CN101144825A

CN101144825A - Method for measuring tobacco protein

Info

Publication number: CN101144825A
Application number: CNA2007100260367A
Authority: CN
Inventors: 瞿先中; 舒俊生
Original assignee: ANHUI ZHONGYAN INDUSTRY Co WUHU TOBACCO PLANT
Current assignee: ANHUI ZHONGYAN INDUSTRY Co WUHU TOBACCO PLANT; China Tobacco Anhui Industrial Co Ltd
Priority date: 2007-08-15
Filing date: 2007-08-15
Publication date: 2008-03-19

Abstract

The present invention discloses a method for measuring the protein in the tobacco, includes extraction, digest, and continuous flowage analysis. Compared with the prior art, the present invention has simple and quick operation, and more exact determination result. Using the method to determine the protein can save a plenty of labor force. Since at present the flowage analyzer has been popularized, the method can be applied and popularized in the industry.

Description

Method of protein in a kind of measurement tobacco

Technical field:

The invention belongs to and measure method of protein in the tobacco, particularly measure method of protein in the tobacco with analyzing the Continuous Flow Analysis method.

Background technology:

Protein is the important compound in the tobacco, but protein content is too high in the tobacco leaf, then can make flue gas intensity excessive, and fragrance and jealous variation produce acid, bitter taste and pungency, also can produce a kind of albumen stink as the burning feather.Therefore, protein content has become the important indicator of estimating cigarette quality, and protein content is significant in the rapid and accurate determination tobacco leaf.The normal in the world Kjeldahl of classical Ke Daerfa or improvement that adopts is measured protein content, and domestic tobacco business mainly adopts Ke Daerfa.The testing result of these methods is more accurate, but complex operation, time-consuming, and can not carry out batch detection.

Summary of the invention:

Technical matters to be solved by this invention provides protein method in a kind of measurement tobacco simple to operate.

The technical scheme of technical solution problem of the present invention is: method of protein in a kind of measurement tobacco, take by weighing 0.3g (being accurate to 0.0001g) offal in conical flask, add 30mL0.5% acetic acid, heated and boiled 15min, suction filtration while hot, and colourless with 0.5% acetum flushing conical flask and sediment to filtrate, shift filter paper then and be deposited in the 75mL digest tube, add 0.1g HgO, 1.0gK ₂SO ₄, the 5mL weight concentration is 98% sulfuric acid, shakes up to be placed on digester digestion, the digester running parameter: 150 ℃ digested 1 hour, and 370 ℃ digested 4 hours; Digestion is cold slightly after finishing, add low amounts of water, shake up, be cooled to room temperature, water is settled to scale, shake up, utilize total nitrogen content in the Continuous Flow Analysis instrument working sample,, be converted into protein content and get final product the total nitrogen content of measuring, do blank assay simultaneously as contrast, Protein content is calculated as follows in the tobacco:

G1 in the formula---the insoluble nitrogen detected value of sample (%);

G0---blank sample detected value (%);

The weight of m---tobacco sample (g);

The moisture of w---sample;

6.25---the conversion coefficient of total nitrogen and protein.

Described digester and digest tube are made by German Bran ﹠ Luebbe.

The model of described Continuous Flow Analysis instrument is AA3, is made by German Bran ﹠ Luebbe.

The applicant thinks: present Continuous Flow Analysis instrument is universal at tobacco business, utilize the method for flow analysis instrument mensuration total nitrogen also very ripe, and classical Ke Daerfa mensuration protein is identical on principle with flow analysis instrument method mensuration total nitrogen.

Because nitrogen-containing compound can be divided into energy water-soluble and water insoluble two big classes in the tobacco, water-fast nitrogen-containing compound mainly is protein-based macromolecular compound, when extract pH is about 4 comparatively suitable, its insoluble nitrogen separates to such an extent that better promptly utilize 0.5% acetic acid with the protein precipitation in the tobacco leaf with soluble nitrogen, the flush away soluble nitrogen, the insoluble nitrogen in the working sample is converted into protein content then, find that by control experiment testing result is more accurate.

