FRUITS AND FEUIT JUICES. 



49 



either the direc*: or the invert reading at room temperature and the 

 percentage of reducing sugar, owing to the variable amounts of cane 

 sugar, but the invert polarization is in a general way indicative of the 

 amount of total sugars. The approximate percentage of levulose in 

 excess of dextrose ma}' be figured from the polarization at 86 ^ by 

 multiplying the degrees of levorotation by 0.42 in case the normal 

 weight has been used for the polarizations. 



Table 13. — Polarization of fruits and fruit juices. 



La bora 

 tory 

 num- 

 ber. 



Description. 



20400 

 20396 



20404 

 20401 

 20397 



20430 

 20427 



20431 

 20429 

 2042(5 



20399 

 20402 



22362 

 22364 

 22366 

 22368 



Apple 



Blackberry 



do. » 



Crab apple 



Grape 



Huckleberry ... 



do. a 



Orange 



Peach 



do. » 



Pear 



Pineapple 



Pineapple husk 



Pineapple » 



Plum 



.-..do 



Red raspberry*. 



Strawberry 



....do 



....do 



....do 



20449 ! Apple 

 20415 

 20418 

 20417 



WHOLE FRUIT. 



20425 

 20444 



Blackberry 

 Crab apple 



Grape 



Orange 



Pineapple . 



Direct Invert 



Invert 



boiariza- Dolariza- Temper- polariza- 



-3. 

 -1. 

 —2. 



-1. 

 -1. 

 -3. 

 -4. 

 +1. 

 +4. 

 +4. 

 +4. 

 +8. 

 +4. 

 +4. 

 +2. 

 +1. 

 -1. 

 -1. 

 -1. 

 — 1. 



-4.6 

 -1.6 

 -2.4 

 -2.4 

 -2.4 

 -4.4 

 -4.8 

 -1.3 

 -2. 2 

 -2.2 

 -6.4 

 -3.7 

 -2.3 

 -4.8 

 +1.3 

 -2.4 

 -2.8 

 -1.0 

 -1.2 

 —1.2 





at 86°. 



a 





18 



-2.9 



18 



-1.1 



30 



-0.0 



18 



-1.1 



18 



-0.6 



18 



-0.9 



30 



-1.0 



18 



0.0 



18 



-0.7 



28 



0.0 



18 



-4.0 



18 



-1.1 



- 18 



- .7 



28 



- .8 



18 



+2.4 



— .7 



- .8 



-2.2 



-3.6 



-1.1 



-1.0 



- .7 



-3.0 



-1.6 



-2.0 



+2.0 



-2.5 



+1.0 



-3.2 



-1.8 

 0.0 



-1.8 

 .0 



- .8 

 .0 



- .8 

 0.0 



Per cent Per cent 



of invert of cane 



sugar. sugar. 



4.00 

 4. .34 

 8.70 

 2.56 

 5.10 

 11.21 

 16. 70 

 1. .52 



2.10 

 5.87 

 2.74 



9.10 

 4.86 

 2.87 

 8.60 

 3.94 

 3.-52 

 3.15 



4.13 

 5.67 

 5.68 

 1.11 

 4.13 

 8.12 



1.18 



1.03 



.89 



.89 



.60 



2. 29 



4.-59 



.5.40 



1.18 



8.96 



4.73 



7.40 



..51 



2.81 



.90 



.15 



.21 



.20 



.40 



1.03 

 .00 



1.70 

 .29 



3.3:3 



3.11 



aA. L. Winton. Conn. Expt. Stat. Report, 1899. Pt. II. p. 12 



A number of the fresh fruits were fermented to determine whether 

 any nonfermentable optically active bodies were present. It was found 

 that in all cases the nonfermentable matter was inappreciable and that 

 with a 10 per cent solution the polarization after fermentation was 

 never more than three or four tenths of a degree either to the right or 

 the left. 



Alcohol precipitate. — The alcohol precipitate consists largely of 

 pectin bodies, and the determination is valued only for the estimation 



17673— No. 66—02 i 



