CN101715844A

CN101715844A - Method for preparing ultrafine tea powder

Info

Publication number: CN101715844A
Application number: CN200910232523A
Authority: CN
Inventors: 胡秋辉; 毛久庚; 李锋; 梁进; 赵立艳; 安辛欣; 辛志宏
Original assignee: Nanjing Agricultural University
Current assignee: Nanjing Agricultural University
Priority date: 2009-12-07
Filing date: 2009-12-07
Publication date: 2010-06-02
Anticipated expiration: 2029-12-07
Also published as: CN101715844B

Abstract

The invention discloses a method for preparing ultrafine green tea powder and belongs to the technical field of deep machining of tea leaves. The method comprises the following steps: screening middle-grade and low-grade summer and autumn fresh green tea leaves in accordance with national pollution-free production standard; spreading the tea leaves, performing fixation on the tea leaves by combining steam heat and frying technology, drying the tea leaves by novel microwave grading technology, and performing low-temperature ultrafine pulverization to prepare the ultrafine green tea powder with D50 more than or equal to 2,500. The method for preparing the ultrafine green tea powder is characterized by simple process, reasonable steps, low cost, and suitability for industrialized production. The ultrafine tea powder produced by the method has complete breaking of cell wall, and high uniformity and dispersibility. During processing, nutrient components and pharmacologic components of green tea are retained to the maximum; a chemical additive can be widely replaced; the shelf life of food is prolonged; food is endowed with natural emerald green color and specific tea flavor; dietary fiber, active polysaccharide and other substances of the green tea are fully utilized; tea drinking is changed into tea eating; and products can be widely used in the fields of food, cosmetics, commodity and the like.

Description

A kind of preparation method of ultrafine tea powder

One, technical field

The present invention relates to a kind of preparing ultrafine green tea powder, belong to field of deep tea processing technology, product can be widely used in fields such as food, cosmetics, commodity.

Two, background technology

In recent years, the effect of drinking tea with health arouses extensive attention at home and abroad.Tealeaves is rich in functional materials such as phenols, caffeine, Tea Pigment, tea polysaccharide body, Tea Saponin, theanine, vitamin and mineral matter; Numerous studies show that tealeaves or tea extract have anti-oxidant, remove oxygen radical, anti-sudden change and chemoprophylaxis effect anticancer, anti-cancer, show that active ingredient is very promising important chemopreventive agent in the tealeaves.Yet, polytrophic tealeaves is difficult to directly edible or digestion, bioavilability is low, traditional method of drinking tea is to brew tealeaves with boiling water, this method can not absorb whole nutritional labeling strippings of tealeaves for human body, under the brewing of generally drinking tea, the leaching rate of Tea Polyphenols is about 60%～70%, vitamin, free amino acid and mineral matter leaching rate are 70%～80%, tealeaves polysaccharide, dietary fiber leaching rate have influenced the nutrition of tealeaves and the performance of health care widely then less than 20%.

Ultrafine green tea powder is that the pure natural superfine that the modern superfine communication technique of a kind of process is produced steams blue or green powder green tea, it has kept the original natural green of green tea and nutrition, pharmaceutical component to greatest extent, very strong surperficial absorption affinity and affinity, solid perfume (or spice) and good organic traits such as suspension stability are arranged, digested and assimilated by stomach especially easily, capable of direct drinking or make an addition in the varieties of food items.Yet up to now, tealeaves ultramicro grinding product granularity great majority are 300 orders, have only only a few to reach 1500 orders.Studies show that,, can make the histocyte wall construction suffer thorough destruction,, easily directly absorbed, can bring into play its effect to greatest extent by the human body stomach because its granularity is superfine when the ultrafine powder particle diameter is controlled at 2500 orders when following; Can produce skin effect, bulk effect, quantum effect and macroscopical tunnel-effect etc. simultaneously and make ultramicron have the biologically active different, significantly improve the activity and the bioavilability of nutriment, improve the dispersion and the dissolution characteristics of powder with macroscopic material.These studies show that the super fine tea powder granularity can its biologically active of appreciable impact.

Three, summary of the invention

Technical problem

The purpose of this invention is to provide a kind of preparing ultrafine green tea powder, its technology is simple, step is reasonable, cost is low, be fit to suitability for industrialized production, can produce the hyperfine green tea powder of D50 〉=2500 purposes, product granularity is even, good dispersion, the purity height can be widely used in fields such as food, cosmetics and commodity.

