Co-Ingestion of Natal Plums (Carissa macrocarpa) and Marula Nuts (Sclerocarya birrea) in a Snack Bar and Its Effect on Phenolic Compounds and Bioactivities.

Vimbainashe E Manhivi,Retha M Slabbert,Dharini Sivakumar

doi:10.3390/molecules27010310

Abstract

This study investigated the effect of co-ingesting Natal plums (Carissa macrocarpa) and Marula nuts (Sclerocarya birrea) on the bioaccessibility and uptake of anthocyanins, antioxidant capacity, and the ability to inhibit α-glucosidase. A Natal plum–Marula nut bar was made by mixing the raw nuts and the fruit pulp in a ratio 1:1 (v/v). The cyanidin-3-O-sambubioside (Cy-3-Sa) and cyanidin-3-O-glucoside content (Cy-3-G) were quantified using the ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS). Inclusion of Natal plum in the Marula nut bar increased the Cy-3-Sa, Cy-3-G content, antioxidants capacity and α-glucosidase inhibition compared to ingesting Marula nut separately at the internal phase. Adding Natal plum to the Marula nut bar increased bioaccessibility of Cy-3-Sa, Cy-3-G, quercetin, coumaric acid, syringic acid and ferulic acid to 80.2% and 71.9%, 98.7%, 95.2%, 51.9% and 89.3%, respectively, compared to ingesting the Natal plum fruit or nut separately.

Highlights

Natal plum (Carissa macrocarpa) and Marula (Sclerocarya birrea) fruits are popular among the rural people from southern Africa
We found that Natal plum showed strong inhibitory properties against carbohydrate-hydrolyzing enzymes, α-glucosidase due to its anthocyanin content [5]
The peak tentatively identified as cyanidin-3-O-sambubioside had an observed m/z of 579.1 [M-2H]− and an expected m/z of 581.5 possibly due to the loss of 2H+ from the parent ion

Summary

Introduction

Natal plum (Carissa macrocarpa) and Marula (Sclerocarya birrea) fruits are popular among the rural people from southern Africa. Foods containing anthocyanins and anthocyaninrich compounds have been shown to display several biological activities with potentially positive health implications These include anti-inflammatory, anti-diabetic, and antioxidant activities [3]. Phenolic compounds may form covalent or non-covalent bonds with fibres, proteins, and carbohydrates that affect their release [11] This interaction may take place prior to harvest in the fruit cells or when the fruit is co-digested with other foods [12]. The concentration of Natal plum phenolics and anthocyanins was seen to decrease during simulated gastrointestinal digestion. It is, realistic to consider the fact that fruits are usually consumed with other fruits or nuts in the form of pestils, with peanuts and raisins, or in snack bars

Methods

Results

Conclusion