NLC properties
Here, the team from the University of Tabriz in Iran began by loading rutin into food grade NLCs in different rutin to lipid ratios (5, 10, and 20%).
Next, the particle properties of different R-NLC formulations, such as size, poly dispersity index, encapsulation efficiency, loading capacity, and encapsulation stability were evaluated.
After this had been carried out, three food samples including milk, orange, apple juices, and their models were fortified with optimum formulation of R-NLC.
In order to remove possible chemical contact between the R-NLCs and the food ingredients, 50 ml of deionized water was utilised as the food model media. The pH of food models was set to 6.51, 3.27, and 3.73 for the milk, orange juice, and apple juices.
Then, 500 µl of the R-NLC (containing 2 mg rutin and an R/L ratio of 10%) was mixed with the 50 ml of the food samples/models.
The stability of the R-NLCs was evaluated based on the particle size and rutin leakage from the R-NLCs during the period of storage (45 days) at 5 °C.
“In this research, R-NLCs were produced from the commonly used and acceptable food grade ingredients such as the cacao butter, oleic acid, and food grade surfactant,” the study explained.
“Preparing NLCs from the common and easily accessible food resources not only produces food grade NLCs, but also makes the final product cheaper, which could provide the large scale production of food grade NLCs.”
NLCs in industry
Up till now, the majority of NLCs formulations have been created for the pharmaceutical and cosmetics industry.
These NLCs are produced with non-food grade excipients, which are not suitable for food applications.
Designing food grade NLCs, which can be utilised in food systems, may provide encapsulation solutions for nutraceuticals and production of functional foods.
NLCs have been used to improve the delivery of phyto-active compounds albeit for short half-life bio-active compounds such as silybin.
Previous attempts in creating NLCs loaded with phyto-active compounds such as quercetin, green tea extracts, silymarin, and curcumin have been carried out in the past.
NLCs have been reported to be an effective method for enhancing the healthier effects of quercetin. NLCs have been found to enhance the antioxidant and antimicrobial effects of green tea extracts.
“Daily intake value of rutin is about 1.5 to 70 mg/kg, which varies by country and nutritional habit,” the study said.
“The main disadvantages are its very low solubility in an aqueous phase that reduces the biological access to this phyto-active compound. Thus, in this research, food grade NLC was prepared to encapsulate rutin for food fortification and development of new functional foods.”
Source: Journal of Functional Foods
Published online ahead of print, doi:10.1016/j.jff.2016.07.017
“Novel nanostructured lipid carriers as a promising food grade delivery system for rutin.”
Authors: Afshin Babazadeh