WO2013035029A1

WO2013035029A1 - Puree preparation method and device

Info

Publication number: WO2013035029A1
Application number: PCT/IB2012/054541
Authority: WO
Inventors: Renjun YU; Xin Chen
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2011-09-07
Filing date: 2012-09-03
Publication date: 2013-03-14

Abstract

The present invention relates to a method of preparing puree including: providing pieces of raw material in a blending unit; heating the pieces of raw material; and blending the pieces of raw material when the pieces of raw material have been heated to a first temperature, wherein during the blending step, the heating step is controlled such that the temperature of the pieces of raw material being blended is between the first temperature and a second temperature, the second temperature being higher than the first temperature. The main advantage of this invention is that more high-temperature-sensitive nutrients can be preserved.

Description

PUREE PREPARATION METHOD AND DEVICE

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of food processing, and more particularly to a method and device for preparing puree.

2. Description of the Prior Art

As a baby grows and becomes more active, breast milk alone is not sufficient to meet his/her nutritional needs. Usually at the age of 6 months, supplementary foods are needed to fill the gap between the total nutritional needs of the baby and the nutrients provided by breast milk.

Fruit puree is a good choice to start supplementary feeding. In addition to learning eating skills, the baby also receives food containing nutrients such as carbohydrates, proteins, vitamins, minerals and polyphenols and the like, which are important to the growth of the baby.

Vitamin C is an essential nutrient which has the following benefits:

- it can form collagen, a tissue that helps to hold cells together;

- it is essential for healthy bones, teeth, gums, and blood vessels; and

- it helps the body to absorb iron and calcium, aids in wound healing, and contributes to brain function.

Polyphenols are a certain group of phytochemicals which have the following benefits:

- they are good antioxidants;

-they can prevent tooth decay, certain kinds of cancers, and hypertension; and - they can kill fungal and pathogenic bacteria.

However, for the human body, both vitamin C and polyphenols must be acquired from an outside source. So it is important for the growing baby to intake enough vitamin C and polyphenols from his/her food, e.g. from fruits and vegetables.

The common preparation process of fruit puree includes several steps such as cleaning, peeling, coring, cutting into smaller pieces, and blending. An electric blender or manual blender is usually used to blend the small fruit pieces. During this preparation process, some unstable nutrients in the fruits are prone to being destroyed. From papers and our research, we learn that vitamin C and polyphenols in apples can be easily destroyed during this preparation process.

Some scientific researches show that the stability of vitamin C decreases with increases of temperature, pH, and concentration of metal ion and oxygen in the immediate environment, and polyphenols are also influenced by those conditions. However, enzymes in fruit, such as ascorbic acid oxidase, polyphenol oxidase and peroxydase, are significant factors which speed up the loss of both vitamin C and polyphenols greatly during or after blending. Before the blending operation, these enzymes and the vitamin C and polyphenols are in different areas of the cells, and therefore the influence of enzymes is limited to a relatively low level. However, during or after the blending process, the enzymes, vitamin C and polyphenols are so well-mixed that the influences of the enzymes are enhanced significantly. Meanwhile, the polyphenol destruction induces unwanted enzymatic browning in the fruit puree, causing its color and flavor to change.

In the food industry, blanching, a short heat treatment using water, is widely used as a pre-treatment in the production of fruit puree and juice to destroy or deactivate enzymes.

However, both vitamin C and polyphenols are high-temperature-sensitive substances; especially vitamin C is very unstable at high temperature. So the pre-heating treatment itself also induces the loss of these nutrients.

Several devices for preparing puree at home are commercially available, incorporating a steamer and a blender, which can steam food before blending it, such as AVENT Combined

Steamer and Blender (a product of Philips) and Beaba Baby Cook (a product of Beaba). The Beaba Baby Cook for example, as shown in Fig. 1 , includes three separate units: a steaming unit 11, a blending unit 12 and a base module 13. The base module 13 contains a power supply, a motor for driving a blade rotator, a control panel and associated circuits. Raw material 14 is placed in the blending unit 12. Steam is generated in the steaming unit 11 and enters the blending unit 12 to heat the raw material 14. Once the heating process is finished, the heated material can be blended in the blending unit 12. However, the choice between steaming and blending is made manually by the user, i.e. if the user wants to blend the cut apple pieces to puree without steaming, he will just use the "blending" function. Only if the user willingly wants to heat the food before blending it, he uses the "steaming" function. The duration of the steaming process can be set by the user with a timer or is determined by the amount of water added into the steaming unit 11. Thus, these devices are inconvenient for use because both heating temperature and time cannot be controlled automatically.

