Effect of Processing Techniques on Bioactive Constituents and Functional Properties of Tamarillo (Solanum betaceum)

Abstract

Background: Tamarillo (Solanum betaceum) is a small but fast-growing, underexploited and seasonal fruit providing significant amounts of micronutrients and bioactive compounds which may produce a range of possible effects. The present study was conducted to determine the effects of processing techniques on the functional properties and bioactive compounds present in Tamarillo. Methods: The procured fruits were cleaned and subjected to two different processing methods; steam cooking directly under liquid boiling at 100 ℃ for 5 minutes and the fruits which were frozen below -45 °C for 42 hours and then lyophilized. Fruit samples were extracted using methanol by ultrasonication. Moreover, functional groups were identification and quantification of phytonutrients by Fourier Transform- Infrared Spectroscopy and UV-Spectrophotometer. Results: The spectra obtained by FTIR allowed identification of functional groups and secondary metabolites in Tamarillo. Fourier Transferred Infrared Spectroscopy revealed the presence of OH stretching alcoholic/phenolic - (3400-3200 cm-1), C=C stretching aromatic - (1650-1600 cm-1), C-H bending aromatic _- (700-420 cm-1) compounds in their respective peaks. The study revealed that total phenolic content of 56.4 and 88.5 mg GAE/g, flavonoids 45.8 and 28 mg QE/g, glycosides 10.6 and 14.5 mg/g and carotenoids content was 0.36 and 0.46 mg/g respectively for both freeze-dried and steamed cooked Tamarillo fruit. Regarding processing of bioactive compounds, the significant differences (P=0.1) were observed. Conclusion: Both the freeze drying and steam cooking effectively preserve its bioactive properties. The functional group and polyphenols present in the fruit confirms the presence of antioxidants which protects cells from free radical damage. Finally, the underexploited fruit may be utilized for its nutritional benefits and nutraceutical potential in treating degenerative diseases