WO2010066235A1 - Method for producing plant tissues suitable for consumption and having an increased content of quercetin and/or quercetin derivatives - Google Patents

Abstract

A method for producing a fruit that is suitable for consumption and has an increased content of quercetin and/or quercetin derivatives in the pulp, characterized by the following steps: cutting the fruit; immersing the cut fruit into an impregnating solution containing quercetin and/or quercetin derivatives; applying a vacuum to the impregnating solution containing the fruit for a predetermined time period; restoring atmospheric pressure; removing the fruit from the solution.

Description

 Process for the preparation of vegetable tissue suitable for consumption with an increased content of quercetin and / or quercetin derivatives

The invention relates to pulp enriched with secondary plant ingredients and to a process for its production.

Secondary plant ingredients have a variety of biological effects, which may include antibacterial, anti-inflammatory, antiallergic, antithrombotic, antiviral and anticarcinogenic nature. Studies show that the associated group of polyphenols reduces the risk of cardiovascular disease when ingested. In particular, flavonoids are said to have preventive properties for heart health and as anti-oxidants against free radicals.

According to the current state of knowledge, free radicals have a negative influence on the development and progression of cancers, rheumatism, arteriosclerosis, immune deficiency disorders, hepatopathies, inflammatory diseases and various infectious diseases. The body's own protection systems against free radicals lose their efficiency in the case of illnesses, sports, environmental conditions and with advancing age, therefore they require a targeted external support. Regular and adequate consumption of fruit and vegetables provides protection against chronic diseases, with polyphenols being given a special role. The average Western polyphenols intake is 23 mg per day and is covered to 60-75% by quercetin [Hertog, M.G.L., E.J.M. Feskens, et al. (1993). "Dietary Antioxidant Flavonoids and Risk of Coronary Heart Disease: The Zutphen Elderly Study." The Lancet 342 (8878): 1007-101 1, Stockt, J.-C, T. Chataigneau, et al. (2004). "Vascular protection by dietary polyphenols." European Journal of Pharmacology 500 (1-3): 299-313].

Polyphenols occur naturally in various plants as flavoring and coloring agents. As flavorings, they are responsible for the protection against predators for the sensory experience of bitterness and astringency. As dyes, they significantly affect the external appearance and, in addition, can lead to enzymatic browning reactions upon the entry of oxygen.

Enrichment of polyphenols in plants by the influence of UV radiation occurs only in the outer marginal layers, e.g. Peel, but not in the pulp itself [Hagen, S.F., G.I.A. Borge, et al. (2007). "Phenolic Contents and other health and sensory related properties of apple fruit" (Malus domestica Borkh., Cv. Aroma): Effect of postharvest UV-B irradiation. " Postharvest Biology and Technology 45 (1): 1-10.].

So far, it has been customary to administer health-promoting polyphenol preparations separately for food in the form of tablets, capsules, dragees, ointments or powders [cf. For example, DE 196 27 344 Al].

Alternatively, functional polyphenols are incorporated as additives in the formulation of foods. Thus, for example, olive oil with polyphenols from leaves of the olive tree, muffins with apple peel powder and pasta with isoflavones of the soybean meal or chicken soup were enriched by the addition of polyphenol-rich plant extracts [Paiva-Martins, F., R. Correia, et al. (2007). "Effects of enrichment of refined olive oil with phenolic compounds from olive leaves." J. Agric. Food Chem. 55 (10): 4139-4143, Rupasinghe, H.P.V., L. Wang, et al. (2008). "Effect of baking on dietary fiber and phenolics of muffins incorporated with apple skin powder." Food Chemistry 107 (3): 1217-1224, Clerici, C, K.D. R. Setchell, et al. (2007). "Pasta naturally enriched with isoflavone aglycons from soy germ reduces serum lipids and improves markers of cardiovascular risk." L Nutr. 137 (10): 2270-2278, Llorach, R., F.A. Tomäs-Barberän, et al. (2005). "Functionalization of commercial chicken soup with enriched polyphenol extract from vegetable by-products." European Food Research and Technology 220: 31-36].

The polyphenol content in native, coherent, intact plant tissue, such as apple fruit pieces, by introducing polyphenols into these tissues to increase, however, has not yet been described. Incorporation of secondary beneficial agents into intact tissues is known only for minerals and vitamins, such as the incorporation of ascorbic acid in eggs, vitamin E in apple tissue and impregnation with calcium and zinc to prevent osteoporosis [US7166314 B2, Park, S I.-L, I. Kodihalli, et al. (2005). "Nutritional, sensory, and physicochemical properties of vitamin E and mineral-fortified fresh-cut apples by use of vacuum impregnation." Journal of Food Science 70 (9): S593-S599].