The present invention compared with prior art, and is easy and simple to handle, and fast, and measurement result is more accurate.Utilize this method to measure protein, can save a large amount of labours.The flow analysis instrument is popularized at tobacco business at present, so this method in industry can be applied.

Embodiment:

Below in conjunction with embodiment the present invention is described in detail.

Device and reagent:

AA3 Continuous Flow Analysis instrument, digester and digest tube (German Bran ﹠ Luebbe); SHB-III circulation ability of swimming is used vacuum pump (Zhengzhou Greatwall Scientific Industrial ﹠ Trading Co., Ltd.) more; Electronics universal electric furnace (the precious people's instrument and equipment in ruins, road, city, Shangyu, Zhejiang Province factory); AG204 electronic balance (sensibility reciprocal: 0.0001g, Switzerland); Glass apparatus is used in suction filtration device (diameter 120mm Buchner funnel, vacuum filtration device) and laboratory always.

Glacial acetic acid, glazier's salt, sodium salicylate, sodium nitroprusside, ammonium sulfate (Chemical Reagent Co., Ltd., Sinopharm Group); 98% concentrated sulphuric acid, sodium hypochlorite, NaOH, sodium chloride (the sincere chemical reagent in Shanghai company limited); Mercury oxide red (Taixing City's chemical reagent factory); Rochelle salt, sodium hydrogen phosphate (chemical reagent factory of HeFei University of Technology); It is pure that above reagent is analysis; Casein (nitrogen content 13%, biochemical reagents, Sigma company).The redried leaf tobacco that Yunnan in 2003, Fujian produce.

Embodiment 1:

Accurately take by weighing 0.3g offal (being accurate to 0.0001g) in the 250ml conical flask, add 30mL0.5% acetic acid, heated and boiled 15min, rapidly with quantitative filter paper suction filtration on the vacuum filtration device, and it is colourless to filtrate with 0.5% acetum flushing conical flask and sediment, shift filter paper then and be deposited in the 75mL digest tube, add 0.1gHg0,1.0gK ₂SO ₄, the 5mL concentrated sulphuric acid, shake up and be placed on digester digestion, the digester running parameter: 150 ℃ digested 1 hour, and 370 ℃ digested 4 hours.Digestion is cold slightly after finishing, and adds low amounts of water, shakes up, and is cooled to room temperature, and water is settled to scale, shakes up, and utilizes the Continuous Flow Analysis instrument to measure total nitrogen content by the method for YC/T161-2002, is converted into protein content.Do blank assay simultaneously.

Protein content calculates:

G1 in the formula---the insoluble nitrogen detected value of sample (%);

GO---blank sample detected value (%);

The weight of m---tobacco sample (g);

The moisture of w---sample;

6.25---the conversion coefficient of total nitrogen and protein.

1, typical curve

Except that taking by weighing through 2 hours ammonium sulfate 0.943g of 110 ℃ of dryings, in beaker, the water dissolving changes in the 100mL volumetric flask, and water is settled to scale, and this solution nitrogen content is 2mg/mL.Pipette 2.5mL respectively, 2.0mL, 1.5mL, 1.0mL, the above-mentioned solution of 0.5mL are in digest tube, and outer, all the other are identical with embodiment 1, and the related coefficient of measuring standard model is 0.9998.

2, replica test

Take by weighing 5 parts of Luliang B ₂The F sample is pressed the method for embodiment 1 and is measured protein content.The results are shown in Table 1:

Table 1:

	1	2	3	4	5
	1	2	3	4	5	Protein (%)	5.10	5.04	5.17	5.07	5.15

Can be got by table 1, the relative standard deviation RSD of sample is 1.1%, and repeatability better.

