CN109596759A

CN109596759A - Potato adds quantity measuring method in a kind of staple food products

Info

Publication number: CN109596759A
Application number: CN201811427337.5A
Authority: CN
Inventors: 范鑫; 张秉诚; 赵大云
Original assignee: Shanghai Jiaotong University
Current assignee: Shanghai Jiaotong University
Priority date: 2018-11-27
Filing date: 2018-11-27
Publication date: 2019-04-09
Anticipated expiration: 2038-11-27
Also published as: CN109596759B

Abstract

The present invention relates to potatos in a kind of staple food products to add quantity measuring method, specifically includes that (1) sample preparation；(2) pre-treatment of sample；(3) the stable isotope relative ratio that detection obtains carbon nitrogen hydrogen-oxygen is carried out using isotopic ratio mass spectrum；(4) qualitative and quantitative analysis is carried out using chemometrics method, determines whether to be added to potato using discriminant analysis, the amount of addition is determined using multiple linear regression equations.Compared with prior art, operation of the present invention is simple, fast and easy, and detection efficiency is high, and accuracy is high, with good stability and reproducibility, there is no the method for potato content in detection potato product in current national standard；The present invention can not only qualitative discrimination product whether be added to potato full-powder, and can quantitative analysis potato full-powder additive amount, there is good market application prospect.

Description

Potato adds quantity measuring method in a kind of staple food products

Technical field

The present invention relates to food quality detection fields, more particularly, to potato additive amount detection side in a kind of staple food products Method.

Background technique

Potato is also known as potato, potato, potato etc., is the annual herb plant of Solanaceae Solanum, and stem tuber can be edible, It is important grain, vegetables dual-purpose crop.Cultivated area and yield of the potato in China occupy first place in the world, but add deeply at present Work level is relatively low, and product variety is more single, in the case where country proposes potato staple food background, develops based on potato The staple food products of raw material are wanted to be of great significance.Potato dry matter main component is starch, is additionally rich in dietary fiber, egg White matter, vitamin, minerals and phenolic substances, it is full of nutrition, it is the fourth-largest cereal crops in the world.Not due to fresh potato Storage endurance and transportation cost height, thus most of producer is all that the mode of addition potato full-powder is taken to make product, Ma Ling The full powder of potato is potato through over cleaning, peeling, slice, rinses, precooks, cools down, thermophilic digestion, after the processing such as smash mud, then is dehydrated Graininess, sheet or powdery product prepared by dry, sieving, are one of dehydrated potato products, even more potato The important source material of food development.

Steamed bun is the staple food that our people dotes on, and is usually formed by Raw material processing of wheat flour, and potato steamed bun is general It is to be fermented by the yeast after wheat flour and potato full-powder mixing plus after water and activation, using provocation, boiling system At.Noodles are also traditional staple food in China, are well received by consumers.The production of potato noodles mainly passes through wheat flour With potato full-powder mixing after plus water, it is agitated, squeeze it is agglomerating, then after pressure surface slitting packaging made of.It is complete using potato Steamed bun and noodles is made by mixing in powder and wheat flour, and nutritive value not only can be improved, and even more realization potato staple food is important Approach.But since potato full-powder is free of mucedin, it will affect the molding of steamed bun and noodles, at present full powder in potato product Accounting is usually less than 30%.

Although the wide yield of potato planting area is big, the price of potato wants expensive compared to other cereal crops prices A bit, correspondingly the price of potato full-powder is also just high much compared to grain dust price, therefore in order to reduce cost, increase benefit Profit, illegal businessman may lie about the potato content of product, and there are mainly two types of the adulterated modes of potato product: one is not Addition potato and declare to be added to or be added to the potato of low dosage and declare be high dose product, another kind is to make Potato is replaced with the cereal of low price, such as replaces potato to reach the mesh obscured in appearance using sweet potato or corn , so that consumer be allowed to buy false potato product.

The method that detection potato product is had no in existing national standard, thus even if there is no adulterated potato product at present Occur, but develop a kind of detection method in advance and provide for a rainy day be it is very necessary, consumer and regular production person are ensured with this Interests.

Summary of the invention

It is an object of the present invention to overcome the above-mentioned drawbacks of the prior art and provide a kind of staple food products, such as Potato adds quantity measuring method in steamed bun, noodles etc., by the Technology application of other field detection of adulterations to potato product In detection, used method is the phase using Stable isotope ratio Mass Spectrometer Method carbon nitrogen four kinds of elemental stable isotopes of hydrogen-oxygen Reduced value.

