A sterilization method of jam containing a high proportion of fruit pulp and a finished jam and jam product thereof

Abstract

The present application provides a sterilization method of jam containing high proportion of fruit pulp, and finished jam and jam product thereof, the sterilization method of jam containing high proportion of fruit pulp comprises conveying the jam into a sterilization machine for sterilization treatment, the sterilization treatment condition is: temperature 100-120 DEG C, time is 30-32 s; after sterilization treatment, the jam is conveyed into a cooling pipe for cooling treatment, and finally stored in a sterile manner; according to the total weight of the jam containing high proportion of fruit pulp, the content of the fruit pulp is 30-45 wt%, and the fruit pulp is slender fibrous pulp. The technical scheme of the present application realizes the sterilization of the jam containing high proportion of fruit pulp, and the phenomenon of equipment alarm discharge does not occur in the sterilization process, avoids the incomplete sterilization of the jam containing high proportion of fruit pulp in the prior art, and solves the problem of raw material waste, so that the normal temperature yogurt product with only fruit pulp jam on the market becomes possible.

Description

Technical Field

[0001] This invention relates to the field of jam sterilization, and in particular to a method for sterilizing jam containing only fruit puree, as well as the finished jam and jam products thereof. Background Technology

[0002] After more than a decade of development, ambient-temperature yogurt now boasts a wide variety of flavors available on the market. In particular, ambient-temperature yogurt with added fruit pieces is especially popular due to its rich flavor. Because ambient-temperature yogurt needs to be stored at room temperature for an extended period, all materials added during the production process must be sterilized before use. For example, for jams containing fruit pieces (which generally refer to fruit cut into small pieces or spheres) added to ambient-temperature yogurt, although the jam has already been sterilized during production and transported to the yogurt factory in aseptic containers, it still needs to be sterilized again before being used in yogurt production.

[0003] Conventional sterilization methods for jams containing fruit pieces are well-established. However, the pulp of citrus fruits (such as lemons and grapefruits) cannot be cut into regular chunks or cubes; instead, it consists of long, thin, fibrous pulp. Therefore, when jams contain a high proportion of citrus pulp, this fibrous pulp easily becomes entangled in the temperature probe of the sterilizer, causing it to malfunction. This leads to a drop in the sterilization temperature displayed by the sterilizer, triggering material discharge and other problems, ultimately affecting the sterilization effect, resulting in sterilization failure and significant material loss, thus wasting raw materials. Therefore, to avoid such problems, current technology for room-temperature yogurt containing jam limits the proportion of fruit pulp in the jam to no more than 20%, and in most cases, no more than 10%.

[0004] In view of this, the present invention aims to solve the sterilization problem of jams (especially red grapefruit) containing a high proportion of fruit puree (30% to 45% fruit puree content), so as to provide a new room temperature yogurt product containing only fruit puree jam. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a method for sterilizing jam containing a high proportion of fruit puree, as well as the finished jam and jam products thereof, to solve the problems in the prior art.

[0006] To achieve the above and other related objectives, the present invention is obtained through the following technical solution.

[0007] The first aspect of the present invention provides a method for sterilizing jam containing a high proportion of fruit puree, comprising conveying the jam containing a high proportion of fruit puree to a sterilizer for sterilization treatment, wherein the sterilization treatment conditions are: temperature 100-120℃ and time 30-32s;

[0008] After sterilization, the jam is transported to a cooling pipe for cooling and then stored aseptically.

[0009] Based on the total weight of the jam containing a high proportion of fruit puree, the content of the fruit puree is 30-45 wt%, and the fruit puree is fine, elongated fibrous fruit pulp. For example, the content of the fruit puree can be 30-35 wt% or 30-40 wt%.

[0010] During the sterilization process, the sterilization of the jam is best achieved when the actual temperature in the sterilizer is between 100 and 120°C, within the sterilization temperature range. The sterilization effect is even better when the temperature is between 105 and 115°C. If the actual temperature is outside this range, the sterilization effect will be compromised.