Technical scheme

The objective of the invention is to realize by following steps:

1. be raw material with low and middle-grade autumn in the summer green tea that reach national nuisanceless production standard, through spreading for cooling 4-6h, water content is controlled at 70-80%, steam heat and fried green technology make water content reduce to 65-70% in conjunction with completing, microwave classification dry technology drying, through orthogonal experiment optimization, best microwave drying machined parameters is for throwing leaf amount 500-1000 gram, transfer rate 450-750r min ^-1, microwave power 4.25-7.65kW;

2. with the oven dry of above-mentioned tea powder, again stem tea just is crushed to fragment about 20 orders with 30B type Universalpulverizer, with blower fan except that dust and impurity; Roll the tea powder 10-15 time with XK-160 type pulverizer again, maximum spacing is 1-3mm, fully destroys plant cell wall;

3. the tea powder that first ultramicro grinding is obtained uses the airslide disintegrating mill secondary to pulverize, processing number of times 5-10 time, and obtaining particle size range is 2～5 μ m (particle diameter D ₅₀〉=2500 orders) ultrafine green tea is weighed, and presses the different size packing.

Beneficial effect

The present invention utilizes the very abundant low and middle-grade summer autumn teas of resource to be raw material, and the tealeaves new product of exploitation high added value has extended the tea industrial chain.Compare with existing patent and correlative study report, as patent " preparation technology of super fine tea powder " (CN95112539.7),, " superfine microtea powder preparation process " (CN200610035375.7), " a kind of preparation method of ultra-fine tea powder " (CN200810073689.5) etc. compare, the super powder tea powder product granularity of their processing is mostly more than 300 orders, this moment, cell membrane did not suffer that complete broken wall or broken wall are insufficient, beneficiating ingredient stripping fully in the tealeaves.Though the tea powder product of part ultramicro grinding processing has reached D ₉₇〉=1250, as " ultra-fine tea powder and preparation method " (CN200410013247.3), but adopted comparatively complicated fluid bed collision type airflow milling equipment and grading plant, technology relative complex; This method combines by levigate technology that China is traditional and modern low temperature superfine powder process technology, prepares hyperfine green tea powder, its granularity D ₅₀〉=2500 orders have improved the fineness of tea powder and the uniformity and the dispersiveness of particle; Plant cell wall is thoroughly destroyed, and can fundamentally quicken the stripping of Tea Polyphenols, tea polysaccharide, theanine, vitamin and some needed by human mineral component and digest and assimilate characteristic in human body; Fundamentally change the resemblance of tealeaves, changed single traditional tealeaves drinking way, nontoxic; Owing to adopt microwave classification dry technology in the process, improved the concentration and the persistence of fragrance simultaneously; Product can be widely used in food additives, substitutes traditional chemical addition agent, has enriched the range of application of tealeaves.Ultrafine tea powder, preparation method thereof of the present invention, technology is simple, and cost is low, and step is reasonable, is applicable to suitability for industrialized production.

The tea powder fineness reaches more than 2500 orders, much smaller than the relevant report of existing super fine tea powder production.The super fine tea powder breaking-wall cell of this explained hereafter is complete, and fineness is extremely low, and the concentration of fragrance and persistence are good, the uniformity of particle and dispersed high; Process has farthest kept nutritional labeling and the pharmaceutical component in the middle of the green tea, extensive instead of chemical additive, prolong the food shelf life, and give bud green color and luster of natural food and peculiar tealeaves local flavor, made full use of the material such as dietary fiber, active polysaccharide of green tea again, changing " drinking tea " is " eating tea "; Product can be widely used in fields such as food, cosmetics and commodity.

Four, description of drawings

(Malvern Instrument Corporation, UK) average grain diameter of mensuration ultra micro yuhua tea powder is 3.398 μ m to Fig. 1 Mastersizer 2000 laser particle size analyzers.

Fig. 2 observes through SEM (SEM) Hitachi S-3000N, and the tea powder particles is the fine dispersion state.

It is 3.462 μ m that Fig. 3 Mastersizer 2000 laser particle size analyzers are measured the rich selenium tea of ultra micro powder average grain diameter.

Fig. 4 observes through SEM (SEM) Hitachi S-3000N, and the tea powder particles is the fine dispersion state.

