JPS60205245A - Measuring apparatus for content of organic acid - Google Patents

Abstract

PURPOSE:To enable a quick and accurate measurement of the content of organic acid continuously by mixing a diluting solvent and a sample liquid and flowing the mixture to a probe as diluted sample to measure the conductivity with a measurement processing circuit. CONSTITUTION:A diluting solvent and a sample liquid from a solvent tube port 1, a sample tube port 2 and an extrusion liquid tube port 3 are forced to a mixer 5 with a microtube pump 8 via a mixing point (MP)10 to be mixed uniformly as a diluted sample and flows to a flow-through type 4-electrode cell 6. When current is applied between a pair of electrodes in a measurement processing circuit 7 with a probe chamber through which the diluted sample in the electrode cell 6, the current flowing is proportional to the conductivity of the solution. So, the conductivity is collated with the calibration curve of the content of organic acid to measure the content of organic acid in the diluted sample. This enables the dilution of a sample liquid at a high rate thereby assuring an accurate measurement of the content of organic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to reduce the amount of P, acid, and M contained in foods.
This relates to a device that continuously measures .

The present inventors first diluted the sample with high-purity water to reduce the organic acid and strong electrolyte content in the sample to 10 moles/min as a method of measuring the acid content in a food sample. ,
This diluted sample is electrically swept through a bright platinum plate, and a minute constant current is applied to the conductivity measuring cell (+Ht) to determine the impedance of the diluted sample.
The specific conductivity of the diluted sample is determined from this impedance, and the acid content in the food sample is determined based on this specific 'nL conductivity. A method for measuring the content was proposed in Q:j Maesho No. 50-144249. The measuring device cleverly used in this suppression method is equipped with a bright platinum plate τB and a pole, and is equipped with an rc il (conductivity measurement cell) and a constant 1 constant current that flows a variable current minute constant current through the conductivity measurement cell and the 01 mark '+iL4 umbrella.
1 [wave circuit, a variable circuit that calculates the ratio ηi4 degrees of the 6111 constant sample from the potential difference generated between the n11'αL poles, and (;I
Lat again comparison l'l! , lead 1n: and the preset 9 points to calculate the organic acid content h1 of the l1lQ constant sample ↑1.
At the same time, we have proposed an apparatus for measuring organic acid age, which is equipped with a zero arithmetic circuit and is characterized by the fact that it is simpler and more accurate than the measuring method for Ai+ when t<sny. Because it can perform accurate measurements, it has become popular at many food production sites.

1- However, after each measurement sample of this +11Q constant device is individually adjusted using a pipette etc. to make a diluted sample, this f+i dilution 11.
gJQ-all! Since it is a punch type that performs g4 L11111 constant in a constant cell, Ki
d, it'l+! Since the number of man-hours required for the process is enormous, it was hoped that the speed of production would be improved by 1ll+ from the ability to perform process control analysis that involves numerous product checks on a daily basis.

The present invention (d1) has been made in view of the above circumstances, and an object of the present invention is to provide a measuring device that can continuously and quickly measure the organic acid content in foods.

Hereinafter, with reference to the drawings, 9 fill containing borosemic acid of the present invention will be described.
The j-setting device will be explained.

FIG. 7 shows an embodiment of the organic acid-containing off-shore fixed equipment according to the first invention. The measuring device shown in this example is
A solvent pipe line 1 for sending a dilution solvent, a sample pipe line 2 for sending a sample liquid, an extrudate pipe line 3 for sending a sample extrudate liquid, and the above-mentioned sample pipe line 2 and extrudate pipe line 3. a mixer 5 that uniformly mixes the combined dilution solvent and sample liquid, and a flow-through type 't'1f that flows the NFC diluted sample mixed by this mixer 5.
The L electrode cell 6 and this flow-through type G electrode cell 6 are connected to the flow 1.
+, recite the conductivity of the diluted sample! Rt611 to 1111
+t management circuit 7, and for pumping the solution in the solvent pipe 1 and the extruded liquid pipe 3, a multi-channel microtube pump (hereinafter abbreviated as pump) is used.
8, and a +-1 hexagonal valve is used as the switching valve 4.

