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1、Analytical methods in assurance of food quality, safety and originRomuald I. ZalewskiPozna University of Economics, Pozna, Poland1IntroductionlEU is establishing a variety of measures to protect quality, safety, authenticity and the rights of all parties in the food chain, between a farm and a consu
2、mer tablelRegulation 178/2002 introduced several procedures in matters of food safety. For example a European Food Safety Authority (EFSA) shall provide scientific advice and technical support, independent information on all matters (see 1 art. 22, 23) establish monitoring procedures for searching f
3、or, collating and analyzing information and data with a view to the identification of risk (1 Art. 34) and rapid alert system (1 Art 35).2Variety of the food related risksPathogenic microorganism, their metabolites, viruses, parasites, toxins etc.,Natural toxic substances normally present in foodstu
4、ffs or raw materials, various chemicals (pesticides, herbicides, antibiotics, detergents, heavy metals) which remain from the various earlier treatments or were added by chance or on purpose (terrorism), Particles of metals, glass, plastics, dust and other unwanted physical matter.3Food born disease
5、slIn past distributed localylNew days distributed globaly through global operation of producers andfrequently as a news due to radio, TV, Internetignoring the warning signs from marketnon effective public relations4The best defencelGood risk assessment analysis (within HACCP implementation),lImmedia
6、te response to signals, lhonest explanation of issue, lundertaken measures to localize treats, ladvertising if a product recall is necessary, lgood co-operation with important clients,lreassurance that the incident is being handled in a controlled manner. 5Risk assessmentshall be based on the availa
7、ble scientific evidence and undertaken in an independent, objective and transparent manner 6Indicators of food quality and authenticity (1/2)The EU has very strict rules of origin referring to degree of “transformation to be fulfilled by product declared as originated in the country X.The system con
8、sists of: PDO protected designation of origin, PGI-protected geographical indication and TSG traditional specialty guaranteed. 7Indicators of food quality and authenticity (2/2)lThe quality characteristics (physical, chemical, sensory) of the products protected by above mentioned designations are gu
9、aranteed by respective Regulatory Councils. lThe sale of products covered by quality protection system steadily increase. lThe voluntary labeling is necessary for signaling high quality of products versus various generic products of lover quality (substitute products). 8New times new methodsl New me
10、thods are frequently time saving, but are more expensive when used. l Their application require a well-trained staff, availability of reference materials, proficiency testing, establishing a net of reference laboratories in each country and other features. Quality assurance systems implemented in a
11、form of HACCP and in addition tracking and tracing system will call for easy and clear analytical methods for examination of parameters at CCP (critical control points). Also the other procedures for a risk assessment (Regulation 178/2002) must relay on proven scientific and analytical methods.9Anti
12、biotics in food important fieldl Antibiotics are often used as feed additives to increase weight gain, to improve the efficiency of the feed conversion and mainly as prophylactic treatment to avoid sickness. lThe EU Directive 70/524/EEC or Council Regulation EEC 2377/90 regulates the use of antibiot
13、ics. Their residues present a potential hazard for a human health. Most commonly used test to determine antibacterial substances is a traditional microbiological test, but the need for more efficient method is obvious. 10New four-step strategyl Identification of broad category (e. g. sulphonamides,
14、beta-lactams, tetracydines, amino glycosides, macrolides, phenicoles etc.) lDetailed chemical identification using GC, GC/MS, HPLC/UV, LC/MS or other. lThe instrumental method must be tested and validated in relation to maximum residue limit (MRL), allowed by EU standards.11Testing of food, water, a