[0011] Preferably, the jam is reheated before being conveyed to the sterilizer.

[0012] Preferably, the cooling process involves cooling the temperature to 18–24°C. For example, the temperatures could be 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, or 24°C.

[0013] Preferably, the sterilization treatment condition is a temperature of 100-120°C, which means that the temperature of the jam monitored in real time by the sterilization machine is 100-120°C during the sterilization process.

[0014] Preferably, the jam containing a high proportion of fruit puree does not contain fruit pieces. The fruit pieces mentioned in this application refer to fruits cut into small granules or spheres, including but not limited to strawberry pieces, blueberry pieces, peach pieces, apple pieces, mango pieces, pineapple pieces, etc.

[0015] Preferably, the jam containing a high proportion of fruit puree is a citrus jam.

[0016] Preferably, the length of the slender fibrous pulp is 0.5 to 1.5 cm.

[0017] Preferably, the warming process includes: warming the jam containing a high proportion of fruit puree at 20-25°C for 18-24 hours. For example, the warming temperature can be 20°C, 21°C, 22°C, 23°C, 24°C, or 25°C; and the warming time can be 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, or 24 hours.

[0018] Preferably, the citrus jam includes one or more of orange jam, grapefruit jam, tangerine jam, and mandarin jam. For example, it can be red grapefruit jam.

[0019] Preferably, the sterilizer is equipped with a heat exchanger; in the sterilization process, boiling water and / or steam are used as the heat exchange medium in the heat exchanger to maintain the target sterilization conditions and enable the sterilization process to proceed smoothly.

[0020] Preferably, in the sterilization step, the temperature range of the heat exchange medium is 95–135°C, and the temperature of the heat exchange medium is adjusted by regulating the content of boiling water and / or water vapor. During the sterilization step, if the actual temperature in the sterilizer exceeds this temperature, the sterilizer will trigger an alarm, or even stop the sterilization process and begin discharging the material.

[0021] In this application, the temperature range of the heat exchange medium in the sterilization process is a crucial parameter and is not arbitrarily set. The maximum and minimum temperatures within this range work together to influence and regulate the actual sterilization temperature. If the maximum temperature of the heat exchange medium is low, the actual temperature will drop rapidly during sterilization, potentially resulting in moments when the temperature of the jam to be sterilized is below 100°C. This can significantly impact the sterilization effect, and in severe cases, the actual temperature may even drop below 95°C, causing the equipment to discharge the jam. Conversely, if the minimum temperature of the heat exchange medium is low (e.g., set to 85°C), the actual temperature may also drop below 100°C during sterilization, failing to meet sterilization requirements and affecting the sterilization effect. If the minimum temperature of the heat exchange medium is high (e.g., set to 102°C), temperature fluctuations during sterilization can easily cause the actual temperature to drop below 102°C, leading to the equipment discharging the jam.

[0022] Preferably, in the sterilization step, the highest temperature of the heat exchange medium is 128–135°C. For example, it can be 128–130°C or 130–135°C.

[0023] Preferably, in the sterilization step, the minimum temperature of the heat exchange medium is 95–99°C. For example, it can be 95°C, 96°C, 97°C, 98°C, or 99°C.

[0024] In a preferred embodiment, the sterilizer is a Tetra Pak Indirect UHT unitPF, which has its own heat exchange system. The heat exchange system uses boiling water as the heat exchange medium, and together with its control system, the temperature of the sterilization process can be controlled.

[0025] Specifically, the sterilizer has a temperature sensor in the sterilization module that can detect and display the real-time temperature of the jam during sterilization.

[0026] The high-temperature setting on the control panel of this sterilizer corresponds to the highest value of the variable temperature of the heat exchange medium.

[0027] The low-temperature setting on the control panel of this sterilizer corresponds to the lowest value of the variable temperature of the heat exchange medium.