The solvent is sent from a dilution solvent tank (not shown) to the solvent pipe line 1.
f7 //'/: Abbreviated as "Idj" is a filter (
Foreign matter is removed by 1 zo 1 (not shown) +'c 11. rr
14, Pump 8V to send, Ru8 This marsh θ■, 1 water-pyridine, water-imidazole, or water-pyridine so that the weak acid 1(:) acid is almost completely separated by h7.
Aminopyridine★q mixed σ medium or deionized water (
ljXio −' Sm −' ), etc. are preferably used.

The pump 8 is a microtube pump with IO channels, in which nine channels are distributed in the solvent line 1, and the remaining /channels are connected to the extrudate line 3 as described below.
The solvent is distributed through the solvent pipe 1 and extruded with the solvent DtffL, and the extrusion liquid flowing through the liquid pipe 3 is pumped at a flow rate ratio of: /. WE lt,V: which has exited the pump 8 is sent to the damper 9. This damper 9 eliminates the pulsation of the solvent sent from the pump 8, and also serves as an air trap to prevent gas vesicles from flowing into the molten crystal in the pipe, as shown in Figure 2. , one damper body 9a made of a hollow cylindrical body, and a resistance tube 9 made of a small diameter tube.
By b, the series *, 1+, and this: #'lKutbah 97? It passes 7' (M tI\ is Myasink 7! India (re= #) and sends 10 to Mikider 5 and t2.

An extrusion liquid such as thin ice or the like is supplied to the extrusion liquid pipe 3 from the illustrated extrusion tank.

The extruded liquid supplied to the extruded liquid pipe 3 is filtered through the solvent pipe 1 and the filter to remove substances, and then sent from the water pump 8 to the switching valve 4 via the damper 9. The ratio of the flow rate of the extrudate flowing through this extrudate pipe 3 and the flow rate of the solvent flowing through the solvent pipe is determined by the upper C pump 80 channel distribution, and should be suitable for this example. Become.

In addition, from a sample source (not shown), a sample line 2 is connected.
3M of a food sample, such as fruit juice, is added to the container. A pump 11 is provided in the sample conduit 2, and the sample liquid is sent to the switching valve 4 via a filter (not shown).

The switching valve 4 consists of 60,000 valves, and the switching valve 4 has a
In addition to the sample pipe line 2 and the extrudate pipe line 3, the sample liquid or extrudate liquid that has been force-fed to the one-way valve 4 is transferred to the AIPI.
Connection ♀t12 to send UK and JJ1 output l to discharge these.
The white 13 is connected to both ends of a sample loop 14 having a predetermined volume for holding four volumes of sample quenching liquid.

The sample liquid and extrusion liquid that have been pressure-fed to this cut-off valve 4 are dissolved, and by switching this cut-off valve 4, the two-way KMPIO is released.
When the switching valve 4 is switched to the state shown in the solid phase in Figure 7, the extruded liquid is sent from the extruded liquid 'W path 3 to the connection [12] to MPlo. The sample liquid sent from the sample conduit 2 that has been removed passes through the sample loop 14 and is discharged from the discharge pipe 13.Next, the switching valve 4 is switched to the state shown by the dotted line in the figure. In this case, the sample liquid present in the sample loop 14 is extruded into the extrudate liquid sent from the extrudate line 3), and
M P l 13 l 1st l1, M I) I
At O, the solvent sent from solvent pipe 1 and υμ)
The sample acid or extrusion liquid sent via valve 4 is combined and sent to mixer 5. The sample Vi that merges with Flj and the solvent is connected to the sample loop 141C.
The Iyr fixed forging in the middle is extruded at a predetermined flow rate by the extrusion liquid sent from the extrusion liquid gas passage 3 by the pump 8 at a flow rate of //P of the solvent.

