A method for stabilizing and reducing bacteria of compound juice by adding cortex periploci pulp and photodynamic action

Abstract

This invention discloses a method for stabilizing and reducing bacteria in a compound fruit juice by adding wampee pulp and photodynamic therapy, belonging to the field of food processing technology. The method includes adding sea buckthorn juice and wampee pulp to mango juice; the amount of sea buckthorn juice added is 5%; and the amount of wampee pulp added is 5-25%. This invention achieves the dual effects of preventing browning based on the clean label concept and improving the suspension stability of the mango juice system. It not only improves cloudiness stability and accelerates centrifugal stability but also increases the total phenolic content and antioxidant activity, and enriches the aroma components of the treated mango juice. In summary, this invention, by combining with photodynamic sterilization technology, not only reduces the number of microorganisms but also further enhances the stability of mango juice.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, and in particular relates to a method for stabilizing and reducing bacteria in compound fruit juice by adding yellow peel pulp and photodynamic therapy. Background Technology

[0002] Mangoes (Mangifera indica L.) have a concentrated harvest period and are highly perishable and do not store well. Processing is an important way to reduce post-harvest losses and increase their added value. Mango juice and its beverages are currently the largest processed mango products both domestically and internationally. Compared with clear juice, cloudy mango juice rich in pulp is more favored by consumers because of its authentic taste and nutritional components. However, the processing and storage of enzymatically hydrolyzed cloudy mango juice still faces bottlenecks such as easy browning and stratification, flavor loss, nutrient degradation, and secondary precipitation. These problems seriously affect the product's appearance, texture, and consumer experience, thus restricting its market competitiveness.

[0003] Regarding stability improvement, current methods in this field primarily utilize physical means such as high-pressure homogenization, ultrasonic enzymatic hydrolysis, and ultrafiltration, along with the addition of food additives or nutrient fortifiers such as hydrophilic colloidal stabilizers and antioxidants, to enhance the suspension stability of turbid juice. However, chemically synthesized additives pose safety risks due to potential residues and accumulation, and do not align with consumers' pursuit of clean labeling in the context of nutritional health. In terms of flavor and nutrient preservation, international juice processing companies generally employ anaerobic or low-oxygen juicing technologies such as vacuum degassing and gas bubbling agitation to stabilize the color and vitamins of the juice. However, deoxygenation can lead to the loss of volatile flavor compounds. Therefore, some juice producers have begun using membrane or enzymatic deoxygenation methods, but these are relatively expensive. Currently, heat sterilization remains the primary method for processing juice, but it easily leads to browning and flavor deterioration. Ultra-high pressure sterilization is also available, but it is costly.

[0004] Therefore, improving the stability and anti-browning properties of mango cloudy juice, and enhancing its sensory, nutritional, and flavor qualities, has always been a hot topic of concern for the industry both domestically and internationally. Furthermore, finding a solution that can both reduce the number of microorganisms and further enhance the stability of the juice is of great significance. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a method for stabilizing and reducing microorganisms in mango juice by adding wampee pulp and combining it with photodynamic therapy. By combining this method with photodynamic sterilization technology, this invention not only reduces the number of microorganisms but also further enhances the stability of mango juice.

[0006] Technical Solution 1: A method for stabilizing and reducing bacteria in compound fruit juice by adding yellow peel pulp and photodynamic therapy, including the step of adding sea buckthorn juice and yellow peel pulp to mango juice.

[0007] Furthermore, the amount of sea buckthorn juice added is 5%.

[0008] Furthermore, the amount of yellow peel pulp added is 5-25%.

[0009] Furthermore, the amount of yellow peel pulp added is 15%.

[0010] Furthermore, it includes the step of processing using LED lighting.

[0011] Technical Solution 2: The application of the compound fruit juice stabilization and sterilization method in preventing browning of mango juice and improving the suspension stability of mango juice system.

[0012] Technical Solution 3: The application of the compound fruit juice stabilization and sterilization method in improving the total phenolic content and antioxidant activity of mango juice.

