Low-sugar compounded antioxidant loquat jam and preparation method thereof

Abstract

The application discloses a low-sugar compound anti-oxidation loquat jam and a preparation method thereof, and relates to the field of food processing. The preparation method comprises the following steps: S1, crushing and filtering loquat raw materials to prepare loquat raw syrup; S2, mixing the loquat raw syrup with a compound sweetening agent and citric acid, stirring until the mixture is dissolved to obtain a mixed solution; S3, heating the mixed solution, adding a compound stabilizing agent, stirring to dissolve and disperse the compound stabilizing agent to form a mixed system; S4, adding a compound antioxidant to the mixed system, uniformly stirring, and then performing low-temperature concentration under vacuum until the solid content of the jam is 45-50%; and S5, sterilizing the concentrated jam, and then filling, sealing and cooling to obtain a finished product. The loquat jam has the advantages of low total sugar content, strong anti-oxidation, good room-temperature storage stability, delicate and mellow taste, and suitability for industrial production.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to a low-sugar compound antioxidant loquat jam and its preparation method. Background Technology

[0002] Loquat (Eriobotrya japonica) belongs to the Rosaceae family. Its fruit is soft, juicy, and has a unique flavor. It is rich in vitamins A, C, and B, as well as minerals such as potassium, calcium, and magnesium, and contains loquat polysaccharides, polyphenolic compounds (such as chlorogenic acid and quercetin derivatives), and flavonoid active ingredients. Traditional Chinese medicine believes that loquat has the effects of moisturizing the lungs and relieving cough, and promoting the production of body fluids and quenching thirst. Modern nutritional research has also confirmed that the naturally occurring active substances in loquat have good antioxidant, anti-inflammatory, and immunomodulatory effects. Therefore, loquat is not only a delicious fresh fruit but also a high-quality raw material for developing functional foods. Jam, as an important form of fruit processing, can significantly extend the shelf life of fruit while retaining its flavor and nutritional components, making it popular with consumers. However, in the industrial production of loquat jam, how to maintain good sensory quality, nutritional value, and storage stability without relying on high-sugar, high-calorie additives is a problem that urgently needs to be solved.

[0003] To ensure gelling properties, texture, and antibacterial effects, commercially available loquat jams often contain a high proportion of sucrose, with sugar content frequently exceeding 60%. Long-term consumption can easily lead to excessive calorie intake and blood sugar fluctuations, contradicting modern consumers' pursuit of low-sugar and healthy diets. This also limits consumption by specific consumer groups such as diabetics and those trying to lose weight. Furthermore, the heat-sensitive active ingredients in loquat pulp, such as polyphenols and vitamin C, are highly susceptible to oxidative browning and degradation during jam processing, especially at high temperatures. This results in a darker color, deteriorated flavor, and a significant reduction in nutritional value. Moreover, traditional jams often use only sucrose for sweetness, resulting in a monotonous, cloyingly sweet taste lacking complexity and failing to meet consumers' demands for high-quality jams.

[0004] Therefore, how to reduce the total sugar content of the jam while maintaining its good taste, color, and nutritional activity has become a key direction for optimizing loquat jam processing technology. Summary of the Invention

[0005] This invention overcomes the shortcomings of the prior art and provides a low-sugar compound antioxidant loquat jam and its preparation method.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: Firstly, the present invention provides a method for preparing a low-sugar compound antioxidant loquat jam, comprising the following steps:

[0007] S1. Crush and filter the loquat raw material to prepare loquat pulp;

[0008] S2. Mix the loquat pulp with the compound sweetener and citric acid, and stir until dissolved to obtain a mixture;

[0009] S3. Heat the mixture, add the compound stabilizer, and stir to dissolve and disperse it to form a mixed system; the compound stabilizer is composed of low-ester pectin and xanthan gum;

[0010] S4. Add the compound antioxidant to the mixture, stir well, and then concentrate under vacuum at low temperature until the jam solids content is 45-50%.

