Mal J Nutr 22(3): 433 -442, 2016

Influence of Pre-treatment on Secondary Metabolites and Hypo-Glycemic Activity of Custard Apple (Annona squamosa) Peel
Nilam Roy & Sasikala S*


ABSTRACT

Introduction: Plant secondary metabolites, present in the outer layers of fruits and vegetables in higher amounts, are structurally diverse and comprise different classes of phyto-constituents that have a number of health-promoting properties. Blanching is an important pre-treatment that is used to inactivate the enzymatic oxidation.
Methods: This study was designed to investigate the effects of steam blanching (3, 5 and 7 min) and drying (50ºC) of custard apple (Annona squamosa) peel on the quantification of secondary metabolites and hypo-glycemic activity. Unblanched sample dried at 50ºC served as control. Quantitative tests for alkaloids, tannins, saponins and flavonoids were carried out for all samples and in vitro alpha amylase inhibition test was done to confirm the hypo-glycemic properties. All analyses were done in triplicates.
Results: Quantitative results for alkaloids, tannins, saponins showed a significant reduction (p<0.05) as the blanching time increased, whereas for the unblanched sample, it was not statistically significant (p>0.05). The exception was observed in the flavonoid content which showed a significant increase for 3 min and 5 min blanched samples, while the 7 min blanched sample showed a reduction in flavonoid content over the unblanched and fresh samples. Alpha amylase inhibition test similarly showed a decreasing trend for blanched samples ranging from IC50 value of 3.31 to 5.53 μg/mL compared to the unblanched with IC50 value of 4.92 μg/mL and fresh sample with IC50 value of 6.37μg/mL.
Conclusion: From the study, it is inferred that steam blanching and drying have a significant impact on the quantification of secondary metabolites and subsequently on its hypo-glycemic activity. A steam blanching time of 5 min is the optimum for processing of custard apple peel.

Keywords: Alpha amylase inhibition, custard apple peel, drying, secondary metabolites, steam blanching

Download full article

March 1995, Vol1 No.1
September 1995, Vol1 No.2
March 1996, Vol2 No.1
September 1996, Vol2 No.2
March 1997, Vol3 No.1
September 1997, Vol3 No.2
December 1998, Vol4 No.1&2
December 1999, Vol5 No.1&2
March 2000, Vol6 No.1
September 2000, Vol6 No.2
Mar/Sept 2001, Vol7 No.1&2
March 2002, Vol8, No.1
September 2002, Vol8, No.2
March 2003, Vol9 No.1
September 2003, Vol9 No.2
March 2004, Vol10 No.1
September 2004, Vol10 No. 2
2005, Vol 11 No.1
2005, Vo l11 No.2
2006, Vol 12 No.1
2006, Vol 12 No.2
2007, Vol 13 No.1
2007, Vol 13 No.2
March 2008, Vol 14 No.1
2008, Vol 14 No.2
2009, Vol 15 No.1
2009, Vol 15 No.2
2010, Vol 16(1)

2010, Vol 16(2)

2010, Vol 16(3)

2011, Vol 17(1)

2011, Vol 17(2)

2011, Vol 17(3)

2012, Vol 18(1)

2012, Vol 18(2)

2012, Vol 18(3)

2013, Vol 19(1)

2013, Vol 19(2)

2013, Vol 19(3)

2014, Vol 20(1)

2014, Vol 20(2)

2014, Vol 20(3)

2015, Vol 21(1)

2015, Vol 21(2)

2015, Vol 21(3)

2016, Vol 22(1)

2016, Vol 22(2)

2016, Vol 22 Supplement

2016, Vol 22(3)

2017, Vol 23(1)

2017, Vol 23(2)