Selection of Experimental Domain using Two-Level Factorial Design to Determine Extract Yield, Antioxidant Capacity, Phenolics, and Flavonoids from Mangifera pajang Kosterm

Abstract

Mangifera pajang Kosterm. is an important underutilized fruit of Malaysia. Two level factorial design was used for initial screening of the following independent factors, namely pH (2-6), ethanol concentration (20–80%), extraction temperature (30–65°C), time (30–240 min) and liquid to solid ratio (20–50 mL/g) to determine the extract yield, the antioxidant capacity, and the phenolic and flavonoid contents from Mangifera pajang pericarp. Among all the factors, ethanol concentration and liquid to solid ratio was very significant (p < 0.0001) in obtaining higher extract yield, antioxidant capacity, and phenolic content, whereas the pH, the extraction time, and temperature did not contribute significantly. From these results, we conclude that by altering ethanol concentration and liquid to solid ratio, significant differences can be noticed in obtaining high or lower concentrations on the recovery of extract yield, antioxidant capacity, and phenolic content.

Keywords:

• antioxidants
• factorial design
• flavonoids
• Mangifera pajang
• phenolic content

ACKNOWLEDGEMENTS

The authors would like to acknowledge Universiti Putra Malaysia for financial support under the Research University Grant Scheme (RUGS) (Project No: 02-01-09-0703RU). We are grateful to the Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia for laboratory facilities to carry out this study.

Notes

A – pH; B – Ethanol cocnetntraiton (%); C – Temperature (°C); D – Time (min); E – Liquid to solid ratio (ml/g) ; Y ₁ – Extract yield (%);Y ₂ – Total phenolic content (gallic acid equivalent µg/g); Y ₃ – Antioxidant capacity(absorbance); Y ₄ – Total flavonoid content (quercetin equivalent µg/g).

^a Center point.

A – pH; B – Ethanol concentration; C – Temperature; D – Time; E – Liquid to solid ratio; Y ₁ – Extract yield; Y ₂ – Total phenolic content; Y ₃ – Antioxidant capacity; Y ₄ – Total flavonoid content.

A – pH; B – Ethanol concentration; C – Temperature; D – Time; E – Liquid to solid ratio; Y ₁ – Extract yield; Y ₂ – Total phenolic content; Y ₃ – Antioxidant capacity; Y ₄ – Total flavonoid content.