BACKGROUND

1. Field

The disclosure of the present patent application relates to food colorants, and particularly to an anthocyanin synthesized from date palm and the method of synthesizing the anthocyanin by extraction from date palm leaves.

2. Description of the Related Art

In general, phytochemicals (such as phenolics, carotenoids, sterols, alkaloids, and anthocyanins) are extracted from natural sources using organic solvents. However, these methods frequently require either expensive, time-consuming steps to remove all traces of the organic solvents and separate the individual phytochemicals, or may result in a contaminated extract containing trace amounts of organic solvents or a mixture of desired and undesired phytochemicals.

Recent work has focused on developing environmentally friendly, cost-effective methods of extraction, including supercritical fluid extraction (SFE), microwave extraction (MWE), pulsed electric field (PEF), high-pressure processing (HPP), ultrasonic extraction (UE), and ohmic heating (OH). These approaches generally avoid issues with thermal degradation and provide easier separation without the risk of retaining residual organic solvents. However, these approaches must be optimized for individual plant compositions, as minor variations in pre-treatment materials and extraction conditions can vary significantly based upon the specific plant composition and desired phytochemical.

Anthocyanins are water-soluble compounds having polyphenolic structures that provide a degree of hydrophobic character. As a result of their polyphenolic structures, anthocyanins are also soluble in organic solvents. The combination of both polar and hydrophobic regions makes anthocyanins particularly difficult to extract.

Thus, an anthocyanin synthesized from date palm solving the aforementioned problems is desired.

SUMMARY

The anthocyanin synthesized from date palm may be obtained by extracting an anthocyanin from date palm leaves and reacting the anthocyanin with phenolic compounds also extracted from the date palm leaves in order to produce a co-pigmented anthocyanin complex. The anthocyanin may be extracted by collecting date palm (Phoenix dactylifera) leaves, shredding and grinding the date palm leaves to obtain date palm leaf powder, mixing the date palm leaf powder with water containing about 1.08% hydrochloric acid (100-150 g date palm leaf powder per liter) in a glass or ceramic lined reactor, and extracting anthocyanins from the date palm leaves by boiling the mixture for an hour until the mixture turns red, indicating the successful extraction of the anthocyanins and their combination with phenolic compounds also extracted from the date palm leaf powder. The color of the co-pigmented anthocyanin complex produced by this method may be adjusted by continuing the heating in half-hour increments in order to deepen the hue of the co-pigmented anthocyanin complex. The co-pigmented anthocyanin complex may be separated from the liquid mixture by first filtering the liquid mixture, refining the liquid mixture by adding gelatin to remove the salt, and freeze-drying the refined liquid mixture.

The co-pigmented anthocyanin complex synthesized from date palm leaves may be useful as a food colorant, nutritional supplement, or anti-oxidant additive to food, pharmaceuticals, beverages, or the like.

These and other features of the present subject matter will become readily apparent upon further review of the following specification.