[0028] When the heat exchange medium is boiling water, its temperature change can be regulated by adjusting the water vapor content in the boiling water. Simply put, if the water vapor content in the heat exchange medium increases, the temperature of the heat exchange medium increases; if the water vapor content in the heat exchange medium decreases, the temperature of the heat exchange medium decreases. However, regardless of whether the temperature of the heat exchange medium decreases or increases, its temperature is between 95 and 135°C.

[0029] The preset temperatures of the high-temperature and low-temperature sections refer to the highest / lowest temperatures at which the sterilizer operates normally during the sterilization process. When the actual temperature of the sterilizer is lower than the preset temperature of the low-temperature section, the sterilizer will stop the sterilization process and enter the discharge and cleaning process, which will cause a large amount of jam in the equipment to be discharged into the waste liquid collection system, resulting in material waste.

[0030] Preferably, during the sterilization process, when the actual displayed temperature of the sterilizer approaches 100°C, boiling water is continuously supplied to the heat exchanger as the heat exchange medium, and the temperature of the heat exchange medium is increased to maintain the target sterilization conditions and ensure that the sterilization process can proceed smoothly.

[0031] Preferably, during the sterilization process, when the actual displayed temperature of the sterilizer approaches 120°C, boiling water is continuously supplied to the heat exchanger as the heat exchange medium, and the temperature of the heat exchange medium is reduced to maintain the target sterilization conditions, so that the sterilization process can proceed smoothly.

[0032] In a preferred embodiment, the sterilizer is a Tetra Pak Indirect UHT unitPF. When the actual displayed temperature of the sterilizer approaches 100°C, the operator turns off the automatic temperature control system on the control panel and switches to manual temperature control. The operator also manually adds 100°C water to the heat exchanger of the sterilizer to keep boiling water in the heat exchanger as the heat exchange medium, thereby increasing the temperature of the heat exchange medium, maintaining the sterilization conditions, and ensuring that the sterilization process can proceed smoothly.

[0033] In this application, boiling water is continuously supplied as the heat exchange medium in the heat exchanger of the sterilizer to maintain the actual sterilization temperature within the sterilization conditions. Specifically, by combining manual temperature control with the addition of a 100°C water bath to the sterilizer, the actual temperature is better maintained at the sterilization condition temperature, avoiding large fluctuations in the actual temperature during the sterilization process. This is more conducive to the smooth completion of sterilization and results in a better sterilization effect.

[0034] A second aspect of the present invention provides a finished jam, wherein the jam is obtained by sterilization using the above-described sterilization method.

[0035] Preferably, the content of fruit puree is 30-45 wt% based on the total weight of the finished jam.

[0036] A third aspect of the present invention provides a product containing the finished jam as described above.

[0037] Preferably, the product includes yogurt products, and more preferably, the product is room temperature yogurt.

[0038] This invention provides a novel method for sterilizing jam, capable of sterilizing jams containing 30-45 wt% fruit puree. The invention effectively maintains the sterilization temperature at the designated sterilization temperature, thus efficiently completing the sterilization process for jams containing a high proportion of fruit puree. Specifically, by introducing boiling water as a heat exchange medium, employing a combination of automatic and manual temperature control, and creatively adjusting the temperature range of the heat exchange medium during sterilization—specifically, the preset parameters for the high / low temperature sections of the sterilizer—multiple factors work synergistically to ensure that the temperature control during sterilization meets the set sterilization conditions, making the sterilization of jams containing a high proportion of fruit puree possible.

[0039] The jam sterilization method provided by the present invention can sterilize jam containing a high proportion of fruit puree without triggering equipment alarms or material discharge during the sterilization process. This avoids the problems of incomplete sterilization and raw material waste in the prior art, making it possible to produce room-temperature yogurt products with only fruit puree and jam on the market. Detailed Implementation

[0040] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0041] Before further describing specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the respective manufacturers.

[0042] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or equivalent to those described, apparatus, and materials in the embodiments of this invention may be used to implement the present invention.

