evaluation of antimicrobial activities and color strength of curcumin in macaroni

macaroni is one of the favorite dishes in iranian,s family food program. in this study, effects of using different level of curcumin as a natural and functional component extracted from curcuma longa plant, against total count , total coliforms, psychrotrophic bacteria, yeasts and moulds and colorimetric properties of macaroni in comparison with beta carotene and turmeric as commercial color additives has been investigated. treatments were five different level of curcumin, c1:0/005, c2:0/01, c3:0/03, c4:0/05, c5:0/07, 0/07 turmeric and 0/01 beta carotene as positive controls and sample with no color additive as a negative control. pca, vrba and mea mediums were used for microbial analysis. colorimetric properties of macaroni in two form (powdered and non powdered ) was measured with a hunter lab colorimeter and the color differences were recorded as cie-lab l*(lightness), a* (redness–greenness) and b* (yellowness–blueness) values and the colorimetric difference (δe) for each sample was calculated. results showed that there is a linear relationship between %curcumin and total count, yeasts and moulds, so with increasing curcumin level in samples, total count, yeasts and moulds were decreased. also, samples containing curcumin in comparison with the samples containing the same percent of beta carotene were lighter, less red and have the same yellowness. in fact, using %0/03 curcumin in macaroni formulation, produces the same δe as %0/07 turmeric and %0/01 beta carotene in comparison with non color additive samples. also, by increasing the amount of curcumin in formulation, macaroni were being less light, redder and more yellow.