A method for preparing preserved fruit with reduced hydroxymethylfurfural and acrylamide content and its product

Abstract

The present invention provides a method for preparing preserved fruits with reduced hydroxymethylfurfural and acrylamide contents and its products, belonging to the technical field of food processing. The present invention provides a new preserved fruit processing technology to solve the problem that hydroxymethylfurfural and acrylamide are easily formed in the traditional preserved fruit processing process. The method of the present invention is: peeling, cored and sliced ​​apples; putting apple slices into a sugar solution, and then subjecting the apple slices to ultra-high pressure treatment, wherein the sugar solution contains sucrose, water, gum arabic, sodium pyrosulfite and citric acid; after the ultra-high pressure treatment, the apple slices are candied in the sugar solution for a period of time; the apple slices are fished out of the sugar solution, and dried to obtain preserved fruits with low hydroxymethylfurfural and acrylamide contents. Compared with preserved fruits prepared by traditional processing methods, the method of the present invention does not produce acrylamide at all and reduces hydroxymethylfurfural by 95%, greatly improving the food safety of preserved fruits, making the preserved fruits more transparent in color and excellent in taste, while reducing processing time and improving production efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and particularly relates to a method for preparing preserved fruits with reduced hydroxymethylfurfural and acrylamide contents and a product thereof. Background Art

[0002] Apples are rich in nutrients, contain a variety of phytochemicals and dietary fiber, help reduce chronic diseases, benefit consumers' health, and are highly adaptable to processing and can be made into a variety of products. Surveys show that about 40% of fruit juices and other fruit products are made from apples. Apple preserves, which use apples as the main raw material, are a traditional Chinese food. Apple preserves have a special taste and flavor, are rich in nutrients, and have the functions of helping digestion, stimulating appetite, and promoting salivation. As a tourist leisure food and local specialty, they are deeply loved by consumers. The production process of apple preserves mainly includes peeling, slicing, core removal, sugar boiling, candied and drying. Sodium metabisulfite is often added to protect the color, and citric acid is added to adjust the acidity and taste.

[0003] At present, the processing technology of preserved apples is still dominated by traditional processing methods. The industry threshold is low, the processing technology is backward, and the supporting technology is lacking, which may lead to high safety risks in preserved apples. Hydroxymethylfurfural and acrylamide are the associated hazards produced by the Maillard reaction during the processing of preserved fruits. Studies have found that hydroxymethylfurfural can irritate human eyes, mucous membranes, skin, etc., causing cell and gene mutations. Excessive intake can cause poisoning, causing skeletal muscle paralysis and visceral damage, and even cancer. Acrylamide has reproductive toxicity, genotoxicity and potential carcinogenicity, and is classified as a Class 2A carcinogen by the International Agency for Research on Cancer, that is, a substance that may cause cancer. High levels of acrylamide (0-1502μg / kg) have been detected in dried fruits represented by preserved fruits. The acrylamide content in some preserved fruit products is even higher than the acrylamide content in fried potato products, which is traditionally considered to be a high risk of acrylamide contamination (20-1068μg / kg). Therefore, the high concentration of thermal processing hazards in preserved fruit foods is attracting great attention from the society.

[0004] Ultra-high pressure processing is also known as high static pressure. The hydrostatic pressure involved in ultra-high pressure processing is usually in the range of 100-1000MPa, while the common pressure range of commercial ultra-high pressure is 400-600MPa, mainly using water as the pressure transmission medium. In 2009, the US Food and Drug Administration approved the application of high pressure to preheat samples and commercial sterilization of low-acid foods. Since then, ultra-high pressure processing technology has been widely used in the food field, and is currently mainly concentrated in juice drinks, meat products, fruit and vegetable products (such as guacamole, baby food, dips and salsa), aquatic products (seafood and shellfish) and dairy products, with market shares of 30%, 30%, 28%, 7% and 2% respectively. Summary of the invention

