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United States Department of Agriculture

Agricultural Research Service

Research Project: Optimization of the Nutritional, Functional, and Sensory Properties of Raw and Processed Legumes, Grains, and Specialty Crops

Location: Healthy Processed Foods Research

Title: Thermal degradation of anthocyanins from purple potato (Cv. Purple Majesty) and their impact on antioxidant capacity

Authors
item Nayak, Balunkeswar -
item Berrios, Jose
item Power, Joseph -
item Tang, Juming -

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 29, 2011
Publication Date: July 29, 2011
Repository URL: http://dx.doi.org/10.1021/jf201923a
Citation: Nayak, B., Berrios, J.D., Power, J.R., Tang, J. 2011. Thermal degradation of anthocyanins from purple potato (Cv. Purple Majesty) and their impact on antioxidant capacity. Journal of Agriculture and Food Chemistry. 59(20):11040-11049. DOI: 10.1021/jf201923a.

Interpretive Summary: Foods with antioxidant capacity provide protection against cardio-vascular, certain forms of cancers, and Alzheimer's diseases caused by oxidative damages and contribute health benefits. Colored potatoes are rich in anthocyanins, which are known for providing natural color to fruits and vegetables and for exhibiting antioxidant properties. Degradation parameters of purified anthocyanins from purple-fleshed potato (Purple Majesty cv.) heated at high temperatures (100 - 150 °C) was determined. Purified anthocyanins, prepared by removing salts, sugars and colorless non-anthocyanin phenolics from the crude extract, were quantified using standard chemical methods. The data demonstrated that the antioxidant capacity in the purified anthocyanins were either increased or retained after the thermal treatment, indicating antioxidant activities of degradation products in the samples.

Technical Abstract: Degradation parameters of purified anthocyanins from purple-fleshed potato (Purple Majesty cv.) heated at high temperatures (100 - 150 °C) was determined. Purified anthocyanins, prepared by removing salts, sugars and colorless non-anthocyanin phenolics from the crude extract, were quantified using HPLC and spectrophotometric methods. The degradation kinetics of purified anthocyanins followed a first order reaction with reaction rate constants (A:-values) of 0.0262 - 0.2855 min'1, activation energy of 72.89 kJ/mol, thermal death time (D-values) of 8.06 - 8789 min and z-value of 47.84 °C over the temperature range of 100 - 150 °C. The enthalpy and entropy of activation was 59.97 kJ/mol and -116.46 J/mol K, respectively. The antioxidant capacity in the purified anthocyanins, measured using DPPH and ABTS assay, were either increased or retained after the thermal treatment indicating antioxidant activities of degradation products in the samples.

Last Modified: 12/19/2014