APPLE JUICE EXTRACTION FOR .IKI.I.V 227 



[iifltteiice of Surcetisive Extract ions 



Three successive extracts, togetlier Mith the pulp ()l)(aiuc(l iu the luiiiuier 

 already described, froui 91 series cotuprisinji in all 361. sauii)Ies, were exam- 

 ined nu^iutitatively for soluble solids (chiefly sugar), pectin and acid. Know- 

 ing the amount of juice recovered at each extraction and keeping the amount 

 of apples used a constant, viz. 3 pounds (1.36 kilograms), it was possible, 

 with the aid of these analytical data, to calculate the percentages of soluble 

 solids, pectin and acid recovered in the several successive extracts and resi- 

 dual pulp. 



Method of Calculating Resulls — To illustrate this method of calculation 

 assume that the first, second, and third extractions and the remaining inilp 

 weighed .50, 40, 32, and 16 ounces respectively. The soluble solids were de- 

 termined to be 10, 6, 3, and 3 per cent while the pectin was 0.20, 0.09, 0.0 1 and 

 0.12 per cent respectively, and the acid as malic 0.20, 0.12, 0.06, and 0.07. 

 The total weight of soluble solids in 3 pounds of apples becomes (50X-10) + 

 (40X-06) + (32X-03) + (16X-03)=8.84 ounces. The total amount of pectin and 

 malic acid extracted in each separation was calculated in a similar manner. 



Knowing the amount and composition of each extract, the exact percentage 

 of the soluble solids, pectin or acid obtained in any of the three extracts or 

 in the remaining pulp was readily calculated. For example, the total solids 

 retained by the pulp after three successive extractions was found to be 

 (16X-03)-^-8.84=5.43 per cent. 



Discussion of Results. Three successive IS-minute extractions of sliced 

 Baldwin apples with water removed from 80 to 94.4. per cent of the soluble 

 solids and from 63.5 to 88.3 per cent of the pectin, whereas the chopped 

 fruit yielded soluble solids ranging from 85.9 to 95.4 per cent, and pectin 

 from 63.1 to 83. In only two cases did the sliced fruit yield more soluble 

 solids than the chopped. In each of these, the extracting temperature was 

 109°C. (228° F.). Though more solids were obtained in the juice by chopping 

 the apple, still the actual gain was slight. It was realized that the amounts 

 of solids or pectin obtained from fruit under different methods of extraction 

 tended to become equalized when the totals of the three extracts were con- 

 sidered. Hence the percentages of solids and pectin recovered by one extrac- 

 tion and by two successive extractions .showed wider differences. For this 

 reason these results were included in the tables. Three successive extrac- 

 tions with equal weights of water removed from the Baldwin apple all except 

 about 10 per cent of the soluble solids, which remained in the residual pulp. 

 The maxinunn amount remaining in the pulp was 22 per cent in the case 

 where the ratio of apple to waiter was 3:2 and the extraction was carried 

 on at temperatures of either 88° or 100°C. The minimum amount of ex- 

 tractable solids remaining in the pulp was only 4.6 per cent. This occurred 

 where the ratio of fruit to water was low, viz. 3:4, and the extraction tem- 

 perature was 100°C. 



In tables 7 to 12 and graphically in Chart 1 data are as.sembied .showing 

 the relative percentage recoveries of soluble solids, pectin and acid which 

 may be exi)ected from one, two, or three successive extractions at varying 

 periods and temperatures. Likewise the influence of acid added to the 

 apples, as well as varying ratios of apple to water, are shown. Charts 1 to 

 5 graphically portray the effect of a variety of conditions on tiie chenucal 

 composition and percentage yield of the extracted juice. 



