CN104292196B - One extracts ascorbic method from sweet tea - Google Patents

Abstract

The present invention is open a kind of extracts ascorbic method from sweet tea, and its step comprises pre-treatment, extraction, filtration, centrifugal and dry.Present method extraction efficiency is high, and cost is low, is easy to suitability for industrialized production.

Description

A method for extracting vitamin C from sweet tea

technical field

The invention belongs to the technical field of agricultural product processing, in particular to a method for extracting vitamin C from sweet tea.

Background technique

Sweet tea, Rosaceae Rubus, perennial thorny shrub. The leaves are sweet and edible, mainly distributed in Guangxi. Sweet tea, sweet in taste, cool and flat in nature, has the effects of clearing away heat, moistening the lungs, relieving sore throat, eliminating phlegm and relieving cough. Japanese studies have found that sweet tea has curative effects on pollen allergies, rhinitis, and dermatitis. The main components of sweet tea are rubusoside, tea polyphenols, total flavonoids, carbohydrates, proteins, amino acids, rich vitamins and minerals, etc. Among them, the vitamin C contained in every 100g of fresh tea leaves is 6406-11475mg.

Vitamin C (VC), that is, L-ascorbic acid, crystalline powder, no smelly acid, long-term exposure to yellow, unsaturated polyol containing 6 carbons, acidic, soluble in water and organic solvents, easily Oxidation, especially in neutral and alkaline solutions; metal ions such as Cu ²⁺ , Fe ²⁺ , etc. can promote its oxidation. Vitamin C is relatively stable in an environment around pH 5.5. Vitamin C not only has the effects of lowering blood sugar, lowering blood fat, beautifying, losing weight and preventing ring blood disease, but also can prevent the formation of carcinogens, drive away harmful free radicals in cells, avoid damage to DNA molecules and promote the body's absorption of iron. Since humans or animals lack enzymes to synthesize ascorbic acid, they cannot synthesize vitamin C by themselves and must obtain it from food. Therefore, it is listed as an essential nutrient element for humans or animals, and plays an irreplaceable role in protecting human health and animal growth. Therefore, it is widely used in pharmaceutical preparations, food and beverage nutritional additives and animal feed fortification additives.

At present, the methods for extracting vitamin C mainly include: solvent extraction, ultrasonic-assisted extraction and microbial fermentation, etc., but the main problems faced by large-scale production of vitamin C are complicated process, high cost and low extraction efficiency.

Contents of the invention

The purpose of the invention is to provide a method for extracting vitamin C from sweet tea. The problem to be solved is to improve the extraction efficiency of extracting vitamin C and reduce the extraction cost. The technical scheme provided by the present invention is:

A method for extracting vitamin C from sweet tea, comprising the following steps:

(1) Pretreatment: crush the dried sweet tea to 20-200 mesh to obtain sweet tea powder.

(2) Extraction: Add sweet tea powder and water respectively according to the solid-liquid ratio of 1:10-1:40, add buffer solution to adjust the pH to 5.0-7.0, soak, and then extract by extraction method to obtain the crude extract of sweet tea powder;

(3) Filtration: the obtained sweet tea powder crude extract is filtered, and then the filtrate is combined;

(4) centrifugation: after step (3) gained sweet tea powder extract, after centrifugation, get supernatant;

(5) Drying: the supernatant collected in step (4) is spray-dried to obtain crude vitamin C powder.

In step (1), the sweet tea is pulverized to 20 orders.

The buffer solution described in step (2) is acetic acid or sodium acetate buffer solution.

The soaking time of step (2) is 10-30min.

The extraction method in step (2) is any one of a single microwave extraction method, a single enzyme-microwave assisted extraction method, a microwave-ultrasonic combined extraction method, and a microwave-ultrasonic-single enzyme assisted extraction method.

Preferably, the single enzyme is cellulase, and its dosage is 1-5%.

Preferably, the microwave power in the single microwave extraction method, single enzyme-microwave assisted extraction method, microwave-ultrasonic combined extraction method and microwave-ultrasonic-single enzyme assisted extraction method is 80-280W, and the extraction time is 5-15min.

Preferably, the ultrasonic power in the microwave-ultrasonic combined extraction method and the microwave-ultrasonic-single enzyme assisted extraction method is 100-250W, and the extraction time is 8-20min.

As preferably, the centrifugation described in step (3), the rotating speed is 10000r/min, and the centrifugation time is 10min.

Beneficial effects of the present invention

1, the extraction method that the present invention adopts can effectively shorten extraction time and improve extraction efficiency.

