DE10339014A1 - Process and assembly to determine the condition and fitness of food for consumption with ion-mobility spectrometer - Google Patents

Abstract

A process and assembly determine the condition and fitness of food for consumption. In the process gaseous or aerosol particles from the food are detected and analyzed by an ion-mobility spectrometer.

Description

Background of the invention

Field of application of the invention

The The invention relates to novel devices and methods for analysis the condition of a food, in particular for the detection of a Production problem or product defect or for detection of known or unknown ingredients of a food. It will be Limitations of conventional Food diagnostics, such as Mass spectrometry, HPLC or Gas chromatography overcome.

Characteristic of the known State of the art

With great Economic effort is the detection of individual pollutants carried out in food, without always an economic benefit in the form of the targeted high-efficiency early detection is provided. An important cause of early detection problems many animal food problems is the most extraordinary complex biochemistry of the animal organism and the high apparatus Effort to measure individual markers that are characteristic for certain Problems are. Therefore, many important issues often go unnoticed for a long time. If she finally to later Times are discovered lead i.a. to much higher Cost of the solution, provided an effective solution then at all still possible is. An example for An undetected food problem for many years is BSE. It would therefore be desirable, an alternative method of early detection to disposal to have a relatively large number of problem markers simultaneously and can rate.

Table 1. Examples of possible chemical emissions for the diagnosis of food problems.

Methods for food detection and control are known (see Table 1) which detect gases or aerosols emitted by the food, eg, vinyl esters, vinyl lactones, esters, aldehydes, ketones, acids, lactones, and norisoprenoids are detected and used for quality control become. In addition to the human nose (see eg Bohaychuk & Greer, 2003, Schifferstein & Miciiaut, 2002), the method of choice is often gas chromatography (GC, see eg Jordan et al., 2003, Valim et al., 2003), mass spectrometry (MS). , GC-MS (see eg Aubert et al., 2003; Qian & Reineccius, 2003; Jordan et al., 2003), or proton transfer reaction mass spectrometry (PTR-MS; see, eg, Boscaini et al., 2003) , All four technical methods are very expensive. In addition, GC takes at concentrations below 1 ppbv typically more than 30 minutes to complete. The relatively fast MS and PTR-MS typically allow only the capture of a tiny fraction of the original emissions of the food without the need for expensive ancillary equipment (eg, virtual impactors) because of the complicated sample intake. There are experiments with chemical sensors, so-called electronic noses (based for example on the change in the resistance of antibody-loaded films or change in the resonance frequency of antibody-equipped transducers), which are relatively insensitive. Even less sensitive is the infrared spectroscopy used, for example, for coffee analysis (Lyman et al., 2003) and GC-FID (see, eg, Aubert et al., 2003). However, for simultaneous early detection prior to the onset of a variety of food problems, a more cost effective technology with significantly better sensitivity is desirable.

Especially can conventional Methods and devices for the diagnosis of foods, such as mass spectrometry, HPLC and GC not or only with great effort odor substances detect at the level of some 1000 molecules. Are known ultrasensitive ion mobility spectrometer (IMS), which, however, for the diagnosis of food so far have no meaning. Regarding the Designs of ion mobility spectrometers and their extremely high sensitivity, see Nölting, B. (2003) Methods in Modern Biophysics. Springer-Verlag, Berlin Heidelberg New York Tokyo.

Object of the invention

The The aim of the invention is the expansion of the possibilities of modern devices and methods to determine the state of food and to discover it of new ingredients by means of ultrasensitive detection and Analysis of substances that enter the gas phase from the food or Aerosol phase transgress.

literature

• Bohaychuk VM, Greer GG (2003) Bacteriology and storage life of moisture-enhanced pork. J Food Prot 66: 293-299
• Boscaini E, van Ruth S, Biasioli F, Gasperi F, Mark TD (2003) Gas chromatography olfactometry (GC-O) and proton transfer reaction mass spectrometry (PTR-MS) analysis of the flavor profile of grana padano, parmigiano reggiano, and grana trentino cheeses. J Agric Food Chem 51: 1782-1790
• Jordan MJ, Margaria CA, Shaw PE, Goodner KL (2003) Volatile components and aroma active compounds in aqueous essence and fresh pink guava fruit puree (Psidium guajava L.) by GC-MS and multidimensional GC / GC-O. J Agric Food Chem. 2003 51: 1421-6
• Kumazawa K, Masuda H (2003) Identification of odor-active 3-mercapto-3-methylbutyl Acetate in volatile fraction of roasted coffee brew isolated by Steam distillation under reduced pressure. J Agric Food Chem 51: 3079-3082
• Lyman DJ, Benck R, Dell S, Merle S, Murray-Wijelath J (2003) FTIR-ATR analysis of brewed coffee: effect of roasting conditions. J Agric Food Chem 51: 3268-3272
• Nölting B (2003) Methods in Modern Biophysics, Springer, Berlin ∙ Heidelberg ∙ New York ∙ Tokyo, 268 pages
• Qian M, Reineccius GA (2003) Quantification of aroma compounds in Parmigiano Reggiano cheese by a dynamic headspace gas chromatography-mass spectrometry technique and odor activity value. J Dairy Sci. 86: 770-776
• Schifferstein HN, Miciiaut AM (2002) Effects of appropriate and inappropriate odors on product evaluations. Percept Mot Skills. 95: 1199-1214
• Valim MF, Rouseff RL, Lin J (2003) Gas chromatographic-olfactometric characterization of aroma compounds in two types of cashew apple nectar. J Agric Food Chem. 51: 1010-1015

