Maize stable carbon isotope value

Figure 8.6 Frequency distribution (histograms) of stable carbon isotope ratio (SCIR) values for non-maize oils (open histograms) and maize oil (shaded histograms).

Table 8.8 Limits of detection of adulteration in maize oil by analysis of fatty acid composition (FAC), of stable carbon isotope ratio (SCIR), by the ratio, = 5 [IV/ ( C)f [where IV is the iodine value and is the SCIR calculated by means of equation (8.1) in text] and by gas...

In Chapter 8 a leading expert in the detection of adulteration of oils and fats, Rossell, explains the economic advantages which tempt unscrupulous dealers to add cheap oils to high-value oils such as olive oil. He then describes a technique which he and his coworkers at Bristol have pioneered where stable carbon isotope ratio (SCIR) measurement has simplified the task of detecting adulteration. He compares sterol and fatty acid methyl ester analysis with SCIR and shows how clearly the latter detects maize oil. 

Figure 14.12 Trends through time in the bulk stable isotope values of collagen (6I3C and 815N), apatite ( 13C) and compound specific 813C values of cholesterol recorded from a number of individuals from the Illinois River Valley, USA, showing contiguous fluctuations in carbon stable isotope composition consistent with differing contributions of maize to the diet (Jim, Ambrose and Evershed unpublished data)...

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