The object of the invention is therefore to develop a method which makes it possible to provide plants or parts of plants with intact tissue, e.g. Fruits, with increased polyphenol content possible.

Another object is to provide apple pulp, in particular enriched with polyphenols, from intact tissue without the disadvantage of undesirable sensory properties, such as bitterness and astringency.

The object is achieved by the method having the features of claim 1. The subclaims reflect advantageous embodiments of the invention.

Surprisingly, a particularly advantageous enrichment of polyphenol in intact plant tissue can be achieved if the method comprising the following steps is used:

Cutting the vegetable fruit into pieces of the shape and size required later to obtain pulp from intact tissue. Dipping the fruit pieces in a polyphenol impregnating solution. Fixing the fruit pieces in the impregnating solution containing polyphenol. Vacuum treatment of the impregnating solution containing the fruit pieces Restoring the atmospheric pressure - The fruit pieces remain in the impregnating solution under atmospheric pressure

- Remove the fruit pieces from the solution

- Drying of fruit pieces, by microwave vacuum drying or freeze-drying.

It may prove to be an advantage if the pieces of fruit are brought to the same time in a commercial form when dividing.

In order not to cause cell damage during the enrichment, it is advantageous to use an isotonic impregnation solution.

Furthermore, it is advantageous if the impregnating solution 1.0 - contains 50 g polyphenols / L.

Advantageously, the fruit pieces should remain fixed in the impregnating solution for up to 30 minutes before applying the vacuum.

The time in which the vacuum is applied should advantageously be 1 to 30 minutes.

The vacuum should preferably be between 50 to 800 hPa.

The time in which the fruit pieces remain in the solution after restoring the atmospheric pressure should advantageously be 1 to 60 minutes.

It is particularly advantageous if the polyphenol is quercetin or a glycosylated derivative of quercetin.

It proves to be a particular advantage if the fruit pieces are apple fruit pieces.

The determination of the content of polyphenols and the increase of the polyphenol content in the pulp produced by the method can be measured by means of HPLC. Naturally, pulp contains practically no quercetin. The shell, on the other hand, has levels of the various quercetin derivatives such as isoquercitrin, hyperin, quercitrin, reynoutrin and avicularin [Wolfe, KL and RH Liu (2003). "Apple peels as a value added food ingredient."].

With the aid of the method according to the invention, it is possible to obtain a significant enrichment of the pulp with polyphenols in the dry mass.

Compared to the polyphenols contained in trays, the availability of polyphenols in the pulp is increased.

Depending on the type of fruit, the size of the fruit pieces, the vacuum setting, the duration of the treatment, the impregnation solution chosen and the appropriate extract addition, the possible salary increases vary.

The achieved accumulation of polyphenols in the pulp is a surprising result, since, in contrast to minerals and vitamins, for which an enrichment in the pulp has already been described, polyphenols differ structurally significantly. The polyphenols with their subclasses hydroxycinnamic acids, hydroxybenzoic acids, anthocyanidins, flavonols, flavanols, isoflavones, stilbenes and lignans are characterized by an aromatic ring structure which may be linked to hydroxyl groups, acid groups and carbohydrates. Quercetin, a flavonol, is composed of two aromatic rings and one heterocyclic ring and contains five hydroxy groups.

quercetin Polyphenols are often glycosylated and are therefore linked to various sugar residues. Transport into the intact tissue of the pulp was not expected in such compounds due to their size and their limited solubility.

The increase in bitterness and astringency of the samples to be expected with increasing polyphenol content could surprisingly be avoided by connecting a freezing or a microwave vacuum drying step to the impregnation process. A taste sensory test showed no increase in bitterness and no astringency of the samples.

This coupling resulted in a polyphenol-rich product with positive sensory properties and pleasant consistency. Undesirable color changes due to enzymatic browning reactions and oxidation reactions due to increased polyphenol contents are unexpectedly not observed.

Figure 1 shows the quercetin content in apple Elstar, in relation to an untreated apple.

