Method of shaping fruits and vegetables

Abstract

The present invention relates to a method for shaping fruits and vegetables using ultrasound, a convenience food comprising fruits and vegetables shaped in this way, and the use of ultrasound for shaping fruits or vegetables.

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for shaping fruits and vegetables using ultrasound, a convenience food comprising fruits and vegetables shaped in this way, and the use of ultrasound for shaping fruits or vegetables. BACKGROUND

[0002] In the field of foodstuffs, melons are part of everyday use due to their variable taste and also because they can be combined with other ingredients to play a role in, for example, "filled" products. High nutritional content and high water content, as well as local availability, are further advantages of this vegetable.

[0003] Driven by social changes related to food, the processing industry, first and foremost the convenience products and "fast food" sector, has also been attracted to these "superfoods". However, this sector of the industry is heavily dependent on standardization and simplification. For fast food restaurants, parameters such as quick preparation, quick serving and quick consumption are of paramount importance. In the case of cucumbers, for example, this means that their shape must be standardized. In addition, they also need to be gouged in order to expand the flavor product with filling. While solutions for external shaping have already been found, for example through a growing process in defined glass containers, or by actually removing the peel, their gouging still presents a problem. This is not necessarily due to the execution of the gouging or because of the seed part (cultivation of seedless cucumbers), but rather to the production of residues, as the hollowing-out procedure removes most of the flesh. In addition, according to the Federal Nutrition Center in Germany, cucumbers are one of the difficult-to-digest varieties with a flatulence effect. The latter can be reduced by, for example, a cooking procedure. However, these intermediate steps again affect the preparation time.

[0004] Therefore, progress would be made if the preparation process (cooking) of the foodstuff could be directly combined with the gouging and / or peeling of the fruits and vegetables, while producing a minimum of residues.

[0005] From the prior art (e.g. DE 10 2014 112 083 A1, EP 1 867 236 A2, US 3,382,900, US 7,096,777 B1 or WO 03 / 043443) it is known that there are automated mechanical methods for the shaping and gouging of specific varieties of fruit and vegetables. However, these methods have the disadvantage that firstly the scraped-off pith which is produced as a result of the mechanical scraping method has to be reused or disposed of, thereby increasing additional costs in the production operation. Furthermore, the mechanical devices which are present in the prior art lack a great deal of flexibility, strict requirements being placed on the shape of the fruit and vegetables in order to achieve satisfactory results. This leads to a large number of fruit and vegetables which are in principle edible being discarded, solely on account of not meeting the strict shape requirements, for example in terms of curvature, length or thickness. Furthermore, the methods of the prior art are used only for the shaping of fruit and vegetables, whereby the shaped fruit and vegetables have to be made edible in a further step, for example by cooking.

[0006] The present application is based on the object of overcoming the above-mentioned disadvantages and surprisingly determined that by means of sonochemistry, i.e. acoustic cavitation of ultrasound, fruit and vegetables can be shaped (independently of shape specifications) without the production of large amounts of residual material, while at the same time they are made edible by means of a micro-cook. SUMMARY

[0007] The present application relates to a method for shaping fruit and vegetables, said method comprising the following method steps:

[0008] a) providing a piece of fruit or a piece of vegetable;

[0009] b) irradiating the piece of fruit or the piece of vegetable with ultrasound;

[0010] c) heating the liquid in the pith of the piece of fruit or the piece of vegetable by means of acoustic cavitation;

[0011] d) destroying the cell structure of the pith by evaporation of the liquid;

[0012] e) forming a cavity in the piece of fruit or the piece of vegetable.

[0013] In a further aspect, the present application relates to a convenience food comprising one or more pieces of fruit or pieces of vegetable which have been shaped using the method described herein.

[0014] In a further aspect, the present application relates to the shaping of fruit or vegetables using ultrasound. DETAILED DESCRIPTION

[0015] The present application relates to a method for shaping fruit and vegetables, said method comprising the following method steps:

[0016] a) providing a piece of fruit or a piece of vegetable;

[0017] b) irradiating the piece of fruit or vegetable with ultrasound waves;

[0018] c) heating the liquid in the flesh of the piece of fruit or vegetable by acoustic cavitation;

[0019] d) destroying the cell structure of the flesh by liquid evaporation;

[0020] e) forming cavities in the piece of fruit or vegetable.

[0021] The method is suitable for any fruit or vegetable whose flesh is hard enough to be shaped by peeling and gouging. Particularly suitable are the cucurbits (Cucurbitaceae), such as pumpkins, melons, cucumbers and zucchinis, in particular cucumbers and zucchinis.

[0022] Preferably, the ultrasound waves are generated in an ultrasonic processor. Such ultrasonic processors are known from the prior art in connection with, for example, ultrasonic manufacturing processes, such as ultrasonic welding or ultrasonic vibration milling, and do not require further modification for the method according to the application.

[0023] The ultrasound waves are preferably transmitted to the piece of fruit or vegetable by means of a sonotrode. The sonotrode is generally the only component of the ultrasonic processor that comes into direct contact with the piece of fruit or vegetable. The sonotrode is preferably immersed in the flesh of the piece of fruit or vegetable. During this process, the liquid in the flesh is heated by acoustic cavitation.