[0043] This application does not limit the specific type and model of the sterilizer. Any commercially available sterilizer with a heat exchanger that can be used for jam sterilization is acceptable. In the following embodiments of this application, the Tetra Pak Indirect UHTunit PF sterilizer is used to perform the sterilization method.

[0044] Example 1

[0045] This embodiment provides a specific method for sterilizing jam containing a high proportion of fruit puree, which includes the following steps:

[0046] 1) Warm-up

[0047] Place the refrigerated red grapefruit puree jam (puree content 30wt%) in an aseptic container at 22℃ for 24 hours to warm up;

[0048] 2) Place in the sterilizer

[0049] The warmed jam is pumped into a jam sterilizer, where it undergoes sterilization and cooling before being transferred to a sterile container for later use. The sterilizer needs to be set to the following conditions:

[0050] a. Set the sterilization conditions of the sterilizer as follows: temperature 110℃, time 30s;

[0051] b. Set the high-temperature sterilization zone of the sterilizer to 135℃ and the low-temperature sterilization zone to 95℃;

[0052] c. When the temperature displayed by the sterilizer approaches 100℃, turn off the automatic temperature control system and switch to manual temperature control. Manually add 100℃ hot water to maintain the sterilization temperature above the preset temperature of the low temperature section by 100℃ until all the jams have been sterilized.

[0053] d. Set the material outlet temperature of the sterilizer to 24℃.

[0054] Example 2

[0055] This embodiment provides a specific method for sterilizing jam containing a high proportion of fruit puree, which includes the following steps:

[0056] 1) Same as Example 1;

[0057] 2) Place in the sterilizer

[0058] The warmed jam is pumped into a jam sterilizer, where it undergoes sterilization and cooling before being transferred to a sterile container for later use. The sterilizer needs to be set to the following conditions:

[0059] a. Set the sterilization target conditions for the sterilizer as follows: temperature 115℃, time 30s;

[0060] b. Set the high-temperature sterilization zone of the sterilizer to 130℃ and the low-temperature sterilization zone to 99℃;

[0061] c. When the temperature displayed by the sterilizer approaches 100℃, turn off the automatic temperature control system and switch to manual temperature control. Manually add 100℃ hot water to maintain the sterilization temperature above the preset temperature of the low temperature section by 100℃ until all the jams have been sterilized.

[0062] d. Set the material outlet temperature of the sterilizer to 22℃.

[0063] Example 3

[0064] This embodiment provides a specific method for sterilizing jam containing a high proportion of fruit puree, which includes the following steps:

[0065] 1) Warm-up

[0066] Place the refrigerated orange jam (35wt% puree content) in an aseptic container at 25°C for 18 hours to warm up.

[0067] 2) Place in the sterilizer

[0068] The warmed jam is pumped into a jam sterilizer, where it undergoes sterilization and cooling before being transferred to a sterile container for later use. The sterilizer needs to be set to the following conditions:

[0069] a. Set the sterilization target conditions for the sterilizer as follows: temperature 105℃, time 32s;

[0070] b. Set the high-temperature sterilization zone of the sterilizer to 128℃ and the low-temperature sterilization zone to 97℃;

[0071] c. When the temperature displayed by the sterilizer approaches 100℃, turn off the automatic temperature control system and switch to manual temperature control. Manually add 100℃ hot water to maintain the sterilization temperature above the preset temperature of the low temperature section by 100℃ until all the jams have been sterilized.

[0072] d. Set the material outlet temperature of the sterilizer to 18℃.

[0073] Comparative Example 1

[0074] This comparative example provides a conventional method for sterilizing jam in the prior art, specifically including the following steps:

[0075] 1) Same as Example 1;

[0076] 2) Place in the sterilizer

[0077] The warmed jam is pumped into a jam sterilizer, where it undergoes sterilization and cooling before being transferred to a sterile container for later use. The sterilizer needs to be set to the following conditions:

[0078] a. Same as Example 1;

[0079] b. Set the high-temperature sterilization zone of the sterilizer to 115℃ and the low-temperature sterilization zone to 95℃;

[0080] c. This condition does not exist;

[0081] d. Same as Example 1.

