Food Biochemistry and Food Processing (2 edition)

BLBS102-c37 BLBS102-Simpson March 21, 2012 14:15 Trim: 276mm X 219mm Printer Name: Yet to Come

37 Natural Food Pigments 713

Basic flavylium ion

Malvidin

Petunidin

Peonidin

Delphinidin

Cyanidin

Pelargonidin

Figure 37.6.Structures of common anthocyanins.

increase in the level of GAD is useful not only because of the

formation of GABA, but also because it can maintain insulin pro-

duction in people with type 1 diabetes (Ludvigsson et al. 2008).

Petunidin, delphinidin, and malvidin can also inhibit glycerol de-

hydrogenase, a key enzyme in glycerolipid metabolism (Carpen-

ter et al. 1967), and malate dehydrogenase that participate in both

the tricarboxylic acid (TCA) cycle (i.e., the dehydrogenation of

malate to oxaloacetate) and in gluconeogenesis (i.e., the synthe-

sis of glucose from noncarbohydrate carbon sources) (Carpenter

et al. 1967). Thus, by inhibiting malate dehydrogenase, antiox-

idants also act indirectly to regulate gluconeogenesis.

Measurement of Anthocyanins

Several methods have been reported for the measurement of an-

thocyanins in samples. These include spectrophotometric pro-

cedures for measuring anthocyanins in wines (Cliff et al. 2007),

and the use of HPLC and ultra performance liquid chromatogra-

phy to measure the pigment levels in food samples (Hosseinian

and Li 2008). Other procedures for measuring anthocyanins in-

clude pH-differential measurements (Giusti and Wrolstad 2001)

and FTIR (Soriano et al. 2007).

FLAVONOIDS

Properties, Structures, and Functions

The term flavanoids is used here to refer to a family of com-

pounds produced by plants that are sometimes referred to as

anthoxanthins. They are water soluble but have lower coloring

power compared to the anthocyanins or anthocyanidins; they

range in color from colorless to shades of yellow, and they