Honey - Sweeteners: Nutritional Aspects, Applications, and Production Technology - page 131

table 5.7 average Values of physical properties of honey at 20°C

physicochemical properties Value
Speciic weight (moisture 17%) 1.425(kg/L)
Speciic gravity 1.423 kg
Speciic heat (moisture 17%) (0.57 cal/g°C (1.825 kJ/Kg°C)
Thermal conductivity 130 × 10 −5 cal/cm s°C
Viscosity at 25°C, 16% H 2 o, clover 90.0 poise
Freezing point −1.42°C to −1.53°C (15% honey solution)
−5.8°C (68% honey solution)
Refractive index 1.490
Sugars (Brix) 81.5
Sourness (acidity) Fairly low (pH 3.9)
Color—Pfund color scale (mm) Water white <8 to Dark amber >114
Source: Adapted from National Honey Board, Storage and usage of tips for honey. Nature's Simple
Sweetener. http://www.honey.com/images/downloads/broch-honey-simpliied.pdf , 2011; White,
J.W., 1992; Krell, R., Value-Added Products from Beekeeping: FAO Agricultural Services
Bulletin No. 124 , Food and Agriculture organization of the United Nations, Rome. http://www
.fao.org/docrep/w0076E/w0076e04.htm , 1996.

Researchers on honey composition and its dielectric properties claim salts and amino acids
couldberesponsibleforhoney'saddedmicrowavereactivityinfoodapplications.Studiesonthe
penetrationdepthofhoneyindicatethatthepenetrationdepthfallsunder1cminbakedgoodswith
lessthan55%honeysolidsanddecreasesastheconcentrationofhoneysolidsincreases.Theloss
factordecreasestoalmosthalfthevalueasthetemperatureincreasesfrom20°Cto65°Cina50%
aqueoussolutionofhoneyat2400MHz,whilethedielectricconstantremainsthesameastempera-
turechanges(Figure5.1).Tables5.8and5.9showdataondielectricpropertiesforvarioushoney-
based compositions and different dilutions (National Honey Board 2011c; Guo et al. 2011a). The
unitsforpenetrationdepth,absorption,andconductancearecentimeters,Napierpercentimeter,and
siemenspermeter,respectively.
Therearenotmuchpublisheddataontheabovedielectricpropertiesofhoney,buthoneyismore
microwavereactivethanothersimilarsyruptypes,forexample,high-fructosecornsyrup(HFCS)
andothersugarsolutions.Inmicrowavebakingand/orcooking,itispreferableforthefoodstuffs
tobecircular,withathicknesslessthan1cmandadiameterequaltomultiplesof112wavelength
(Cuietal.2008).

50

45

40

35

30

25

20

15

10

Dielectric constant
Loss factor

5

0

20 40 60 80 100

Temperature - °C

Figure 5.1 Temperature dependence of dielectric properties of honey. (Data from National Honey Board,

Different white technical papers, http://www.honey.com/nhb/technical/technical-reference/ , 2011.)