[0082] Comparative Example 2

[0083] This comparative example provides a specific method for sterilizing jam, which lowers the preset value of the sterilization low temperature range to 85°C, and specifically includes the following steps:

[0084] 1) Same as Example 1;

[0085] 2) Place in the sterilizer

[0086] The warmed jam is pumped into a jam sterilizer, where it undergoes sterilization and cooling before being transferred to a sterile container for later use. The sterilizer needs to be set to the following conditions:

[0087] a. Same as Example 1;

[0088] b. Set the high-temperature sterilization zone of the sterilizer to 115℃ and the low-temperature sterilization zone to 85℃;

[0089] c. This condition does not exist;

[0090] d. Same as Example 1.

[0091] Comparative Example 3

[0092] This comparative example provides a specific method for sterilizing jam, which does not employ a combination of automatic and manual modes, and specifically includes the following steps:

[0093] 1) Same as Example 1;

[0094] 2) Place in the sterilizer

[0095] The warmed jam is pumped into a jam sterilizer, where it undergoes sterilization and cooling before being transferred to a sterile container for later use. The sterilizer needs to be set to the following conditions:

[0096] a. Same as Example 1;

[0097] b. Set the high-temperature sterilization zone of the sterilizer to 135℃ and the low-temperature sterilization zone to 95℃;

[0098] c. This condition does not exist;

[0099] d. Same as Example 1.

[0100] The applicant added the jam containing a high proportion of fruit puree prepared in Examples 1-3 and Comparative Examples 1-3 to room temperature yogurt and conducted a heat preservation test on the yogurt. The specific heat preservation test method was as follows: the sample was placed at 37°C for 1 month, and then the relevant indicators such as microorganisms were tested (using standard GB 19302). The results are shown in Table 1.

[0101] Table 1

[0102]

[0103] As shown in Table 1, the sterilization methods for jams containing a high proportion of fruit puree provided in Examples 1-3 of this application can meet the sterilization conditions during the sterilization process of large batches of jam. There will be no alarm due to temperature fluctuations of the sterilizer exceeding the preset high / low temperature, resulting in a large amount of jam being discharged into the waste liquid collection system. The entire sterilization process can be completed smoothly. At the same time, the jam obtained in this way will not cause the product to fail to meet microbial standards during its shelf life when added to room temperature yogurt.

[0104] As can be seen from Comparative Example 1 and Example 1 in Table 1, compared with Example 1, if a conventional sterilization method is used, the high proportion of fruit puree in the jam will easily entangle the temperature probe, causing the probe to malfunction. The temperature cannot be maintained above the preset minimum temperature of the sterilizer, which will eventually cause the sterilizer to enter the discharge and cleaning process. A large amount of jam will be discharged into the waste liquid collection system, resulting in sterilization failure and waste of raw materials.

[0105] As shown in Comparative Example 2 and Example 1 in Table 1, compared to Example 1, if only the preset value of the low-temperature sterilization zone is lowered without raising the preset value of the high-temperature zone, then during the sterilization process, since both the high-temperature and low-temperature zones are relatively low, although the sterilizer temperature will not fall below the low-temperature zone and therefore the sterilizer will not enter the discharge and cleaning process, the actual temperature of the sterilizer will still be below 100℃, or even below 95℃, during the actual sterilization process. This results in the jam not meeting the requirements for commercial sterility. When subsequently added to yogurt for heat preservation testing, a significant exceedance of microbial levels occurs, making it unsuitable for normal use in room-temperature yogurt production.

[0106] As shown in Comparative Example 3 and Example 1 in Table 1, compared to Example 1, if 100°C water is added to the sterilizer without using the automatic mode, the actual temperature displayed by the sterilizer will fluctuate significantly during sterilization, falling below the lower limit of 100°C. However, by increasing the preset value of the high-temperature section, the actual sterilization temperature will not be too low (e.g., below 95°C). Therefore, in subsequent tests, a certain percentage of microorganisms will exceed the standard. Consequently, when the sterilized jam is added to yogurt for heat preservation testing, the final product will also exhibit a certain percentage of microorganisms exceeding the standard during the heat preservation test, rendering it unusable.