The purpose of the present invention can be achieved through the following technical solutions:

Potato adds quantity measuring method in a kind of staple food products, using following steps:

Step 1: sample to be tested pre-processes: drying, grind after sample to be tested is cooled to room temperature and be sieved；

Step 2: carbon nitrogen hydrogen and oxygen stable isotope detects:

(1) it is calibrated using standard items, then using stable isotope mass spectrograph detection sample to be tested¹³C/¹²C and¹⁵N/¹⁴N,

(2) it is calibrated using standard items, then detects sample to be tested using stable isotope mass spectrograph²H/¹H and¹⁸O/¹⁶O；

Step 3: carrying out qualitative and quantitative analysis using linear discriminant analysis (LDA) and multiple linear regression (MLR), sentence Whether disconnected sample is added to potato full-powder, determines the amount of the potato dry matter of addition.

By sample to be tested, at 65 DEG C ± 2, drying to constant weight in step 1, smashes it through 40-60 mesh through flour mill.

It is detected in step 2 using III-Isoprime of Vario EL¹³C/¹²C and¹⁵N/¹⁴N。

Detection¹³C/¹²C and¹⁵N/¹⁴When N, using following technological parameter:

Elemental analysis condition: oxidation tube filling tungstic acid, 1150 DEG C of temperature；Reduction tube fills linear copper and silver-colored cotton, temperature 810 DEG C of degree；High-purity He as carrier gas and reference gas,

Stable isotope Mass Spectrometry Conditions: continuous flow sampling system, CO are applied₂、N₂As reference gas, casein is as standard Product (δ¹³C_V-PDB=-26.98 ± 0.13 ‰, δ¹⁵N_AIR=5.94 ± 0.08 ‰) to reference gas CO₂、N₂It is calibrated.

It is detected in step 2 using EA Isolink-253Plus²H/¹H and¹⁸O/¹⁶O。

Detection²H/¹H and¹⁸O/¹⁶When O, using following technological parameter:

Elemental analysis condition: reaction tube filling glass carbon, 1380 DEG C of temperature；High-purity He is as carrier gas, H₂With CO as ginseng Compare gas；

Stable isotope Mass Spectrometry Conditions: continuous flow sampling system, CO, H are applied₂As reference gas, EMA-P1 (δ²H=- 25.3 ‰, δ¹⁸O=20.99 ‰) and EMA-P2 (δ²H=-87.8 ‰, δ¹⁸O=26.88 ‰) it is used as standard referring to product to reference gas CO、H₂It is calibrated.

Dimensionality reduction is carried out to the data measured using linear discriminant analysis, two-dimensional discriminant analysis figure is obtained, to distinguish sample Whether product are added to potato and additive amount is approximate horizontal.

Linear discriminant analysis handles number using 23.0 version software of SPSS or the similar statistical software with corresponding function According to, the four kinds of elemental isotope ratios measured are analyzed first with principal component analysis (PCA), it is anti-in extraction initial data Reflect the feature vector of main variance as principal component, with principal component make axis and by data projection to reference axis to realize from height Dimension data is to the intuitive visual analyzing of low-dimensional.

Additive amount and four kinds of Stable isotope ratio δ are fitted using multiple linear regression¹³C、δ¹⁵N, δ D and δ¹⁸Between O Relationship, i.e., differentiated using linear discriminant analysis (LDA), and carry out cross validation using leaving-one method, to be obtained to product The result of quantitative analysis out.It comprises the concrete steps that, between-group variance small as far as possible according to intra-class variance thought big as far as possible acquires differentiation letter Number, then classifies to sample using the discriminant function of foundation；It is analyzed through projection, first by finding out K group m metadata is projected to the direction of another more low-dimensional by feature vector w, so that dividing as much as possible between group and group after projection It opens, and then the sample in same group is as close to classifying to sample in new space；After PCA dimensionality reduction, then tie It closes LDA to classify, so that it may differentiate the product of Different adding amount, in analytic process, first carry out original differentiation, then Cross validation is carried out using " leaving-one method ".