[0011] S5. The concentrated jam is sterilized, then filled, sealed, and cooled to obtain the finished product.

[0012] In a preferred embodiment of the present invention, the weight parts of each raw material are as follows: 60-80 parts of loquat pulp, 10-25 parts of compound sweetener, 0.1-0.3 parts of citric acid, 2-5 parts of water; 0.2-1 parts of compound stabilizer; and 0.05-0.2 parts of compound antioxidant.

[0013] In a preferred embodiment of the present invention, the mass ratio of low-ester pectin to xanthan gum in the compound stabilizer is 2-4:1.

[0014] In a preferred embodiment of the present invention, the compound sweetener is composed of xylitol and erythritol in a mass ratio of 2-3:1.

[0015] In a preferred embodiment of the present invention, the compound antioxidant is composed of vitamin C and rosemary extract in a mass ratio of 1-2:1.

[0016] In a preferred embodiment of the present invention, in step S1, the method for preparing the loquat pulp is as follows: select fresh loquats with a maturity of 80-90%, wash them, peel and pit them, crush them into a paste, and filter them through an 80-100 mesh sieve.

[0017] In a preferred embodiment of the present invention, in step S2, the stirring speed is 100-150 r / min and the stirring time is 5-10 min; in step S3, the heating temperature is 50-60 ℃ and the stirring time is 20-30 min.

[0018] In a preferred embodiment of the present invention, in step S4, the low-temperature concentration temperature is 70-80 °C, the vacuum degree is 0.06-0.08 MPa, and the concentration time is 20-30 min.

[0019] In a preferred embodiment of the present invention, in step S5, the sterilization method is pasteurization, the sterilization temperature is 90-95 ℃, the sterilization time is 5-8 min, and the filling temperature is ≥85 ℃.

[0020] Secondly, the present invention provides a low-sugar compound antioxidant loquat jam, which is prepared by the preparation method of the low-sugar compound antioxidant loquat jam described in any one of the above-mentioned methods.

[0021] This invention addresses the shortcomings of the prior art and has the following beneficial effects:

[0022] (1) This invention provides a low-sugar compound antioxidant loquat jam and its preparation method. It uses xylitol and erythritol as sweeteners. Both xylitol and erythritol are natural sugar alcohols that are not easily fermented and utilized by human oral microorganisms. They have low absorption rates in the small intestine and are mostly excreted through urine. They do not cause drastic fluctuations in blood sugar. Compared with traditional high-sucrose jams, this invention can effectively reduce the total sugar content of the jam and significantly reduce calories while ensuring that the sweetness is close to that of sucrose. It avoids the problem of a hard taste or insufficient sweetness that may be caused by single sugar alcohols. It produces a synergistic effect in taste, making the sweetness more rounded and natural. It solves the defects of traditional low-sugar jams, such as a single taste and strong sweetness, thereby meeting the needs of diabetic patients, people who are trying to lose weight, and consumers who pay attention to healthy eating for low-sugar and low-calorie jam.

[0023] (2) This invention uses vitamin C and rosemary extract as antioxidants. As a powerful reducing antioxidant, vitamin C can preferentially react with dissolved oxygen in the system and quickly consume oxygen, thus rapidly inhibiting the enzymatic browning reaction of polyphenol oxidase in loquat pulp in the early stage of processing. Rosemary extract is rich in polyphenols such as rosmarinic acid and rosmarinic acid. Its phenolic hydroxyl structure can capture lipid peroxidation free radicals, block chain oxidation reaction, and provide long-lasting and stable antioxidant protection. After compounding, vitamin C plays a rapid color-protecting role, and rosemary extract provides long-lasting protection, which can form a complementary effect of antioxidant space and time. This effectively inhibits non-enzymatic browning and degradation of active ingredients in loquat jam during heating, concentration and long-term storage, keeping the jam bright in color and greatly improving the retention rate of polyphenols. This solves the problem of nutrient loss and color deterioration caused by high temperature oxidation in traditional jam processing, thereby improving the nutritional value and sensory quality of the product.

