Physico-Chemical Characteristics and Level of Some Selected Metal in Edible Oils

Abstract

The physico-chemical properties and level of some essential metals of four edible oils, two imported (Viking and Avena) and two processed in Ethiopia (Selam and Nur) oil samples, were analyzed using classical wet chemical method and flame atomic absorption spectroscopy techniques, respectively. The result of physico-chemical properties shows that acid value in Avena and Viking oils which is <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mn fontstyle="italic">0.091</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.0042</mml:mn><mml:mo> </mml:mo></mml:math>mgKOH/g and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mn fontstyle="italic">0.082</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.0047</mml:mn><mml:mo> </mml:mo></mml:math>mgKOH/g, respectively, from palm oil variety and in Selam and Nur oils <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mn fontstyle="italic">0.276</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.0056</mml:mn><mml:mo> </mml:mo></mml:math>mgKOH/g and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mn fontstyle="italic">0.188</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.0050</mml:mn></mml:math> mgKOH/g, respectively, from noug oil variety, saponification value in Avena and Viking oils which is <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M5"><mml:mn fontstyle="italic">190.27</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">3.528</mml:mn></mml:math> mgKOH/g and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M6"><mml:mn fontstyle="italic">189.80</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">3.528</mml:mn></mml:math> mgKOH/g, respectively, and in Selam and Nur oils <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M7"><mml:mn fontstyle="italic">187.00</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">5.668</mml:mn></mml:math> mgKOH/g and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M8"><mml:mn fontstyle="italic">143.05</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">8.527</mml:mn></mml:math> mgKOH/g, respectively, iodine value in Viking and Avena oils which is <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M9"><mml:mn fontstyle="italic">97.545</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.6345</mml:mn></mml:math> g and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M10"><mml:mn fontstyle="italic">53.807</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">1.0150</mml:mn></mml:math> g, respectively, and Nur and Selam oils <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M11"><mml:mn fontstyle="italic">116.410</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.3863</mml:mn></mml:math> g and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M12"><mml:mn fontstyle="italic">88.153</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.5300</mml:mn></mml:math> g, respectively, and peroxide value in Viking and Avena oils which is <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M13"><mml:mn fontstyle="italic">1.413</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.0808</mml:mn><mml:mo> </mml:mo></mml:math>meq/kg and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M14"><mml:mn fontstyle="italic">1.233</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.0305</mml:mn><mml:mo> </mml:mo></mml:math>meq/kg, respectively, from palm oil variety and in Selam and Nur oils <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M15"><mml:mn fontstyle="italic">0.893</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.0503</mml:mn></mml:math> meq/kg and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M16"><mml:mn fontstyle="italic">1.460</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.0600</mml:mn></mml:math> meq/kg, respectively, from noug oil variety were obtained. The level of essential metals in edible oil samples was analyzed after wet digestion. The results show that levels of Cu in Viking and Avena oils that were <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M17"><mml:mn fontstyle="italic">0.62</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.022</mml:mn></mml:math> mg and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M18"><mml:mn fontstyle="italic">0.28</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.004</mml:mn></mml:math> mg, respectively, and in Selam and Nur oils <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M19"><mml:mn fontstyle="italic">0.86</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.003</mml:mn></mml:math> mg and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M20"><mml:mn fontstyle="italic">0.42</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.005</mml:mn></mml:math> mg, respectively, and the levels of Zn in Viking and Avena oils that were <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M21"><mml:mn fontstyle="italic">1.58</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.154</mml:mn></mml:math> mg and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M22"><mml:mn fontstyle="italic">1.27</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.255</mml:mn></mml:math> mg, respectively, and in Selam and Nur oils <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M23"><mml:mn fontstyle="italic">1.19</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.160</mml:mn></mml:math> mg and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M24"><mml:mn fontstyle="italic">1.47</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">0.567</mml:mn></mml:math> mg, respectively, were obtained. The physico-chemical properties and level of essential metal revealed that four edible oils were acceptable to human consumption.