Food bait which is rich in nitrogen has an intensive impact on physiology and behavior of fruit flies. Addition of ammonia to food baits can improve their effectiveness and the pH-level of these baits plays an important role in attracting fruit flies, since the effectiveness of bait is diminished by decreasing the pH-level. Therefore, the current study examined the effectiveness of several mixtures of the protein-based bait, Buminal, and ammonia compounds (ammonium acetate, ammonium chloride, di-ammonium phosphate and phosphoric acid) in attracting the Mediterranean fruit fly, Ceratitis capitata. Traps provided with each of these different mixtures were hanged in two fruit orchards (Novel orang and Mandarin) and examined in three-day intervals for 12 day period. In each inspection time, fifty milliliters of each mixture in the field were taken to estimate the pH-level. Regardless, the concentration of ammonia compounds, addition of di-ammonium phosphate to Buminal attracted more fruit flies than other mixtures. Further, all the tested mixtures attracted more females than males in both orchards. Although, the highest captures of C. capitata were by mixture of Buminal 5%+di-ammonium phosphate 1%, it did not coincide with changing in pH levels of this mixture. Only, the changes in pH-level of Buminal 5%+di-ammonium phosphate 2% led to significant increase in the number of trapped flies. This study might suggest that increasing the pH-level of food lure above 7.6 might adversely decline the number of trapped flies. Buminal+di-ammonium phosphate mixture can be generalized in IPM programs for C. capitata in Egyptian fruit farms.