Finally, establishing the pass between potato additive amount and four element isotopic ratios using multiple linear regression (MLR) System.Residual test is carried out to model first, is that Y-axis establishes coordinate system to standardize predicted value as X-axis, standardized residual, is seen Examine whether all samples for participating in returning fully fall in valid interval.By residual analysis, discriminate whether to need to reject any sample This.The analogue value that model obtains is compared with original true value, the absolute error between predicted value and true value is observed, sentences Prediction effect and the feasibility using regression equation unknown sample predicted of the constant linear regression equation for sample.

Compared with prior art, the present invention is pioneering using the adulterated of stable isotope technology detection potato product, is passing through It crosses after scientific experiment and practice summary, whether unknown sample accurately can be analyzed according to the database that self-control sample is set up Its potato additive amount can be determined simultaneously for potato samples.This method is easy to operate, few to sample size demand, claims every time The amount of amount is milligram grade, and result precision is high, and whether be potato product, be also able to satisfy the need of quantitative detection if can effectively identify It asks.

Detailed description of the invention

Fig. 1 is the linear discriminant analysis figure of potato steamed bun；

Fig. 2 is the linear discriminant analysis figure of potato noodles.

Specific embodiment

The present invention is described in detail combined with specific embodiments below.Following embodiment will be helpful to the technology of this field Personnel further understand the present invention, but the invention is not limited in any way.It should be pointed out that the ordinary skill of this field For personnel, without departing from the inventive concept of the premise, various modifications and improvements can be made.These belong to the present invention Protection scope.

Step 1: sample to be tested pre-processes: at 65 DEG C ± 2, drying to constant weight after sample to be tested is cooled to room temperature, through grinding Powder machine smashes it through 40-60 mesh；

Step 2: carbon nitrogen hydrogen and oxygen stable isotope detects:

(1) it is calibrated using standard items, then using stable isotope mass spectrograph detection sample to be tested¹³C/¹²C and¹⁵N/¹⁴N is detected using III-Isoprime of Vario EL in this step¹³C/¹²C and¹⁵N/¹⁴N；

Detection¹³C/¹²C and¹⁵N/¹⁴When N, using following technological parameter: elemental analysis condition: oxidation tube fills tungstic acid, 1150 DEG C of temperature；The linear copper of reduction tube filling and silver-colored cotton, 810 DEG C of temperature；High-purity He is as carrier gas and reference gas, stable isotope Mass Spectrometry Conditions: continuous flow sampling system, CO are applied₂、N₂As reference gas, casein is as standard items (δ¹³C_V-PDB=-26.98 ± 0.13 ‰, δ¹⁵N_AIR=5.94 ± 0.08 ‰) to reference gas CO₂、N₂It is calibrated；

(2) it is calibrated using standard items, then detects sample to be tested using stable isotope mass spectrograph²H/¹H and¹⁸O/¹⁶O is detected using EAIsolink-253Plus in this step²H/¹H and¹⁸O/¹⁶O；

Detection²H/¹H and¹⁸O/¹⁶When O, using following technological parameter: elemental analysis condition: reaction tube filling glass carbon, temperature 1380 DEG C of degree；High-purity He is as carrier gas, H₂With CO as reference gas；Stable isotope Mass Spectrometry Conditions: continuous flow sample introduction system is applied System, CO, H₂As reference gas, EMA-P1 (δ²H=-25.3 ‰, δ¹⁸O=20.99 ‰) and EMA-P2 (δ²H=-87.8 ‰, δ¹⁸O =26.88 ‰) as standard reference product to reference gas CO, H₂It is calibrated.

Wherein, dimensionality reduction is carried out to the data measured using linear discriminant analysis, two-dimensional discriminant analysis figure is obtained, thus area Divide whether sample is added to potato and additive amount is approximate horizontal.Linear discriminant analysis using 23.0 version software of SPSS or Similar statistical software with corresponding function handles data, same to the four kinds of elements measured first with principal component analysis (PCA) The plain ratio in position is analyzed, and is extracted the feature vector for reflecting main variance in initial data as principal component, is made axis with principal component And by data projection to reference axis to realize from high dimensional data to low-dimensional intuitive visual analyzing.

It is more detailed embodiment below, further illustrates the technical solution adopted in the present invention by these embodiments And the technical effect that can be obtained.

