Feasibility study about the use of element profiles determined by ED-XRF as screening method to authenticate coconut sugar commercially available

Tereza Zdiniakova,María Beatriz De La Calle

doi:10.1007/s00217-020-03559-z

Tereza Zdiniakova, María Beatriz De La Calle

Open Access

https://doi.org/10.1007/s00217-020-03559-z

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Abstract

Financial gain is a main driver for committing food fraud and replacement of ingredients with cheaper alternatives is an easy way to do it. Coconut sugar is becoming popular as an alternative to beetroot or cane sugar due to its high mineral content and lower glycaemic index. As its market price is about twice as high as that of conventional sugar, coconut sugar may become target to fraudulent manipulation. The present work explores the feasibility of using energy-dispersive X-ray fluorescence as a screening tool to verify its authenticity. Mass fractions of P, Cl, S, K, Ca, Fe, Cu, Br, Rb, and Sr determined in eleven coconut, ten cane, and one beetroot sugar samples, purchased in Belgian, Spanish, Polish, and Italian supermarkets were used for discriminating the different sugars. On average, the mass fractions of all the mentioned elements were higher in coconut than in cane and beetroot sugars. Multivariate analysis of the elemental fingerprint by Soft Independent Modelling of Class Analogies was used for authentication purposes. Models constructed were characterised by zero false positives; three coconut sugars (27%) could not be classified as such, neither as cane sugars.

Highlights

The expression “food fraud” covers a set of malpractices aiming at deceiving consumers to increase financial profit as reflected in the definitions given by several organisations [1].Substitution of expensive products by cheaper ones is an easy way to achieve economic benefit and it is one of the main types of food fraud.Palm sugars are natural sugars obtained from the sap or nectar of the flowers of several species of palms: sugar palm (Arenga pinnata), palmyra palm (Borassus flabellifer), nipa palm (Nypa fruticans), and coconut palm (Cocos nucifera) [2]
The beetroot sugar was produced in the EU, no information about geographical origin was given for three cane sugars, four coconut sugars were produced in Indonesia, two cane sugars in the Antilles, and one cane sugar in Latin America, according to their labels
One of the reasons why the price of coconut sugar is higher than that of cane and beetroot sugars is the claim that it contains higher levels of essential elements

Summary

Introduction

The expression “food fraud” covers a set of malpractices aiming at deceiving consumers to increase financial profit as reflected in the definitions given by several organisations [1]. Other approaches have been applied to detect adulteration of sugars Nine different parameters, such as pH, reducing sugars, titratable acidity, and others, were used to detect adulteration of palm sugar [17] and trace-element fingerprints obtained by inductively coupled plasma-mass spectrometry (ICP-MS) has been used to control the authenticity of organic cane sugar [13]. Rodushkin et al [16] characterised raw and refined cane and beetroot sugars using different analytical approaches, Atomic Emission Spectrometry-Inductively Coupled Plasma (AES-ICP), mass spectrometry-ICP (MS-ICP), and thermal ionization MS (TIMS); the concentrations of most elements were higher in raw than in refined sugars. The multivariate evaluation by Soft Independent Modelling of Class Analogies (SIMCA), of the elemental fingerprint of coconut, cane, and beetroot sugars obtained by ED-XRF, was used to classify coconut sugars

Materials and methods

Results and discussion

Conclusions

Compliance with ethical standards