Comparative studies on phenolic profiles, antioxidant capacities and carotenoid contents of red goji berry (Lycium barbarum) and black goji berry (Lycium ruthenicum)

Baojun Xu,Tanvir Singh Badwal,Xiaoming Yu,Tahidul Islam

doi:10.1186/s13065-017-0287-z

Abstract

BackgroundThe study on phytochemical difference between red and black goji berry is limited.MethodsAntioxidant activities and phenolic profiles in terms of total phenol content, total flavonoid contents, condensed tannin content, monomeric anthocyanin content, and total carotenoid content of red goji berry (Lycium barbarum) and black goji berry (L. ruthenicum) were compared using colorimetric assays.ResultsAll goji berries were rich in phenolics. Black goji berry had the highest phenolic, condensed tannin content and monomeric anthocyanin content. Black goji berry samples possessed higher antioxidant capacities than red goji berry, while the red goji berry had the highest carotenoid content. Goji berries exhibited a positive linear correlation between phenolic compounds and antioxidant capacities. The average value of carotenoid content in red goji berry was 233.04 µg/g.ConclusionThe phenolics and antioxidant capacities are much higher in black goji berry than red goji berry, while carotenoid content is much higher in red than black.

Highlights

The study on phytochemical difference between red and black goji berry is limited
Chemicals and reagents 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), Folin–Ciocalteu reagent, 2-diphenyl-1-picryhydrazyl (DPPH), potassium persulphate (K2S2O8), sodium carbonate, gallic acid, sodium hydroxide, sodium nitrite, sodium acetate, acetic acid, hydrogen chloride, 2,4,6-tri(2pyridyl)-s-triazine (TPTZ), ferric chloride, ferrous sulfate, aluminum chloride hexahydrate, (+)-catechin, 6-hydroxy2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), acetone, phosphate buffer saline (PBS), hydrogen chloride (HCl), potassium chloride (KCl), vanillin, methanol, butylated hydroxytoluene (BHT), potassium hydroxide, n-hexane was obtained from Sigma-Aldrich Co. (Shanghai, China)
Phenolic compounds in goji berry The highest total phenolic content (TPC) value was recorded as 9.01 mg GAE/g while the lowest TPC value was recorded as 2.17 mg GAE/g

Summary

Introduction

In the form of pure compounds or extracts with antioxidant activity, may help the endogenous defense system of the body [1]. As carcinogenic properties have been reported for some synthetic antioxidants, recent research on the potential applications of natural antioxidants from natural food products, for stabilizing foods against oxidation, have received much attention [2]. Antioxidant supplements or antioxidant containing foods may be used to help the human body to reduce oxidative damage or to Chinese traditional medicinal food goji berry is used for its anti-aging properties, tranquilizing and thirst quenching effects, as well as its ability to increase stamina. There are several clinical and experimental reports showing an anti-diabetic effect of Lycium barbarum as it is wellknown in traditional Chinese herbal medicine for diabetes.

Methods

Results

Discussion

Conclusion