detailed Description of the invention

The invention has for its object to enable certain detections of food problems and food ingredients, without being bound by the limitations of conventionally used means. According to the invention, the object is achieved by the use of ion mobility spectrometry, wherein chemical substances are detected and analyzed, which are released from the food into the gas phase or aerosol phase. These substances referred to below as "material emissions" are, for example, acids, aldehydes, sulfides, hydrocarbons, pheromones, hormones, lipids, peptides, proteins. The food contains eg meat, fish, cheese, fruits, cereals. Based on the occurrence or non-occurrence of the material emissions, for example, the person's foodstuff condition is determined. This The conclusion is made, for example, by the occurrence or non-occurrence of problem-specific marker substances or, for example, by changes in the concentration of a large number of substances. The conclusion may be, for example, a diagnosis or a risk assessment or a probability of a diagnosis. The methods and devices may also find application, for example, to researching new food ingredients.

1st embodiment

Of the Sample inlet of a IMS sniffer detector is a few inches over the production line of a slaughterhouse while the in the snoop detector integrated pump draws about 10 ml / min of air and this to the sample inlet membrane of the sniffer detector leads. An ion mobility spectrum is measured and in the IMS snoop detector evaluated or transferred to a computer, which the spectrum on the presence of desired Ingredients and unwanted bacterial metabolites and food modifications analyzed. Due to the ultrasensitive detection can production problems be detected relatively cheap before they exceed the allowable limits.

An example of an arrangement of the measuring technique is in 1 sketched: a hose ( 1 ) is on the sample inlet ( 2 ) of an IMS snoop detector. On the end of the tube facing away from the detector is a replaceable coarse filter ( 3 ), which prevents coarse particles. The hose end with coarse filter ( 3 ) ends in the immediate vicinity of a conveyor belt ( 4 ) on which the food to be examined passes. The IMS sniff detector contains a preconcentrator or prefilter ( 5 ), a sample inlet pump ( 6 ), a fast gas chromatography ( 7 ), an outlet for the drift gas ( 8th ), a battery ( 9 ), the drift channel ( 10 ) of the IMS, a thermal insulation and temperature control ( 11 ), an inlet for the drift gas ( 12 ), a handle ( 13 ), an ad ( 14 ) or instead an interface to a PC. The spectral analysis is carried out for example by means of neural network analysis ( 2 ): The spectra (current ( 15 ) at the collector of the IMS as a function of the drift time ( 16 )) are analyzed by means of a neural network consisting of input layer ( 17 ), hidden layer ( 18 ), weighted compounds ( 19 . 20 ), a preference ( 21 ) and the output node ( 22 . 23 . 24 ), consists. Signals at the output node ( 22 . 23 . 24 ) correspond, for example, spoiled meat or polluted meat or proper condition of the meat.

• • Es wird eine Vielzahl von biochemischen Parametern simultan erfaßt und ausgewertet, d.h. Indikatoren für eine Vielzahl von Lebensmittelproblemen können simultan erfaßt werden.
• • Durch die spezielle Form der Probennahme, die hauptsächlich Geruchsmoleküle erfaßt, gibt es keine allzugroße Überlappung mit anderen Methoden (z.B. herkömmliche GC oder HPLC), so daß zu erwarten ist, daß bestimmte Lebensmittelprobleme besser diagnostiziert werden können, als mit herkömmlichen Methoden.
• • IMS-Detektion ist ultrasensitiv. Das theoretische Limit der Methode (ca. 1000 Moleküle) ist viele Größenordnungen besser, als beispielsweise bei herkömmlicher GC, GC/MS oder HPLC. Daher können Stoffe nachgewiesen werden, deren Vorkommen im tierischen Organismus bisher unbekannt ist. Es ist damit zu rechnen, daß neue problemtypische Emissionen entdeckt werden. Dadurch besteht ein erhebliches Potential für die Grundlagenforschung zur Entdeckung neuer in Verderbmechanismen involvierter Substanzen.
• • Die Messung ist sekundenschnell und das Meßergebnis kann nach Entwicklung einer geeigneten Auswertesoftware innerhalb von Sekunden vorliegen.

The advantages of IMS detection of chemical food emissions include:

• • A large number of biochemical parameters are simultaneously recorded and evaluated, ie indicators for a variety of food problems can be recorded simultaneously.
• • Due to the special form of sampling, which mainly detects odor molecules, there is not too much overlap with other methods (eg conventional GC or HPLC), so that it can be expected that certain food problems can be better diagnosed than with conventional methods.
• • IMS detection is ultrasensitive. The theoretical limit of the method (about 1000 molecules) is many orders of magnitude better than for example in conventional GC, GC / MS or HPLC. Therefore, substances can be detected whose occurrence in the animal organism is unknown. It is to be expected that new problem-typical emissions will be discovered. There is thus considerable potential for basic research to discover new substances involved in spoilage mechanisms.
• • The measurement takes seconds and the measurement result can be available within seconds after developing a suitable evaluation software.

2nd embodiment

One IMS sniffer detector triggers alarm when, when the Kafferöstung a production error threatens. As a result, the roasting process can be regulated without errors in a timely manner become.

Claims (2)

Detection device, characterized in that - a substance or substance mixture which is released from a food into the gas phase or aerosol phase is detected by means of an ion mobility spectrometer, - from the result of the detection on the state of the food or a known or hitherto unknown Ingredient is closed. Detection method, characterized in that - a material or mixture of substances from a food to the gas phase or aerosol phase, by ion mobility spectrometry is detected, - out the result of detection on condition of food or one known or previously unknown ingredient is closed.