[0013] Technical Solution 4: Compared with existing technologies, the compound fruit juice stabilization and sterilization method described above has the following advantages and technical effects in reducing the number of microorganisms in mango juice:

[0014] This invention achieves the dual effects of preventing browning and improving the suspension stability of the mango juice system based on the clean label concept by adding yellow peel pulp and natural plant component sea buckthorn to mango juice. It not only improves cloudiness stability and accelerates centrifugal stability, but also increases the total phenol content and antioxidant activity. The aroma components of the mango juice are also richer. By combining it with photodynamic sterilization technology, it not only reduces the number of microorganisms, but also further enhances the stability of the juice. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 The cloudiness stability of the juice in each treatment group;

[0017] Figure 2 The instability index of the juice in each treatment group;

[0018] Figure 3 The instability index of the group with 0% yellow peel and 5% sea buckthorn juice added;

[0019] Figure 4 The instability index of the group with 5% yellow peel and 5% sea buckthorn juice added;

[0020] Figure 5 The instability index of the group with 7.5% yellow peel and 5% sea buckthorn juice added;

[0021] Figure 6 The instability index of the group with 10% yellow peel and 5% sea buckthorn juice added;

[0022] Figure 7 The instability index of the group with 15% yellow peel and 5% sea buckthorn juice added;

[0023] Figure 8 The instability index of the group with 20% yellow peel and 5% sea buckthorn juice added;

[0024] Figure 9 The instability index of the group with 25% yellow peel and 5% sea buckthorn juice added;

[0025] Figure 10 The total phenol content of the juice in each treatment group;

[0026] Figure 11 The DPPH scavenging activity of the juice in each treatment group;

[0027] Figure 12 The aroma components of the juice from each treatment group;

[0028] Figure 13 The sterilization effect of fruit juice under different sterilization methods is shown; where A represents no sterilization, B represents 20 minutes of LED light irradiation, and C represents 30 minutes of LED light irradiation.

[0029] Figure 14 The stability of fruit juice under unsterilized conditions;

[0030] Figure 15 To assess the stability of the juice under LED lighting conditions;

[0031] Figure 16 The stability of the juice under LED light irradiation for 30 minutes was measured. Detailed Implementation

[0032] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0033] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0034] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0035] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0036] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0037] Pectinase and cellulase were purchased from Henan Wanbang Huagong Technology Co., Ltd.

[0038] Example 1

[0039] Preparation of mango juice for each treatment group: Fresh mangoes were peeled, pitted, and pulped. 0.03% pectinase and cellulase (mass ratio of pectinase to cellulase was 2:1) were added to the mango pulp. The mixture was enzymatically hydrolyzed at 50℃ for 2 hours, filtered, and 5% sea buckthorn juice and different proportions (0%, 5%, 7.5%, 10%, 15%, 20%, 25%) of wampee pulp (fresh wampee was peeled, pitted, and pulped to obtain wampee pulp) were added. The mixture was dispersed and homogenized using a homogenizer. After homogenization, the mixture was placed into sample bottles. The group without wampee pulp and sea buckthorn juice was the control group.

[0040] Experimental Example 1

[0041] The cloudiness stability of mango juice was determined in groups with different proportions of yellow peel pulp (0%, 5%, 7.5%, 10%, 15%, 20%, 25%) and 5% sea buckthorn juice, as well as in the control group.

[0042] The determination method is as follows: 10 mL of each sample is drawn, and the absorbance of the juice is measured before and after centrifugation at 8000 rpm for 15 min. The absorbance is measured in 1 cm diameter tube cells at 625 nm.

[0043] The method for calculating cloud stability is as follows:

[0044] CS% = CA / CO × 100%

[0045] In the formula, CO and CA are the absorbance before and after centrifugation, respectively.

[0046] The results are as follows Figure 1 As shown, the results indicate that adding different amounts of yellow peel pulp and 5% sea buckthorn juice to mango juice can improve the cloudiness stability of the compound juice in each treatment group.

[0047] Experiment Example 2

[0048] The instability index of mango juice was determined in groups with different proportions of yellow peel pulp (0%, 5%, 7.5%, 10%, 15%, 20%, 25%) and 5% sea buckthorn juice, as well as in the control group.

[0049] The determination method is as follows: accelerated centrifugation stability is determined by a full-function stability analyzer, specifically by using the fraction of transmitted light during centrifugation as a function of sample stability.

