If I were an apple,and grew on a tree.Apple Peel and Core Extract.

Phloridzin-rich phenolic fraction and use thereof as a cosmetic, dietary or nutraceutical agent.

Apple Peel and Core Extract Apple Polyphenol photo picture image The present invention relates to a phenolic fraction from fruit and also to the process for obtaining this fraction. This extract rich in an antioxidant compound, phloridzin, can be used as a cosmetic, dietary or nutraceutical preparation.

It is known that polyphenolic compounds are relatively widespread and in large amount in the plant kingdom. In the Rosaceae family in particular, the analysis of the polyphenols of apple has led to the identification of at least 37 phenolic compounds, the most abundant of which are chlorogenic acid, procyanidins B1 and B2, epicatechin, phloretin, phloridzin and p-coumaric acid. Some of these compounds have physiological properties such as antioxidant, anti-mutagenic, antiallergic, anticancer and antidiabetic properties, and the like.

Among the phenolic compounds, phloretin and its glycosylated derivative, phloridzin, are typical of apple and the other fruit of the Rosaceae family. In particular, phloridzin is found in large amount in the pips, but it is also present in apple juice and skin. Phloridzin has antioxidant activity allowing a cardiovascular protection similar to that of estrogens. Moreover, phloridzin is capable of acting on melanogenesis by activating a cascade of enzymes including tyrosinase, thus allowing increased protection against ultraviolet radiation. Phloridzin also has antidiabetic action by competitive inhibition of the sodium-dependent blood transport of metabolites such as glucose, galactose and the like. Phloridzin is also involved in inhibiting the growth of tumor cells by blocking the activity of protein kinase C.

However, in apple (homogenate or juice), the dihydrochalcones (phloretin and phloridzin) are present in small amount relative to the other polyphenols. Chlorogenic acid and the procyanidins are the major polyphenols in apples, whether these are cider apples or dessert apples, phloridzin and phloretin never representing more than 5% by weight of the total polyphenols of ripe cider apples (analysis of 15 different varieties).

In the known polyphenolic extracts, the proportions between the various phenolic molecules are conserved relative to the proportions present in the various starting materials, with the exception of the polymeric procyanidins, which are lost or degraded during the extraction.

Polyphenolic extracts rich in hydroxycinnamic acids (caffeic acid, chlorogenic acid and coumaric acid) and in flavanols (catechin, epicatechin and procyanidins), and poor in dihydrochalcones (phloridzin and phloretin) are thus conventionally obtained.
Apple Peel and Core Extract Apple Polyphenol photo picture image

Details of the invention as following:

The polyphenolic fraction in accordance with the invention comprises at least 20% by weight of polyphenols and preferably 50%, at least 10% by weight of which is composed of phloridzin, and preferably between 10% and 70%. This extract can also comprise in its composition chlorogenic acid, epicatechin, procyanidin B2, quercitrin, p-coumaric acid and also phloretin.

One composition that is particularly preferred of this polyphenolic fraction is that it contains, by weight: more than 20% and preferably more than 50% of total polyphenols; at least 30% and preferably from 30% to 40% by weight of the polyphenols as phloridzin; not more than 11% and preferably between 2% and 11% by weight of the polyphenols as chlorogenic acid; not more than 4% of the polyphenols as epicatechin; not more than 2% of the polyphenols as procyanidin B2; not more than 1.5% of the polyphenols as quercitrin; not more than 0.4% of the polyphenols as p-coumaric acid; and less than 0.2% of the polyphenols as caffeic acid.

Another subject of the invention is that the caffeic acid is present in weight proportions of less than 20% of the weight of phloridzin present. Preferably, the caffeic acid represents less than 1% by weight of the total polyphenols in the extracts. The proportion of phloridzin is 9 times as great by weight as that of the catechin. The amount of phloridzin present is at least equivalent by weight to that of the chlorogenic acid.

Another subject of the invention is characterized in that it contains phloretin. By means of a controlled acid hydrolysis, virtually all of the phloridzin can be converted into phloretin, which is less water-soluble.

Another subject is characterized in that the dihydrochalcones are present in proportions of greater than or equal to 40% by weight relative to the hydroxycinnamic acids.

The extraction process for selectively extracting a dihydrochalcone-rich polyphenolic fraction from ripe apples is characterized in that it comprises the following steps: the crushed apples are subjected to one or more solid/liquid extractions, in the presence or absence of added water; the wet solid extract obtained is then either dried or enzymatically liquefied to obtain a liquid extract; the dry solid extract undergoes further extractions over a period of between 10 minutes and 2 hours with a polar organic solvent, preferably a C₁ C₄ aliphatic alcohol, pure or as a mixture with water, to obtain an organic extract; this organic extract is evaporated to dryness at a temperature of less than or equal to 60 deg C., preferably under reduced pressure; this residue is then taken up in water, after which it is depleted several times, preferably 4 times, with a water-immiscible solvent, preferably ethyl acetate or methyl or propyl acetate; the organic solutions obtained are mixed together and evaporated to dryness at a temperature of less than 60 deg C., and preferably less than 50 deg C., to obtain the polyphenolic fraction which is the subject of the present invention.

Via another route, the wet solid extract is mixed with water in the presence of an enzymatic mixture for a period of between 1 and 4 hours at a temperature of between 30 and 50 deg C., and preferably between 40 and 45 deg C., to obtain a liquid extract; this liquid extract is clarified by centrifugation or by filtration and then by ultrafiltration; the extract is loaded onto a chromatography column filled with an adsorbent resin of styrene-divinylbenzene type. The resin is washed with acidified water to remove the impurities and the residual sugars. The polyphenols are then eluted with an aqueous-alcoholic solution containing between 40% and 70% and preferably between 50% and 60% by weight of ethanol. Other C₁ C₄ aliphatic alcohols may be used, such as methanol or butanol; if necessary, a dewaxing step is introduced during the process; the product obtained by extraction is taken up a final time in water and then dried, preferably by atomization or lyophilization to give a beige-colored powder containing at least 20% by weight of polyphenols, preferably more than 50% of polyphenols, 10% by weight of which, and preferably between 10% and 70% of the polyphenols are dihydrochalcones, preferably phloridzin.

The fractions are obtained by the process described above, preferably from ripe apples of the Rosaceae family and in particular of the species Malus sylvestris Mill.

This extract of eating apples having the characteristics stated, obtained according to the process described above, may be used as a dietary or nutraceutical supplement.

The dihydrochalcone-rich phenolic fraction according to the invention has properties as an agent for protecting against ultraviolet radiation, and has antioxidant properties.

A subject of the invention is also a cosmetic composition comprising, inter alia, the dihydrochalcone-rich polyphenolic fraction described above.

The compositions according to the invention may be ingested or applied to the skin. According to the mode of administration, the composition according to the invention may be in any form usually used in cosmetics.

The compositions according to the invention may especially be in the form of gel capsules, milks, lotions, creams, gels or beverages.

The nutraceutical, dietary or cosmetic compositions of the present invention are conventionally formulated according to the applications for which they are intended.

The examples which follow illustrate the invention without limiting it in any way.