The eighth medium and the sample liquid that have been combined in the MPIO are mixed in a mixer 5 consisting of a thin tube wound into a coiled shape. As a result, the sample liquid is diluted at a predetermined ratio to become a diluted sample, which is sent to a flow cell type p'Fi electrode cell (hereinafter referred to as a flow cell) 6. Note that each diluted sample is separated by a mixed liquid of a solvent and an extrusion liquid. The dilution rate of this diluted sample is mainly referred to as the injection volume below c, the tail of the sample liquid that merges with the solvent at the MPIO. ) is determined by the volume of the sample loop 14. The graph shown in FIG. 3 shows the relationship between the dilution rate and the injection volume, and it can be seen from this graph that the dilution rate increases as the injection volume decreases.

The dilution rate varies depending on the type of food sample and the type of solvent, but is usually set at jo to 300 times KjQ, and the injection volume is adjusted as appropriate based on this IK.

Flow cell 6 it, lli barrel degree of dil'm liquid! As shown in Figs. 1. The middle part of this flow cell 6 is the probe 1, 6b through which the diluted sample and the mixed solution pass. In this probe chamber 6b, gloves are placed on both rings of the probe 6b. A pair of '+1 f' 11? Electrode (ic, 6c, this) lT1 electric r (j
, 4 @ 6 c , 6 c placed between fl ? C-Sentence/J's probe et al. n-c. Kotoriki et al. Ji74@6c, 6cm6d, 6
d, and the tip J:4 is made to coincide with the wall surface of the probe *6b. Kub 1, Ra no 11
1 (4J1 platinum 'l'i for 6c, 5c/6d, 6d
Platinum is preferably used.

The sample is sent from the mixer 5 to the probe chamber 6b of this flow cell 6.
And the glove electric handle 6d, l'idK 111: conductivity is iliQ 5i: ) 1, and 71 (, the combined liquid is
The probe chamber 6b itself and each of the electrodes 6c, 6c, 6d, and 6d are cleaned, and then discharged from the discharge port 16 via the back pressure coil 15. This back pressure coil 15 is
il 'f (formed by K, f, v1 exit 16
Apply resistance along the swamp toward this point and increase the pressure in the flow path to prevent the generation of bubbles.Next, the flow cell 6 is opened to
6c and probe electrode 6d, fidK contact field f'lt
The nt measurement processing circuit 7 will be explained. Keioki 1 processing circuit 7
DIE f-i, 70-106 11. The reference numeral 17 in FIG. 1 is an oscillator.

From this excavator 17, an alternating current of a predetermined frequency is applied to an automatic gain control amplifier (AGCA) 18.
Itt.

AC 1 (4 voltages are applied between the 1n1 electrodes 6c and 6c)
do.

At this time, the voltage drop 111 between the probe electrodes 6d and 6d is detected by the high input impedance differential amplifier 19, and this detection (no. The difference between the two signals is integrated and negative feedback is provided to the automatic gain control amplifier 18.

Due to the bending, the voltage between the current-carrying 1L pole 5c, ('ic) is
The drop of the probe electrodes 6d, 6d iJ'l is always constant and
111 for iK, pole 1j c,
The 11frW where li c IIIK is 1 is removed from the flow cell 6 and the liquid is 2r! It will be proportional to the electric rate. Therefore, the t potential difference generated between the two ends of this 4j; The measurement signal is sent to the recorder 26 via the absolute value circuit 25.
Send to 11. , where the conductivity of the fE liquid passing through the blow cell 6 is expressed as +1.

Since the ratio of rare f< sample is proportional to the organic mixture + Hi, the calibration curve of the ratio - organic mixture jd and the 1111 constant 71 f'r, J li rate is
By meeting iQ Shi, you can taste Tumbul's organic formulation 1.

