Method for increasing sorbitol content of prune powder

Abstract

The invention discloses a method for increasing the content of sorbitol in prune powder, and belongs to the technical field of food deep processing. The method for increasing the sorbitol content of the prune powder comprises the following steps: removing pits from fresh prune fruits, and pulping; then drying the prune pulp in a drying oven at 80-100 DEG C for 5-8 hours; then carrying out vacuum freeze drying until the moisture content reaches 8-10%; and crushing and sieving to obtain the prune powder. The prune powder obtained through the method is high in sorbitol content, loss of flavonoid substances can be effectively reduced, and the prune powder has the unique flavor and color of prune.

Description

Technical Field

[0001] The invention relates to a method for increasing the sorbitol content in prune powder, belonging to the technical field of deep processing of food. Background Art

[0002] Prunes have a laxative effect. According to the data from the Chinese Food Composition Table, the content of sorbitol in fresh prunes is as high as 2.6 grams per 100 grams. Sorbitol contained in prunes is a natural sugar alcohol substance. It has super hydrophilic properties, can "bind" a large number of water molecules, and increase the osmotic pressure of intestinal contents, thereby stimulating intestinal movement and helping to relieve constipation. Studies have shown that prune juice containing sorbitol, pectin and polyphenols can improve constipation and hard stools, while normalizing stools, and plays an effective and safe natural food therapy for chronic constipation. In the development of prune products, the corresponding effects are usually enhanced by adding materials such as sorbitol. However, no attention has been paid to the enrichment and development of sorbitol in prunes themselves and the protection of flavonoids during the heating and powdering process.

[0003] The prune industry has problems such as short fresh fruit picking period, high moisture content, and difficulty in transportation and preservation. Therefore, processing prunes into prune powder is not only convenient for storage and carrying, but also can extend the shelf life. During the preparation process of prune powder, it usually undergoes a certain heat treatment for dehydration. During the heat treatment and dehydration process, the naturally produced sucrose will be converted into glucose, fructose and sorbitol, etc.; but at the same time, it will cause the destruction of flavonoid nutrients, resulting in a significant reduction in flavonoids, which in turn affects its nutritional value. Summary of the invention

[0004] In view of the defects and shortcomings of the prior art, the object of the present invention is to provide a method for increasing the sorbitol content of prune powder while reducing the damage to its flavonoids.

[0005] In order to achieve the above purpose, the technical solutions provided are as follows:

[0006] The present invention provides a method for increasing the sorbitol content of prune powder, the method comprising the following steps:

[0007] S1: Prune pretreatment: remove the pits from the fresh prunes and beat them into pulp;

[0008] S2: Drying: drying the prune pulp in an oven at 80-100°C for 5-8h;

[0009] S3: freeze drying: freeze drying the prune pulp dried in S2 in a vacuum manner until the moisture content reaches 8% to 10%;

[0010] S4: The freeze-dried prune pulp in S3 is crushed and sieved to obtain prune powder.

[0011] In one embodiment, the drying temperature in S2 is 80° C. and the time is 5 to 8 hours.

[0012] In one embodiment, the drying temperature in S2 is 80° C. and the time is 5 hours.

[0013] In one embodiment, the drying in S2 is performed until the moisture content reaches 10%.

[0014] In one embodiment, the drying in S2 is to microwave dry the prune pulp at 800-900W for 5-8h.

[0015] In one embodiment, the drying in S2 is to dry the prune pulp in a microwave at 900 W for 5 hours.

[0016] In one embodiment, the drying in S2 is to dry the prune pulp in an oven at 90-100° C. for 3 h, and then coupled with infrared drying at 100-120° C. for 2-3 h.

[0017] The present invention also provides a method for increasing the sorbitol content of prune powder and reducing the loss of flavonoids, the method comprising the following steps:

[0018] S1: Prune pretreatment: remove the pits from the fresh prunes and beat them into pulp;

[0019] S2: Drying: drying the prune pulp in an oven at 80-100°C for 5-8h;

[0020] S3: freeze drying: freeze drying the prune pulp dried in S2 in a vacuum manner until the moisture content reaches 8% to 10%;

[0021] S4: The freeze-dried prune pulp in S3 is crushed and sieved to obtain prune powder.