2, the present invention adopts water as extraction solution, adopts acetic acid and sodium acetate as buffer solution, greatly reduces production cost, and can improve the extraction rate of VC;

detailed description

The present invention will be more readily understood with reference to the following examples, which are given without limiting the scope of the invention.

Example 1

Weigh 1g of sweet tea powder passed through a 20-mesh sieve, add water at a solid-to-liquid ratio of 1:18, and adjust the pH to 5.0 with acetic acid solution. 4 times. The combined filtrates were suction filtered, centrifuged at 10000 r/min for 10 min, and the supernatant was collected and spray-dried to obtain vitamin C powder. It was determined that the VC obtained by this method was 9.975 mg, and the yield reached 90.8%.

Example 2

Weigh 1g of sweet tea powder passed through a 20-mesh sieve, add water at a solid-to-liquid ratio of 1:15, and adjust the pH to 5.0 with sodium acetate buffer solution. After soaking for 15 minutes, use a single enzyme-microwave-assisted extraction method and add 2% cellulase. 43°C, microwave power 180W, extraction for 18min, repeated twice. The combined filtrates were suction filtered, centrifuged at 10000 r/min for 10 min, and the supernatant was collected and spray-dried to obtain vitamin C powder. It was determined that the VC obtained by this method was 10.075 mg, and the yield reached 91.6%.

Example 3

Weigh 1g of sweet tea powder passed through a 20-mesh sieve, add water at a solid-to-liquid ratio of 1:16, add acetic acid solution to adjust the pH to 5.0, soak for 10 minutes, and use microwave-ultrasonic combined extraction at 43°C with microwave power 150W to extract 12min, and then ultrasonic extraction at 200W ultrasonic power for 16min, repeated 3 times. The combined filtrates were suction filtered, centrifuged at 10,000 r/min for 10 min, and the supernatant was collected and spray-dried to obtain sweet tea VC powder. It is determined that the method can obtain a vitamin C content of 10.46 mg and a yield of 95.16%.

Example 4

Weigh 1g of sweet tea powder passed through a 20-mesh sieve, add water at a solid-to-liquid ratio of 1:14, adjust the pH to 5.0 with sodium acetate buffer solution, soak for 10 minutes, use microwave-ultrasonic-single enzyme-assisted extraction method, and add 1.5% cellulose Enzymes were then extracted at 43°C for 10 minutes at a microwave power of 120W, and then at an ultrasonic power of 180W for 16 minutes, repeated twice. The combined filtrate was suction filtered, centrifuged at 10,000 r/min for 10 min, and the supernatant was collected and spray-dried to obtain sweet tea vitamin C powder. It is determined that the content of vitamin C obtained by the method is 10.76 mg, and the yield reaches 97.8%.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling others skilled in the art to make and use various exemplary embodiments of the invention, as well as various Choose and change. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims (5)

1. from sweet tea, extract an ascorbic method, it is characterized in that, comprise the following steps:

(1) pre-treatment: dried sweet tea powder is broken to 20-200 order, obtains sweet tea powder.

(2) slightly extracting: be that 1:10-1:40 adds sweet tea powder and water respectively according to solid-to-liquid ratio, add buffered soln and adjust pH5.0-7.0, soak, then obtaining sweet tea powder crude extract through extracting;

(3) filter: by gained sweet tea powder crude extract after filtration, then merging filtrate;

(4) centrifugal: by step (3) gained sweet tea powder extracting solution, after centrifugal, to get supernatant liquor;

(5) dry: by spray-dried for the supernatant liquor collected in step (4), the crude vitamin C powder namely obtained;

Buffered soln described in step (2) is NaAc_HAc buffer solution;

The time of the immersion described in step (2) is 10-30min;

The method of the thick extraction described in step (2) is single microwave loss mechanisms, single enzyme-microwave―assisted extraction, microwave-ultrasonic in combination extraction method and microwave-ultrasonic-single enzyme assisted Extraction follow the example of in any one.

2. method according to claim 1, is characterized in that: dried sweet tea powder is broken to 20 orders in (1) by step.

3. method according to claim 1, is characterized in that: described single enzyme is cellulase, and its consumption is 1-5%.

4. method according to claim 1, it is characterized in that: described single microwave loss mechanisms, single enzyme-microwave―assisted extraction, microwave-ultrasonic in combination extraction method and microwave-ultrasonic-single enzyme assisted Extraction follow the example of in microwave power be 80-280W, extraction time 5-15min; Described microwave-ultrasonic in combination extraction method and microwave-ultrasonic-single enzyme assisted Extraction follow the example of in ultrasonic power be 100-250W, extraction time 8-20min.

5. method according to claim 1, is characterized in that: centrifugal described in step (4), and rotating speed is 10000r/min, centrifugation time 10min.