Effectiveness of modified zeolites as adsorbent materials for frying oils

Abstract

Natural zeolite was modified by four different techniques namely using Tween80, β‐cyclodextrine and olive mill waste water at RT and hydrochloric acid at 110°C, and then modified zeolites were used as adsorbent materials in six consecutive days dough frying with refined hazelnut oil. Some parameters in the oil samples of control and experimental groups were measured and the ranges were determined as following; total polar materials (TPM)‐chromatography (4.09–70.22%), free acidity (0.16–1.19%), smoke point (221.50–184.00°C), conjugated dienoic acids (0.36–2.19%), L value (35.65–52.15), a* value (−0.18–5.98), b* value (−3.73–10.40), turbidity (0.70–10.40 NTU), viscosity (67.67–825.50 cP), and oil absorbed by the dough (5.10–8.85%). The results of this study have shown that both natural zeolite and modified zeolites have different level of activities as frying oil adsorbent materials. The best results were achieved with Tween80 modified zeolite for the TPMs, free acidity, instrumental color values, smoke point, and conjugated dienoic acid measurements. Similarly better result for turbidity was with olive mill waste water modified zeolite and for viscosity was with hydrochloric acid modified zeolite. It was determined that adsorbent treatment did not affect fat absorption level of fried dough.Practical applications: The results of this study have shown that natural zeolite modification with different techniques can improve its adsorption capacity significantly. In this respect, utilization of modified zeolite for frying oil recovery applications can be an industrially sound practice since natural zeolite is a very cheap and easily found material.

Regeneration of Used Frying Oils by Selected Metal–Organic Frameworks as Adsorbents

“…The slurry was mixed at 80°C for 1.5 h in an orbital shaker at 250 rpm speed. The parameters of the treatment were chosen by justification of previous literature (Bulut and Yilmaz, ; Dülger and Yılmaz, ; Ismail et al, ; Nayak et al, ; Turan and Yalcuk, ; Udomkun et al, ) and commercial application routines to clearly observe the specific effects of each adsorbent. Finally, treated oil was filtered through Whatman no.…”

“…Refractive indices of the samples were measured using the Abbe 5 (Bellingham and Stanley, UK) refractometer at 25°C. Turbidity values of the samples were read with the Hach 2100 AN Turbidimeter (USA) at 25°C (Aydeniz and Yilmaz, , ; Dülger and Yılmaz, ).…”

“…To prolong frying oil life cycle and/or to regenerate used frying oils, different efforts have been taken. Usually, starting with suitable and good quality frying oil, cleaning and maintenance of equipment, applications of proper frying conditions, frying under vacuum or a neutral gas atmosphere, usage of oil dilution techniques, addition of natural additives into frying oil, and application of passive and active filtration have been sought by the industry (Aydeniz and Yilmaz, , ; Bhattacharya et al, ; Blumenthal, ; Bulut and Yilmaz, ; Choe and Min, ; Dülger and Yılmaz, ; Udomkun et al, ). Active filtration, one of the most common treatment techniques, is based on mixing used frying oil with an adsorbent material to selectively adsorb polar materials, free fatty acids (FFA), oxidized compounds, dimers and polymers, and other particles to remove from oil by filtration to regenerate the oil to extend its shelf life.…”

“…Active filtration, one of the most common treatment techniques, is based on mixing used frying oil with an adsorbent material to selectively adsorb polar materials, free fatty acids (FFA), oxidized compounds, dimers and polymers, and other particles to remove from oil by filtration to regenerate the oil to extend its shelf life. Quite diverse adsorbent materials including activated carbon, diatomaceous earth, clays, aluminum hydroxides, charcoal, ceramics, silicas, zeolites, magnesium oxide, oyster shell, elephant apple powder, coffee silverskin, and many more have been searched for frying oil regeneration purpose (Bhattacharya et al, ; Bulut and Yilmaz, ; Choe and Min, ; Dülger and Yılmaz, ; Ismail et al, ; Nayak et al, ; Turan and Yalcuk, ; Udomkun et al, ).…”

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

“…Synthetic magnesium silicate is an amorphous, insoluble white powder with a high specific surface area and is widely used as an analytical and industrial adsorbent and as an adsorbent to regenerate frying oils and purify biodiesel [12,13]. Many different adsorbent materials including activated carbon, clay, aluminum hydroxides, char-coal, celite, silica gel, silicon dioxide, and some other adsorbents have been, also, studied for this purpose [14].…”