Five, the specific embodiment

Ultrafine tea powder granularity Detection key instrument and detection method:

Grain size analysis: (Malvern Instrument Corporation, UK) Particle Size Analyzer detects the particle diameter of the hyperfine green tea powder of preparation to use Mastersizer 2000.Get a certain amount of tea powder and be mixed with certain density weak solution, use processor for ultrasonic wave (100W) with solution dispersion treatment 10min, make ultramicron dispersion, even, solution system reaches certain stable state, last instrument detecting.

Particle morphology is observed: take by weighing an amount of tea powder sample, oven dry after the ion sputtering instrument metal spraying is handled, places SEM (SEM) Hitachi S-3000N to observe (operating voltage 15kV).

Embodiment one:

With the bright leaf of plucking of yuhua tea, spread 4-6h, water content is controlled at 75-78%, complete through 6CZS-150 type steam heat green-keeping machine (Zhejiang Sunyoung Machinery Co., Ltd.), water content further drops to 65-68%, utilize microwave classification dry technology drying, machined parameters is for throwing leaf amount 500-1000 gram, transfer rate 450-750r min ^-1, microwave power 4.25-7.65kW; With above-mentioned tea powder oven dry, water content further drops to 6-10%, again stem tea just is crushed to fragment about 20 orders with 30B type Universalpulverizer (Changzhou strong drying equipment Co., Ltd), with the vertical winnowing machine of 6CFX-30 type (Wuyi, Zhejiang China handsome tea machinery Co., Ltd) by removing dust and impurity behind its weight sub-sieve; Use XK-160 type pulverizer (Changzhou No. 1 Rubber Plastic Equipment Co., Ltd.) to roll the tea powder 10-15 time again, maximum spacing is 1-3mm, fully destroys plant cell wall; The tea powder that first ultramicro grinding is obtained uses QLM-100KA airslide disintegrating mill (Zhejiang Province Heli Powder Prodn. Co.,Ltd., shangyu City) secondary to pulverize, processing number of times 5-10 time.It is 3.398 μ m (Fig. 1) that product is measured average grain diameter through laser particle size analyzer; Through scanning electron microscopic observation, tea grain uniform particles is fine dispersion state (Fig. 2).

Embodiment two:

Selenium-rich green tea with newly plucking spreads 4-6h, and water content is controlled at 75%, complete through 6CZS-150 type steam heat green-keeping machine, water content further drops to 65-68%, utilizes microwave classification dry technology drying, machined parameters is for throwing leaf amount 500-1000 gram, transfer rate 450-750r min ^-1, microwave power 4.25-7.65kW; With above-mentioned tea powder oven dry, again stem tea just is crushed to about 100 orders with 30B type Universalpulverizer, remove dust and impurity with blower fan; Roll the tea powder 10-15 time with XK-160 type pulverizer again, maximum spacing is 1-3mm, fully destroys plant cell wall; The tea powder that first ultramicro grinding is obtained uses the airslide disintegrating mill secondary to pulverize, processing number of times 5-10 time.It is 3.462 μ m (Fig. 3) that product detects average grain diameter through laser particle size analyzer; Through scanning electron microscopic observation, tea grain uniform particles is fine dispersion state (Fig. 4).

Claims

1. preparing ultrafine green tea powder is characterized in that:

1. be raw material with the low and middle-grade summer autumn teas that reach national nuisanceless production standard, through spreading for cooling 4-6h, water content is controlled at mass ratio 70-80%, steam heat completes and makes water content reduce to 65-70%, microwave classification dry technology drying, best microwave drying machined parameters is for throwing leaf amount 500-1000 gram, transfer rate 450-750r min ^-1, microwave power 4.25-7.65kW;

2. with above-mentioned tea powder oven dry, again stem tea just is crushed to 20 purpose fragments with 30B type Universalpulverizer, removes dust and impurity with blower fan; Roll the tea powder 10-15 time with XK-160 type pulverizer again, the pulverizer maximum spacing is 1-3mm, fully destroys plant cell wall;

3. the tea powder that first ultramicro grinding is obtained uses the airslide disintegrating mill secondary to pulverize, and processing number of times 5-10 time obtains the ultrafine green tea that particle size range is 2～5 μ m.

2. the hyperfine green tea powder product that obtained of the described method of claim 1.