Quality characteristics of physically refined soyabean oil: effects of pre‐treatment and processing time and temperature

Abstract

Conventional alkali refining of edible oils is being replaced progressively by physical refining, which offers improved yields, reduced processing times and few by-product problems. The variables involved in physical refiningpre-treatment, processing time and processing temperature-have been studied on a laboratory scale for the refining of soyabean oil, and related to the quality characteristics of the refined products. The best results are obtained with phosphoric acid degummed, partially bleached oil processed at up to 250°C for not more than 2 hr. Higher temperatures and longer times lead to quality defects such as loss of stability, increased viscosity, darkening and chemical changes reflected in reduction of iodine value and increase in free fatty acids.

Seed Oil ofMorinda citrifoliaL. as a Surfactant for Deinking Flotation

“…Long saturated hydrocarbons can be produced if fatty acids have been exposed to hightemperature surfaces such as the bottom of an extraction flask. This explains the findings in previous studies of soya bean oil that high temperature and longer refining times lead to the reduction of unsaturation [16]. These results also indicate that different methods of extraction produce different compositions of FAMC.…”

“…The amount of omega-3 decreases sharply as extraction proceeds and temperature is raised [15]. Research into the refining process of soya bean oil indicates that temperatures higher than 250 ∘ C and refining time longer than 2 h lead to quality defects such as loss of stability, increased viscosity, darkening, and chemical changes reflected in reduction of the iodine value (loss of unsaturation) and increase in free fatty acids [16].…”

Grape seed oil deacidification by molecular distillation: Analysis of operative variables influence using the response surface methodology

“…Physical refining has many advantages: oil yield is increased, fatty acid recovery is more direct, effluents are minimized, process time is reduced and capital investment costs are lower. However, it is necessary to make a proper pretreatment of the crude oil before the deacidification step in order to remove components such as phospholipids, heavy metals, pigments and waxes that would adversely affect the operation (Jawad, Kochhar, & Hudson, 1983).…”

How Variation of Turbidity of Bleached Oils Characterizes Purity Oil and Bleaching Processes

“…Various minor components of vegetable oils will have a significant impact on soy oil oxidative stability, and the amount of these various minor components decreases as degree of processing increases (Jain et al, 2008a(Jain et al, , 2008b. The reason for refining vegetable oils is to remove substances that reduce oil quality (Jawad, 1983). The steps of refinement are degumming, bleaching, winterizing, steam distillation, neutralizing, and deodorizing (Hoffman, 1989).…”