[0024] (3) This invention uses a combination of low-ester pectin and xanthan gum as a stabilizer. The low-ester pectin molecular chain contains a lot of free carboxyl groups. In the presence of trace amounts of calcium ions naturally contained in loquat pulp, it can form an egg-box structure gel network through ion bridging, providing a stable three-dimensional skeleton for the jam system. Xanthan gum molecules have a double helix structure, which can form a high-viscosity continuous phase in water. It can also generate physical cross-links through hydrogen bonding between its side chains and low-ester pectin molecules, enhancing the density and elasticity of the gel network. A composite network of gel and thickening synergy can be constructed with only a low total addition amount, effectively fixing the dispersed phase, inhibiting the sedimentation of solid particles, and enhancing the water-holding capacity of the system, preventing dehydration and shrinkage caused by temperature fluctuations or gravity. Compared with traditional single stabilizers, this invention can solve the problems of easy layering, sedimentation, and water separation in low-sugar jams, so that the jam can maintain a uniform texture and good spreadability during long-term storage, and has a delicate and mellow taste without gel breakage or water separation, thereby greatly extending the shelf life of the product at room temperature.

[0025] (4) This invention combines compound sweeteners with citric acid, resulting in a suitable sweet and sour ratio and a rich taste. It avoids the cloying sweetness and harshness of a single sweetener, meets the taste needs of the general public, and the preparation process uses conventional food processing equipment. The steps are simple, the operation is convenient, the raw materials are readily available and the cost is low, making it suitable for large-scale industrial production and giving it high market promotion value. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic flowchart of a method for preparing a low-sugar compound antioxidant loquat jam according to the present invention. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0030] Application Overview:

[0031] Loquat pulp has a high water content, typically exceeding 85%, a relatively low pectin content, and a limited concentration of natural calcium ions. This makes it highly susceptible to stratification, sedimentation, and water seepage when processed into jam due to water migration and solid sedimentation.

[0032] The applicant's research found that traditional jams often use a single stabilizer, such as high-ester pectin or a single thickener, to maintain system stability. However, such solutions are not effective in loquat jam: high-ester pectin requires high sugar and high acid conditions to form a stable gel, making it difficult to apply to low-sugar systems; while single thickeners, such as xanthan gum and sodium carboxymethyl cellulose, can increase the viscosity of the system, they are difficult to build a stable three-dimensional gel network. During long-term storage, the system is still prone to dehydration and shrinkage due to factors such as gravity settling and temperature fluctuations, resulting in uneven product texture and liquid phase precipitation, which seriously affects the product's appearance and consumer acceptance.

[0033] To address the aforementioned issues, this invention provides a low-sugar compound antioxidant loquat jam and its preparation method. By compounding low-ester pectin and xanthan gum in a specific ratio, it can function in the trace amounts of calcium ions naturally present in loquat pulp and in an acidic environment: low-ester pectin forms an eggshell-structured gel network with calcium ions, providing stable skeletal support; xanthan gum further stabilizes the system by increasing the viscosity of the continuous phase and forming hydrogen bonds between pectin molecules. The gel-thickening composite network constructed by the compound effectively inhibits layering, sedimentation, and water exudation even at low addition levels, thereby significantly improving the long-term storage stability of the jam while maintaining its delicate and mellow taste. This provides a feasible path for the industrial production of high-quality low-sugar loquat jam.

[0034] It should be noted that the raw materials, equipment and reagents used in this invention can all be purchased from the market or obtained through existing preparation methods.

[0035] like Figure 1 As shown, a method for preparing a low-sugar compound antioxidant loquat jam includes the following steps:

[0036] S1. Crush and filter the loquat raw material to prepare loquat pulp;

[0037] S2. Mix loquat pulp with compound sweetener and citric acid, and stir until dissolved to obtain a mixture;

[0038] S3. Heat the mixture, add the compound stabilizer, and stir to dissolve and disperse it to form a mixed system; the compound stabilizer is composed of low-ester pectin and xanthan gum.