Accordingly, there is a need to improve the heating process of such a puree preparation method and device.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a method of preparing puree, using a well-controlled heating process.

To this end, a method of preparing puree is provided, which comprises the steps of:

- providing pieces of raw material in a blending unit;

- heating the pieces of raw material; and

- blending the pieces of raw material when the pieces of raw material have been heated to a first temperature;

wherein during the blending step, the heating step is controlled such that the temperature of the pieces of raw material being blended is between the first temperature and a second temperature, the second temperature being higher than the first temperature.

The first temperature may be a reversible deactivating temperature and the second temperature may be an irreversible deactivating temperature.

According to an example of the invention, the method of preparing puree may further comprise a step of obtaining temperature parameters, associated with the first temperature and/or the second temperature, from a user interface or from a memory which pre-stores temperature parameters associated with the first and second temperatures of multiple kinds of raw materials.

According to an example of the invention, the heating step is controlled to heat the pieces of raw material discontinuously.

According to an example of the invention, during the period of blending and after said period of blending, the heating step is controlled to keep the temperature of the pieces of raw material at the first temperature for a first period, then heat them to the second temperature, and subsequently keep the pieces of raw material at the second temperature for a second period to irreversibly deactivate the enzymes.

Since, by using this method, the first temperature and the second temperature are each associated with the characteristics of the raw material, and the method implements the blending step in a certain temperature range (between first and second temperature), the method can improve the preservation of nutrients as compared to the prior art. The method also shortens the time necessary for making puree, because instead of first heating and then blending the raw material, the blending step demonstrates an overlap with the heating step.

According to an example of the invention, the step of providing the pieces of raw material in the blending unit comprises the steps of cutting the raw material into pieces and storing them in the blending unit manually or mechanically.

According to an example of the invention, the step of heating the pieces of raw material further comprises at least one of the following steps: generating steam by a steam generator arranged inside or outside the blending unit; and emitting microwaves by means of a microwave heater arranged in the blending unit.

According to an example of the invention, the step of controlling the heating process comprises the step of detecting the temperature of the pieces of raw material by means of a temperature sensor mounted in the blending unit. The temperature sensor may be a needle-shaped sensor mounted at the bottom of the blending unit.

According to an example of the invention, the first temperature of the pieces of raw material and the second temperature are controlled through adjusting the heating time. An embedded control program can be designed by using both physical calculations and results of experiments to determine the heating time for different desired temperatures. The embedded control program uses different heating time settings to control the first temperature and the second temperature of the pieces of raw material. According to another example of the invention, the raw material is selected from one or more components of a group comprising fruit, vegetables, fish and meat.

According to still another example of the invention, the first temperature is a reversible deactivating temperature and the second temperature is an irreversible deactivating temperature. For most enzymes in fruit and vegetables, the reversible deactivating temperature is about 50-60°C and the irreversible deactivating temperature is about 70-80°C.

The present invention also provides a device for preparing puree, which comprises:

- a base module;

- a blending unit arranged on the base module for blending pieces of raw material used for preparing the puree; and

- a heating unit arranged within or outside the blending unit for heating the pieces of raw material;

wherein the device further comprises a control unit for controlling the blending unit to blend the pieces of raw material when the pieces of raw material have been heated to a first temperature, and for controlling the heating unit in such a manner that the temperature of the pieces of raw material being blended is between the first temperature and a second temperature, the second temperature being higher than the first temperature.

According to an example of the invention, the control unit comprises a needle- shaped temperature sensor mounted at the bottom of the blending unit for sensing the temperature of the pieces of raw material.