Table 1 shows the comparison of Quercetinglykosidgehalte of apple slices according to the invention with commercial apple chips

Table 1: Comparison of quercetin glycoside contents, including quercetin, of apple slices of the invention with commercial apple chips

Content of quercetin and quercetin glycosides calculated as quercetin-3-glucoside equivalents As plants or parts of plants are root, shoot, leaves and especially fruits in question, which are used as fruit or vegetables.

When fruit, in particular apples, are used, the products according to the invention are eminently suitable for use in compound foods to which dry fruits are added, e.g. Muesli, cereal bar.

Material and methods:

The invention will be explained in more detail with reference to a preferred exemplary embodiment:

Elstar apples are sliced and dipped into the impregnating solution. By means of a device which prevents the discs from rising, it can be ensured that the plant material is in the solution during the entire impregnation phase. In order not to cause cell damage during enrichment, an isotonic impregnation solution is used. In the experiment, a 0.3% apple peel extract added apple juice with 11.3 ° Brix was used. In addition to quercetin, the extract obtained from the skins of apples also contains other typical aphypal polyphenols which are enriched during treatment. In the next step, the vacuum treatment of the samples in a vacuum oven at 100 mbar for a period of 5 minutes. During this vacuum phase, the air of the porous apple tissue bubbles out. Subsequently, the atmospheric pressure is restored and the apple slices remain in the impregnating solution for 10 minutes. In this phase, the fluid, including the polyphenols, is sucked into the intercellular spaces of the tissue. After the service life, the fully soaked samples can be removed from the solution and dripped off. Finally, the apple slices are dried.

The Flavonoidbestimmung and caused by the impregnation process increase Quercetinderivatgehalte by means of HPLC-DAD at 365 nm. HPLC method

The detection of the contents of quercetin and quercetin derivatives took place in a

Wavelength of 365 nm by means of reversed-phase HPLC (Agilent technology, Waldbronn).

Diode Array Detector: HP l 100 Series, G 1315 A

Autosampler: HP l 100 Series, G 1313 A

Pump: HP l 100 Series, G 1311 A

Degasser: HP l 100 Series, G 1322 A

Column: CC 125/4 Nucleodur Sphinx RP, 5 μm (Macherey-Nagel,

Düren)

Temp .: 30 ° C

Injection volume: 10 μl Flow rate: 1 ml / min Eluent A: 0.5% formic acid (Carl Roth GmbH & Co., Karlsruhe) Eluent B: acetonitrile (HPLC grade, Carl Roth GmbH & Co., Karlsruhe)

Tab. 2: Gradient program

Time [min]% acetonitrile

0 5

25 20

28 35

30 80

35 5

38 5

Claims

1. A method for producing a fruit suitable for consumption with an increased content of quercetin and / or quercetin derivatives in the pulp, characterized by the steps: - cutting the fruit; - dipping the sliced fruit in an impregnating solution containing quercetin and / or quercetin derivatives; Applying a vacuum to the impregnation solution containing the fruit for a predetermined period of time; - restore the atmospheric pressure; - Remove the fruit from the solution. 2. The method according to claim 1, characterized in that the quercetin derivative is a glycosylated derivative of quercetin. 3. The method according to any one of the preceding claims, characterized in that the impregnating solution contains a content of 0.1 to 5% quercetin and / or quercetin derivatives. 4. The method according to any one of the preceding claims, characterized in that the fruit remains immersed in the impregnating solution for 30 minutes prior to application of the vacuum. 5. The method according to any one of the preceding claims, characterized in that the vacuum is 50 to 800 hPa. 6. The method according to any one of the preceding claims, characterized in that the vacuum is applied at least for 1 min and at the longest for 30 min. 7. The method according to any one of the preceding claims, characterized in that the fruit remains after recovering the atmospheric pressure for 1 min to 60 min immersed in the impregnating solution. 8. The method according to any one of the preceding claims, characterized in that the cutting of the fruit is carried out to produce cut into a commercial shape pieces. 9. The method according to any one of the preceding claims, characterized in that the fruit is fixed in the impregnating solution. 10. The method according to any one of the preceding claims, characterized in that the impregnating solution is isotonic. 11. The method according to any one of the preceding claims, characterized in that the fruit between the restoring of the atmospheric pressure and the removal of the fruit from the impregnating solution for a predetermined time remains in the impregnating solution. 12. The method according to any one of the preceding claims, characterized in that the fruit removed from the impregnating solution is dried. 13. The method according to claim 12, characterized in that the drying takes place by means of microwave vacuum drying or freeze-drying. 14. The method according to any one of the preceding claims, characterized in that the fruit is an apple.