[0039] S4. Add the compound antioxidant to the mixture, stir well, and then concentrate under vacuum at low temperature until the jam solids content is 45-50%.

[0040] S5. The concentrated jam is sterilized, then filled, sealed, and cooled to obtain the finished product.

[0041] In some specific embodiments, the weight parts of each raw material are as follows: 60-80 parts loquat pulp, 10-25 parts compound sweetener, 0.1-0.3 parts citric acid, 2-5 parts water; 0.2-1 parts compound stabilizer; and 0.05-0.2 parts compound antioxidant.

[0042] In some specific implementations, the mass ratio of low-ester pectin to xanthan gum in the compound stabilizer is 2-4:1.

[0043] In some specific implementations, the compound sweetener is a mixture of xylitol and erythritol in a mass ratio of 2-3:1.

[0044] In some specific implementations, the compound antioxidant is composed of vitamin C and rosemary extract in a mass ratio of 1-2:1.

[0045] In some specific embodiments, in step S1, the method for preparing loquat pulp is as follows: select fresh loquats with a maturity of 80-90%, wash them, peel and pit them, crush them into a paste, and filter them through an 80-100 mesh sieve.

[0046] In some specific implementations, in step S2, the stirring speed is 100-150 r / min and the stirring time is 5-10 min; in step S3, the heating temperature is 50-60 ℃ and the stirring time is 20-30 min.

[0047] In some specific implementations, in step S4, the low-temperature concentration temperature is 70-80 °C, the vacuum degree is 0.06-0.08 MPa, and the concentration time is 20-30 min.

[0048] In some specific implementations, in step S5, the sterilization method is pasteurization, the sterilization temperature is 90-95 ℃, the sterilization time is 5-8 min, and the filling temperature is ≥85 ℃.

[0049] This invention provides a low-sugar compound antioxidant loquat jam, which is prepared by any of the above-mentioned methods for preparing low-sugar compound antioxidant loquat jam.

[0050] To further simplify and make the present invention achieve its objectives and effects, the present invention will be further illustrated in conjunction with the following specific embodiments and comparative examples, but the present invention is not limited to the scope of the embodiments described herein.

[0051] It should be noted that the raw materials used in the examples and comparative examples are as follows: the rosemary extract is food grade, and the rosmarinic acid content is ≥20%; the degree of esterification of the low-ester pectin is 30%.

[0052] Example 1:

[0053] A low-sugar, compound, antioxidant loquat jam is composed of the following ingredients in parts by weight:

[0054] 60 parts loquat puree, 10 parts compound sweetener (xylitol: erythritol = 2:1), 0.2 parts compound stabilizer (low-ester pectin: xanthan gum = 3:1), 0.05 parts compound antioxidant (vitamin C: rosemary extract = 1:1), 0.1 parts citric acid, and 2 parts water.

[0055] The preparation method includes the following steps:

[0056] S1. Select fresh loquats that are 80% ripe, wash them, peel and pit them, crush them into a paste, filter them through a 90-mesh sieve to remove coarse fibers and impurities, and prepare loquat pulp.

[0057] S2. Pour the loquat pulp into a jacketed kettle, add water, stir well, slowly add the compound sweetener and citric acid while stirring (stirring speed 100 r / min), stir for 5 minutes until completely dissolved to obtain a mixture;

[0058] S3. Heat the mixture to 50 ℃, slowly add the compound stabilizer while stirring, maintain 50 ℃, and stir for 20 minutes to completely dissolve and disperse the stabilizer to form a fine mixture system;

[0059] S4. Add compound antioxidant to the mixture, stir evenly, raise the temperature of the jacketed kettle to 70 ℃, control the vacuum degree at 0.06 MPa, concentrate at low temperature for 20 min, and stop the concentration when the soluble solids content of the jam is 45%.

