A rapid method for determination of polar compounds in used frying fats and oils

Preparation of a Regioselective Quercetin-3-palmitate and Its Using for Boosting Cooking Oil Stability

Due to over worldwide use of frying oil, and due to its oxidation and deterioration after the usage for short time, huge oil amounts are wasted. So, most attempts are aimed to increase oil stability. Quercetin is a common name for the lipophobic strong natural phenolic antioxidant 2-(3,4-Dihydroxyphenyl)-5,7-dihydroxy-4H-1-benzopyran-4-one. Thus, its solubility had been improved by converting it to a lipophilic compound via its appending to a fatty acid residue. So, regioselectively 2-(3,4-Dihydroxyphenyl)-5,7-dihydroxy-3-[Hexadecanyl]oxychromen-4-one commonly named as (Quercetin-3-palmitate) was synthesized. The formed compound was confirmed based on its elemental analysis and spectral data (IR, ¹H NMR and MS). The partition coefficient of Quercetin-3-palmitate in octanol/water (k) was determined and compared to that of palmitic acid and quercetin individually to prove its solubility enhancement. Its radical scavenging activity was then tested. The effect of this new antioxidant compound on the oil stability was studied through the frying process. All physical and chemical parameters of this oil were considered before and after the frying process compared to another reference antioxidant (TBHQ) and control sample. The safety of this compound was determined by acute oral toxicity using albino mice. The liver and kidney functions of these mice were also examined. The results showed non-significant change. A sensory evaluation of the fried potato chips has been done. The results showed that the properties of the potato chips were improved by adding Quercetin-3-palmitate to the oil. Thus, good protection against frying oils oxidation was achieved via the addition of Quercetin-3-palmitate. The Quercetin-3-palmitate effectiveness is mainly attributed to its stability at high temperatures. Moreover, Quercetin-3-palmitate was found to be a safe compound according to an acute lethal toxicity test. Consequently, it can be used as a food additive.

The formation, determination and health implications of polar compounds in edible oils: Current status, challenges and perspectives

To effectively control the quality of edible oil, polar compounds in edible oils have been studied extensively in the past few decades, particularly in the field of frying. This article critically reviews the formation, determination, and health implications of the polar compounds in edible oils via comprehensive literature research. The challenges and perspectives of polar compounds in edible oils are also discussed. Three chemical reactions, including oxidation, hydrolysis, and polymerization, elaborate polar compound formation. Many techniques are used to determine the total polar compound content of edible oils, with comparative analysis; Fourier transform infrared technique is a relatively ideal method. A major obstacle for nutritional studies focused on polar compounds formed during frying is that few pure compounds have been quantified. To inhibit the formation of the polar compounds effectively, investigations into the applications of enzymatic method in developing new lipophilized antioxidants may be a new direction in research.