In the measuring device of A1 Tsutsuki Mixture-18 configured as shown in [C], the extrusion liquid and the sample liquid are sent alternately by switching the valve 4, and the diluted
The mixed liquid and the diluted sample are mixed uniformly with the mixer 5 and sent to the flow cell 6.
Here, the conductivity is measured by the FIt6111 processing circuit 7, and the cold mixture along the sample can be measured, so a large number of sample liquids such as fruit juice can be easily and quickly prepared. l! I'? becomes.

'1t1I of this organic acid content! The 111 constant device is distributed to the solvent pipe line 1 that sends the dilution solvent to the core channel in the IO channel of the microtube pump 8, and the remaining rich channel is used as the extrusion liquid that sends the extrusion liquid that pushes out the sample liquid. Having been distributed in line 3, the sample liquid is gradually injected into the dilution solvent. As a result of this, the dilution rate of the sample liquid becomes high, making this measuring device suitable for measuring the organic acid content. Components that are the same as those in the embodiment of the first invention shown in FIGS. 1 to 6 are given the same reference numerals, and the explanation thereof will be simplified.

In the apparatus for measuring organic acid content in this example, the solvent pipe l
A microtube pump 3 with a common sample pipe line 2
The liquid is being pumped to 0. Micro tube pump 30
The zero channel distribution is 71 with sample 6/channel in path 2 and 2 channels in solvent rrj path 1. Then, CIIv: The solvent coming from the pipe 3 and the sample liquid coming from the sample 6 route 2 and the sample liquid coming from the pipe 2 are flowed through the converging pipe 31 to the switching valve 4. Send it. This confluence pipe 31KFi is provided with a preliminary mixer 32, and the solvent and sample liquid that flow through the confluence conduit 31 are premixed in advance before being sent to the switching valve 4.

In this example, in the 6111 constant device (2), the sample liquid is combined with the solvent before being sent to the switching valve 4, so the dispersion of the sample liquid becomes large, and therefore the 70-cell 6
The dilution ratio of the diluted sample sent to 2L can be increased by installing a mixer 32 in the confluence pipe 31 to make the dilution of the sample liquid more uniform.
). Therefore, from this measuring device, it is possible to more accurately determine that I1sugi'> CIiL +1fl1.

Next & this, real! L:+2 Examples of specific formulations of this invention
The 11111 constant '*''Il'+ of it will be explained in more detail.

[4 Practical Examples] The organic acid content determination device shown in Figure 7 was created in '17. 44. ) Compound resistance (
Based on citric acid conversion n), the correlation between electrical conductivity and organic acid content was determined from Kono 1 et al., and the regression equation (! + rc 0) The specifications of the measuring device are shown below.

A 5KVi mixer was used, in which a Teflon tube with an inner diameter/wmJ of 100 cm was coiled into a coil with a radius/j++m.

The flow cell 6 has a cylindrical main body 6 made of polycarbonate #1 with a diameter of 2 rm and a length of 3 cm.
A probe chamber 6b with a diameter of ff gllllll+ was used. For electrodes 4Ii6c, 6C, 6d, and 6d, [diameter/fighting platinum wire is used;
was fixed at the same level as the wall surface of the probe chamber 6b so that the tip would not protrude into the globe chamber 6b. In addition, the distance between the probe electrodes 6d and 6d is 1 (i Wtt
The device used in the t0 tree experiment with the distance between cC16C set to 1lilF′i/co has a low conductivity of 1! Rate (] ~ / j X /
0=S-sn-') Since bJFlt is set so as to be suitable within a limited range, it is used as a standard solution for calculating cell constants. When the cell constant was calculated using the solution (IO'''3 to 10-4M), the cell constant θ-z-px7
02m-1? It was 1t.