[0005] In view of the serious pollution of harmful substances (hydroxymethylfurfural and acrylamide) in the traditional preserved fruit process, the first technical problem to be solved by the present invention is to provide a preserved fruit preparation method with reduced hydroxymethylfurfural and acrylamide content. The second technical problem to be solved by the present invention is to provide a preserved fruit product with reduced hydroxymethylfurfural and acrylamide content.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing preserved fruit with reduced hydroxymethylfurfural and acrylamide contents comprises the following steps:

[0008] (1) Peel, core and slice the apples;

[0009] (2) placing the apple slices in a sugar solution containing sucrose, water, gum arabic, sodium pyrosulfite, and citric acid, and then subjecting the apple slices to ultrahigh pressure treatment;

[0010] (3) After the ultrahigh pressure treatment, the apple slices are candied in a sugar solution for a period of time;

[0011] (4) The apple slices are removed from the sugar solution and dried to obtain preserved fruits with reduced hydroxymethylfurfural and acrylamide contents.

[0012] Preferably, in order to avoid oxidation reaction, the apples are peeled and cored and then immediately soaked in pure water.

[0013] Preferably, the thickness of the apple slices is controlled at 1±0.3cm, which is conducive to the next step of ultra-high pressure and sugar treatment.

[0014] Preferably, in step (2), the sugar solution is prepared by using sucrose and water as raw materials to prepare a 55-65% sugar solution; preparing 3700-3800 g of sugar solution for every 500 g of apple slices, and adding 1.9-2.1 g of sodium metabisulfite, 3.5-4 g of citric acid, and 11-15 g of gum arabic.

[0015] Preferably, in step (2), the specific ultrahigh pressure treatment conditions are: room temperature, water as the medium, and treatment at 400-600 MPa for 10-20 min.

[0016] Preferably, in order to achieve the best effect, the specific ultrahigh pressure treatment conditions are: at room temperature, with water as the medium, and at 500 MPa for 10 minutes.

[0017] Preferably, in order to allow the apple slices to be fully soaked in the sugar solution, the sugaring time is 12-36 hours.

[0018] Preferably, the drying method for preparing the preserved apples is: in a forced air drying oven at 50-70°C.

[0019] In order to achieve the best taste of the preserved fruit, preferably, the apple variety selected is Shandong Qixia Red Fuji.

[0020] The product prepared by any of the above methods.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention provides a method for preparing preserved fruits with reduced hydroxymethylfurfural and acrylamide contents. Compared with preserved fruits prepared by traditional heat processing methods, the method of the present invention can reduce 95% of hydroxymethylfurfural and completely eliminate acrylamide, greatly improve the food quality of preserved fruits, reduce processing time, and improve production efficiency. The added edible colloid (gum arabic) forms an edible coating (film) on the surface of the preserved fruits during processing, which becomes a protective barrier, reduces the degree of freedom of water molecules in the system, and inhibits the formation of hydroxymethylfurfural and acrylamide during processing. In addition, the added colloid substance also increases the fullness and transparency of the preserved fruits, making the taste better. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The apple preserves obtained by different processing techniques in Example 2 and the comparative example;

[0024] Figure 2 This is a comparison chart of the hydroxymethylfurfural and acrylamide contents in preserved apples obtained by different processing techniques in Example 3 and the comparative example. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with specific embodiments, but the embodiments are merely exemplary and do not constitute any limitation to the protection scope of the present invention.

[0026] The ultrahigh pressure processing equipment used in the following examples was produced by Suyuan Zhongtian Food Machinery Co., Ltd., model number CQC30L-600.

[0027] Comparative Example:

[0028] The traditional method of processing preserved fruit includes the following steps:

[0029] Step 1: Raw material processing: peel and core the apples, and immediately soak them in pure water for later use;

[0030] Step 2, slicing: Cut the apples processed in step 1 into 12 pieces evenly, with each piece being about 1 cm thick;

[0031] Step 3, preparing sugar solution: mix sucrose and water in a mass ratio of 3:2, and prepare 3750g of 60% sugar solution for every 500g of apple slices;

[0032] Step 4, adding ingredients: for every 500g of apples, weigh 2g of sodium metabisulfite and 3.5-4g of citric acid and add them to the sugar solution in step 3;

[0033] Step 5, sugar boiling: immerse the apple segments processed in step 2 into the sugar solution prepared in step 4, and cook over low heat for 1 hour until the apple segments become translucent;

[0034] Step 6: Sugar pickling: continue to soak the apple slices processed in step 5 in the sugar solution in step 4 and sugar pickle at room temperature for 24 hours;

[0035] Step 7, drying: Take out the preserved fruits from step 6 and put them into a forced air drying oven at 70°C and dry them for 12 hours.