According to an example of the invention, the control unit comprises an embedded control program for determining heating times associated with different desired temperatures.

Preferably, the heating unit comprises a steam generator arranged within or outside the blending unit for generating heating steam and/or a microwave heater arranged in the blending unit for emitting heating microwaves. The steam generator can also generate cooling steam for cooling the pieces of raw material to a desired temperature.

Other objects, advantages, and novel features of the present invention will be apparent from the following detailed description of a preferred embodiment thereof with reference to the attached drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic view of the structure of a prior art puree preparing device;

Fig. 2 is a schematic view of the structure of a puree preparing device according to the present invention; and

Fig. 3 is a schematic block diagram showing a method of preparing puree according to the present invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

Definitions of technical terms

Raw material: material(s) such as fruit, vegetables, fish and/or meat that can be blended to puree.

Reversible enzyme deactivating temperature (RDT): a temperature (usually 45-65°C, preferably 50-60°C and most preferably 55°C) at which the activity of enzymes in the raw material (chiefly fruit and vegetables) is temporally deactivated, but can recover at a lower temperature.

Irreversible enzyme deactivating temperature (IDT): a temperature (usually 65-85°C, preferably 70-80°C and most preferably 75°C), at which the activity of the enzymes in the raw material (chiefly fruit and vegetables) is permanently deactivated, and cannot recover later.

Detailed description

As shown in Fig. 2, the device for preparing puree according to the present invention includes a base module 23, a blending unit 22 arranged on the base module 23 for blending pieces of raw material 24 used for preparing the puree, a heating unit 21 arranged outside the blending unit 23 for heating the pieces of raw material (the heating unit 21 may optionally be arranged within the blending unit 23, for instance arranged at a top cover (now shown) of the blending unit 23), and a control unit (not shown) arranged in the base module 23 for controlling the blending unit 22 to blend the pieces of raw material 24 when the pieces of raw material 24 have been heated to a first temperature and for controlling the heating unit 21 in such a manner that the temperature of the pieces of raw material 24 being blended is between the first temperature and a second temperature, the second temperature being higher than the first temperature.

The control unit comprises a needle-shaped temperature sensor 25 mounted at the bottom of the blending unit 22 for sensing the temperature of the pieces of raw material 24. Optionally, the control unit may comprise an embedded control program for determining heating times associated with different desired temperatures.

Preferably, the heating unit 21 comprises a steam generator arranged within or outside the blending unit 22 for generating heating steam and/or a microwave heater arranged in the blending unit 22 for emitting heating microwaves. The steam generator can also generate cooling steam for cooling the pieces of raw material 24 to a desired temperature.

With reference to Figs. 2 and 3 together, the method of preparing puree includes the steps of: starting the device for preparing puree (step 301); introducing pieces of raw material 24 into the blending unit 22 (step 302); heating the pieces of raw material 24 (step 303); blending the pieces of raw material 24 when the pieces of raw material 24 have been heated to a first temperature (step 304); taking out the blended pieces of raw material 24 (i.e. the puree) from the blending unit 22 for the purpose of drinking or eating it (step 305); and turning off the puree preparation device(step 306).

During the blending step, the heating step is controlled such that the temperature of the pieces of raw material 24 being blended is between the first temperature (a reversible enzyme deactivation temperature) and a second temperature (an irreversible enzyme deactivation temperature), the second temperature being higher than the first temperature.

During the period of blending and after said period of blending, the heating step is controlled to keep the temperature of the pieces of raw material 24 at the first temperature for a first period, then heat them to the second temperature, and subsequently keep the pieces of raw material 24 at the second temperature for a second period for irreversibly deactivating the enzymes. The duration of the first period is determined by or associated with the taste preference of the user, the desired consumption(?) time of the user, the nature of the raw material, e.g. the enzyme deactivating characteristics over time, the specific heating requirement of the raw material and the temperature/time sensitivity of the nutrients (i.e. at which temperature and how long will it take before the nutrients are destroyed), and so on. In general, the duration of the second period is set as short as possible as long as the enzymes in the raw material are sufficiently deactivated. In general, the duration of the second period is determined by or associated with the taste preference of the user, the desired consumption, the nature of the raw material (especially the temperature/time sensitivity of the nutrient destruction characteristics over time and the enzyme deactivation characteristics over time), and so on.

