Review of rapid tests available for measuring the quality changes in frying oils and comparison with standard methods.
Repeated use of oils and fats for frying of food brings about many changes in their physical and chemical properties. Due to increasing health concerns, the assessment of the quality of reused oils has received much attention, since such assessment is useful in determining the discarding point of the oils. The official analytical methods used in laboratories for this purpose need skill, time, and a large consumption of solvents. To make the oil testing simpler, several rapid test kits have been developed based on either physical parameters (such as viscosity or dielectric changes) or chemical parameters (such as free fatty acids, oxidized fatty acids, or carbonyl compounds). These test kits usually comprise a portable instrument or colorimetric reaction sticks, capable of providing a direct or indirect measurement of a single parameter. The review presented in this paper evaluates the use of such rapid test kits and highlights the need to develop multi-parameter test kits in order to establish the quality of reused oil and the point at which it should be discarded. The review also encompasses pertinent details on the standard analytical methods, and deterioration of frying oils that occur during and after their use and the associated health consequences.
Bansal
Geeta
G
Food Science and Technology Programme, c/o Department of Chemistry, National University of Singapore, Singapore.
Zhou
Weibiao
W
Barlow
Philip J
PJ
Joshi
Pranav S
PS
Lo
Hui Ling
HL
Chung
Youne Kow
YK
D000818:Animals; D003124:Colorimetry / Q000295:instrumentation / Q000379:methods; D005227:Fatty Acids / Q000032:analysis; D005504:Food Analysis / Q000295:instrumentation / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D005511:Food Handling / Q000379:methods; D006358:Hot Temperature; D009821:Oils / Q000009:adverse effects / Q000737:chemistry*; D010084:Oxidation-Reduction; D011786:Quality Control; D011934:Reagent Strips; D014783:Viscosity
D005227:Fatty Acids; D009821:Oils; D011934:Reagent Strips