Analytical methods in assurance of food quality, safety and origin在保证食品质量的分析方法安全和起源

1、Analytical methods in assurance of food quality, safety and originRomuald I. ZalewskiPozna University of Economics, Pozna, Poland1IntroductionEU 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 consum

2、er tableRegulation 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 for

3、, 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 foodstuff

4、s 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 diseasesI

5、n past distributed localyNew 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 defenceGood risk assessment analysis (within HACCP implementation),Immediate res

6、ponse to signals, honest explanation of issue, undertaken measures to localize treats, advertising if a product recall is necessary, good co-operation with important clients,reassurance that the incident is being handled in a controlled manner. 5Risk assessmentshall be based on the available scienti

7、fic 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 consists of: P

8、DO protected designation of origin, PGI-protected geographical indication and TSG traditional specialty guaranteed. 7Indicators of food quality and authenticity (2/2)The quality characteristics (physical, chemical, sensory) of the products protected by above mentioned designations are guaranteed by

9、respective Regulatory Councils. The sale of products covered by quality protection system steadily increase. The voluntary labeling is necessary for signaling high quality of products versus various generic products of lover quality (substitute products). 8New times new methods New methods are frequ

10、ently time saving, but are more expensive when used. 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 form of HACCP and

11、 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.9Antibiotics in food i

12、mportant field 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. The EU Directive 70/524/EEC or Council Regulation EEC 2377/90 regulates the use of antibiotics. Their residues

13、 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 strategy Identification of broad category (e. g. sulphonamides, beta-lactams, tetrac

14、ydines, amino glycosides, macrolides, phenicoles etc.) Detailed chemical identification using GC, GC/MS, HPLC/UV, LC/MS or other. The instrumental method must be tested and validated in relation to maximum residue limit (MRL), allowed by EU standards.11Testing of food, water, and equipment for the p

15、resence of pathogenic organisms (1/2)Current 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 Escherichia coli. The m

16、ethod 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 pathogenic organisms (2/2)RNA

17、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 with photogenic alive org

18、anism. Another way of fast analysis for microorganisms relay on ATP fluorescence. The special easy kit has been introduced.13Heavy metals in soil and plasticsatomic absorption spectrometry,laser-induced breakdown spectrometry (LIBS)The analyte is heated locally by the pulsed laser beam and evaporate

19、d 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.coupling LIBS with laser-included fluorescence allows decreasing this limit t

20、o 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)Till now various techniques are used and approved as official methods by ASTM, EPA and ISO. One can mention: ion selective electrodes, tit

21、rations, 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 pesticedes difficult task (1/2

22、)For screening purpose - multi residue methods (MRMs), because single analyte methods are not practical. MRMs allow inspecting a few dozen of compounds, methods applying GC/MS increase this number to 200-300 compounds. Perhaps the best and most comprehensive method allowing detection of 567 differen

23、t pesticide, metabolites and endocrine disrupters, has been described (Wylie, Meng, 2001). 16Residues of pesticedes difficult task (2/2)method with two GC instruments equipped with Mass Selective Detector and Atomic Emission Detector, and a ChemStation software for instrument control, data collectio

24、n 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) Application of NIRS (800 2500 nm) in food analysis is growing r

25、ecently dramatically due to a progress in computing facilities.Various 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, protein, fats and oils, carbohydrates, pigments and other additives. NIR analyzer measures absorption, transmission or reflection of the light as a function of wavelength. Results are produced and anal