Utilization of Super Red Dragon Fruit Peel (Hylocereus Costaricensis (F.A.C. Weber) Britton & Rose) in the Making of Fermented Beverage

Abstract

Utilization of super red dragon fruit (Hylocereus costaricensis) are often limited to its flesh, whereas the peel as much as 30-35% weight of fruit was rich in antioxidants. Further processing is needed to increase the consumption of the dragon fruit peel. Effort achievement was made through fruit peel powder application on fermented beverage. Fermentation process (42°C within 14 hours) was conducted with 6.0% (v/v) of Streptococcus thermophilus: Lactobacillus plantarum: Lactobacillus bulgaricus = 1:1:1, skim milk (5% and 10%), and the peel powder of red dragon fruit (1.0, 1.5, 2.0%). Skim milk (1%) and dragon fruit peel powder (5%) were the best formulation based on pH value (4.05-4.08), total of titrated acids [TTA] (0.74%), and total of lactic acid bacteria [LAB] (Log 8.77-8.91 CFU/ml). The best formulation was then used to determine LAB culture ratio (S. thermophilus: L. plantarum : L. bulgaricus (1:1:1, 1:1:2, 1:2:1, 2:1:1). The ratio of 1:1:1 is selected as the best ratio based on pH (4.14), TTA (0.69%), total LAB (Log 9.41 CFU/ml). The product with preferred formulation contains phenolic 483.67 mg GAE/ml, flavonoid 315.59 mg QE/ml, IC50 39.94x104 mg/l (increased 241% [very strong level]), declared microbiologically safe (free of coliform), and still acceptable by consumers in hedonic (4.69 of 7.0).