Use of some agricultural waste hull ashes for the regeneration of fried sunflower oil

Abstract

SummaryThe present study was aimed at improving the quality of fried sunflower oil. Synthetic (Magnesol XL), natural (diatomaceous earth) and hull ashes of rice, wheat and barley (agriculture plant wastes) were used to adsorb the oxidation products of fried sunflower oil. The mineral pattern (Si, Mg, Ca, Fe, Al, Mn and Cu) of the aforementioned substances were determined. The physico-chemical properties [refractive index, viscosity, colour, smoke point, acid value, peroxide value, thiobarbituric acid (TBA) value, conjugated dienes and trienes, polar content, polymer content and oxidised fatty acids] of non-fried, fried and fried-treated sunflower oil were determined. The frying process was carried out at 180°C ± 5°C for 20 h, 4 h heating cycle per day for five consecutive days. The fried sunflower oil was treated with synthetic, natural and agricultural hull ashes at 105°C for 15 min. The results indicate that Magnesol XL, diatomaceous earth, rice hull ash, wheat hull ash and barley hull ash contained Si + Mg + Mn, Si + Mn + Ca, Si + Mn, Si +Mn and Mn + Si as the basic metals, respectively. Frying of sunflower oil led to significant increase in refractive index, viscosity, colour, smoke point, acid value, peroxide value, TBA value, conjugated dienes and trienes, polar content, polymer content, and oxidised fatty acids and decrease in iodine value. Treatments of fried sunflower oil with the aforementioned substances greatly improved the quality of fried oil. Under the present experimental conditions all adsorbing substances performed similarly in removing the fried sunflower oil oxidation products.

Changes in Quality Characteristics of Different Deep Frying Fats During Frying and Regeneration Potentials of Different Adsorbents in Wasted Frying Oils

“…On the other hand, a previous study indicated a better reducing effect of SMS for model sunflower oil which had been obtained by heating to 180°C for 4h without food. This study indicated a decrease in TPM from 19 % to 4 %, while TPM reducing effect of SMS didn't show any difference with diatomaceous earth, rice hull ash, wheat hull ash and barley hull ash, likewise results obtained in our study [22]. Also another study showed that SMS can reduce TPM content from 11% to 4.3% when the SMS amount was approximately 2% of wasted oil [13].…”

“…This can be explained by the equilibrium concentration of FFA content for adsorption to SMS which is approximately 0.3% in our study. In a previous study, FFA reducing effect of SMS as a filter aid was studied and nearly 50 % of reduction was achieved during filtration of model sunflower oil [22].…”

Dry washing in biodiesel purification: a comparative study of adsorbents

“…[22][23][24] The textural characteristics of the silica and Magnesol ® were investigated using N 2 isotherms, which are presented in Figure 1. The Magnesol ® adsorption curve is a typical "type I" isotherm, characteristic of microporous materials, where the main adsorption occurs at low relative P/P 0 pressures.…”

Agricultural Wastes

“…Synthetic (Magnesol XL), natural (diatomaceous earth) and agricultural plant wastes (hull ashes of rice, wheat and barley) were used to absorb the oxidation products of fried sunflower oil to improve the quality of the oil (Farag et al, 2009 Batch experiments were conducted to examine the effects of using pineapple stem waste as low-cost adsorbent to remove methylene blue from aqueous solutions by adsorption at 30 °C . It was found that the maximum monolayer adsorption capacity was 119.05 mg g -1 .…”