Embodiment 1

The detection and analysis of potato steamed bun

The preparation and processing of sample: weighing 400g, 360g respectively, then 320g and 280g wheat flour successively adds Ma Ling The full powder of potato makes the quality of mixed powder reach 400g, then is separately added into the yeast 4g that warm water activated, and then adds 250g respectively, 260g, 280g and 350g tap water are simultaneously stirred, and stirring is put into the fermenting case of 37 DEG C of temperature, humidity 75% after five minutes and sends out Ferment 0.5h takes out point group and then the 15min that is steamed in pot after fermentation, is cooled to room temperature after cooking and crumbs into fritter again and be put into 65 DEG C Oven drying 48-72h grinds and is crossed with pulverizer 60 meshes after the completion of dry, then sealed with valve bag, it is standby to be put into drier With.Then the content of potato full-powder in product is converted into the content of potato dry matter, calculation method are as follows:

Wherein 4.8% is potato full-powder water content, and 8.9% is wheat flour water content.

The parameter setting and test of isotope mass spectrometry:

(1) measurement of carbon and nitrogen stable isotope ratio: key instrument and device: elemental analysis isotope mass spectrometry combined instrument: Model Vario EL III-Isoprime, German Elementar Products, be furnished with high temperature combustion furnace, absorption-desorption device, Highly sensitive thermal conductivity detector (TCD) (TCD), Isoprime detection device；M5X microgram electronic balance: Switzerland's plum Teller- Hold in the palm benefit Products

Main material and reagent: tungstic acid, purity linear copper and silver-colored cotton, being purchased from Ai Limengta trade (Shanghai) has Limit company；High-purity He, concentration >=99.999% (Shanghai four seasons gas apparatus Co., Ltd)；High-purity O₂, concentration >=99.999% (five steel gas Co., Ltd of Shanghai)；High-purity N₂, concentration >=99.999% (five steel gas Co., Ltd of Shanghai)；It is high Pure CO₂, concentration >=99.995% (Shanghai success gas industry Co., Ltd)；Casein standard items (Britain Elmental Microanalysis company).

Experimental condition: elemental analysis condition oxidation tube filling tungstic acid, 1150 DEG C of temperature；Reduction tube fill linear copper and Silver-colored cotton, 810 DEG C of temperature；High-purity He is as carrier gas and reference gas.Stable isotope Mass Spectrometry Conditions application continuous flow sampling system, CO₂、N₂As reference gas, USGS40 (L-glutamic Acid) is used as standard items (δ¹³C_VPDB=-26.39 ± 0.04 ‰, δ¹⁵N_AIR=-4.52 ± 0.06 ‰) to reference gas CO₂、N₂It is calibrated.

(2) measurement of hydrogen and oxygen stable isotope ratio:

Key instrument and device: elemental analyser: 2000 isotope mass spectrometer of model Flash: model MAT 253 Plus, German Thermo Products are furnished with high temperature combustion furnace；M5X microgram electronic balance: Switzerland's plum Teller-support Benefit Products

Main material and reagent: vitreous carbon, silica wool and silver-colored cotton are purchased from Thermo company；High-purity He, concentration >= 99.999% (liquid air company)；High-purity CO, concentration >=99.99% (liquid air company)；High-purity H2, concentration >=99.999% (liquid air Company)；Standard items EMAP1, EMAP2

Experimental condition: elemental analysis conditioned response pipe filling glass carbon, 1380 DEG C of temperature；High-purity He is as carrier gas, H₂With CO is as reference gas.Stable isotope Mass Spectrometry Conditions application continuous flow sampling system, CO, H₂As reference gas, EMA-P1 (δ²H =-25.3 ‰, δ¹⁸O=20.99 ‰) and EMA-P2 (δ²H=-87.8 ‰, δ¹⁸O=26.88 ‰) it is used as standard items to reference gas CO、H₂It is calibrated.The data measured are as shown in the table:

Table 1

Additive amount	δ13C	δ15N	δD	δ180
					0.00%	-27.59	-0.50	-31.97	29.02
0.00%	-27.57	-0.46	-31.75	28.96
					0.00%	-27.56	-0.61	-32.38	29.16
0.00%	-27.52	-0.44	-32.66	28.81
					10.40%	-27.56	-0.36	-35.60	28.35
10.40%	-27.36	-0.43	-36.86	28.61
					10.40%	-27.29	-0.36	-36.15	28.61
10.40%	-27.29	-0.43	-35.76	28.76
					20.71%	-27.12	-0.35	-38.71	29.13
20.71%	-27.20	-0.29	-40.16	29.37
					20.71%	-27.11	-0.35	-39.72	29.32
20.71%	-27.14	-0.29	-39.52	29.27
					30.93%	-26.89	-0.23	-42.83	28.99
30.93%	-26.89	-0.30	-43.45	29.48
					30.93%	-27.06	-0.23	-43.82	29.26
30.93%	-27.10	-0.30	-42.92	28.97