[0060] S5. Heat the concentrated jam to 90 ℃ and maintain for 5 minutes for pasteurization. After pasteurization, quickly pour the jam into sterilized glass bottles at a filling temperature of 85 ℃. Seal immediately after filling and invert to cool to room temperature to obtain the finished product.

[0061] Finished product testing: total sugar content 42%, polyphenol retention rate 85%, browning degree ΔE=2.8, taste is moderately sweet and sour, delicate and mellow.

[0062] Example 2:

[0063] This embodiment is basically the same as Example 1, except that the amount of low-ester pectin in the compound stabilizer is different. Specifically, the mass ratio of low-ester pectin to xanthan gum is 2:1.

[0064] Example 3:

[0065] This embodiment is basically the same as Example 1, except that the amount of low-ester pectin in the compound stabilizer is different. Specifically, the mass ratio of low-ester pectin to xanthan gum is 4:1.

[0066] Comparative Example 1:

[0067] This comparative example is basically the same as Example 1, except that: high-fat pectin with an esterification degree of 65% is used to replace the compound stabilizer. The loquat jam is composed of the following raw materials in parts by weight: 60 parts loquat pulp, 10 parts compound sweetener (xylitol: erythritol = 2:1), 0.2 parts high-fat pectin, 0.05 parts compound antioxidant (vitamin C: rosemary extract = 1:1), 0.1 parts citric acid, and 2 parts water.

[0068] Comparative Example 2:

[0069] This comparative example is basically the same as Example 1, except that sodium carboxymethyl cellulose is used instead of the compound stabilizer. The loquat jam is composed of the following raw materials in parts by weight: 60 parts loquat pulp, 10 parts compound sweetener (xylitol: erythritol = 2:1), 0.2 parts sodium carboxymethyl cellulose, 0.05 parts compound antioxidant (vitamin C: rosemary extract = 1:1), 0.1 parts citric acid, and 2 parts water.

[0070] Comparative Example 3:

[0071] This comparative example is basically the same as Example 1, except that a single stabilizer is used. The loquat jam is composed of the following raw materials in parts by weight: 60 parts loquat pulp, 10 parts compound sweetener (xylitol: erythritol = 2:1), 0.2 parts low-ester pectin, 0.05 parts compound antioxidant (vitamin C: rosemary extract = 1:1), 0.1 parts citric acid, and 2 parts water.

[0072] Comparative Example 4:

[0073] This comparative example is basically the same as Example 1, except that a single stabilizer is used. The loquat jam is composed of the following raw materials in parts by weight: 60 parts loquat pulp, 10 parts compound sweetener (xylitol: erythritol = 2:1), 0.2 parts xanthan gum, 0.05 parts compound antioxidant (vitamin C: rosemary extract = 1:1), 0.1 parts citric acid, and 2 parts water.

[0074] Comparative Example 5:

[0075] This comparative example is basically the same as Example 1, except that the amount of low-ester pectin in the compound stabilizer is different. Specifically, the mass ratio of low-ester pectin to xanthan gum is 1:1.

[0076] Comparative Example 6:

[0077] This comparative example is basically the same as Example 1, except that the amount of low-ester pectin in the compound stabilizer is different. Specifically, the mass ratio of low-ester pectin to xanthan gum is 5:1.

[0078] Stability test: The loquat jams obtained in Examples 1-3 and Comparative Examples 1-6 were stored at room temperature for 12 months. The centrifugal sedimentation rate, water separation rate and viscosity retention rate were recorded. The results are shown in Table 1.

