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Article
Publication date: 19 June 2019

Mohammad Ghiath Naser Aldeen, Rita Mansour and Malak AlJoubbeh

This paper aims to study the effect of cooking and food additives, such as lemon juice and vinegar, on phenols and flavonoids contents and antioxidant activity of purslane.

Abstract

Purpose

This paper aims to study the effect of cooking and food additives, such as lemon juice and vinegar, on phenols and flavonoids contents and antioxidant activity of purslane.

Design/methodology/approach

The Folin–Ciocalteu method was used to determine total phenols content (TP), while total flavonoid content (TF) was determined by the aluminum chloride method. Two methods were used for determination of antioxidant activity: DPPH (1, 1-diphenyl-2-picrylhydrazyl) assay to determine radical scavenging activity, and ferric-reducing antioxidant power (FRAP) to measure the reducing power.

Findings

According to the results, leafs had higher values of TP, TF and antioxidant activity than aerial parts. Both lemon juice and vinegar retracted antioxidant properties of leafs. TP and TF of leaves showed deterioration after treatment with lemon by 58% and 21.8%, respectively, and FRAP and radical scavenging activity decreased by 75.8% and 74.5%, respectively (p <0.001). Also, TP, TF, FRAP and DPPH radical scavenging activity decreased in leaves by 82.2%, 30.5%, 87.8% and 90.9%, respectively, after treatment of leaves with vinegar. TF increased after cooking in studied parts, where no significant statistical difference was observed in TP and antioxidant activity (DPPH assay and FRAP) of cooked aerial parts. Adding lemon juice after cooking increased antioxidant properties of purslane (p <0.001).

Originality/value

Purslane has antioxidant activity because it is rich in polyphenols and flavonoids. Effects of food additives and cooking were studied using different measurements. According to the authors’ knowledge, this is the first work that studied the effect of food additives on antioxidant properties of purslane.

Details

Nutrition & Food Science , vol. 50 no. 1
Type: Research Article
ISSN: 0034-6659

Keywords

Article
Publication date: 11 January 2023

Akram M. Mohammed, Ayman Mohammed El-Anany, Sami A. Althwab, Raghad M. Alhomaid, Hend F. Alharbi, Reham M. ALgheshairy and Rehab F.M. Ali

The purpose of this current investigation is to evaluate the effect of adding different levels of cheeseweed Malva parviflora L. mallow leaves powder (MPLP) on the nutritional and…

Abstract

Purpose

The purpose of this current investigation is to evaluate the effect of adding different levels of cheeseweed Malva parviflora L. mallow leaves powder (MPLP) on the nutritional and quality characteristics of bread.

Design/methodology/approach

Wheat flour was partially replaced with MPLP at 0%, 1%, 2%, 3%, 4% and 5% levels to obtain the wheat– MPLP composite flour. Chemical composition, phenolics, flavonoids and antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl of wheat flour and MPLP were determined. Physicochemical and sensory characteristics of bread enriched with various levels of MPLP were evaluated.

Findings

MPLP contains 23.9% of protein, 10.1% of crude fiber and 9.8% of ash, respectively. MPLP had a significantly higher concentration of micronutrients than wheat flour. The content of total phenolics, flavonoids as well as free radical scavenging activity of MPLP were 17.6, 38.2 and 6.0 fold, respectively, higher compared to wheat flour. Protein content in bread samples increased with the addition of the MPLP in a range of 1.2%–6.6%. The increasing replacement of MPLP in the composite flours resulted in progressively higher dietary fiber and ash contents for fortified bread samples. The higher level of MPLP reduced the specific volume of fortified breads. The highest scores for the sensory attributes were noted for bread samples fortified with 2% and 3% of MPLP, whereas the lowest scores for bread samples fortified with 4% and 5% MPLP.

Research limitations/implications

Supplementation of wheat bread with different levels of MPLP resulted in significant increases in macro and microelements of fortified breads.

Originality/value

Supplementation of wheat bread with different levels of cheeseweed Mallow (Malva parviflora L.) leaves powder resulted in significant increases in macro and microelements of fortified breads.

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