Chemical and Functional Properties of Food Saccharides

© 2004 by CRC Press LLC
6.3.2.2 Organic Acids
Organic acids contribute substantially to the characteristic flavor of honey. They
enrich and diversify the taste of honey varieties. Experienced honey tasters can detect
the adulteration even with a 20% admixture of bee-inverted sucrose. 7 Butyric, acetic,
formic, lactic, succinic, folic, malic, citric and gluconic acids have been identified
in honey, the last two being the main acids. Gluconic acid is the product of specific
catalytic oxidation of D-glucopyranose with glucose oxidase, a honey flavoprotein
enzyme. Glucolactone, which results from the oxidation, readily hydrolyzes into
gluconic acid. 8 In this oxidase-mediated oxidation, a strongly antibacterial hydrogen
peroxide is formed.
6.3.2.3 Mineral Substances
Potassium, magnesium, sodium, calcium, phosphorus, iron, manganese, cobalt, copper
and some other elements have been identified in honey by spectral analysis.
Potassium was found to be a major element in honey, the content of which exceeded
that of other elements by several orders. A high correlation was also found between
potassium and magnesium content. 9 Mineral salts, organic acids, and amino acids
in honey dissociate, making honey an electrolyte. The standardization requires
measurements for 20% honey solutions (on dry weight basis) at 20°C. The unit of
specific conductivity is millisiemens per centimeter (mS/cm). 10,11 Typical conductivity
of honey ranges from 0.09 to 1.4 mS/cm, but for chestnut honey a value of
2.07 mS/cm has been found. 12
6.3.2.4 Dyes and Other Components
Honey dyes belong to carotenoids, flavones, and anthocyanines (Table 6.2). The
levels of the β-carotenoids (µg/100 g) in particular honey varieties are as follows:
rapeseed honey, 4.18–8.45; linden honey, 19.25–183.07; buckwheat honey,
1.49–7.34; multifloral honey, 1.49–10.44; honeydew honey, 3.44–13.06.
Honey is poor in vitamins. Only some varieties such as heather honey and
honeydew honey contain traces of vitamins A, B2, C, B6, and PP.
About 80 aromatic compounds have been detected in honey, including carboxylic
acids, aldehydes, ketones, alcohols, hydrocarbons, and phenols. They also contribute
to the organoleptic properties of honey. 13
6.4 HONEY ADULTERATION AND POSSIBILITIES OF
DETECTION
Despite improved methods to determine the quality of honey, any evaluation of
various forms of honey adulteration presents a difficult task. The ratio of natural
carbon isotopes, 13 C and 12 C, in the nectar of honey plants and in sugars of maple
and sugar cane syrup is entirely different. 14 It allows the detection of honey adulteration
by feeding those syrups to bees. A modification of this method allows
detection of a 7% admixture of enzymatically hydrolyzed sucrose; however, this