Preparation method of dried orange peel jam

Abstract

The invention provides a preparation method of dried orange peel jam, and belongs to the technical field of food processing. The method comprises the following steps: (1) preparing a pericarpium citri reticulatae fermentation substrate, (2) performing fermentation treatment, and (3) blending and sterilizing. The method mainly solves the problems of high bitterness residue, unstable low-sugar system and potential safety hazard of chemical additives in the prior art, obviously reduces the bitterness and bleeding rate of the jam, realizes low sugar and no chemical additives, and improves the utilization rate of citrus peel resources.

Description

Technical field

[0001] The invention relates to the technical field of food processing, and in particular to a method for preparing tangerine peel jam. [Background Technology]

[0002] Tangerine peel (Dried Tangerine Peel) is the dried, mature peel of the citrus plant (Citrus sinensis) and its cultivated varieties. As a traditional Chinese medicinal ingredient, it has a fragrant aroma and a bitter taste. It has the effects of dispelling dampness, regulating qi and strengthening the spleen, and clearing dampness and resolving phlegm. It is primarily used to treat indigestion, chest and abdominal distension, loss of appetite, and cough with phlegm. Tangerine peel also has high medicinal value and is a traditional seasoning, enjoying a long-standing reputation. The development of tangerine peel jam has promising market prospects.

[0003] However, the current development of tangerine peel jam has the following technical difficulties:

[0004] First, bitter substances such as limonin and naringin in tangerine peel (the limonin threshold is only 1 ppm) make the directly processed products poorly palatable. Existing debittering technologies have obvious drawbacks: adsorption methods (such as β-cyclodextrin embedding) result in the loss of more than 30% of functional components; enzymatic treatment is costly and ineffective for limonin; and single lactic acid bacteria fermentation is inefficient in debittering.

[0005] Second, traditional jam relies on high sugar content (60-65% sugar content and a microorganism) for preservation, which is inconsistent with the trend of healthy low-sugar diets. Although some studies have tried low-sugar jams, their stability is poor and chemical stabilizers are added, which affects the flavor.

[0006] Third, the stabilizer of jam includes the use of ordinary pectin, but ordinary pectin is prone to cause protein flocculation in an acidic environment.

[0007] Based on this, the present invention proposes a method for preparing tangerine peel jam, which systematically solves the above bottlenecks and provides a new path for the deep processing of tangerine peel. [Summary of the invention]

[0008] The invention aims to provide a method for preparing tangerine peel jam, which solves the problems of high bitterness residue, instability of low-sugar system and potential safety hazards of chemical additives in the existing process.

[0009] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0010] A method for preparing tangerine peel jam, comprising the steps of:

[0011] (1) preparing a tangerine peel fermentation matrix: crushing tangerine peel into 40-60 meshes, mixing the tangerine peel with water in a mass ratio of 1:5-8, then adding β-cyclodextrin, and then ultrasonically treating at 45-55° C. for 20-40 minutes to obtain a tangerine peel fermentation matrix;

[0012] (2) Fermentation treatment: Fermentation is carried out in stages (pure fermentation, i.e., no sugar or acidulant is added to the fermentation system), and Leuconostoc mesenteroides LMS1, Pichia pastoris YBHSF9-3, and Lactobacillus plantarum LDVS007 are sequentially introduced into the fermentation matrix, and fermented in this order to obtain a fermentation product for use;

[0013] (3) Preparation and sterilization: add white sugar, citric acid, pectin and sodium alginate to the fermented product, adjust the soluble solids to 35-45%, and the pH to 3.5-3.8; then sterilize at 95-100° C. for 5-8 minutes, and fill to obtain the finished tangerine peel jam.

[0014] In the present invention, further, the amount of β-cyclodextrin added in step (1) is 0.5-1.5% of the mass of dried tangerine peel.

[0015] In the present invention, further, the staged fermentation in step (2) specifically includes the following three stages:

[0016] 1) Stage 1: Inoculate 3-5% of Leuconostoc mesenteroides LMS1 and ferment at 25-28°C for 24-48 hours;

[0017] 2) Second stage: inoculate 2-4% Pichia pastoris YBHSF9-3 and ferment at 30-32°C for 36-72 hours;

[0018] 3) The third stage: inoculating 5-8% Lactobacillus plantarum LDVS007 and fermenting at 36-38° C. for 24-36 hours.

