Totox value

Solid Fat Index—Dilatometric Method (SFI) (Cd 10-57) estimates the percentage of solids in a semi-solid fat on the basis of changes in volume with temperature. This method utilizes glass dilatometers, and is the primary method in the United States. Totox Value an estimate of the degree of oxidation of a fat or oil, calculated as ... 

There are a number of analytical measures of oxidative deterioration of oils and fats. The most widely used are the peroxide value (PV) (15), which measures the hydroperoxide content by iodine titration and the anisidine value (AV) (15), which detects aldehydes by a color reaction. As an oil suffers damage because of autoxidation, the hydroperoxide content, and PV rise but do not do so indefinitely. As the hydroperoxides break down, the concentration of aldehydes and AV increase. Oxidation is better assessed by a combination of PV and AV, the Totox value... 

The Totox value is a measure of the total oxidation, including primary and secondary oxidation products. It is a combination of PV and p-AnV ... 

During lipid oxidation, it is often observed that PV first rises, then falls as hydroperoxides decompose (38). PV and p-AnV reflect the oxidation level at early and later stages of oxidation reaction, respectively. Totox value measures both hydroperoxides and their beakdown products, and provides a better estimation of the progressive oxidative deterioration of fats and oils (38). However, Totox value has no scientific basis because it is a combination of two indicators with different dimensions (7). Recently, Wanasundara and Shahidi used TEA values and defined TotoxjBA as 2PV + TEA using the TEA test in place of the p-AnV assay (60). 

Anisidine value. The p-anisidine value (p-AnV) measures the amount of unsaturated aldehydes in fats and oils. In this method, p-anisidine reacts with aldehydes in acetic acid to afford a yellowish color that is measured at 350 nm. The color intensity depends on the amount of aldehydes as weU as on their structure. The AOCS Method Cd 18-90 (22) has been standardized for anisidine value analysis. The Totox value, which is 2 PV + p-AnV, provides information about the current status of oxidation as well as its history and is used by the industry. 

Another processability factor is TOTOX value that is related to the degree of oil deterioration due to lipoxygenase action on polyunsaturated fatty acids in the oil (Mounts et al., 1990). Products of oxidation degrade flavor and stability of edible oils. A low TOTOX value <3.0 meq/kg is desirable. TOTOX was calculated as two times the peroxide value as determined by AOCS Method Ca9f-57 plus the anisidine value (AOCS, 1987). 

The totox value is defined as 2 x Peroxide value + Anisidine value. The induction period is usually measured by the Rancimat apparatus and expressed in hours. The induction period of unused oils is approximately 10 to 15 Rancimat hours. This period can be reduced to 1 to 2 hours in 1 or 2 days of commercial frying. 

The so-called TOTOX value has been used as an oxidative indicator, combining peroxide (POV) and p-anisidine values (PAV) as follows ... 

Although the totox value gives, somewhat a better, indication of the quality and rancidity of the oil, still it does always correlate well with sensorial observations, as it holds for both the POV and PAV... 

TMS ether derivatives, 280 Tobacco seed oil, 93, 94,165 Tocopherols, 138,161,271, 453, 455 Tomato, 44,458,459 Torulopsis Candida, 153,154 Totox value, 202 Trachycarpus fortunei, 79 Trading specifications for crude oils, 189 Tragopogon porrifolius, 20 Trans acids, 23,175,208, 348,470 Trans determination, 257 Transesterification, 212, 282, 478 Transition temperatures, 362, 367 Trehalose mycolate, bacterial lipids,... 

FIG U RE 11.3 Totox value in potato crisps during storage. 

FIGURE 11.4 Totox value in Berlin doughnuts during storage. 

Totox Value an estimate of the degree of oxidation of a fat or oil, calculated as Totox = 2(Peroxide Value) + Anisidine Value. 

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