, 7 I'll 6111 processing circuit 7 standard resistance 23K
Vi, 20 Ω was used. Further, the capacitor of the oscillator 17 is /K11z, and the current-carrying electrode 6c of the 70-cell 6,
%lL pressure applied between probe electrodes 6d, 6d
The potential between 1t and 1 below is always 200 Her V regardless of the resistance of the solution.

Next, the 'c experimental conditions will be explained.

l If the injection volume is less than H, ko Opt, p + si two branches Jf (1) will be lower, and if Q is more than soμ, the appropriate dilution rate of the sample will be 1 n - from fL, and the time to return to the baseline will be lower. The influence of the inn, which is also growing, is J, Il.
, Wakuru tmeJ j /l l and t.

λ Current velocity #1, 1Ill in low jji offshore! 5 if 1
＋'＋°IJ'l is low, and a) to the baseline! It takes a long time to get home. If the vIC series is too large, the pulse IA by Bonf will increase and the measurement sheath R will decrease.
Consider measurement time and response reproducibility 1. And flow speed / de J t
ge/m+.

3 The dilution rate is injection volume 33 μt.
As a result of setting K, the value was about 100 times larger, and when the rpQ of citrus juice was measured each time under conditions of t0 or more, the chart shown in FIG. 7 was obtained. In FIG. 7, the vertical axis shows electric conductivity, and the horizontal axis shows time, and the numbers shown above the peaks are the brutal landscapes determined by the titration method for the same sample.

When the conductivities measured q times for the same sample were compared, the coefficient of variation was less than aS, confirming that the reproducibility of this device was good.

By the way, I found out that if I use this 811 (determination device 6) to determine the above φ, I can make 61 samples of 10 samples 4"■1 in 7 hours.

Next, what about unshu mandarin juice from different regions? 11. As a result of measuring a large number of ratios and requesting the organic content (converted to citric acid) using an appropriate method, a regression line was obtained, which is indicated by (a) in the figure. This regression line becomes the regression formula % formula %, and the correlation coefficient of j - &9.1r = 0 tata λ, and J (a good straight line is 111 et t).

When I diluted the juice of Satsuma mandarin orange 1' to 3 times and injected it into the sample conduit 2, a regression straight line (indicated by BL) occurred. L'IC9 of this 11) Expression tmay=31r, lu, 2X+i, 31i Also, phase 1:'+l 4'p, AQ
t, t r = 05) ri j, and s C-, K J'
S-good fx @m? 'l et al. 7Ii'c,.

KofL et al.’s conclusion! 1! :kac), Konotill,' Determined!
−°Ir't K YoJ Follow the fruit juice Noraku+1i rate 1
ji 〒゛ノ゛The presence of fruit juice 4 (1# acid-containing country)
'X! Tekitai 1, eggplant...! ＼By using the whole invention 1lljl constant device, salt addition (like products and margarine, one serving pot contains M is 111 ft11.j'+'
If it is sufficiently high compared to l"j"I, simply dilute Oo
o~/30θ times) or simply by breaking the emulsion, fl/> can be added to the above-mentioned organic G7' content measurement method to add salt'-,, +, t.
However, the salt concentration in food (generally widely used as a method of adding salt) 1 is the salt content claimed by the Kusaribe method,
This measurement is compared with 0 degrees of table salt;
As a result, the (inl difference with the temperature control method is O/CH for Worcestershire sauce (/soo times diluted), margarine (72 times M)
Add hot water to break the emulsion and then cool it? In the case of foods with the highest concentration, such as t0 mayonnaise, where f1χ is 002 (a given aqueous phase), water-ethanol (/+, 2) is used instead of dilution water. The amount of inhibition of dissociation can be measured with high accuracy. According to the final method, it is possible to simultaneously analyze the salt content and the acid content.The final method measures the total amount of sodium and chlorine, so the net chloride is given. It turns out. Furthermore, the response in the final method is directly proportional to the total concentration of both sodium and chloride ions, so the measurement accuracy is high. Moreover, the device of the present invention allows easy automation of measurement, f
It does not require special consideration for maintenance and management, and it has the advantage of being able to be cleaned with strong acids and detergents to prevent contamination.
The measurement method using this device is made by Food Products Inc. It is useful as a management analysis method in the field.