Qualitative analysis: four isotopic ratios measured are handled using linear discriminant analysis, are obtained by dimensionality reduction Three linear discriminant functions, do scatter plot using discriminant function, as shown in Figure 1, the attached drawing is the linear discriminant of potato steamed bun Analysis chart, the steamed bun that " group " 1-4 represents wheat flour production are added to 0,10%, 20%, 30% potato full-powder figure respectively In 1,2,3,4 be respectively potato full-powder additive amount 0,10%, 20%, 30% steamed bun.It can be seen that four groups from scatter plot The steamed bun of Different adding amount has different differentiation group mass centers, and potato steamed bun and common steamed bun differentiate that effect is obvious.

Table 2

Classification results^{A, c}

A. correctly 100.0% original case that has been grouped is classified.

B. cross validation is carried out only for the case in analysis.In cross validation, each case by those from this The function that all cases other than case derive from is classified.

C. the case of grouping for correctly having carried out cross validation to 100.0% is classified.

Quantitative analysis: carrying out linear fit to additive amount and four isotopic ratios using multiple linear regression analysis, can To obtain the linear relationship between additive amount and four independents variable:

Additive amount=51.222+4.398* δ¹³C+4.327*δ¹⁵N-2.464*δD-0.25*δ¹⁸O

By measuring and calculating, it is found that the maximum difference of potato steamed bun true value and predicted value is no more than 2.32%.

Table 3

Actual value	Predicted value	Absolute error
			0.00%	- 0.77%	0.77%
0.00%	- 1.05%	1.05%
			0.00%	- 0.14%	0.14%
0.00%	1.56%	- 1.56%
			10.40%	9.09%	1.31%
10.40%	12.72%	- 2.32%
			10.40%	11.57%	- 1.17%
10.40%	10.26%	0.14%
			20.71%	18.54%	2.17%
20.71%	21.99%	- 1.28%
			20.71%	21.03%	- 0.32%
20.71%	20.67%	0.04%
			30.93%	30.25%	0.68%
30.93%	31.33%	- 0.40%
			30.93%	31.86%	- 0.93%
30.93%	29.25%	1.68%

Embodiment 2

The detection and analysis of potato noodles

The preparation and processing of sample: weighing 400g, 360g respectively, then 320g and 280g wheat flour successively adds Ma Ling The full powder of potato makes the quality of mixed powder reach 400g, then adds 120g tap water and is stirred, pressure is put in stirring ten minutes later Face machine carries out pressure surface, and gradually turning the edge of a knife down makes dough be pressed into the dough sheet that thickness is about 1mm and surface is smooth, is then cut It cuts, makes noodles common on the market, then spread out and be put into 65 DEG C of oven drying 48-72h, pulverizer is used after the completion of dry The solarization of 60 mesh is ground and crossed, is then sealed with valve bag, it is spare to be put into drier.Then the content of potato full-powder in product is changed It is counted as the content of potato dry matter, calculation method are as follows:

The parameter setting and test of isotope mass spectrometry:

Main material and reagent: tungstic acid, purity linear copper and silver-colored cotton, being purchased from Ai Limengta trade (Shanghai) has Limit company；High-purity He, concentration >=99.999% (Shanghai four seasons gas apparatus Co., Ltd)；High-purity O2, concentration >=99.999% (five steel gas Co., Ltd of Shanghai)；High-purity N 2, concentration >=99.999% (five steel gas Co., Ltd of Shanghai)；It is high Pure CO₂, concentration >=99.995% (Shanghai success gas industry Co., Ltd)；Casein standard items (Britain Elmental Microanalysis company).

Experimental condition: elemental analysis condition oxidation tube filling tungstic acid, 1150 DEG C of temperature；Reduction tube fill linear copper and Silver-colored cotton, 810 DEG C of temperature；High-purity He is as carrier gas and reference gas.Stable isotope Mass Spectrometry Conditions application continuous flow sampling system, CO₂、N₂As reference gas, USGS40 (L-glutamic Acid) is used as standard items (δ 13CVPDB=-26.39 ± 0.04 ‰, δ 15NAIR=-4.52 ± 0.06 ‰) to reference gas CO₂、N₂It is calibrated.