[0022] The present invention also provides application of the above-mentioned method in the field of deep processing of prunes.

[0023] Beneficial effects:

[0024] The invention realizes the enrichment of sorbitol in the preparation process of prune powder through a specific drying technology, reduces the destruction of flavonoids in the prune powder, and improves the overall sensory quality of the prune powder. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. The following specific implementation methods further describe the present invention.

[0026] The test method involved in the present invention is:

[0027] Total flavonoids detection method: refer to NY / T 2010-2011 Determination of total flavonoids in citrus fruits and products.

[0028] Sorbitol detection method: refer to "Determination of mannitol, maltose, xylitol and sorbitol in food by liquid chromatography tandem mass spectrometry".

[0029] Example 1

[0030] A method for increasing the sorbitol content of prune powder comprises the following steps:

[0031] S1: Prune pretreatment: remove the pits from the fresh prunes and beat them into pulp;

[0032] S2: Oven drying: Dry the prune pulp in an oven at 80°C for 5 h;

[0033] S3: Freeze drying: vacuum freeze drying the dried prune pulp until the moisture content reaches 10%;

[0034] S4: Grind the dried prune pulp and sieve it to obtain prune powder.

[0035] Example 2

[0036] A method for increasing the sorbitol content of prune powder comprises the following steps:

[0037] S1: Prune pretreatment: remove the core of the fresh prunes, slice them, and beat them into pulp;

[0038] S2: Oven drying: dry the prune pulp in an oven at 100°C for 5 h;

[0039] S3: freeze drying: freeze drying the dried prune pulp in a vacuum until the moisture content reaches 10%; S4: crushing the dried prune pulp, sieving it, and obtaining prune powder.

[0040] Example 3

[0041] A method for increasing the sorbitol content of prune powder comprises the following steps:

[0042] S1: Prune pretreatment: remove the core of the fresh prunes, slice them, and beat them into pulp;

[0043] S2: Drying: Dry the prune pulp in a microwave oven at 900 W for 5 h;

[0044] S3: freeze drying: freeze drying the prune pulp in a vacuum oven until the moisture content reaches 10%;

[0045] S4: Grind the dried prune pulp and sieve it to obtain prune powder.

[0046] Example 4

[0047] A method for increasing the sorbitol content of prune powder comprises the following steps:

[0048] S1: Prune pretreatment: remove the core of the fresh prunes, slice them, and beat them into pulp;

[0049] S2: Drying: drying the prune pulp in an oven at 100°C for 3 hours, followed by infrared drying at 100°C for 2 hours; S3: Freeze drying: vacuum freeze drying the prune pulp until the moisture content reaches 10%;

[0050] S4: Grind the dried prune pulp and sieve it to obtain prune powder.

[0051] Example 5

[0052] A method for increasing the sorbitol content of prune powder comprises the following steps:

[0053] S1: Prune pretreatment: remove the pits from the fresh prunes and beat them into pulp;

[0054] S2: Oven drying: Dry the prune pulp in an oven at 80°C for 8 h;

[0055] S3: freeze drying: freeze drying the dried prune pulp in a vacuum until the moisture content reaches 10%; S4: crushing the dried prune pulp, sieving it, and obtaining prune powder.

[0056] Comparative Example 1

[0057] A method for increasing the sorbitol content of prune powder comprises the following steps:

[0058] S1: Prune pretreatment: remove the pits from the fresh prunes and beat them into pulp;

[0059] S2: Oven drying: dry the prune pulp in an oven at 120°C for 5 h;

[0060] S3: freeze drying: freeze drying the dried prune pulp in a vacuum until the moisture content reaches 10%; S4: crushing the dried prune pulp, sieving it, and obtaining prune powder.

[0061] Comparative Example 2

[0062] A method for increasing the sorbitol content of prune powder comprises the following steps:

[0063] S1: Prune pretreatment: remove the core of the fresh prunes, slice them, and beat them into pulp;

[0064] S2: Oven drying: drying the prune pulp in an oven at 60°C for 5 h;

[0065] S3: freeze drying: freeze drying the prune pulp in a vacuum oven until the moisture content reaches 10%;

[0066] S4: Grind the dried prune pulp and sieve it to obtain prune powder.

