Study of Calcium and Sodium Behavior to Identify Milk Adulteration Using Flame Atomic Absorption Spectrometry

Poliana M Dos Santos,Edenir R Pereira-Filho,Lenon F B Costa

doi:10.4236/fns.2012.39161

Poliana M Dos Santos, Edenir R Pereira-Filho + Show 1 more

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https://doi.org/10.4236/fns.2012.39161

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Abstract

A fast and direct method for determination of milk adulteration by monitoring of calcium and sodium concentrations variations was described. Milk samples were furnished by a dairy company located at S?o Carlos (S?o Paulo State, Brazil) and and spiked with tap-water, whey, hydrogen peroxide, synthetic urine, urea and synthetic milk in the ranged from 5% to 50% (v/v), expect for caustic soda. Caustic soda was added in the milk until establish the original pH. The milk samples were analyzed by using flame atomic absorption spectrometry (FAAS) and no acid digestion process was required. Results showed a significant decrease in the Na and Ca concentrations with addition of synthetic milk and tap-water, a nonlinear variation with addition of synthetic urine, whey and hydrogen peroxide and a largest increase in the Na concentration with addition of NaOH. Correlation between Na and Ca concentrations in pure and adulterated milk were evaluated by paired t-test at a 95% confidence level. Results showed that the method proposed is efficient to identify samples adulterated with tap-water, caustic soda, synthetics milk and urine.

Highlights

Food adulteration is a common and serious problem in many countries [1,2,3,4]
Milk samples were furnished by a dairy company located at São Carlos (São Paulo State, Brazil) and spiked with tap-water, whey, hydrogen peroxide, synthetic urine, urea and synthetic milk in the ranged from 5% to 50% (v/v), expect for caustic soda
Mabrook et al and Sadat et al have investigated the use of single frequency electrical conductance measurements to detect the adulteration by addition of water and synthetic milk [14,15] and results obtained showed a significant difference in the conductance values from the pure to adulterated milk

Summary

Introduction

Food adulteration is a common and serious problem in many countries [1,2,3,4]. Liquid milk is one of the most serious problems for the dairy industry [5,6] and it is commonly adulterated by addition of water to increase the volume, neutralizers to mask acidity, salt or sugar to mask extra water, among others [7,8]. In Brazil, an experimental study to evaluate the milk authenticity showed the presence of at least one of adulterant studied (chlorine, formol, hydrogen peroxide and urine) in all samples analyzed [9]. In China, the addition of melamine in liquid and powder milk has resulted in numerous cases of renal complications in children and six deaths [10]. A new type of impedance sensor was developed to identify milk adulteration with tap-

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