Falade Ayodeji Osmund, Oboh Ganiyu
Functional Foods and Nutraceuticals Unit, Department of Biochemistry, Federal University of Technology, PMB 704, Akure 340252, Nigeria.
Int J Food Sci. 2015;2015:806524. doi: 10.1155/2015/806524. Epub 2015 Mar 3.
This study sought to investigate the effect of thermal oxidation on the physicochemical properties, malondialdehyde, and β-carotene content of arachis oil. Pure arachis oil was heated for 20 mins with a corresponding temperature of 220°C. Thereafter, changes in the physicochemical properties (acid, iodine, and peroxide values) of the oil samples were determined. Subsequently, the level of lipid peroxidation was determined using change in malondialdehyde content. Then, the total carotenoid and β-carotene contents were evaluated using spectrophotometric method and high performance liquid chromatography, respectively. The results of the study revealed a significant increase (P < 0.05) in the acid and peroxide values and malondialdehyde concentration of the heated oil when compared with the fresh arachis oil. In contrast, a significant decrease (P < 0.05) was observed in the iodine value, total carotenoid, 13-cis-, 15-cis-, trans-, and 9-cis-β-carotene, and total β-carotene content of the heated oil. Hence, thermal oxidation induced lipid peroxidation and caused changes in the physicochemical properties and carotenoid contents of arachis oil, thereby reducing its nutritive value and health benefit. Therefore, cooking and frying with arachis oil for a long period might not be appropriate as this might lead to a loss of significant amount of the insignificant β-carotene in arachis oil.
本研究旨在探讨热氧化对花生油理化性质、丙二醛及β-胡萝卜素含量的影响。将纯花生油在220°C的相应温度下加热20分钟。此后，测定油样的理化性质（酸值、碘值和过氧化值）变化。随后，利用丙二醛含量的变化测定脂质过氧化水平。然后，分别采用分光光度法和高效液相色谱法评估总类胡萝卜素和β-胡萝卜素含量。研究结果显示，与新鲜花生油相比，加热后油样的酸值、过氧化值和丙二醛浓度显著增加（P<0.05）。相反，加热后油样的碘值、总类胡萝卜素、13-顺式、15-顺式、反式和9-顺式β-胡萝卜素以及总β-胡萝卜素含量显著降低（P<0.05）。因此，热氧化会引发脂质过氧化，并导致花生油的理化性质和类胡萝卜素含量发生变化，从而降低其营养价值和健康益处。所以，长时间用花生油烹饪和油炸可能不合适，因为这可能会导致花生油中大量重要的β-胡萝卜素流失。