[0036] Embodiment 1:

[0037] A method for preparing preserved fruit comprises the steps of:

[0038] Step 1: Raw material processing: Peel and core the apples, and immediately soak them in pure water for later use;

[0039] Step 2, slicing: Cut the apples processed in step 1 into 12 pieces evenly, with each piece being about 1 cm thick;

[0040] Step 3, preparing sugar solution: mix sucrose and water in a mass ratio of 3:2, and prepare 3750g of 60% sugar solution for every 500g of apple slices;

[0041] Step 4, adding ingredients: for every 500g of apples, weigh 2g of sodium metabisulfite and 3.5-4g of citric acid and add them to the sugar solution in step 3;

[0042] Step 5, candied: soak the apple slices processed in step 2 in the sugar solution prepared in step 4 and candied at room temperature for 24 hours;

[0043] Step 6, drying: Take out the preserved fruits from step 5 and put them into a forced air drying oven at 70°C and dry them for 12 hours.

[0044] Embodiment 2:

[0045] A method for preparing preserved fruit comprises the steps of:

[0046] Step 1: Raw material processing: Peel and core the apples, and immediately soak them in pure water for later use;

[0047] Step 2, slicing: Cut the apples processed in step 1 into 12 pieces evenly, with each piece being about 1 cm thick;

[0048] Step 3, preparing sugar solution: mix sucrose and water in a mass ratio of 3:2, and prepare 3750g of 60% sugar solution for every 500g of apple pieces;

[0049] Step 4, adding ingredients: for every 500g of apples, weigh 2g of sodium metabisulfite and 3.5-4g of citric acid and add them to the sugar solution in step 3;

[0050] Step 5, ultra-high pressure treatment: immerse the apple segments treated in step 2 in the sugar solution prepared in step 4, put them into a 20*24 cm ultra-high pressure resistant bag and place them in an ultra-high pressure device, working medium: water, working temperature: room temperature, treat at 500 MPa for 10 minutes;

[0051] Step 6: Sugar pickling: continue to soak the apple slices processed in step 5 in the sugar solution in step 4 and sugar pickle at room temperature for 24 hours;

[0052] Step 7, drying: Take out the preserved fruits from step 6 and put them into a forced air drying oven at 70°C and dry them for 12 hours.

[0053] Embodiment 3:

[0054] A method for preparing preserved fruit comprises the steps of:

[0055] Step 1: Raw material processing: Peel and core the apples, and immediately soak them in pure water for later use;

[0056] Step 2, slicing: Cut the apples processed in step 1 into 12 pieces evenly, with each piece being about 1 cm thick;

[0057] Step 3, preparing sugar solution: mix sucrose and water in a mass ratio of 3:2, and prepare 3750g of 60% sugar solution for every 500g of apple pieces;

[0058] Step 4, adding ingredients: for every 500g of apples, weigh 2g of sodium metabisulfite and 3.5-4g of citric acid and add them to the sugar solution in step 3;

[0059] Step 5, adding harmful substance inhibitors: adding 0.3% gum arabic to the sugar solution in step 3;

[0060] Step 6, ultra-high pressure treatment: immerse the apple segments treated in step 2 in the sugar solution prepared in step 5, put them into a 20*24cm ultra-high pressure resistant bag and place them in an ultra-high pressure device, working medium: water, working temperature: room temperature, treat at 500MPa for 10 minutes;

[0061] Step 7, candied: continue to soak the apple slices processed in step 6 in the sugar solution of step 5, and candied at room temperature for 24 hours;

[0062] Step 8, drying: Take out the preserved fruits from step 6 and put them into a forced air drying oven at 70°C and dry them for 12 hours.