[0079] project Centrifugal sedimentation rate (%) Water separation rate (%) Viscosity retention rate (%) Example 1 2.2 2.8 92.6 Example 2 2.5 3.0 90.3 Example 3 2.3 2.9 91.1 Comparative Example 1 8.5 7.2 78.5 Comparative Example 2 7.8 6.5 80.2 Comparative Example 3 5.6 5.1 85.3 Comparative Example 4 6.2 5.8 83.6 Comparative Example 5 4.5 4.2 87.9 Comparative Example 6 4.1 3.9 88.5

[0080] As shown in Table 1:

[0081] A comparison of Example 1 and Comparative Examples 1-2 reveals that: Comparative Example 1, using high-ester pectin instead of the compound stabilizer, achieved a centrifugal sedimentation rate of 8.5%, a water separation rate of 7.2%, and a viscosity retention rate of 78.5%. The gelation mechanism of its high-ester pectin relies on a high-sugar (typically above 55%) and high-acid environment, forming a gel network through hydrophobic interactions and hydrogen bonds. In the low-sugar system of this invention, the hydrogen bonding force within the system is insufficient, preventing the high-ester pectin from forming a stable three-dimensional network structure. It only provides a limited thickening effect and is difficult to effectively fix loquat pulp particles, thus easily causing sedimentation and dehydration shrinkage under gravity.

[0082] Comparative Example 2 used sodium carboxymethyl cellulose as a single thickener, and its performance was also significantly inferior to that of Example 1. Sodium carboxymethyl cellulose is a linear polymer. Although it can increase the viscosity of the system, it lacks the cross-linking points required to form a strong gel network between its molecular chains. It can only form a viscous continuous phase and cannot build a gel skeleton with elasticity and rigidity. During the long-term storage of 12 months, the single thickening system lacked structural support and could not suppress the liquid phase migration and solid particle sedimentation caused by temperature fluctuations and gravity, resulting in obvious stratification and water exudation, and a significant decrease in viscosity.

[0083] A comparison of Example 1 with Comparative Examples 3-4 reveals that: Comparative Example 3, using only low-ester pectin as a single stabilizer, exhibited a centrifugal sedimentation rate and a water separation rate of 5.6% and 5.1%, respectively, with a viscosity retention rate of 85.3%. Although low-ester pectin can form an egg-box structure gel network with calcium ions in the system, providing a stable three-dimensional framework, this network has limited flexibility and resistance to deformation under dynamic storage conditions. Lacking the synergistic effect of xanthan gum, the gel network contains tiny voids that cannot completely bind all free water, resulting in the slow precipitation of some liquid phases after long-term storage. Furthermore, it lacks sufficient suspension capacity for small fruit pulp particles that sink due to gravity.

[0084] Comparative Example 4 used only xanthan gum as a single stabilizer, with a centrifugal sedimentation rate and water separation rate of 6.2% and 5.8%, respectively, and a viscosity retention rate of 83.6%. Xanthan gum forms a high-viscosity continuous phase through its double-helix structure and a weak gel through intermolecular hydrogen bonds, but its network structure is loose and lacks the rigid eggshell-like structural framework formed by low-ester pectin and calcium ions. Therefore, this system mainly relies on high viscosity for physical hindrance when solid particles settle, rather than structural locking. During long-term storage, gravity gradually overcomes the viscous resistance, causing the pulp particles to slowly settle and form a sediment layer. At the same time, due to the weak gel structure, dehydration and shrinkage easily occur, resulting in water separation.

[0085] A comparison of Examples 1-3 and Comparative Examples 5-6 reveals that in Examples 1-3, when the mass ratio of low-ester pectin to xanthan gum is controlled within the preferred range of 2-4:1, all three components exhibit excellent stability. Within this ratio range, the egg-box structured gel network formed by low-ester pectin and natural calcium ions provides a dense and continuous structural framework. Xanthan gum, on the one hand, fills the network voids, and on the other hand, enhances the network's elasticity and water-holding capacity through hydrogen bonding interactions with pectin molecules via its side chains, thus forming a dense composite network with excellent mechanical properties.

