Heating effect on quality characteristics of mixed canola cooking oils

Abstract

Background The subcontinent is famous for its variety of seasonal foods cooked in vegetable seed cooking oils at elevated heating. Oils are often of poor quality that effect to consumer health. The work, therefore, planned to examine the effects of heat on the quality of mixed canola cooking oils (MCCOs). MCCOs were analyzed by preparing volatile fatty acid methyl esters (FAMEs) and for physiochemical properties. Results A major change was observed in the FAs composition of various MCCOs as coded K-1 to K-5. MCCOs were found rich in unsaturated 9-octadecanoic acid (oleic acid C18:1) and 9, 12-octadecadienoic acid (linoleic acid C18:2) along saturated octadecanoic acid (stearic acid C18:0). Results reveals that canola oil samples are mixed in the range of 4–30% with other vegetable oils and animal fats. The quality of canola cooking oils further reduced after heating to 100 °C, 200 °C and 350 °C, respectively. Quality parameters of MCCOs were significantly altered after heating and found as color (510–520 nm to 570–600 nm), mass 220–237 g to 210–225 g, volume 250 mL to 239 mL, pH (6.76–6.89), specific gravity (0.87–0.92), refractive index (1.471–1.475), saponification value (SV) (0.7–2.5), un-saponifiable matter (2.4–9.8%) and acid value (AV) (1.20–5.0 mg KOH). Conclusion Heating of oils at elevated temperature have shown a significant effect on pH, specific gravity and un-saponifiable matter (p-value < 0.05). Large changes in the physicochemical parameters and FAs composition help to develop a conclusion that cooking at high temperatures affects the quality of mixed canola cooking oils.

Comparative Study of Quality and Thermo-Oxidative Stability of Soybean, Palm Olein and Canola Oils with Their Blends

“…The increasing trend in SV of the oils reveals a significant variation due to triglycerides that transform into FFAs in the process of heating. This provides clear information that more FFAs may be generated, consequently raising the SV (Baig et al, 2022). The smaller SV change observed in POO under this heat treatment may be due to the presence of SFAs which prevent the development of FFAs.…”

“…It provides the information about the occurrence of microorganisms/pathogens, industrial/agricultural processing conditions and other variables. Darkening of oil color takes place because of thermal decomposition and oxidation of FAs during heat treatment in which nonvolatile disintegrated products and unsaturated α-, β-carbonyl compounds in the form of pigments could develop (Baig et al, 2022). Table 2 shows that as heating time increases, the oil color also starts to get dark.…”

Effective Improvement of the Oxidative Stability of Acer truncatum Bunge Seed Oil, a New Woody Oil Food Resource, by Rosemary Extract

“…Therefore, the level of oxidation rises and the viscosity of the oil increases. In addition, it is well known that oils deteriorate due to the effects of heating and oxidation [ 49 ]. This deterioration is accompanied by odours that worsen the cooking environment.…”

ROS-Induced DNA-Damage and Autophagy in Oral Squamous Cell Carcinoma by Usnea barbata Oil Extract—An In Vitro Study

“…When vegetable oils are heated at a high temperature, various chemical reactions (hydrolysis, oxidation, and polymerization) occur [ 116 ]. Previous studies proved that the natural antioxidants from herbs and spices could improve their oxidative stability [ 117 , 118 ].…”