[0024] Cavitation is understood to mean the formation of bubbles and oscillation of bubbles under the influence of high-frequency fluctuations in pressure and / or density within a liquid. The inelastic properties of parts of the medium lead to the disruption of the continuous fluid phase and the formation of bubbles. Inhomogeneities within the fluid promote cavitation. After the bubbles have formed, vapour from the surrounding liquid or gas dissolved in the liquid diffuses into the bubbles in succession. In the case of "vapour cavitation" (hard / transient cavitation), the bubbles implode after a few oscillations, locally releasing high energy intensities. When cavitation is caused by sound waves, such as ultrasound waves, it is referred to as acoustic cavitation.

[0025] Preferably, the sonotrode is adjustably mounted. By means of positional adjustment in at least one dimension, preferably in all three dimensions, and / or by means of angular adjustment, the adjustably mounted sonotrode can be adapted to the individual shape of the piece of fruit or vegetable.

[0026] The method is therefore suitable both for different kinds of fruit and vegetables having different overall shapes (for example, cherry tomatoes and watermelons); and, in one kind of fruit or vegetable, for pieces of fruit or vegetable that deviate from the regular norm in terms of curvature, length or thickness, etc.

[0027] Due to the pressure and density fluctuations of the ultrasound waves during the acoustic cavitation process, the liquid in the fruit pulp, which is usually in close proximity to the immersed ultrasound probe, is heated. As a result of the heating, the fruit pulp is preferably micro-cooked, i.e. cooked by means of the heating of the ultrasound waves.

[0028] The gouging and cooking steps can also be separated in time and / or in space.

[0029] Thus, for example, the fruit pieces or vegetable pieces can be gouged in a first step described herein. The gouged fruit pieces or vegetable pieces can then be cooked with the help of ultrasound waves in a second step. Before the cooking, the gouged fruit pieces or vegetable pieces can be filled with a food product, for example a cheese product or a meat product, for example a ground meat product. This food product can then likewise be heated (optionally micro-cooked during the heating of the liquid in the fruit pulp).

[0030] The cooking process makes the fruit or vegetable, in particular melon, more easily digestible. Thus, further cooking procedures can be dispensed with in the production of convenience foods. Thus, already edible food products can be produced with the help of the method of the present application.

[0031] The frequency of the ultrasound waves is preferably between 20 and 2000 kHz. The liquid in the fruit pulp can be locally exposed to temperatures of up to 5000 K. Further, the liquid in the fruit pulp can be locally exposed to pressures of up to 1000 bar. Further still, the liquid in the fruit pulp can be locally exposed to flow rates of up to 400 km / h. In certain locations, the heating can be accompanied by temperature jumps of up to 110 K / s. The conditions obtained here usually depend on the frequency of the ultrasound waves.

[0032] Given an appropriate duration of the exposure to the ultrasound waves, the liquid in the fruit pulp is usually heated to such an extent that it evaporates, resulting in the cell structure of the fruit pulp being disrupted. The fruit pulp thus broken up thus loses its cell stability, which is preferably pressed against the side walls of the fruit piece or vegetable piece by means of the pulses of ultrasound waves. This creates cavities in the fruit piece or vegetable piece.

[0033] The side walls, which are not affected by the ultrasound waves, are preferably compacted and reinforced by their fruit pulp, thus forming a stable container structure which is suitable for being filled with, for example, a suitable food product, for example a preserve, a chutney, a cheese product, a meat product, a chopped or ground fruit or vegetable or a mixture thereof.

[0034] In addition to the cavities in the fruit piece or vegetable piece, the method described herein can also be used to partially or completely remove the skin or peel of the fruit piece or vegetable piece.

[0035] The method described herein can also be used to form patterns or multi-dimensional structures in the fruit piece or vegetable piece.

[0036] In another aspect, the present invention relates to a convenience food comprising one or more fruit pieces or vegetable pieces shaped with the method described herein.

[0037] Preferably, the convenience food comprises fruit pieces or vegetable pieces shaped with the method described herein, preferably filled with one or more other food items (e.g. a preserve, a chutney, a cheese product, a meat product, a chopped or ground fruit or vegetable or a mixture thereof).

[0038] The convenience food can be a food item for the end consumer market or for the catering industry.

[0039] Preferably, the food item for the end consumer market is a ready-to-eat food item, which is generally from the consumer market, already prepared or ready to be consumed.

[0040] Preferably, the food item for the catering industry is a meal or a part of a meal for a fast food restaurant.

[0041] The convenience food of the present invention has the following advantages for the market:

[0042] • The method of the present invention produces less residue or waste, since the fruit flesh is not cut off but pressed against the side walls of the fruit pieces or vegetable pieces.

[0043] • The stability of the side walls of the produced fruit pieces or vegetable pieces can provide a stable container for the filling. This opens the market for filled fruits or vegetables in a way that hitherto has been considered unsuitable for fruit or vegetable varieties due to their insufficient stability.

