2009_Book_FoodChemistry

888 19 Sugars, Sugar Alcohols and Honey
ble 19.13), hence this enzyme is not a suitable indicator
of the thermally treatment of honey.
Catalase in honey most probably originates from
pollen which, unlike flower nectar, has a high activity
of this enzyme. Similarly, honey acid phosphatase
originates mainly from pollen, although
some activity comes from flower nectars.
19.2.1.5.4 Proteins
Honey proteins are derived partly from plants and
partly from honeybees. Figure 19.14 shows that
bees fed on sucrose provide proteins with less
complex patterns than, for example, cottonflower
honey.
19.2.1.5.5 Amino Acids
Table 19.15. Free amino acids in honey
Amino mg/100 g Amino mg/100 g
acid honey (dry acid honey (dry
weight basis)
weight basis)
Asp 3.44 Tyr 2.58
Asn + Gln 11.64 Phe 14.75
Glu 2.94 β-Ala 1.06
Pro 59.65 γ-Abu 2.15
Gly 0.68 Lys 0.99
Ala 2.07 Orn 0.26
Cys 0.47 His 3.84
Val 2.00 Trp 3.84
Met 0.33 Unidentified
Met-O 1.74 AA ′ s (6) 24.53
Ile 1.12
Leu 1.03
Arg 1.72
Total 118.77
Honey contains free amino acids at a level of
100 mg/100 g solids. Proline, which might originate
from bees, is the prevalent amino acid and is
50−85% of the amino acid fraction (Table 19.15).
Based on several amino acid ratios, it is possible
Fig. 19.15. Regional origin of honey as related to its
amino acid composition. (according to White, 1978)
Honey origin: △ Australia, • Canada, United States
(clover), ◦ Yucatan
to identify the geographical or regional origin of
honeys (Fig. 19.15).
Fig. 19.14. Protein profiles of two honey varieties as revealed
by gel filtration on Sephadex G-200. (a) Cottonflower
honey (b), honey from sugar-fed bees (according
to White, 1978)
19.2.1.5.6 Acids
The principal organic acid in honey is gluconic
acid, which results from glucose oxidase activity.