15、nd equipment for the presence of pathogenic organisms (1/2)lCurrent methods are painstaking and lengthy. The development of portable easy-to-use kits basing on biosensors will bring large improvements. Two microorganisms are of high interest for detection with biosensors: Criptosporidium parvum and
16、Escherichia coli. The method relay on separation of messenger RNA using heat shock, extraction and purification. Finally isothermal (410 C) Nucleic acid Sequence-Based Amplification is applied, as a very convenient technique for field-use and portable detection. 12Testing for the presence of pathoge
17、nic organisms (2/2)lRNA is than quantified with membrane based DNA/RNA biosensor, using liposome signal amplification. Liposomes are nano-vesicles with an inner cavity surrounded by a phospho-lipid bilayer. Inside this cavity marker molecule (dye) is entrapped, which change the color when interact w
18、ith photogenic alive organism. lAnother way of fast analysis for microorganisms relay on ATP fluorescence. The special easy kit has been introduced.13Heavy metals in soil and plasticslatomic absorption spectrometry,llaser-induced breakdown spectrometry (LIBS)The analyte is heated locally by the puls
19、ed laser beam and evaporated to excited plasma which emit radiation. The radiation is observed with Czarny-Tuner or Pascher-Runge spectrometer Typical limits of detection of several heavy metals in soil with this technique are in the range 10-100ppm.lcoupling LIBS with laser-included fluorescence al
20、lows decreasing this limit to 1 ppm. The flexible measuring probe, consuming less energy and using fiber optics are now under development. 14Determination of ions in water (for purity check)lTill now various techniques are used and approved as official methods by ASTM, EPA and ISO. One can mention:
21、ion selective electrodes, titrations, spectrofotometry and electrochemistry,ion chromatography is well established (Whitehead, 2001) F-, Cl-, Br-, NO2-, NO3-, SO42- - 5 pptNH4+, Ca2+, Li+, Mg2+, Na+, K+ - 1 pptCo2+, Co2+, Fe3+, Mn2+, Ni2+, Zn2+ - 2 pptCH3COO-, HCOO-, (COO)2-, - 50 ppt15Residues of p
22、esticedes difficult task (1/2)lFor screening purpose - multi residue methods (MRMs), because single analyte methods are not practical. MRMs allow inspecting a few dozen of compounds, lmethods applying GC/MS increase this number to 200-300 compounds. Perhaps the best and most comprehensive method all
23、owing detection of 567 different pesticide, metabolites and endocrine disrupters, has been described (Wylie, Meng, 2001). 16Residues of pesticedes difficult task (2/2)lmethod with two GC instruments equipped with Mass Selective Detector and Atomic Emission Detector, and a ChemStation software for in
24、strument control, data collection and analysis. The Pesticide Database has been prepared and used. The run took 42 minutes and allow identification of compounds with detection limit bellow 500 pg/ml (or at the ppt range).17Near infrared reflectance spectrometry (NIRS)l Application of NIRS (800 2500
25、nm) in food analysis is growing recently dramatically due to a progress in computing facilities.lVarious overtones and combination bands of fundamental IR bands (CH, OH, NH) can be found and provide capability for the identification and quantification of various food constituents such as moisture, p
26、rotein, fats and oils, carbohydrates, pigments and other additives. lNIR analyzer measures absorption, transmission or reflection of the light as a function of wavelength. Results are produced and analyzed in 2-3 minutes. 18Near infrared reflectance spectrometry (NIRS)lLiquid or solid samples are us
27、ed without special complicated treatment. Solids and grain could be grinded. Various viscous liquids, emulsions, creams, pasta could be measured in instrument compartment on even at distance with a special fiberglass adapter. lThe recorded spectra are not well developed (as compared to multi peak IR
28、) and advanced chemometric software is necessary for analysis of spectra. In many cases derivatives of spectra are applied.19Natural yoghurts20Preliminary clustering in tri-dimensional space of PCDanoneDanone+sugarBakomaFarmaKocian21Mayonnaise22NIRS spetctra of fats23Fats distribution in a space of PCAs24x1.xny1.yns1s1.X.Y.(NIRS).snsnPLS1PLS2PLS1, PLS2, SIMCA25Correlation of unsaturated fatty acids measured by reference method and predicted by NIRS26