[0050] 1.6 mL of juice was extracted and transferred into a polycarbonate centrifuge tube with a path length of 10 mm. The apparatus parameters were set as follows: rotation speed 1500 r / min, temperature 25℃; 1 minute interval, 15 cycles. The "instability index" was calculated and recorded by the instrument software (SepView 6.0, LUM, Berlin, Germany). The instability index is a dimensionless number ranging from 0 (very stable) to 1 (very unstable).

[0051] The results are as follows Figure 2 As shown, the results indicate that adding different amounts of yellow peel pulp and 5% sea buckthorn juice to mango juice can reduce the instability index of mango juice in each treatment group.

[0052] Experimental Example 3

[0053] Accelerated centrifugal stability of mango juice was determined in groups with different proportions of yellow peel pulp (0%, 5%, 7.5%, 10%, 15%, 20%, 25%) and 5% sea buckthorn juice, as well as in the control group.

[0054] The determination method is as follows: accelerated centrifugation stability is determined by a full-function stability analyzer, specifically by using the fraction of transmitted light during centrifugation as a function of sample stability.

[0055] 1.6 mL of juice was extracted and transferred into a polycarbonate centrifuge tube with a path length of 10 mm. The apparatus parameters were set as follows: rotation speed 1500 r / min, temperature 25℃; 1 minute interval, 15 cycles. The "instability index" was calculated and recorded by the instrument software (SepView 6.0, LUM, Berlin, Germany). The instability index is a dimensionless number ranging from 0 (very stable) to 1 (very unstable).

[0056] The results are as follows Figures 3-9 As shown, the results indicate that adding different amounts of yellow peel pulp and 5% sea buckthorn juice to mango juice can reduce the instability index of mango juice in each treatment group.

[0057] Experiment Example 4

[0058] The total phenolic content of mango juice in groups with different proportions of yellow peel pulp (0%, 5%, 7.5%, 10%, 15%, 20%, 25%) and 5% sea buckthorn juice, as well as the control group, was determined.

[0059] The determination method is as follows: the total phenol content in the sample is determined by the Folin-Ciocalteu method, and the total phenol content in the sample is expressed as gallic acid equivalent.

[0060] The results are as follows Figure 10 As shown, the results indicate that adding different amounts of yellow peel pulp and 5% sea buckthorn juice to mango juice gradually increases the total phenol content in the mango juice of each treatment group.

[0061] Experimental Example 5

[0062] The DPPH scavenging activity of mango juice in groups with different proportions of yellow peel pulp (0%, 5%, 7.5%, 10%, 15%, 20%, 25%) and 5% sea buckthorn juice, as well as the control group, was determined.

[0063] The determination method is as follows: DPPH-stock solution preparation:

[0064] For the DPPH- scavenging activity test, the sample was added to an ethanol solution of DPPH- (4 mg / 100 mL) and shaken to ensure complete dissolution. After storing in the dark for 30 minutes, the absorbance at 517 nm was recorded.

[0065] Plotting the standard curve:

[0066] Accurately weigh 0.5 mg of vitamin C and prepare a 0.5 mg / mL vitamin C standard stock solution in 1 mL of 80% ethanol. Dilute the stock solution with 80% ethanol to obtain concentration gradients of 0, 5, 10, 15, 20, and 25 μg / mL. Measure the absorption spectrum at 517 nm. Plot the mass concentration of vitamin C on the x-axis and absorbance on the y-axis to obtain a standard curve.

[0067] Sample determination:

[0068] Add DPPH- (4 mg / 100 mL) ethanol to the sample and shake to dissolve completely. After storing the mixture in the dark for 30 minutes, measure the absorbance at 517 nm. Calculate the DPPH- radical scavenging capacity, expressed in μg / mL.

[0069] The results are as follows Figure 11 As shown, the results indicate that adding different amounts of yellow peel pulp and 5% sea buckthorn juice to mango juice can gradually increase the DPPH scavenging activity of mango juice in each treatment group.

[0070] Experimental Example 6

[0071] Aroma components of mango juice were determined in groups with different proportions of yellow peel pulp (0%, 5%, 7.5%, 10%, 15%, 20%, 25%) and 5% sea buckthorn juice, as well as in the control group.

[0072] The determination method was as follows: aroma components were analyzed using gas chromatography-mass spectrometry.

[0073] Chromatographic conditions: Column: VF-WAX column; Temperature program: 40℃ for 5 minutes, increase to 180℃ at 5℃ / min, then increase to 230℃ at 10℃ / min and hold for 2 minutes; Carrier gas: helium, flow rate: 3.0 mL / min; Split ratio: 5:1.

