Gamma irradiated date syrup for sucrose substitution in yogurt: effect on physicochemical properties, antioxidant capacity and sensory evaluation

In the search for domestic natural additives favored by consumers for food flavor and antioxidant enhancement, this work aimed to estimate the influence of the substitution of sucrose by date syrup treated with gamma rays on the physico-chemical properties, antioxidant capacity and organoleptic quality of yogurt. Date syrup was irradiated by two different doses: 1 kGy and 2 kGy and incorporated into yogurt with different sucrose substitution percentages. The obtained results showed that gamma irradiation improved the microbiological quality of the date syrup while retaining its physicochemical quality. In fact, a significant reduction of the microbial charge was observed. The two-irradiation doses were proven not affected the total sugars, proteins, phenols or the syrup antioxidant activity. Besides, water content and color indices were found to decrease. The substitution of sucrose at the rate of 75 and 100% with date syrup irradiated by the dose of 1 kGy enhances the antioxidant activity, phenol, protein and sugar content of the prepared yogurt. Furthermore, yogurt with irradiated date syrup gave good sensory scores. The treated syrup, especially by the dose of 1 kGy, could be a promising technological path. This gamma irradiation guarantees a biological method for preserving the syrup for its use in the engineering of processes applied to the dairy industry.

Automated summary

Substituting sucrose with date syrup treated with gamma rays at different doses improved the antioxidant activity and sensory quality of yogurt while maintaining its physico-chemical properties. Irradiation improved the microbiological quality of date syrup, with no significant effects on total sugars, proteins, phenols, or antioxidant activity of the syrup. The substitution enhanced antioxidant activity, phenols, proteins, and sugar content in yogurt, with good sensory scores.