Fortification of Functional Yogurt with Dragon Fruit (Hylocereus polyrhizus) Pulp: A Nutritional Approach

Khondoker Moazzem  Hossain; Narayon Chandro  Sarker Nirob; Anika Maharin  Roza; Nazmul Rahman  Chowdhury

doi:10.18502/jnfs.v11i2.21432

Khondoker Moazzem Hossain Department of Genetic Engineering and Biotechnology, Daffodil International University, Daffodil Smart City (DSC), Birulia, Savar, Dhaka-1216, Bangladesh
Narayon Chandro Sarker Nirob Biotechnology and Genetic Engineering Discipline, Khulna University, Khulna, Bangladesh.
Anika Maharin Roza Biotechnology and Genetic Engineering Discipline, Khulna University, Khulna, Bangladesh.
Nazmul Rahman Chowdhury Biotechnology and Genetic Engineering Discipline, Khulna University, Khulna, Bangladesh.

DOI: https://doi.org/10.18502/jnfs.v11i2.21432

Keywords: Fortified yogurt; Dragon fruit pulp; Antioxidant properties; Antibacterial properties; Functional food.

Abstract

Background: The incorporation of fruit pulp into yogurt has created a new dimension in the field of functional foods. Dragon fruit (Hylocereus polyrhizus) is a highly nutrient rich food which offers a range of health benefits, enriched in water-soluble fiber, vitamin C and antioxidants. The present study was aimed to evaluate antioxidant and antibacterial activities of both fresh and cold stored yogurts fortified with dragon fruit pulp. Methods: Laboratory made set yogurt was divided into four categories. The first one was used as control (T0) while the other three T1, T2 and T3 were fortified with 5, 7.5 and 10% dragon fruit pulp, respectively. Antioxidant activity was measured using DPPH method, pH was determined by a pH meter, syneresis was measured by centrifugation procedure, and antibacterial properties were assessed by disk diffusion method. Results: The experimental results showed that the pH of the yogurts decreased with the addition of dragon fruit pulp. Syneresis in yogurts increased with the addition of dragon fruit pulp. Treatments with 5%, 7.5%, and 10% dragon fruit pulp showed a significant increase in DPPH scavenging activity compared to the control group. Yogurt supplemented with 10% dragon fruit pulp demonstrated the most effective growth-inhibiting properties against the pathogens A. hydrophila, Bacillus cereus, E. coli, and K. pneumoniae. Conclusion: The results suggest that incorporating dragon fruit pulp to yogurt fortification improves its functional properties, especially its antibacterial and antioxidant activities, with the most significant benefits demonstrated at 10% fortification.