[0019] In the present invention, further, the amount of white sugar, citric acid, pectin and sodium alginate added to the fermentation product in step (3) is, based on the total mass of the fermentation product, 20-30% white sugar, 0.1-0.3% citric acid, 0.4-0.8% pectin and 0.1-0.3% sodium alginate.

[0020] In the present invention, the pectin is further prepared by the following steps: a. treating citrus peel with lipase at 45°C and pH 6.5 for 2 hours, followed by supercritical CO2 defatting; b. inoculating 5-8% Lactobacillus plantarum LDVS007 and fermenting the peel for 48-53 hours at 37°C; c. adding 0.1% complex enzyme preparation and performing enzymatic hydrolysis at 50°C for 2.5 hours; d. performing ultrasonic-assisted extraction at 80°C for 40 minutes, and purifying the peel by alcohol precipitation to obtain the pectin (degree of esterification ≤ 40%).

[0021] In the present invention, further, the composite enzyme preparation is prepared by mixing cellulase and papain in a mass ratio of 2:1.

[0022] The present invention also provides tangerine peel jam prepared by the above method, wherein the tangerine peel jam has a limonin content of ≤15 mg / kg, a naringin content of ≤100 mg / kg, and a water separation rate of ≤1.5% after storage at 4°C for 90 days.

[0023] In summary, due to the adoption of the above technical solution, the present invention has at least the following beneficial effects:

[0024] The present invention provides a method for preparing tangerine peel jam, which addresses the problems of high residual bitterness, instability of the low-sugar system, and potential safety hazards of chemical additives in tangerine peel jam, and solves the core problems existing in the prior art:

[0025] (1) Deep degradation of bitterness: Three-stage purebred relay fermentation efficiently decomposes bitter substances such as limonin in a sugar-free and acid-free environment, significantly improving the taste;

[0026] (2) Stabilization of low-sugar system: low-ester pectin extracted from citrus peel silage is compounded with sodium alginate to form a natural gel network, effectively preventing the separation of water and stratification of low-sugar jam;

[0027] (3) All-natural ingredient guarantee: Abandoning chemical stabilizers, using self-extracted pectin and fermentation metabolism to achieve anti-corrosion and freshness preservation, the product has no risk of chemical additives;

[0028] (4) Resource recycling: Citrus peels are used simultaneously for pectin extraction and fermentation matrix, greatly improving the utilization rate of raw materials;

[0029] In summary, this method breaks through the bottleneck of activity inhibition of fermentation strains in a sugar-acid environment, achieves deep degradation of bitter substances, and utilizes citrus peel resources to prepare special stabilizers, ultimately obtaining tangerine peel jam with low bitterness, low sugar content, stable texture and no chemical additives. The product's water extraction rate is significantly reduced and the shelf life is extended. [Specific implementation method]

[0030] The following examples may help those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0031] Example 1: Baseline Process

[0032] The present embodiment provides a preparation method of tangerine peel jam, the method comprising the steps of:

[0033] (1) Preparation of dried tangerine peel fermentation matrix:

[0034] The dried tangerine peel was crushed into 50 meshes, mixed with dried tangerine peel and water in a mass ratio of 1:6, and then 1% of β-cyclodextrin by mass of the dried tangerine peel was added, followed by ultrasonic treatment at 50° C. for 30 minutes to obtain a dried tangerine peel fermentation matrix;

[0035] (2) Fermentation treatment:

[0036] Fermentation was carried out in stages (pure fermentation, i.e. no sugar or acidulant was added to the fermentation system). The three stages are shown in Table 1 below:

[0037] Table 1 Three-stage pure fermentation

[0038] stage Bacterial strain and inoculation amount condition Core role Phase 1 LMS1, 4% 26℃, 36h, pH 4.2 Limonin degradation 46.7% Phase II YBHSF9-3,3% 31℃,48h 8 new esters Phase 3 LDVS007, 6% 37℃,30h pH dropped to 3.52

