Food Biochemistry and Food Processing (2 edition)

BLBS102-c01 BLBS102-Simpson March 21, 2012 11:8 Trim: 276mm X 219mm Printer Name: Yet to Come

20 Part 1: Principles/Food Analysis

Table 1.18.Naringenin Chalcone Biosynthesis

Enzyme Reaction

Phenylalanine ammonia-lyase (EC 4.3.1.5) l-phenylalanine→Trans-cinnamate+NH 3

Trans-cinnamate 4-monoxygenase (EC 1.14.13.11) Trans-cinnamate+NADPH 2 +O 2 →4-hydroxycinnamate+

NADP+H 2 O

4-Coumarate-CoA ligase (EC 6.2.1.12) 4-Hydroxycinnamate (4-coumarate)+ATP+CoA→

4-Coumaroyl-CoA+AMP+Diphosphate

Naringinin-chalcone synthase (EC 2.3.1.74) Naringinin chalcone+4CoA+3CO 2

Source: Eskin 1990, Croteau et al. 2000, IUBMB-NC Enzyme (www.iubmb.org).

biosynthesis. Considerable interest has been given to the stil-

bene trans 3,5,4′-trihydroxystilbene commonly called resvera-

trol in red grapes and red wine that may have human nutraceuti-

cal and/or pharmaceutical applications (Narayanan et al. 2009).

Table 1.19 summarises various phytochemicals and their sources

that are thought to confer health benefits (Gropper 2009).

Cholesterol

Cholesterol is an important lipid in animal biochemical pro-

cesses that controls the fluidity of membranes and is the precur-

sor for all steroid hormones. Cholesterol’s structure is made up

of adjacent carbon rings, making it hydrophobic (fat soluble),

and thus it must be transported through the blood complex as

a lipoprotein in structures called chylomicrons. The densities

of lipoproteins vary greatly; an excessive level of low-density

lipoprotein (LDL) is a critical risk factor for heart disease. In

contrast, plants produce related molecules called phytosterols,

which have various nutraceutical applications (Kritchevsky and

Chen 2005).

Terpenoids

Terpenoids, a diverse and complex chemical group, are lipid-

type molecules important to flavours and aromas of seasonings,

herbs and fruits. Most terpenoids are multi-cyclic compounds

made via successive polymerisation and cyclisation reactions de-

rived from the 5-carbon building block isoprene, which contains

two double bonds. Terpenoids are components of the flavour pro-

files of most soft fruit (Maarse 1991). In some fruit species, they

are of great importance for the characteristic flavour and aroma

Table 1.19.Phytochemicals and Their Sources

Phytochemical Source

Anthocyanins Cyanidin Berries, cherries, plums, red wine

Carotenoids β-carotene,α-carotene, lutein, lycopene Tomato, pumpkin, squash, carrot, watermelon,

papaya, guava

Flavanols Catechins, epicatechins Green tea, pear, wine, apple

Flavones Apigenin, luteolin Parsley, some cereals

Flavonols Quercetin, kaempferol, myricetin Onions, tea, olive, kale, leaf lettuce, cranberry,

tomato, apple, turnip green, endive,Gingko

biloba

Glucosinolates Gucobrassicin, gluconapin, sinigrin,

glucoiberin

Broccoli, cabbage, Brussels sprouts, mustard,

watercress

Isoflavones Genistein, daidzein, equol Soy, nuts, milk, cheese, flour, miso, legumes

Isothiocyanates Allylisothiocyanates, indoles, sulforaphane Broccoli, cabbage, Brussels sprouts, mustard,

watercress

Lignans Secoisolariciresinol, mataresinol Berries, flaxseed, nuts, rye bran

Organosulfides Diallyl sulphide, allyl methyl sulphide,

S-allylcysteine

Garlic, onions, leeks, broccoli, cabbage,

brussel sprouts, mustard, watercress

Phenolic acids Hydroxycinnamic acids (caffeic, ferukic,

chlorogenic, curcumin) and hydroxybenzoic

acids (ellagic, gallic)

Blueberry, cherry, pear, apple, orange,

grapefruit, white potato, coffee bean, St.

John’s wort,Echinacea, raspberry,

strawberry, grape juice

Phytosterols β-Sitosterol, campesterol, stigmasterol Oils: soy, rapeseed, corn, sunflower

Saponins Panaxadiol, panaxatriol Alfalfa sprouts, potato, tomato, ginseng

Terpenes Limonene, carvone Citrus fruits, cherries,Gingko biloba

Source: Adapted from Gropper et al. 2009.