Effect of Stevia (Stevia rebaudiana) Sweetener Addition on Chemical Quality of Synbiotic Yoghurt Containing Extract of Evaporated Red Dragon Fruit Peels (Hylocereus polyrhizus)

The research was held from August 2021 until October 2021 in Laboratory Livestock Product Technology Universitas Brawijaya, Malang, Indonesia. Synbiotic yoghurt is a combination of probiotics and prebiotics, so adding stevia sweetener can improve the chemical quality. The purpose of this study was to determine the effect of adding stevia sweetener to synbiotic yoghurt of evaporated red dragon fruit peel extract in terms of chemical quality. The research method used is a laboratory experiment using a completely randomized design (CRD) pattern with four treatments and five replications. The percentage treatment of stevia sweetener carried out was the control treatment 0% (T0), 0.5% (T1), 2% (T2), 3.5% (T3). Data analysis used Analysis of Variance (ANOVA); if the results obtained were significant, the analysis will continue with Duncan's Multiple Range Test (DMRT). The analysis results showed that stevia sweetener concentration added a very significant difference (P<0.01) to total lactic acid, protein content, fat content, and antioxidant activity. Furthermore, based on SNI 2981:2009 regarding the quality of yoghurt, the treatment that has the best chemical quality is T1 with the addition of stevia sweetener 0.5%, with an average total value of lactic acid 1.33%; protein content 3.95%; 2.41% fat content; and 10.14% antioxidant activity.