The Effect Of Sunflower Oil Refining On Oil Stability And Other Quality Attributes

Tocopherol, commonly known as Vitamin E, is a fat soluble bioactive compoundwhich has been extensively used as antioxidant. It exerts various nutritional andphysiological functions to the human body. The antioxidant effectiveness of tocopherolsin reducing the formation of carcinogenic compounds, minimizing the risk of seriousdisease, such as cardiovascular, inflammatory, neurological disorders, cataract and age-related macular degeneration, as well as its role in the maintenance of the immune systemwas demonstrated.The present study aimed to investigate the effect of sunflower oil refining steps(Neutralization, Bleaching, Winterization and Deodorization) on total tocopherols content(VE), total fatty acids composition (TFA), free fatty acids (FFA), oil stability index (OSI),oil colours (LCY) and (LCR). The results revealed that during these steps deodorizationstep had significant effect on the quality attributes of sunflower oil.The effect of sunflower oil deodorization using short path distillation (SPD) comparedwith deodorization conventional method (DCM) on trans fatty acids formation, FFA,OSI, VE, LCY and LCR was investigated. The results revealed that with increasingtemperature (180-240) C the content of tocopherols and other quality attributes weredecreased. However there was no formation of trans fatty acids even with highesttemperature (240C), although at this temperature the overall loss of FFA was96%, oilstability was 27.5%, total tocopherols was78%, LCR and LCY were88%and95%respectively.While these above quality attributes during the deodorization conventional method(DCM) in range of temperature (180-240) C were decreased by94%in term of FFA,9.4%in case of OSI, and the overall loss of VE was29.3%, LCR and LCY were90%and96%respectively. However,0.58%formation of trans fatty acids was observed.When the effect deodorizing conventional method on basic quality attributes of sunfloweroil (FFA, OSI, VE, LCY and LCR) was investigated, it was observed that the contents ofall these quality attributes decreased during the deodorizing step (P<0.05). Theprocessing parameters of sunflower oil deodorization (time and temperature) wereoptimized using response surface methodology (RSM). Time and temperature influencedthe quality of sunflower oil (FFA, OSI, VE, LCY and LCR) were decreased as time andtemperature increased (P<0.05). Based on the optimization of high oil stability withminimum retained FFA and colour, deodorization parameters can be defined. At aconstant vacuum3mm Hg vacuum, a temperature range of (200-250) C anddeodorization time of (30-90) min were defined.(218-224) C and (59-64) min appears tobe an optimum temperature and time respectively. In this area, the deodorized sunfloweroil has excellent organoleptic value, the retentions of total tocopherols are above570.69ppm the residual FFA content is below0.05%, maximum oxidative stability is2.58h,LCY and LCR are2.31and0.59respectively.