More specifically, the pieces of raw material 24 can be blended in several ways, as shown by way of examples, which are not to be construed as limitations in table 1 , in which TO denotes the original temperature (in general, room temperature) of the raw material; Tl denotes the RDT of the raw material; T2 denotes the IDT of the raw material.

Table 1

heating raw material from Tl to T2 yes

keeping the temperature of raw material at T2 no

heating raw material from TO to Tl no keeping the temperature of raw material at Tl yes

5

heating raw material from Tl to T2 yes keeping the temperature of raw material at T2 yes

From table 1 we can see that the pieces of raw material can be heated discontinuously or continuously. The different time requirements can be fulfilled by selecting different heating patterns.

It is to be understood that starting the blending step when the pieces of raw material have been heated to a first temperature means that the blending step is implemented when the first temperature is reached so as to make sure the enzyme is deactivated during the blending step, but this does not mean that the blending step must be implemented immediately when the first temperature is reached; the blending step can also be performed after the first temperature is reached. This depends on the time requirement of the user; for example, if the user wants to make puree as quickly as possible, he may want to implement the blending step immediately when the first temperature is reached, thereby shortening the puree making process.

The first temperature is a reversible deactivating temperature (preferably 50-60°C for most fruits and vegetables). The second temperature is an irreversible deactivating temperature (preferably 70-80°C for most fruits and vegetables). However, the second temperature can also be higher (e.g. 100°C) for some vegetables, which need to be fully cooked to be suitable for consumption. The first temperature and the second temperature of the pieces of raw material may be controlled through adjusting the heating time. An embedded control program can be designed by means of both physical calculations and results of experiments to determine the heating time for different desired temperatures. The embedded control program uses different heating time settings to control the temperature of the pieces of raw material 24. As an alternative, the temperature of the pieces of raw material 24 may also be detected and controlled by a needle-shaped temperature sensor 25 mounted at the bottom of the blending unit 22. According to an example of the invention, the step of providing the pieces of raw material 24 into the blending unit 22 can be performed by cutting the raw material into pieces and introducing them into the blending unit 22 manually or mechanically; the method of preparing puree may further comprise a step of obtaining temperature parameters associated with the first temperature and/or the second temperature from a user interface (not shown) or from a memory which pre-stores temperature parameters associated with the first and second temperatures of multiple kinds of raw materials; and the step of heating the pieces of raw material 24 further comprises a step of generating steam by a steam generator arranged inside or outside the blending unit; and/or emitting microwaves by a microwave heater arranged in the blending unit.

Our experiments show that a well-controlled heating process before blending can increase the preservation of the vitamin C and polyphenols. Apples are first cleaned, peeled, cored and cut into smaller pieces of similar size. Some apple pieces are directly blended into puree using an AVENT blender (SCF860/20). Others are pre-heated for different periods, using the AVENT combined steamer and blender (SCF870/21). The final internal temperature of each piece is recorded just after heating. And then the heated apple pieces are blended into puree using the AVENT blender (SCF860/20). The vitamin C content and total polyphenols in each puree are measured right after the blending process. The experiment results show that:

- a well-controlled heating process (for instance instant steaming for 180s (instant steaming means that materials are steamed just after the steam has been generated in the steamer and blender)) can increase the preservation of vitamin C in the puree by 20% and of the total of polyphenols by 180%, while continuous further heating will not further increase the preservation of vitamin C or polyphenol, since they may be decomposed by the high temperature; and

- the browning of the puree is also inhibited greatly.

The main advantage of this invention is that: during the puree preparation process, the heating temperature and period are well-controlled by the control unit. Consequently, more high-temperature-sensitive nutrients can be preserved and the puree making time is shortened.

It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, number, and arrangement of parts within the scope of the invention as indicated to the full extent by the broad general meaning of the terms in which the appended claims are expressed.