[0086] In Comparative Example 5, the ratio of low-ester pectin to xanthan gum was 1:1, meaning xanthan gum was in excess. While excess xanthan gum significantly increased the system viscosity, it interfered with the normal cross-linking of low-ester pectin and calcium ions, diluting the density and strength of the egg carton network structure. This resulted in an overall structure that resembled a viscoelastic fluid rather than a stable gel, leading to a decrease in the ability to suspend solid particles. The centrifugal sedimentation rate and water separation rate increased to 4.5% and 4.2%, respectively. In Comparative Example 6, the ratio of low-ester pectin to xanthan gum was 5:1, meaning low-ester pectin was in excess. In this case, the system lacked sufficient xanthan gum to stabilize the continuous phase and cooperate with the pectin network. As a result, although the formed gel network was relatively rigid, it lacked toughness. When subjected to external disturbances or temperature changes, the network structure was prone to local rupture, failing to effectively bind all water, thus resulting in dehydration and shrinkage. The water separation rate increased to 3.9%, and the viscosity retention rate decreased to 88.5%.

[0087] The above description is based on the preferred embodiments of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of the invention is defined by the appended claims rather than the foregoing description, and all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0088] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for preparing a low-sugar compound antioxidant loquat jam, characterized in that, Includes the following steps: S1. Crush and filter the loquat raw material to prepare loquat pulp; S2. Mix the loquat pulp with the compound sweetener and citric acid, and stir until dissolved to obtain a mixture; S3. Heat the mixture, add the compound stabilizer, and stir to dissolve and disperse it to form a mixed system; the compound stabilizer is composed of low-ester pectin and xanthan gum; S4. Add the compound antioxidant to the mixture, stir well, and then concentrate under vacuum at low temperature until the jam solids content is 45-50%. S5. The concentrated jam is sterilized, then filled, sealed, and cooled to obtain the finished product.

2. The method for preparing a low-sugar compound antioxidant loquat jam according to claim 1, characterized in that: The weight proportions of each raw material are as follows: 60-80 parts loquat pulp, 10-25 parts compound sweetener, 0.1-0.3 parts citric acid, 2-5 parts water; 0.2-1 parts compound stabilizer; and 0.05-0.2 parts compound antioxidant.

3. The method for preparing a low-sugar compound antioxidant loquat jam according to claim 1, characterized in that: In the compound stabilizer, the mass ratio of low-ester pectin to xanthan gum is 2-4:

1.

4. The method for preparing a low-sugar compound antioxidant loquat jam according to claim 1, characterized in that: The compound sweetener is composed of xylitol and erythritol in a mass ratio of 2-3:

1.

5. The method for preparing a low-sugar compound antioxidant loquat jam according to claim 1, characterized in that: The compound antioxidant is composed of vitamin C and rosemary extract in a mass ratio of 1-2:

1.

6. The method for preparing a low-sugar compound antioxidant loquat jam according to claim 1, characterized in that: In step S1, the loquat pulp is prepared by selecting fresh loquats with a maturity of 80-90%, washing them, peeling and removing the pits, crushing them into a paste, and filtering them through an 80-100 mesh sieve.

7. The method for preparing a low-sugar compound antioxidant loquat jam according to claim 1, characterized in that: In step S2, the stirring speed is 100-150 r / min and the stirring time is 5-10 min; in step S3, the heating temperature is 50-60 ℃ and the stirring time is 20-30 min.

8. The method for preparing a low-sugar compound antioxidant loquat jam according to claim 1, characterized in that: In step S4, the low-temperature concentration temperature is 70-80 ℃, the vacuum degree is 0.06-0.08 MPa, and the concentration time is 20-30 min.

9. The method for preparing a low-sugar compound antioxidant loquat jam according to claim 1, characterized in that: In step S5, the sterilization method is pasteurization, the sterilization temperature is 90-95 ℃, the sterilization time is 5-8 min, and the filling temperature is ≥85 ℃.

10. A low-sugar compound antioxidant loquat jam, characterized in that, The low-sugar compound antioxidant loquat jam is prepared by any one of the methods described in claims 1-9.

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