(2) measurement of hydrogen and oxygen stable isotope ratio:

Experimental condition: elemental analysis conditioned response pipe filling glass carbon, 1380 DEG C of temperature；High-purity He as carrier gas, H2 and CO is as reference gas.Stable isotope Mass Spectrometry Conditions application continuous flow sampling system, CO, H2 are as reference gas, EMA-P1 (δ 2H =-25.3 ‰, δ 18O=20.99 ‰) and EMA-P2 (δ 2H=-87.8 ‰, δ 18O=26.88 ‰) as standard items to reference Gas CO, H₂It is calibrated.The data measured are as shown in the table:

Table 4

Additive amount	C	N	H	O
					0.00%	-27.66	-0.60	-33.74	29.51
0.00%	-27.71	-0.54	-33.83	29.59
					0.00%	-27.68	-0.60	-30.87	29.36
0.00%	-27.60	-0.54	-33.16	29.67
					10.40%	-27.57	-0.44	-40.88	29.37
10.40%	-27.52	-0.52	-45.13	28.89
					10.40%	-27.45	-0.44	-39.75	28.65
10.40%	-27.47	-0.52	-40.09	29.13
					20.71%	-27.32	-0.41	-43.10	29.67
20.71%	-27.34	-0.52	-49.55	28.72
					20.71%	-27.24	-0.41	-45.38	29.69
20.71%	-27.27	-0.52	-45.69	29.42
					30.93%	-27.15	-0.35	-51.92	29.19
30.93%	-27.15	-0.35	-53.24	29.30
					30.93%	-27.12	-0.35	-51.79	29.05
30.93%	-27.08	-0.35	-51.99	29.17

Qualitative analysis: four isotopic ratios measured are handled using linear discriminant analysis, are obtained by dimensionality reduction Three linear discriminant functions, do scatter plot using discriminant function, as shown in Fig. 2, the attached drawing is the linear discriminant of potato noodles Analysis chart, the noodles that " group " 1-4 represents wheat flour production are added to 0,10%, 20%, 30% potato full-powder respectively.From It can be seen that the noodles of four groups of Different adding amounts have different differentiation group mass centers in scatter plot, potato noodles and common noodles differentiate Effect is obvious.

Table 5

Classification results^{A, c}

A. correctly 100.0% original case that has been grouped is classified.

Additive amount=722.758+28.059* δ 13C+12.943* δ 15N-0.685* δ D+1.296* δ 18O

By measuring and calculating, it is found that the maximum difference of true value and predicted value is no more than 2.5%.

Table 6

True value	Predicted value	Absolute error
			0.00%	0.23%	- 0.23%
0.00%	- 0.23%	0.23%
			0.00%	- 2.49%	2.49%
0.00%	2.50%	- 2.50%
			10.40%	9.54%	0.86%
10.40%	12.20%	- 1.80%
			10.40%	11.20%	- 0.80%
10.40%	10.46%	- 0.06%
			20.71%	18.85%	1.86%
20.71%	20.05%	0.66%
			20.71%	22.68%	- 1.97%
20.71%	20.28%	0.43%
			30.93%	29.82%	1.11%
30.93%	30.86%	0.07%
			30.93%	30.39%	0.54%
30.93%	31.80%	- 0.87%

Embodiment 3

Step 1: sample to be tested pre-processes: at 63 DEG C, drying to constant weight after sample to be tested is cooled to room temperature, through flour mill Smash it through 50 meshes；

Step 2: carbon nitrogen hydrogen and oxygen stable isotope detects:

(1) it is calibrated using standard items, then using stable isotope mass spectrograph detection sample to be tested¹³C/¹²C and¹⁵N/¹⁴N is detected using III-Isoprime of Vario EL¹³C/¹²C and¹⁵N/¹⁴N, detection¹³C/¹²C and¹⁵N/¹⁴When N, use is following Technological parameter: elemental analysis condition: oxidation tube filling tungstic acid, 1150 DEG C of temperature；Reduction tube fills linear copper and silver-colored cotton, temperature 810 DEG C of degree；Stable isotope Mass Spectrometry Conditions: high-purity He applies continuous flow sampling system, CO as carrier gas and reference gas₂、N₂Make For reference gas, casein is as standard items (δ¹³C_V-PDB=-26.98 ± 0.13 ‰, δ¹⁵N_AIR=5.94 ± 0.08 ‰) to reference Gas CO₂、N₂It is calibrated；