It should be noted that the abovementioned embodiments illustrate rather than limit the invention and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, the word "comprising" does not exclude the presence of elements or steps not listed in a claim or in the description. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. In the apparatus claims enumerating several units, several of these units can be embodied by one and the same item of hardware or software. The usage of the words first, second and third, et cetera, does not indicate any ordering. These words are to be interpreted as names.

Claims

1. A method of preparing puree comprising the steps of:

- providing (302) pieces of raw material (24) in a blending unit (22);

- heating (303) the pieces of raw material (24); and

- blending (304) the pieces of raw material (24) when the pieces of raw material (24) have been heated to a first temperature;

wherein, during the blending step, the heating step is controlled such that the temperature of the pieces of raw material (24) being blended is between the first temperature and a second temperature, the second temperature being higher than the first temperature.

2. The method of preparing puree as claimed in claim 1 , wherein the first temperature is a reversible enzyme deactivation temperature and the second temperature is an irreversible enzyme deactivation temperature.

3. The method of preparing puree as claimed in claim 1 , wherein during the period of blending and after said period of blending, the heating step (303) is controlled to keep the temperature of the pieces of raw material (24) at the first temperature for a first period, and then heat them to the second temperature, and subsequently keep the pieces of raw material (24) at the second temperature for a second period for irreversibly deactivating the enzymes.

4. The method of preparing puree as claimed in claim 1 , wherein the step (302) of providing the pieces of raw material (24) in the blending unit (22) comprises the steps of cutting the raw material into pieces and introducing them into the blending unit (22) manually or mechanically.

5. The method of preparing puree as claimed in claim 1 , wherein the step (303) of heating the pieces of raw material (24) further comprises at least one of the following steps: - generating steam by a steam generator arranged inside or outside the blending unit (22);

- emitting microwaves by means of a microwave heater arranged in the blending unit (22).

6. The method of preparing puree as claimed in claim 1 , wherein the step of controlling the heating process comprises a step of detecting the temperature of the pieces of raw material (24) by means of a temperature sensor (25) mounted in the blending unit (22).

7. The method of preparing puree as claimed in claim 1 , further comprising a step of obtaining temperature parameters associated with the first temperature and/or the second temperature from a user interface or from a memory which pre-stores temperature parameters associated with the first and second temperatures of multiple kinds of raw materials.

8. The method of preparing puree as claimed in claim 1 , wherein the heating step (303) is controlled to heat the pieces of raw material (24) discontinuously.

9. The method of preparing puree as claimed in claim 1 , wherein the raw material is selected from fruits and/or vegetables.

10. The method of preparing puree as claimed in claim 2, wherein the reversible deactivating temperature is about 50-60°C and the irreversible deactivating temperature is about 70-80°C. 1. A device for preparing puree comprising:

a base module (23);

a blending unit (22) arranged on the base module (23) for blending pieces of raw material (24) used for preparing the puree; and a heating unit (21) arranged within or outside the blending unit (22) for heating the pieces of raw material (24);

characterized in that the device further comprises a control unit for controlling the blending unit (22) to blend the pieces of raw material (24) when the pieces of raw material (24) have been heated to a first temperature, and for controlling the heating unit (21) in such a manner that the temperature of the pieces of raw material (24) being blended is between the first temperature and a second temperature, the second temperature being higher than the first temperature.

12. The device for preparing puree as claimed in claim 1 1 , wherein the control unit comprises a needle-shaped temperature sensor (25) mounted at the bottom of the blending unit (22) for sensing the temperature of the pieces of raw material (24).

13. The device for preparing puree as claimed in claim 1 1 , wherein the control unit comprises an embedded control program for determining heating times associated with different desired temperatures.

14. The device for preparing puree as claimed in claim 1 1 , wherein the heating unit (21) comprises a steam generator arranged within or outside the blending unit (21) for generating heating steam and/or a microwave heater arranged in the blending unit (21) for emitting heating microwaves.

15. The device for preparing puree as claimed in claim 14, wherein the steam generator can also generate cooling steam for cooling the pieces of raw material (24) to a desired temperature.