[0067] Comparative Example 3

[0068] A method for increasing the sorbitol content of prune powder comprises the following steps:

[0069] S1: Prune pretreatment: remove the core of the fresh prunes, slice them, and beat them into pulp;

[0070] S2: Oven drying: drying the prune pulp in an oven at 80°C for 10 h;

[0071] S3: freeze drying: freeze drying the prune pulp in a vacuum oven until the moisture content reaches 10%;

[0072] S4: Grind the dried prune pulp and sieve it to obtain prune powder.

[0073] Comparative Example 4

[0074] A method for increasing the sorbitol content of prune powder comprises the following steps:

[0075] S1: Prune pretreatment: remove the core of the fresh prunes, slice them, and beat them into pulp;

[0076] S2: Drying: The prune pulp is subjected to infrared drying at 80°C for 5 h;

[0077] S3: freeze drying: freeze drying the prune pulp in a vacuum oven until the moisture content reaches 10%;

[0078] S4: Grind the dried prune pulp and sieve it to obtain prune powder.

[0079] Comparative Example 5

[0080] A method for increasing the sorbitol content of prune powder comprises the following steps:

[0081] S1: Prune pretreatment: remove the core of the fresh prunes, slice them, and beat them into pulp;

[0082] S2: Freeze drying: vacuum freeze drying the prune pulp until the moisture content reaches 10%;

[0083] S4: Grind the dried prune pulp and sieve it to obtain prune powder.

[0084] Comparative Example 6

[0085] A method for increasing the sorbitol content of prune powder comprises the following steps:

[0086] S1: Prune pretreatment: remove the core of the fresh prunes, slice them, and beat them into pulp;

[0087] S2: Drying: drying the prune pulp in an oven at 80°C for 3 h followed by infrared drying at 130°C for 1 h;

[0088] S3: freeze drying: freeze drying the prune pulp in a vacuum oven until the moisture content reaches 10%;

[0089] S4: Grind the dried prune pulp and sieve it to obtain prune powder.

[0090] Results Analysis

[0091] 1. The total flavonoids and sorbitol contents of the prune powder prepared in the examples and comparative examples were measured. The results are shown in Table 1:

[0092] Table 1 Contents of total flavonoids and sorbitol in prune powder

[0093]

[0094] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for increasing the sorbitol content of prune powder, characterized in that: The method comprises the following steps: S1: Prune pretreatment: remove the pits from the fresh prunes and beat them into pulp; S2: Drying: drying the prune pulp in an oven at 80-100°C for 5-8h; S3: freeze drying: freeze drying the prune pulp dried in S2 in a vacuum manner until the moisture content reaches 8% to 10%; S4: The freeze-dried prune pulp in S3 is crushed and sieved to obtain prune powder.

2. The method according to claim 1, characterized in that The drying temperature in S2 is 80° C. and the drying time is 5 to 8 hours.

3. The method according to claim 1, characterized in that The drying temperature in S2 is 80° C. and the drying time is 5 h.

4. The method according to claim 1, characterized in that: The drying is carried out as described in S2 until the moisture content reaches 10%.

5. The method according to claim 1, characterized in that The drying in S2 is to dry the prune pulp in a microwave at 800-900W for 5-8h.

6. The method according to claim 1, characterized in that The drying in S2 is to dry the prune pulp at 900W in a microwave for 5 hours.

7. The method according to claim 1, characterized in that The drying in S2 is to dry the prune pulp in an oven at 90-100° C. for 3 hours, and then coupled with infrared drying at 100-120° C. for 2-3 hours.

8. A method for increasing the sorbitol content of prune powder and reducing the loss of flavonoids, characterized in that: The method comprises the following steps: S1: Prune pretreatment: remove the pits from the fresh prunes and beat them into pulp; S2: Drying: drying the prune pulp in an oven at 80-100°C for 5-8h; S3: freeze drying: freeze drying the prune pulp dried in S2 in a vacuum manner until the moisture content reaches 8% to 10%; S4: The freeze-dried prune pulp in S3 is crushed and sieved to obtain prune powder.

9. Application of the method according to any one of claims 1 to 8 in the field of deep processing of prunes.

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