[0063] Embodiment 4:

[0064] 20 evaluators scored the comparative example and Examples 1-3 respectively. It can be seen from Table 1 that there is no significant difference in the color and tissue morphology scores of the traditional preserved fruits of the comparative example and the preserved fruits of Examples 2-3, but the taste and smell of the preserved fruits of Examples 2 and 3 are significantly better than those of the traditional preserved fruits. From a comprehensive comparison, the total sensory score of the preserved fruits of Examples 2 and 3 is significantly higher than that of the traditional preserved fruits, which indicates that the apple preserved fruits prepared by ultrahigh pressure have better sensory quality and are more popular among the evaluators. It can also be found from Table 1 that the scores of the preserved fruits prepared in Example 1 are all low. From the perspective of color, tissue morphology, taste and smell, the reasons for the data in Table 1 are that the preserved fruits of Example 1 are lighter in color, harder in texture and chewy, and have a poor taste. The preserved fruits of the comparative example have a bright yellow appearance, a slightly too sweet taste, and a slightly light apple aroma; the preserved fruits of Examples 2-3 have a similar appearance, a yellow appearance, a uniform, clear and bright color, a dense taste, moderate sweetness and an apple aroma. It may be that in the production process of the apple preserves in the comparative example, the aroma substances dissipated during the long cooking process, while the ultra-high pressure treatment in Examples 2 and 3 better retained the volatile aroma substances such as phenols and aldehydes in the preserves, making the aroma of the preserves in Examples 2 and 3 more intense. The reason why Example 3 scored higher than Example 2 may be that the addition of gum arabic improved the plumpness and transparency of the preserves, making the taste better. Figure 1 shown.

[0065] Table 1 Comparison of sensory scores of different preserved fruits in the embodiments and comparative examples

[0066] Comparative Example Example 1 Example 2 Example 3 Color <![CDATA[26.00±1.67 a ]]> <![CDATA[18.57±4.96 b ]]> <![CDATA[23.22±2.44 ab ]]> <![CDATA[24.13±5.44 ab ]]> Organizational form <![CDATA[22.80±3.87 ab ]]> <![CDATA[17.86±4.72 b ]]> <![CDATA[22.44±2.97 ab ]]> <![CDATA[24.44±4.30 a ]]> Taste and smell <![CDATA[23.73±4.19 b ]]> <![CDATA[28.78±8.14 ab ]]> <![CDATA[30.06±7.14 a ]]> <![CDATA[30.56±7.15 a ]]> Total score <![CDATA[72.53±5.40 b ]]> <![CDATA[65.21±15.41 c ]]> <![CDATA[75.72±9.73 ab ]]> <![CDATA[79.13±10.27 a ]]>

[0067] Note: Different letters in each row indicate significant differences (p < 0.05)

[0068] Embodiment 5:

[0069] The preserved fruits prepared in the comparative example and examples 2 and 3 were tested for hydroxymethylfurfural and acrylamide.

[0070] Detection methods for hydroxymethylfurfural and acrylamide:

[0071] Sample pretreatment: weigh 1g of apple preserves, homogenize them in a grinder and place them in a 50mL centrifuge tube, add 10mL of water, vortex extract for 2min, then add 10mL of acetonitrile, vortex extract for 2min, and ultrasonic extract for 15min; add 4g of anhydrous magnesium sulfate and 1g of sodium chloride to the solution after ultrasonication, vortex for 2min; centrifuge at 10000rpm for 15min, take the supernatant and place it in a 15mL centrifuge tube for nitrogen blowing; reconstitute with 1mL of ultrapure water, vortex for 1min; filter through a 0.22μm water filter membrane and place it in an injection vial for UPLC-MS / MS detection.

