Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 31100
The Effect of Hylocereus polyrhizus and Hylocereus undatus on Physicochemical, Proteolysis, and Antioxidant Activity in Yogurt

Authors: Zainoldin, K.H., Baba, A.S.


Yogurt is a coagulated milk product obtained from the lactic acid fermentation by the action of Lactobacillus bulgaricus and Streptococcus thermophilus. The additions of fruits into milk may enhance the taste and the therapeutical values of milk products. However fruits also may change the fermentation behaviour. In this present study, the changes in physicochemical, the peptide concentration, total phenolics content and the antioxidant potential of yogurt upon the addition of Hylocereus polyrhizus and Hylocereus undatus (white and red dragon fruit) were investigated. Fruits enriched yogurt (10%, 20%, 30% w/w) were prepared and the pH, TTA, syneresis measurement, peptide concentration, total phenolics content and DPPH antioxidant inhibition percentage were determined. Milk fermentation rate was enhanced in red dragon fruit yogurt for all doses (-0.3606 - -0.4126 pH/h) while only white dragon fruit yogurt with 20% and 30% (w/w) composition showed increment in fermentation rate (-0.3471 - -0.3609 pH/h) compared to plain yogurt (-0.3369pH/h). All dragon fruit enriched yogurts generally showed lower pH readings (pH 3.95 - 4.03) compared to plain yogurt (pH 4.05). Both fruit yogurts showed a higher lactic acid percentage (1.14-1.23%) compared to plain yogurt (1.08%). Significantly higher syneresis percentage (57.19 - 70.32%) compared to plain yogurt (52.93%) were seen in all fruit enriched yogurts. The antioxidant activity of plain yogurt (19.16%) was enhanced by the presence of white and red dragon fruit (24.97- 45.74%). All fruit enriched yogurt showed an increment in total phenolic content (36.44 - 64.43mg/ml) compared to plain yogurt (20.25mg/ml). However, the addition of white and red dragon fruit did not enhance the proteolysis of milk during fermentation. Therefore, it could be concluded that the addition of white and red dragon fruit into yogurt enhanced the milk fermentation rate, lactic acid content, syneresis percentage, antioxidant activity, and total phenolics content in yogurt.

Keywords: antioxidant activity, yogurt, Hylocereus undatus, Hylocereus polyrhizus

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 4573


[1] Apostolidis, E., Kwon, Y.,-I., Shetty, K. (2007). Inhibitory potential of herb, fruit, and fungal-enriched cheese against key enzymes linked to type 2 diabetes and hypertension. Innovative Food Science and Emerging Technologies, 8, 46-54.
[2] Aryana, K., J., McGrew, P. (2007). Quality attributes of yogurt with Lactobacillus casei and various probiotics. LWT-Food Science Technology.
[3] Brabandere, A., G., Baerdemaeker, J., G. (1999). Effects of process conditions on the pH development during yogurt fermentation. Journal of Food Engineering, 41, 221-227.
[4] Coisson, J. D., Travaglia, F., Piana, G., Capasso, M., Arlorio, M. (2005). Eurtepe Oleracea juice as a functional pigment for yogurt. Food Research International, 38, 893-897.
[5] Cueva, O., Aryana, K., J. (2007). Quality attributes of a heart healthy yogurt. LWT-Food Science Technology.
[6] Davis, J., G. (1973). Yogurt manufacture. Fd Mf. June,p.23.
[7] Farnsworth, J.P., Li, J., Hendricks, G.M., Guo, M.R. (2006). Effects of transglutaminase treatment on functional properties and probiotic culture survivability of goat milk yogurt. Small Ruminant Research, 65, 113- 121.
[8] Guggisberg, D., Eberhard, P., Albrecht, B. (2007). Rheological characterization of set yoghurt produced with additives of native whey proteins. International Dairy Journal, 17, 1353-1359
[9] Joel Isanga., Guonong Zhang. (2009). Production and evaluation of some physicochemical parameters of peanut milk yoghurt. LWT-Food and Science Technology, 42, 1132-1138.
[10] Li-chen Wu , Hsiu-Wen Hsu, Yun-Chen Chen, Chih-Chung Chiu, Yu-In Lin, Ja-an Annie Ho. (2006). Antioxidant and antiproliferative activities of red pitaya. Food Chemistry, 95, 319-327.
[11] Lourens-Hattingh, A., Viljoen, B. C. (2001). Yogurt as probiotic carrier food. International Dairy Journal, 11, 1-17.
[12] McCue, P., P., Shetty, K. (2005). Phenolic antioxidant mobilization during yogurt production from soymilk using Kefir cultures. Process Biochemistry, 40, 1791-1797.
[13] Penna., A. L. B., Sivieri, K., Oliviera, M. N. (2001). Relation between quality and rheological properties of lactic baverages. Journal of Food Engineering, 49, 7-13.
[14] Saint-Eve, A., Levy, C., Le Moigne, M., Ducruet, V., Souchon, I. (2008). Quality changes in yogurt during storage in different packaging materials. Food Chemistry, 110, 285-293.
[15] Shihata, A., Shah, N. P. (2000). Proteolytic profiles of yogurt and probiotic bacteria. International Dairy Journal, 10, 401-408.
[16] Vargas, M., Chafer, M., Albors, A., Chiralt, A., Gonzalez-Martinez, C. (2008). Physicochemical and sensory characteristic of yoghurt produced form mixture of cows- and goat-s milk. International Dairy Journal, 18, 1146-1152.
[17] Vasco, C., Ruales, J., Kamal-Eldin, A. (2008). Total phenolic compounds and antioxidant capacities of major fruits in Ecuador. Food Chemistry 11, 816-823.
[18] Vijayendra, S. V. N., Palanivel, G., Mahadevamma, S., Tharanathan, R. N. (2008). Physico-chemical characterization of an exopolysaccharide produced by a non-ropy strain of Leuconostoc sp. CFR 2181 isolated from dahi, an Indian traditional lactic fermented milk product. Carbohydrate Polymers, 72, 300-307.