412 EXPERIMENT STATION" EECOED. 



" Samples for oxygen may be taken and transported elsewhere for titration in 

 ground glass stoppered bottles with part of the chemicals added, either in alka- 

 line or acid condition, if kept out of contact with air. The alkaline condition is 

 preferable." 



Estimation of starch and dextrin in sugar products, confectionery, etc., 

 A. AiJGUET (Ann. Falsif., 6 (1913), No. 53, pp. IJ/S-l^l; ab.s. in Jour. Chem. Soc. 

 [London], lOJf (1913), No. 601, II, p. .^.^8).— In the method 0.5 gm. of the sub- 

 stance under examination is inverted at 70° C. with 1 per cent hydrochloric 

 acid. Another 0.5 gm. portion is inverted by heating with 2 per cent hydro- 

 chloric acid for 1 hour at 110°. The I'educing sugars are then estimated with 

 Fehling's solution in the usual manner. The difference between the two estima- 

 tions, expressed in terms of invert sugar, is multiplied by 0.9 to give the 

 quantity of starch or dextrin. 



"A preliminary examination of the substance under the microscope, and a test 

 with iodin solution, will show whether starch or dextrin is present, or which 

 of these preponderates." 



Determination of quercetin in wine, T. vON Fellenberg (Mitt. Lehensm. 

 Vntersuch. u. Hyg., Schweiz. Gsndhtsamt., 4 (1913), No. 1, pp. 1-14). — lo the 

 examination of red wine a yellow coloring matter was noted which gave the 

 reactions applied by Heise to similar substances, i. e., those with lead acetate, 

 iron acetate, ammonia, and concentrated sulphuric acid. 



The coloring matter present in wine was found to be more soluble in water 

 than that from other sources and did not give a blood red reaction with silver 

 nitrate. Various wines were then examined for the presence of this substance 

 and the results obtained were compared with those given by standards of wool 

 dyed with authentic quercetin. It colored wool, mordanted with clay, yellow, 

 and wool, mordanted with clay and tin salts, a very pure yellow. When the 

 tin salt was in preponderance the color was more intense. Unmordanted plant 

 or animal fibers were not affected by the coloring matter. 



The coloring matter which exists only in traces in white wines and in larger 

 amounts in red and white wines, and red wines made from dregs, is formed 

 during fermentation, especially from the substances which make up the dregs, 

 i. e., skins, stems, and seeds; con.sequently the detection of this coloring matter 

 is a medium whereby one can often determine wine made from dregs. Heating 

 wine with dilute sulphuric acid was found to increase the coloring matter 

 content of wine. 



For the purpose of determining whether Neubauer's conclusions were coi*- 

 rect, 1 kg. of grape wine was exti'acted with .3 liters of water in an autoclave 

 at 130° C. The solution was treated with ether, the ether extract was brought 

 to dryness, and the crystalline residue extracted with water and recrystallized 

 from dilute alcohol. In this experiment 0.17 gm. of the coloring matter was 

 obtained in the form of fine microscopic needles which melted at 250°. The 

 combustion showed a formula similar to that calculated for quercetin. The 

 reactions for the substances were also positive. The green plants, or plant 

 parts green during some stage of their growth, such as .skins and hulls of fruits, 

 and flowers, yield on heating with dilute sulphuric acid yellow coloring matters 

 which are considered decomposition products of a substance which accom- 

 panies chlorophyll. The yellow coloring matter of wine in all probability 

 consists of quercetin, traces of quercetin, and the decomposition product of an 

 accompaniment of chlorophyll. 



Estimation of the bromin absorption of wines, T. von Fellenberg (Mitt. 

 Lel)eri8m. Unter.'^uch. u. Hyg.. Schweiz. Gsndhtsamt.. .'t (1913), No. 1, pp. I't-^l, 

 figs. 5). — The results show the possibilities in this determination for detecting 

 adulterations in wines. Sugaring and watering can be easily detected. 