[0072] Liquid phase method: Chromatographic separation conditions: AcquityUPLC HSS T3 column (2.1×100 mm, 1.8 μm, Waters, USA); mobile phase (A) 0.1% formic acid aqueous solution, (B) acetonitrile, gradient elution conditions; flow rate 0.3 mL / min; column temperature 40°C; sample chamber temperature 10°C; injection volume 1 μL. The gradient elution program is as follows: 99% A0-0.5 min, 99-98.5% A0.5-1.0 min, 98.5-55% A1.0-1.5 min, 55-50% A1.5-2.0 min, 50-20% A2.0-3.0 min, 20-99% A3.0-3.1 min, 99% A3.1-4.5 min.

[0073] Mass spectrometry method: Mass spectrometry detection (MS) conditions are: capillary voltage 0.5 kV; source temperature 100°C; desolvation temperature 500°C; conical gas flow 150 L / h; desolvation gas flow 1000 L / h; collision gas flow rate 0.12 mL / min.

[0074] Table 2 Mass spectrometry conditions for detection of hydroxymethylfurfural and acrylamide

[0075]

[0076]

[0077] Note: 13 C-acrylamide was used as internal standard for acrylamide

[0078] Table 3 shows the contents of hydroxymethylfurfural and acrylamide in the comparative example, Example 2 and Example 3. Compared with the conventional heat-treated preserved fruit in the comparative example, the method for preparing preserved fruit in Examples 2 and 3 reduces 95% of hydroxymethylfurfural and eliminates 100% of acrylamide in the preserved fruit, wherein the comparison of the contents of hydroxymethylfurfural and acrylamide in the comparative example and Example 3 is shown in the figure below. Figure 2 shown.

[0079] Table 3 Hydroxymethylfurfural and acrylamide contents in the products of the examples and comparative examples

[0080] Hydroxymethylfurfural content mg / kg Acrylamide content μg / kg Comparative Example 66.98±1.11 139.76±14.48 Example 2 3.61±0.47 ND Example 3 1.88±0.26 ND

[0081] Note: ND: not detected

[0082] In summary, the processing method of the present invention can greatly improve the production efficiency, food safety and edible quality of preserved fruits.

[0083] Although the present invention has been described above through embodiments, those skilled in the art should understand that without departing from the spirit and substance of the present invention, all improvements and modifications made to the present invention should fall within the protection scope of the present invention.

Claims

1. A method for preparing preserved fruit with reduced hydroxymethylfurfural and acrylamide contents, characterized in that: The steps include: (1) Peel, core and slice the apples; (2) placing the apple slices in a sugar solution containing sucrose, water, gum arabic, sodium pyrosulfite, and citric acid, and then subjecting the apple slices to ultrahigh pressure treatment; (3) After the ultrahigh pressure treatment, the apple slices are candied in the sugar solution for 12-36 hours; (4) removing the apple slices from the sugar solution and drying them at 50-70° C. to obtain preserved fruits with reduced hydroxymethylfurfural and acrylamide contents; Wherein, in step (2), the preparation method of the sugar solution is: using sucrose and water as raw materials to prepare a 55-65% sugar solution; preparing 3700-3800g of sugar solution for every 500g of apple slices, and adding 1.9-2.1g of sodium metabisulfite, 3.5-4g of citric acid, and 11-15g of gum arabic; the specific ultrahigh pressure treatment conditions are: room temperature, using water as the medium, and treating at 400-600MPa for 10-20min.

2. The method for preparing preserved fruit for reducing hydroxymethylfurfural and acrylamide content according to claim 1, characterized in that: The step (1) further comprises: peeling and core the apples and immediately soaking them in pure water.

3. The method for preparing preserved fruits that reduces the content of hydroxymethylfurfural and acrylamide according to claim 1, characterized in that: In step (1), the thickness of the apple slices is controlled at 1±0.3 cm.

4. The method for preparing preserved fruit with reduced hydroxymethylfurfural and acrylamide contents according to claim 1, characterized in that: At room temperature, with water as the medium, the treatment was carried out at 500 MPa for 10 min.

5. The method for preparing preserved fruit with reduced hydroxymethylfurfural and acrylamide contents according to claim 1, characterized in that: The apple variety is Shandong Qixia Red Fuji.

6. The product prepared by the method according to any one of claims 1 to 5.

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