[0074] Mass spectrometry conditions: EI ion source; ion source temperature: 230℃; interface temperature: 240℃; solvent delay time: 1.00 min; scan mode: Scan; m / z: 40~500.

[0075] The results are as follows Figure 12 As shown, the results indicate that adding different amounts of yellow peel pulp and 5% sea buckthorn juice to mango juice can enrich the aroma components in the mango juice of each treatment group.

[0076] Experimental Example 7

[0077] Fresh mangoes were peeled, pitted, and pulped. 0.03% pectinase and cellulase (mass ratio of pectinase to cellulase was 2:1) were added to the mango pulp and enzymatically hydrolyzed at 50°C for 2 hours. After filtration, 5% sea buckthorn juice and 15% wampee pulp (fresh wampee was peeled, pitted, and pulped to obtain wampee pulp) were added and dispersed and homogenized using a homogenizer. After homogenization, the pulp was placed in sample bottles to compare the sterilization effect of unsterilized and LED-illuminated pulps.

[0078] The specific steps for LED light treatment are as follows: irradiate with a 405nm LED visible light source (output light power density of 180-200mW / cm2) for 20min and 30min respectively. The sterilization effect is shown in Table 1.

[0079] like Figure 13 As shown in the figure, the results indicate that the number of microorganisms in the fruit juice treated with LED light was significantly reduced compared to the untreated juice.

[0080] Table 1 Sterilization effect

[0081] Grouping Total bacterial count Control group (logCFU / mL) 2.75±0.26 Experimental group - LED light irradiation for 20 min (log CFU / mL) 2.18±0.09 Experimental group - LED light irradiation for 30 min (log CFU / mL) 1.73±0.15

[0082] Experimental Example 8

[0083] Fresh mangoes were peeled, pitted, and pulped. 0.03% pectinase and cellulase (mass ratio of pectinase to cellulase was 2:1) were added to the mango pulp and enzymatically hydrolyzed at 50°C for 2 hours. After filtration, 5% sea buckthorn juice and 15% wampee pulp (fresh wampee was peeled, pitted, and pulped to obtain wampee pulp) were added and dispersed and homogenized using a homogenizer. After homogenization, the pulp was placed in sample bottles to compare its stability before sterilization and after LED light exposure.

[0084] The specific steps for LED illumination treatment are to illuminate the LED with a wavelength of 405nm (output light power density of 180-200mW / cm2) for 20min and 30min respectively.

[0085] The determination method was as follows: Accelerated centrifugation stability was measured using a full-function stability analyzer, specifically by using the fraction of transmitted light during centrifugation as a function of sample stability. 1.6 mL of juice was taken and transferred to a polycarbonate centrifuge tube with a 10 mm optical path length. The device parameters were set as follows: centrifugation speed 1500 r / min, temperature 25℃; interval 1 minute, 15 cycles. The "instability index" was calculated and recorded by the instrument software (SepView 6.0, LUM, Berlin, Germany). The instability index is a dimensionless number ranging from 0 (very stable) to 1 (very unstable).

[0086] The results are as follows Figure 14 As shown in (unsterilized), 15 (LED light irradiation for 20 min), and 16 (LED light irradiation for 30 min), the results show that adding 15% yellow peel pulp and 5% sea buckthorn juice to mango juice, followed by LED light irradiation for sterilization, can reduce the number of microorganisms in the juice and further improve its stability.

[0087] The results above show that by adding natural plant components of sea buckthorn and yellow peel pulp to the enzymatically hydrolyzed mango juice, this invention achieves the dual effects of preventing browning based on the clean label concept and improving the suspension stability of the mango juice system. It not only improves cloudiness stability and accelerates centrifugal stability, but also increases the total phenol content and antioxidant activity. The aroma components of the mango juice are also richer. By combining it with photodynamic sterilization technology, it not only reduces the number of microorganisms, but also further enhances the stability of the juice.

[0088] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method of improving the suspension stability of a mango juice system, characterized in that, The method comprises adding sea buckthorn juice and wampee original paste into mango juice and treating by LED light; The sea buckthorn juice is added in an amount of 5%; The wampee original paste is added in an amount of 15%.

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