Determination of External Properties of Crackers with Grape and Tomato Pomace by Non-Destructive Methods

U ovom diplomskom radu ispitan je utjecaj dodatka tropa grožđa i rajčice u različitim udjelima na vanjska svojstva kvalitete krekera. Uzorci krekera proizvedeni su u laboratorijskim uvjetima pri čemu je pšenično brašno djelomično supstituirano brašnom od tropa grožđa i rajčice u udjelima od 2, 4, 6, 8 i 10 %. Na uzorcima krekera provedene su analize boje i geometrijskih značajki prije i nakon postupka pečenja primjenom računalne analize slike. Iz dobivenih rezultata proizlazi da dodatak ispitivanog tropa u većim udjelima utječe na boju krekera povećavajući im vrijednost ukupne promjene boje, a smanjujući svjetlinu. Razlika u utjecaju dodatka tropa grožđa i rajčice na boju krekera vidljiva je u ponašanju kromatske komponente b*. Kod krekera s dodatkom tropa grožđa, povećanjem udjela tropa smanjuje se vrijednost parametra b*. Dok je kod uzoraka krekera s dodatkom tropa rajčice ponašanje ovog parametra suprotno (porastom udjela dodatka b* raste). Dodatkom tropa grožđa i rajčice značajno se povećava površina i opseg, a smanjuje sferičnost i ujednačenost površine krekera u odnosu na krekere od pšeničnog brašna. Krekeri s dodatkom tropa rajčice imaju ujednačeniju površinu i veću sferičnost u odnosu na krekere s dodatkom tropa grožđa.This study was conducted to determine the effect of grape and tomato pomace addition on quality characteristics of crackers (colour and shape). Cracker samples were produced under laboratory conditions where wheat flour was partially substituted by grape and tomato pomace flour in proportions of 2, 4, 6, 8 and 10%. The computer image analysis method was used to analyse the colour and geometric features of the crackers before and after the baking process. The obtained results showed that the addition of the tested pomace in larger proportions affects the colour of the crackers, increasing the value of the total colour changes, and reducing the lightness of the samples. Between the tested pomace of grape and tomato, there is observed different influence on the chromatic components b* of the crackers. The addition of grape pomace proportionally decrease the b* value of the crackers. While the crackers with addition of tomato pomace showed opposite behaviour, increased addition of tomato pomace increase the b* value. The addition of grape and tomato pomace significantly increases the area and perimeter, and reduces the circularity and solidity of crackers, compared to wheat flour crackers. Crackers with the addition of tomato pomace have a more uniform surface (greater solidity) and greater circularity compared to crackers with the addition of grape pomace