As explained above, the 811! of this invention! The fixing device rj uses a mixer to uniformly mix the diluted solvent sent from the 11j W Pii and the sample liquid sent from the sample or path. J/, diluted tb (Fl), and inside the globe chamber of the blow cell fA (shi, il++! In this flow cell, the conduction 1+ of the constant solution is measured and the organic acid content etc. is calculated. The measuring device of the invention is capable of (1) diluting a large number of sample solutions from various foods and their raw materials at a high rate, and continuously measuring them simply, quickly, and accurately; This device allows you to accurately determine the organic acid content, etc.

4. A block diagram 1 showing an embodiment of the first invention.
, FIG. 2 is a partially sectional 1-fc front view showing the damper,
Figure 3 shows the injection volume and dilution rate of 1v1.
Fig. 5 is a cross-sectional view of IQI, Fig. 6 is a block diagram showing an embodiment of the invention of Fig. 11r1.7. The chart diagram showing the electrical conductivity obtained in the experiment, and the second figure is a graph showing the regression line between the electrical conductivity obtained in the experiment and the organic acid content.

1... Solvent pipe line, 2... Sample pipe line, 3... Extruded liquid pipe line, 4... Switching valve,
5...Mixer, 6...Blow-through type a 191 Pole cell (flow cell), 7...
A total of 6111 Asahi circuits, 31...merging pipes.

Applicant Fujihei Kogyo Co., Ltd. Injector 7 cylinder volume (L12) Fig. 4 Figure 5 Figure 7 time Figure 8 Confucian r4 alcohol content 6/.

I−'Ij−+1 in place of 1Li (/) expression)
, =l ('l display Showa 59 (+ 1! I u'l Ill No. 62261
No. 2, title of the invention (11 included)
1 sentence 11 series with J name・li +'l 'R1;+'l applicant ゛ Hatake Ippei' - Gyo Co., Ltd. (Haka 1 person) 4, agent 11jl III;) 9il' 6 Jl 29th
(Delivery date) Contents of 61 Book f] was filed on March 30, 1980, in I.J., without attaching the letter, and then filed in 1982, s [June 9, 1982]
Attach the power of attorney for Fujihira Kogyo Co., Ltd. J3 and Right Limited Association N1 Fuden Kuwa Manufacturing Co., Ltd.
However, 1985E June 261] (=J's subsequent arrest)
I received the I order (method), but as you can see from the above progress, 63 defects that should have been corrected have been repaired.

Claims (1)

[Claims] (1) Solvent pipe for delivering dilution solvent and sample liquid
3°, an extrudate pipe to send the sample extrudate, and a pipe to the sample and an extrudate 'i>'.
A switching valve that can be used to switch off and on from the flow, a mixer that uniformly mixes the dilution 61W and the sample liquid, and a flow-through type that allows the diluted sample to flow through the mixer. +,
(A cell and this flow-through type electrode cell are jlr
I + r to measure the dirt 119 rate of fl dilution test 1
(2) A solvent pipe line for feeding the dilution solvent, and a swarm '1τ mode for feeding the sample liquid: 1 and N rf.
Dilute j1 from jMi line to llz1 and sample t“
? The sample liquid from i'ii merges with 1 Atn;
``The switching valve that cuts off the i path, and the bamboo valve are used to uniformly mix the above q'i'r 1 < Jl stroke + i numb and sample 1). a flow-through type electrode cell through which the diluted sample mixed in the mixer flows, and a measurement processing circuit that measures the N9 electric rate of the diluted sample flowing through this flow-through type electrode cell on the H1 side. J
l. Measuring device for organic acid content.