[0107] In summary, the sterilization method for jams containing a high proportion of fruit puree provided in this application ensures that the actual sterilization temperature of the sterilizer remains within the sterilization conditions during the sterilization process. This prevents the sterilizer from triggering alarms due to temperature fluctuations exceeding the preset high / low temperatures, thus avoiding premature discharge and ensuring successful sterilization. Furthermore, jam sterilized using this method will not exhibit microbial deficiencies when added to room-temperature yogurt within its shelf life, resulting in a novel room-temperature yogurt product containing only fruit puree and jam.

[0108] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for sterilizing jam containing a high proportion of fruit puree, characterized in that, This includes conveying the jam containing a high proportion of fruit puree to a sterilizer for sterilization. The sterilization conditions are: temperature 100~120℃, time 30~32s; After sterilization, the jam is transported to a cooling pipe for cooling and then stored aseptically. Based on the total weight of the jam containing a high proportion of fruit puree, the content of the fruit puree is 30-45 wt%, and the fruit puree is fine and long fibrous fruit pulp; The sterilization treatment conditions are a temperature of 100~120℃, which means that the temperature of the jam monitored in real time by the sterilization machine is 100~120℃ during the sterilization process. The length of the slender fibrous pulp is 0.5~1.5cm; the jam containing a high proportion of fruit puree does not contain fruit pieces; The sterilizer is equipped with a heat exchanger; In the sterilization process, boiling water is used as the heat exchange medium in the heat exchanger to maintain sterilization conditions. The temperature range of the heat exchange medium is 95~135℃, and the temperature of the heat exchange medium is controlled by adjusting the content of boiling water. When the actual displayed temperature of the sterilizer is 100℃, turn off the automatic temperature control system and switch to manual temperature control. Manually add 100℃ water to the heat exchanger of the sterilizer to keep boiling water in the heat exchanger as the heat exchange medium, increase the temperature of the heat exchange medium, and maintain the temperature conditions for sterilization.

2. The jam sterilization method according to claim 1, characterized in that, The jam is reheated before being conveyed to the sterilizer; And / or, the cooling process involves cooling the temperature to 18~24℃; And / or, the jam containing a high proportion of fruit puree is a citrus jam.

3. The jam sterilization method according to claim 2, characterized in that, The warming process includes: warming the jam containing a high proportion of fruit puree at 20-25°C for 18-24 hours; And / or, the citrus jams include one or more of orange jams, grapefruit jams, tangerine jams, and mandarin jams.

4. The jam sterilization method according to claim 1, characterized in that, During the sterilization process, when the actual displayed temperature of the sterilizer is 120°C, boiling water is continuously supplied to the heat exchanger as the heat exchange medium, and the temperature of the heat exchange medium is reduced to maintain the target sterilization conditions, so that the sterilization process can proceed smoothly.

5. The jam sterilization method according to claim 4, characterized in that, During the sterilization process, the maximum temperature of the heat exchange medium is 128~135℃; And / or, in the sterilization process, the minimum temperature of the heat exchange medium is 95~99℃; And / or, the sterilizer monitors the real-time temperature of the jam containing a high proportion of fruit puree during the sterilization process.

6. A finished jam for direct use in yogurt products, characterized in that, The finished jam is obtained by sterilization using the sterilization method described in any one of claims 1 to 5.

7. The finished jam according to claim 6, characterized in that, Based on the total weight of the finished jam, the content of fruit puree is 30-45 wt%.

8. A product containing the finished jam as described in any one of claims 6 to 7.

9. The product according to claim 8, characterized in that, The products include yogurt products.

10. The product according to claim 9, characterized in that, The product in question is room-temperature yogurt.

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