| Abstract | Problemi patvorenja hrane uzrokuju nepoštenu konkurenciju, negativno utječu na kvalitetu proizvoda, povjerenje potrošača i njihovo zdravlje. Cilj ovog rada bio je ispitati primjenu blisko infracrvene spektroskopije (engl. Near Infrared Spectroscopy, NIRs) u detekciji patvorenja češnjaka u prahu škrobom. Analizirana su slijedeća svojstva uzoraka: raspodjela veličine čestica, nasipna gustoća, Hausnerov omjer, aktivitet vode, vlaga, boja, vodljivost, ukupne otopljene tvari, pH, koncentracije polifenola i škroba, a isti su podvrgnuti i mikrosposkoj analizi. Snimljeni NIR spektri praškastih uzoraka podvrgnuti su multivarijatnoj analizi glavnih komponenta (engl. Principal Component Analysis, PCA). Temeljem rezultata PCA analize i eksperimentalnih podataka razvijeni su PLS (engl. Partial Least Squares) modeli koji su pokazali da se NIR spektroskopija može koristiti za kvantitativno određivanje: percentila raspodjele d(0,5) i D[3,2], aktiviteta vode, Hunterovih koordinata boja a* i b*, tona boje, kuta boje, ukupne promjene boje, vodljivosti, ukupnih otopljenih tvari, pH, koncentracija ukupnih polifenola i škroba. |
| Abstract (english) | Food adulteration creates unfair competition, harming product quality, consumer trust, and safety. Spices, such as garlic powder are frequent targets for adulteration, they can be easily substituted with any white powder. The aim of this study was to investigate the application of near-infrared spectroscopy (NIRs) in the detection of garlic powder adulteration with starch. Analyzed properties included: particle size distribution, bulk density, Hausner ratio, water activity, moisture, color, conductivity, total dissolved solids (TDS), pH, concentrations of polyphenols and starch, with microscopic analysis. NIR spectra of powdered samples were recorded and subjected to principal component analysis (PCA). Models, derived from PCA and experimental data using the partial least squares (PLS) method showing that NIR spectroscopy can be used for the quantitative determination of particle size distribution d(0,5) and D[3,2], water activity, Hunter color coordinates a* and b*, color tone, color angle, total color change, conductivity, TDS, pH and total polyphenol/starch concentrations. |