[0039] Among them, strain LMS1, classified and named Leuconostoc mesenteroides, has a deposit number of GDMCCNo: 61745, which is the applicant's prior deposited strain and has been disclosed in the Chinese patent application number 202111349838.8; strain YBHSF9-3, with a deposit number of GDMCCNo: 64681, is the applicant's prior deposited strain and has been disclosed in the Chinese patent application number 202411075418.9; strain LDVS007, with a deposit number of CGMCC NO: 20028, is the applicant's prior deposited strain and has been disclosed in the Chinese patent application number 202011244087.9.

[0040] (3) Preparation and sterilization:

[0041] The following components were added to the fermentation product: 25% white sugar, 0.2% citric acid, 0.5% pectin, and 0.2% sodium alginate, based on the total weight of the fermentation product. The soluble solids content was adjusted to 40% and the pH to 3.6. The pectin was prepared as follows: a. Citrus peels were treated with lipase at 45°C and pH 6.5 for 2 hours, followed by supercritical CO2 defatting; b. 5-8% Lactobacillus plantarum LDVS007 was inoculated and the product was ensiled and fermented at 37°C for 50 hours; c. 0. 1% complex enzyme preparation (cellulase and papain mixed in a mass ratio of 2:1) is subjected to enzymatic hydrolysis at 50°C for 2.5 hours; d. ultrasonic-assisted extraction is performed at 80°C for 40 minutes, followed by alcohol precipitation purification to obtain the pectin (esterification degree ≤40%); then, the product is sterilized at 97°C for 6 minutes and bottled to obtain the finished tangerine peel jam. The finished tangerine peel jam has a limonin content of ≤15 mg / kg and a naringin content of ≤100 mg / kg. The water separation rate is ≤1.5% after storage at 4°C for 90 days.

[0042] Example 2: Verification of the effect of sugar acid addition timing

[0043] This example verifies the effect of the timing of sugar and acid addition on

[0044] The control group was set up as follows: 25% white sugar + 0.2% citric acid were added in advance in step (1); the number of LMS1 viable bacteria and the hesperidin retention rate in the control group and the experimental group were tested. The test results are shown in Table 2:

[0045] Table 2 Effect of the timing of sugar and acid addition

[0046]

[0047] According to the above test results, adding sugar acid first will cause high osmotic pressure to inhibit the proliferation of LMS1 (the number of viable bacteria ↓96%). In addition, the acidic environment promotes the hydrolysis of hesperidin.

[0048] Example 3: Pectin preparation process verification

[0049] This example compares the effects of different treatment methods on the degree of esterification and the water extraction rate of the finished jam, and the groups are as follows:

[0050] The present invention group: pectin silage in the manner described in Example 1;

[0051] Commercially available chemically deesterified pectin group: "Wanguo" brand low-ester pectin purchased from Anhui Yuning Biological;

[0052] Group without ensiling and pectin extraction: The step of ensiling strain LDVS007 (6%) for 50 h was omitted, and the other methods were the same as those in Example 1.

[0053] Comparison of the effects of the above groups of pectin on the degree of esterification and the water separation rate of the finished jam. The results are shown in Table 3:

[0054] Table 3 Effects of different pectins on esterification degree and water separation rate of finished jam

[0055] Pectin type Degree of esterification (%) Jam water separation rate (90 days, %) Silage pectin of the present invention 38.5±1.6 1.2±0.3 Commercially available chemically deesterified pectin 42.3±2.1 8.5±0.7 Unsilaged pectin 65.8±3.0 12.7±1.1

[0056] According to the results in Table 3, silage fermentation was used to activate the endogenous esterase of the peel, achieving simultaneous extraction and deesterification, and the hydrogen bond network was more stable. At the same time, using the silage pectin of the present invention, Lactobacillus plantarum LDVS007 silage fermentation activated endogenous enzymes, synchronously achieving pectin extraction and directional deesterification, obtaining low-ester pectin, and the jam water separation rate (90 days) was only about 1.2%. This is considered to be due to the dense gel network, which effectively locked in moisture, resulting in a uniform jam texture and more stable jam quality.