(2) it is calibrated using standard items, then detects sample to be tested using stable isotope mass spectrograph²H/¹H and¹⁸O/¹⁶O is detected using EAIsolink-253Plus²H/¹H and¹⁸O/¹⁶O, detection²H/¹H and¹⁸O/¹⁶When O, using following technological parameter: Elemental analysis condition: reaction tube filling glass carbon, 1380 DEG C of temperature；High-purity He is as carrier gas, H₂With CO as reference gas；Stablize Isotope mass spectrometry condition: continuous flow sampling system, CO, H are applied₂As reference gas, EMA-P1 (δ²H=-25.3 ‰, δ¹⁸O= ‰) and EMA-P2 (δ 20.99²H=-87.8 ‰, δ¹⁸O=26.88 ‰) it is used as standard referring to product to reference gas CO, H₂Carry out school It is quasi-；

Step 3: carrying out qualitative and quantitative analysis using linear discriminant analysis (LDA) and multiple linear regression (MLR), sentence Whether disconnected sample is added to potato full-powder, determines the amount of the potato dry matter of addition, wherein utilizes linear discriminant analysis pair The data measured carry out dimensionality reduction, two-dimensional discriminant analysis figure are obtained, to distinguish whether sample is added to potato and addition It measures approximate horizontal.Linear discriminant analysis is handled using 23.0 version software of SPSS or the similar statistical software with corresponding function Data analyze the four kinds of elemental isotope ratios measured first with principal component analysis (PCA), extract in initial data Reflect the feature vector of main variance as principal component, with principal component make axis and by data projection to reference axis to realize from High dimensional data is to the intuitive visual analyzing of low-dimensional.Additive amount and four kinds of stable isotope ratios are fitted using multiple linear regression Value δ¹³C、δ¹⁵N, δ D and δ¹⁸Relationship between O is differentiated using linear discriminant analysis (LDA), and is carried out using leaving-one method Cross validation, to obtain the result of quantitative analysis to product.It comprises the concrete steps that, between-group variance small as far as possible according to intra-class variance Thought big as far as possible acquires discriminant function, is then classified using the discriminant function of foundation to sample；Pass through the side of projection Formula is analyzed, and first by finding out feature vector w, k group m metadata is projected to the direction of another more low-dimensional, so that throwing Separated as much as possible between movie queen's group and group, and the sample in same group as close to, then in new space to sample into Row classification；After PCA dimensionality reduction, classify in conjunction with LDA, so that it may the product of Different adding amount be differentiated, analyzed In the process, original differentiation is first carried out, cross validation is then carried out using " leaving-one method ".Finally, using multiple linear regression (MLR) Establish the relationship between potato additive amount and four element isotopic ratios.Residual test is carried out to model first, with standard Change predicted value is X-axis, standardized residual is that Y-axis establishes coordinate system, observes whether all samples for participating in returning have fully fallen in Imitate section.By residual analysis, discriminate whether to need to reject any sample.The analogue value that model is obtained and original true value into Row comparison, observes the absolute error between predicted value and true value, determine equation of linear regression for sample prediction effect with And the feasibility that unknown sample is predicted using regression equation.

Embodiment 4

Step 1: sample to be tested pre-processes: at 67 DEG C, drying to constant weight after sample to be tested is cooled to room temperature, through flour mill Smash it through 60 meshes；

Step 2: carbon nitrogen hydrogen and oxygen stable isotope detects:

(2) it is calibrated using standard items, then detects sample to be tested using stable isotope mass spectrograph²H/¹H and¹⁸O/¹⁶O is detected using EA Isolink-253Plus²H/¹H and¹⁸O/¹⁶O, detection²H/¹H and¹⁸O/¹⁶When O, joined using following technique Number: elemental analysis condition: reaction tube filling glass carbon, 1380 DEG C of temperature；High-purity He is as carrier gas, H₂With CO as reference gas； Stable isotope Mass Spectrometry Conditions: continuous flow sampling system, CO, H are applied₂As reference gas, EMA-P1 (δ²H=-25.3 ‰, δ¹⁸O ‰) and EMA-P2 (δ=20.99²H=-87.8 ‰, δ¹⁸O=26.88 ‰) it is used as standard referring to product to reference gas CO, H₂It carries out Calibration；

Although the embodiments of the present invention have been disclosed as above, but its is not only in the description and the implementation listed With it can be fully applied to various fields suitable for the present invention, for those skilled in the art, can be easily Realize other modification, therefore without departing from the general concept defined in the claims and the equivalent scope, the present invention is simultaneously unlimited In specific details and legend shown and described herein.

