Effect of soaking, boiling, and steaming on total phenolic contentand antioxidant activities of cool season food legumes

Baojun Xu; Sam K C Chang

doi:10.1016/j.foodchem.2008.01.045

Effect of soaking, boiling, and steaming on total phenolic contentand antioxidant activities of cool season food legumes

Food Chem. 2008 Sep 1;110(1):1-13. doi: 10.1016/j.foodchem.2008.01.045. Epub 2008 Feb 2.

Authors

Baojun Xu¹, Sam K C Chang²

Affiliations

¹ Department of Cereal and Food Sciences, North Dakota State University, Fargo, ND 58105, United States; The Pharmaceutical Institute, Dalian University, Dalian 116622, China.
² Department of Cereal and Food Sciences, North Dakota State University, Fargo, ND 58105, United States. Electronic address: kow.chang@ndsu.edu.

PMID: 26050159
DOI: 10.1016/j.foodchem.2008.01.045

Abstract

The effects of soaking, boiling and steaming processes on the total phenolic components and antioxidant activity in commonly consumed cool season food legumes (CSFL's), including green pea, yellow pea, chickpea and lentil were investigated. As compared to original unprocessed legumes, all processing steps caused significant (p<0.05) decreases in total phenolic content (TPC), DPPH free radical scavenging activity (DPPH) in all tested CSFL's. All soaking and atmospheric boiling treatments caused significant (p<0.05) decreases in oxygen radical absorbing capacity (ORAC). However, pressure boiling and pressure steaming caused significant (p<0.05) increases in ORAC values. Steaming treatments resulted in a greater retention of TPC, DPPH, and ORAC values in all tested CSFL's as compared to boiling treatments. To obtain cooked legumes with similar palatability and firmness, pressure boiling shortened processing time as compared to atmospheric boiling, resulted in insignificant differences in TPC, DPPH for green and yellow pea. However, TPC and DPPH in cooked lentils differed significantly between atmospheric and pressure boiling. As compared to atmospheric processes, pressure processes significantly increased ORAC values in both boiled and steamed CSFL's. Greater TPC, DPPH and ORAC values were detected in boiling water than that in soaking and steaming water. Boiling also caused more solid loss than steaming. Steam processing exhibited several advantages in retaining the integrity of the legume appearance and texture of the cooked product, shortening process time, and greater retention of antioxidant components and activities.

Keywords: Antioxidant activity; Boiling; Cool season food legumes; Legumes; ORAC; Peas and lentils; Phenolics; Soaking; Steaming.