[0057] Example 4: Irreplaceability of three-strain sequential fermentation

[0058] This example compares the different effects of three strains in sequential fermentation, mainly testing the residual limonin.

[0059] The groups are as follows:

[0060] The present invention group: fermentation was carried out according to the time sequence of Example 1 of the present application;

[0061] Change the sequence group: the sequence is changed to: LDVS007→LMS1→YBHSF9-3, and the other parameters are the same as in Example 1;

[0062] Mixed fermentation: three strains were added at one time for fermentation (31°C, 72h).

[0063] The results are shown in Table 4:

[0064] Table 4 The decisive influence of time sequence on bitterness degradation

[0065]

[0066] According to the results in Table 4, the sequential fermentation of the three strains achieved synergistic efficiencies through metabolic division of labor, environmental adaptation, and precursor transfer, significantly reducing the bitter substances in the jam. The processing method is safe and additive-free, and is worthy of promotion.

[0067] This application solves the problems of high bitterness residue, unstable low-sugar system and safety hazards of chemical additives in the existing process. It significantly reduces the bitterness and water extraction rate of jam, achieves low sugar and no chemical additives, and improves the utilization rate of citrus peel resources.

[0068] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A method for preparing tangerine peel jam, characterized in that: The method comprises the following steps: (1) preparing a tangerine peel fermentation matrix: crushing tangerine peel into 40-60 meshes, mixing tangerine peel and water in a mass ratio of 1:5-8, then adding β-cyclodextrin, and then ultrasonically treating at 45-55° C. for 20-40 minutes to obtain a tangerine peel fermentation matrix; (2) Fermentation treatment: Fermentation is carried out in stages, and Leuconostoc mesenteroides LMS1, Pichia pastoris YBHSF9-3, and Lactobacillus plantarum LDVS007 are sequentially introduced into the fermentation matrix, and fermented in this order to obtain a fermentation product for use; (3) Preparation and sterilization: add white sugar, citric acid, pectin and sodium alginate to the fermented product, adjust the soluble solids to 35-45%, and the pH to 3.5-3.8; then sterilize at 95-100° C. for 5-8 minutes, and fill to obtain the finished tangerine peel jam.

2. The method according to claim 1, characterized in that The amount of β-cyclodextrin added in step (1) is 0.5-1.5% of the mass of dried tangerine peel.

3. The method according to claim 1, characterized in that The staged fermentation in step (2) specifically includes the following three stages: 1) Stage 1: Inoculate 3-5% of Leuconostoc mesenteroides LMS1 and ferment at 25-28°C for 24-48 hours; 2) Second stage: inoculate 2-4% Pichia pastoris YBHSF9-3 and ferment at 30-32°C for 36-72 hours; 3) The third stage: inoculating 5-8% Lactobacillus plantarum LDVS007 and fermenting at 36-38° C. for 24-36 hours.

4. The method according to claim 1, wherein In the step (3), the amount of white sugar, citric acid, pectin and sodium alginate added to the fermentation product is, based on the total mass of the fermentation product, 20-30% white sugar, 0.1-0.3% citric acid, 0.4-0.8% pectin and 0.1-0.3% sodium alginate.

5. The method according to claim 1, wherein The pectin is prepared by the following steps: a. citrus peels were treated with lipase at 45°C and pH 6.5 for 2 hours, followed by supercritical CO2 defatting; b. 5-8% Lactobacillus plantarum LDVS007 was inoculated and ensiled at 37°C for 48-53 hours; c. 0.1% complex enzyme preparation was added and enzymatic hydrolysis was performed at 50°C for 2.5 hours; d. Ultrasonic-assisted extraction was performed at 80°C for 40 minutes, and purification was performed by alcohol precipitation to obtain the pectin.

6. The method according to claim 5, characterized in that The complex enzyme preparation is prepared by mixing cellulase and papain in a mass ratio of 2:

1.

7. The tangerine peel jam prepared according to the method described in any one of claims 1 to 6, characterized in that The tangerine peel jam has a limonin content of ≤15 mg / kg and a naringin content of ≤100 mg / kg.

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