3, recovery test

Take by weighing 5 parts of Luliang B ₂The F sample adds the casein standard models of different amounts, press after embodiment 1 method handles the mensuration protein content.The results are shown in Table 2:

The caseic recovery of table 2

Example weight (g)	Casein addition (mg)	Measured value (mg)	Yield (mg)	The recovery (%)
Example weight (g)	Casein addition (mg)	Measured value (mg)	Yield (mg)	The recovery (%)	0.3005	0	15.3	0
0.3007	5.0	20.3	5.0	100.0	0.3005	0	15.3	0
0.3007	5.0	20.3	5.0	100.0	0.3001	7.5	22.9	7.6	101.3
0.3004	10.0	25.2	9.9	99.0	0.3001	7.5	22.9	7.6	101.3
0.3004	10.0	25.2	9.9	99.0	0.3010	12.5	28.0	12.7	101.6
0.3009	15.0	30.0	14.7	98.0	0.3010	12.5	28.0	12.7	101.6

4, the comparison of flow analysis instrument method and Ke Daerfa:

Accurately take by weighing six kinds of samples below two parts, a embodiment 1 method of pressing is measured protein content, and a processing Ke Daerfa that presses detects.Result such as table 3:

Table 3:

The sample title	Embodiment 1 method is measured protein content (%)	The protein content (%) that Ke Daerfa measures
The sample title	Embodiment 1 method is measured protein content (%)	The protein content (%) that Ke Daerfa measures	Luliang B2F	5.10	4.88
Luliang C3F	4.89	4.69	Luliang B2F	5.10	4.88
Luliang C3F	4.89	4.69	Luliang X2F	4.62	4.49
Longyan B3F	6.15	5.97	Luliang X2F	4.62	4.49
Longyan B3F	6.15	5.97	Longyan C4F	5.64	5.50
Longyan X2F	5.54	5.39	Longyan C4F	5.64	5.50

Table 3 result shows that the measurement result difference of two kinds of methods is less, and the result that Ke Daerfa records is generally less than flow analysis instrument method.Have following reason: Ke Daerfa and detect, operation steps is more, and the loss of sample in operating process is than flow analysis instrument fado; During Ke Daerfa digestion, accurately temperature control has the ammonia volatilization of part digestion generation, makes testing result on the low side.And flow analysis detects, and operation steps is few, and sample loss is little, digester temperature precise control and can temperature programme, and the ammonia loss that nitrifying process produces is less.Therefore, flow analysis instrument method is measured Protein in Tobacco content, and the result is more accurate.

Claims

1. measure method of protein in the tobacco for one kind, it is characterized in that: take by weighing the 0.3g offal in conical flask, add 30mL0.5% acetic acid, heated and boiled 15-20min, suction filtration while hot, and colourless with 0.5% acetum flushing conical flask and sediment to filtrate, shift filter paper then and be deposited in the 75mL digest tube, add 0.1gHgO, 1.0gK ₂SO ₄, the 5mL weight concentration is 98% sulfuric acid, shakes up to be placed on digester digestion, the digester running parameter: 150 ℃ digested 1-1.5 hour, and 370 ℃ digested 4-6 hour; Digestion is cold slightly after finishing, add low amounts of water, shake up, be cooled to room temperature, water is settled to scale, shake up, send sample to the Continuous Flow Analysis instrument, press the method for YC/T161-2002 and measure total nitrogen content, with the total nitrogen content of measuring, be converted into protein content and get final product, do blank assay simultaneously as contrast, Protein content is calculated as follows in the tobacco:

G1 in the formula---the insoluble nitrogen detected value of sample (%);

G0---blank sample detected value (%);

The weight of m---tobacco sample (g);

The moisture of w---sample;

6.25---the conversion coefficient of total nitrogen and protein.

2. method of protein in a kind of measurement tobacco according to claim 1, it is characterized in that: described digester and digest tube are made by German Bran ﹠ Luebbe.

3. method of protein in a kind of measurement tobacco according to claim 1, it is characterized in that: the model of described Continuous Flow Analysis instrument is AA3, is made by German Bran ﹠ Luebbe.