Phenolics of pomegranate peels: extraction optimization by central composite design and alpha glucosidase inhibition potentials

Creative Commons License

ÇAM M., İçyer N. C.

JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE, vol.52, no.3, pp.1489-1497, 2015 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 52 Issue: 3
  • Publication Date: 2015
  • Doi Number: 10.1007/s13197-013-1148-y
  • Journal Name: JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1489-1497
  • Keywords: Pomegranate peel, Central composite design, Fractional factorial design, Alpha glucosidase inhibition
  • Erciyes University Affiliated: Yes

Abstract

Optimum water extraction conditions for phenolics of pomegranate peels were investigated by fractional factorial and face-centered central composite designs. Five potential factors were selected for the fractional factorial design: extraction technique, extraction temperature, extraction time, particle size and solvent to solid ratio. After eliminating statistically unimportant factors, a face-centered central composite design was set up with two controllable factors and with two responses: total phenolics and a-glucosidase inhibition activity. Optimum conditions were found as 100 degrees C for extraction temperature and 1 min for extraction time. There were no statistically significant differences (p > 0.05) between water extracts at optimized conditions and classical methanol extracts. Total phenolic content by HPLC was 192.0 mg/g of pomegranate peels on dry matter basis. Phenolics of pomegranate peels showed alpha-glucosidase inhibition activity with an IC50 (concentration of phenolics required to inhibit 50% of the enzyme activity) value of 5.56 +/- 2.23 mu g/ml. Pomegranate peel phenolics with its antioxidant and a-glucosidase inhibition properties might be a suitable ingredient for functional food applications.