Claims

1. potato adds quantity measuring method in a kind of staple food products, which is characterized in that this method uses following steps:

Step 2: carbon nitrogen hydrogen and oxygen stable isotope detects:

(1) it is calibrated using standard items, then using stable isotope mass spectrograph detection sample to be tested¹³C/¹²C and¹⁵N/¹⁴N；

Step 3: carrying out qualitative and quantitative analysis using linear discriminant analysis (LDA) and multiple linear regression (MLR), sample is judged Whether product are added to potato full-powder, determine the amount of the potato dry matter of addition.

2. potato adds quantity measuring method in a kind of staple food products according to claim 1, which is characterized in that step 1 Middle by sample to be tested, at 65 ± 2 DEG C, drying to constant weight, smashes it through 40-60 mesh through flour mill.

3. potato adds quantity measuring method in a kind of staple food products according to claim 1, which is characterized in that step 2 It is middle to be detected using III-Isoprime of Vario EL¹³C/¹²C and¹⁵N/¹⁴N。

4. potato adds quantity measuring method in a kind of staple food products according to claim 3, which is characterized in that detection¹³C/¹²C and¹⁵N/¹⁴When N, using following technological parameter:

Elemental analysis condition: oxidation tube filling tungstic acid, 1150 DEG C of temperature；Reduction tube fills linear copper and silver-colored cotton, temperature 810 ℃；High-purity He as carrier gas and reference gas,

Stable isotope Mass Spectrometry Conditions: continuous flow sampling system, CO are applied₂、N₂As reference gas, casein is as standard items (δ¹³C_V-PDB=-26.98 ± 0.13 ‰, δ¹⁵N_AIR=5.94 ± 0.08 ‰) to reference gas CO₂、N₂It is calibrated.

5. potato adds quantity measuring method in a kind of staple food products according to claim 1, which is characterized in that step 2 It is middle to be detected using EAIsolink-253Plus²H/¹H and¹⁸O/¹⁶O。

6. potato adds quantity measuring method in a kind of staple food products according to claim 5, which is characterized in that detection²H /¹H and¹⁸O/¹⁶When O, using following technological parameter:

Elemental analysis condition: reaction tube filling glass carbon, 1380 DEG C of temperature；High-purity He is as carrier gas, H₂With CO as reference gas；

Stable isotope Mass Spectrometry Conditions: continuous flow sampling system, CO, H are applied₂As reference gas, to detect H and O isotopes concentration Standard items EMA-P1 (δ²H=-25.3 ‰, δ¹⁸O=20.99 ‰) and EMA-P2 (δ²H=-87.8 ‰, δ¹⁸O=26.88 ‰) To reference gas CO, H₂It is calibrated.

7. potato adds quantity measuring method in a kind of staple food products according to claim 1, which is characterized in that utilize line Property discriminant analysis dimensionality reduction is carried out to the data that measure, two-dimensional discriminant analysis figure is obtained, to distinguish whether sample is added to horse Bell potato and additive amount are approximate horizontal.

8. potato adds quantity measuring method in a kind of staple food products according to claim 7, which is characterized in that the line Property discriminant analysis produced using the staple food of elemental analysis-isotope mass spectrometry combined instrument (EA-IRMS) detection gradient potato additive amount Four kinds of element δ of carbon nitrogen hydrogen-oxygen of product¹³C、δ¹⁵N、δD、δ¹⁸The stable isotope concentration of O, uses respectively based on principal component analysis Linear discriminant analysis (PCA-LDA) or single linear discriminant analysis (LDA) carry out data processing.

9. potato adds quantity measuring method in a kind of staple food products according to claim 1, which is characterized in that utilize more First linear regression fit goes out additive amount and four kinds of Stable isotope ratio δ¹³C、δ¹⁵N, δ D and δ¹⁸Relationship between O, thus to production Product obtain the result of quantitative analysis.

10. potato adds quantity measuring method in a kind of staple food products according to claim 9, which is characterized in that described Multiple linear regression establishes multiple linear regression equations using SPSS or other statistical softwares, obtain potato additive amount with Equation of linear regression between four element isotopic ratios.