Élelmiszerek roncsolásmentes analitikai vizsgálata fototermikus módszerekkel = Non-destructive analysis of foods by photothermal methods

A projekt kereteben ket fototermikus jelenseget kihasznalo merőberendezes megepitesere es ezek elelmiszeranalitikai alkalmazasara kerult sor. Egyreszt, egy por alaku elelmiszeripari mintak vizsgalatat lehetőve tevő fotoakusztikus (PA) berendezesre, masreszt egy un. "optothermal window" (OW) rendszerre, amelyet kolloid mintak analizisere hasznaltunk. Eredmenyesen vizsgaltuk zsiros tejpor oxidacios folyamatait, linearis kapcsolatot talaltunk az oxidaciot jellemző peroxidertek es a mert PA jel kozott. Az infravoros tartomanyban a PA modszer gyors viztartalom meghatarozast tesz lehetőve, amit szinten tejporon demonstraltunk. Ugyancsak korrelaciot talaltunk koleslisztek osszpolifenol tartalma es az UV tartomanyban mert PA jel kozott. Sikeresen alkalmaztuk a PA modszert elelmiszer szinezekek (sunset yellow) gyors, kozvetlen kimutatasara is pezsgőtablettaban. Az OW modszert borok polifenol tartalmanak meghatarozasara, szabad zsirsavak kimutatasara, valamit mez viztartalmanak meghatarozasa alkalmaztuk sikeresen. Osszesegeben azt lehet megallapitani, hogy a fenti vizsgalatok soran minden esetben a hagyomanyos standard modszereknel gyorsabb, roncsolasmentes es kozvetlen merest valositanak meg a fototermikus eljarasok. | In the frame of this project two setups were built up, both operate on the basis of the photothermal effect. The equipments were used to food analysis. One of them is a photoacoustic (PA) setup offering a possibility to investigate powdered food samples. The other one is the optothermal window (OW) setup, which was applied to analyse colloidal food samples. The oxidative processes were effectively investigated in whole milk powder, linear behaviour was found between the peroxide value and the measured PA signal. The PA method offers a fast water determination in foodstuff in the infrared region, which was also demonstrated on milk powder. Linear correlation was also found between the total polyphenol content of red sorghum and the measured PA signal in the ultra-violet region. The PA method was successfully applied to the fast and direct determi-nation of sunset yellow in effervescent tablet. The OW method was successfully used to the determination of the polyphenol content of wines, free fatty acids in cooking oil and water content of honey as well. Summarizing we can say the above mentioned photothermal methods can be realized as a fast, non-destructive and direct analysis of foodstuff.