HONEY, ANALYSIS OF 
465 
latter in water and make up to a definite 
volume. If the alcohol precipitate weighs 
as much as 0.5 gram, the volume should be 
50cc.; from 0.5 to 1.0 gram, it should be 
lOOcc.; from 1.0 to 1.5 grams 150cc. and 
so on. Determine the sugars in aliquots 
from the filtered solution of the alcohol 
precipitate, both before and after inver¬ 
sion. The total alcohol precipitate less the 
weight of invert sugar and sucrose gives 
the weight of dextrin, from which the per 
cent can be obtained. 
REDUCING SUGARS. 
Take lOcc. of the solution used for the 
immediate polarization determination (see 
later) before inversion and make up to 
250cc. in a flask with water. Use 25cc. 
for reduction according to Allihns’ method. 
Calculate the results expressed as dextrose 
to invert sugar by the factor 1.044. If 
Munson and Walker’s method is used for 
reducing sugar determination, use 25ce. of 
the above sugar solution and 25cc. off 
water. Allihns’ method and also Munson 
and Walker’s method are given in detail 
in the Official Methods of the Association 
of Agricultural Chemists, in various hand¬ 
books for sugar chemists, such as Browne’s, 
Spencer’s, and in most works on food an¬ 
alysis as Leach’s, etc. 
SUCROSE. 
Determine the total sugars after inver¬ 
sion by transferring lOcc. of the 55ee. 
solution (see .later) used for the invert 
polarization to a 250cc. flask and making 
up to the mark with water. Take 25cc. 
for a reduction by either Allihns’ or Mun¬ 
son and Walker’s method. Calculate to 
per cent invert sugar. Subtract the per 
cent of invert sugar before inversion from 
this figure and multiply the difference by 
the factor 0.95 to obtain the per cent of 
sucrose. The percentage of sucrose cannot 
be determined accurately from the polari¬ 
zations. 
POLARIZATIONS. 
Transfer 26 grams of honey to a lOOcc. 
(true cc.) flask with water, and add 5cc. 
of alumina cream; make up the solution to 
volume at 20° C, and filter and polarize the 
liquid at once for the “immediate polariza¬ 
tion.” Transfer 50ee, of this filtrate to a 
50-55cc. flask; add 5cc. of concentrated 
hydrochloric acid, and allow the whole to 
stand over night for inversion. Place the 
remainder of the filtrate in a flask, after 
removing the quantity necessary for the 
reducing sugar determination, and allow 
to stand over night. On the following day 
again polarize the two solutions at -20° and 
also at 87° C, making a total of five differ¬ 
ent readings. 
The polarization at 87° C is a rather 
difficult one to make. It is necessary to 
have a water-jacketed tube and run water 
at about 95° thru at first to bring quickly 
the temperature up to around 85°, then run 
the water at about 90°. When the solution 
itself has readied 87°, make a reading. If 
much time is necessary to bring the solu¬ 
tion up to 87°, it might-be well nearly to 
neutralize the invert solution before mak¬ 
ing the reading. This practice will give 
different results, and also the solutions will 
turn much darker, making a reading more 
difficult. 
The purpose of the 87° reading is to 
obtain a reading after the invert sugar has 
become optically inactive. With substances 
other than honey dextro readings at 87° on 
the inverted solution would indicate the 
presence of commercial glucose. In honeys 
the reading is due to the excess of dextrose 
plus the natural dextrins. Many chemists 
have fallen into this mistake. 
ACIDITY. 
Dissolve 10 grams of honey in water and 
titrate with tenth-normal sodium hydrox¬ 
ide, using phenolphthalein as indicator. 
Express the acidity as formic acid. 
It is known that the sting of a bee is due 
to formic acid, so all analyses are calcu¬ 
lated to formic acid. Experimental work 
on the acids of natural honey has shown 
that there are two groups of acids, present, 
volatile and non-volatile acids. Of the 
former, formic acid forms about one-half, 
the others being butyric, valeric, caproic, 
and capric. Of the non-volatile acids lactic 
acid predominates, then malic acid, suc¬ 
cinic, and oxalic have been recognized. 
Where the honey has soured or fermented 
the acid formed is acetic. 
DEXTROSE AND LEVULOSE.’ 
The percentage of these sugars can be 