[0044] • Using the method of the present invention, fruits and vegetables with different shapes and sizes can be processed, thus less of the usually edible fruits and vegetables is discarded.

[0045] • Using the method of the present invention, fruits and vegetables can be shaped and cooked in one procedure, thus saving further preparation steps and opening the market for raw fruits and vegetable varieties which are relatively indigestible.

[0046] • By means of the micro-cooking method by way of acoustic waves, the flavour of the convenience food of the present invention can also be controlled to some extent. Due to acoustic cavitation, chemical decomposition processes can start in the fruit pieces or vegetable pieces or in the filling exposed to the ultrasound, which can influence the flavour. Furthermore, the intended flavour is not changed by pyrolysis, as is the case with other heating techniques, such as boiling, frying or deep-frying.

[0047] • The heat input and thus the cooking process can also be controlled in a locally directed manner by the ultrasound probe.

[0048] • The method of the present application can also be used to shape frozen or deep-frozen fruits or vegetables while bringing them to the desired consumption temperature, so that an additional heating step can be dispensed with.

[0049] • Thus, by the method of the present application, convenience foods can be produced in a simple, standardized and thus cost-effective process according to the requirements of the fast-food industry, without excessive waste and with few process steps.

[0050] In another aspect, the present application relates to the use of acoustic waves for shaping fruits or vegetables.

[0051] Thereby, preferably, the acoustic waves are used according to all aspects and embodiments described herein for the method of the present application.

[0052] Example

[0053] The method of the present application for shaping fruits and vegetables is illustratively depicted in the following in connection with the gouging of a salad cucumber:

[0054] The test setup is schematically shown in Figure 1 :

[0055] The salad cucumbers were treated using a titanium ultrasound probe with a diameter of 20 mm. For other forms of fruits and vegetables, other ultrasound probes with a larger or smaller diameter can be used instead of this ultrasound probe.

[0056] The ultrasound probe was connected to an ultrasound device comprising an ultrasound generator and an ultrasound transducer, which was operated at 20 kHz with a power of 1000 W. The power can likewise be adapted individually to the fruit piece or vegetable piece to be shaped.

[0057] The salad cucumber was brought into contact with the ultrasound probe for a few seconds, during which it was guided to move upwards along the ultrasound probe. In addition, depending on the shape of the fruit piece or vegetable piece, other movements can also be carried out along the ultrasound probe, such as a transverse movement or a circumferential movement.

[0058] As can be seen in Figures 2 to 4 , the ultrasound waves produced a cylindrical hole in the salad cucumber, while the surrounding tissue was not affected.

[0059] In Figures 5 to 7 , the X-ray tomography picture shows the smooth surface of the cylindrical hole without adverse effects on the surrounding tissue. In particular, it can be seen in Figure 6 and 7 that the fruit flesh is pressed against the side wall of the resulting cylindrical hole.

[0060] During the shaping process, there is no other waste than the tissue fluid that flows out of the seed region or the cavity region.

Claims

1. A method for shaping fruits or vegetables, the method comprising the following steps: a) Provide fruit or vegetable chunks; b) Irradiate the fruit or vegetable pieces with ultrasound; c) Heating the liquid in the pulp of the fruit or vegetable chunks by acoustic cavitation, wherein, The liquid in the pulp is locally exposed to temperatures of up to 5000 K; d) Disruption of the cellular structure of the pulp through liquid evaporation; e) Forming cavities within the fruit or vegetable pieces. Forming cavities in the fruit or vegetable pieces involves pressing the damaged cellular structure of the pulp to the sides.

2. The method as described in claim 1, wherein, The fruit or vegetable pieces are irradiated with ultrasound using an ultrasonic probe.

3. The method as described in claim 1, wherein, The frequency of the ultrasound is 20 to 2000 kHz.

4. The method of claim 1, wherein, During the process of heating by acoustic cavitation, the liquid in the pulp is locally exposed to a pressure of up to 1000 bar and / or a flow rate of up to 400 km / h.

5. The method of claim 1, wherein, During the heating process of the liquid, the pulp is micro-cooked.

6. The method of claim 1, wherein, Food is used to fill hollowed-out fruit or vegetable pieces, which are then irradiated with ultrasound. As the liquid heats up, the filling is also cooked.

7. The method of claim 1, wherein, The outer skin or peel of the fruit or vegetable pieces is partially or completely removed by acoustic cavitation.

8. The method of claim 1, wherein, The cavity forms a pattern or multidimensional structure within the fruit or vegetable block.

9. The method of claim 1, wherein, The fruit or vegetable pieces are selected from melons.

10. A convenience food comprising one or more fruit or vegetable pieces formed by the method of any one of claims 1 to 9.

11. The use of ultrasound to shape fruits or vegetables by locally exposing the liquid in the pulp to a temperature of up to 5000K during a process of heating via acoustic cavitation, and by creating cavities in fruit or vegetable pieces, wherein, Forming cavities in the fruit or vegetable pieces involves pressing the damaged cellular structure of the pulp to the sides.

Images