Arri.E .TUICE EXTRACTION' FOR .li:i.l.^- -.'.jj 



Seasonal Variation of Baldwin Apples 



Data were collected for the three years, 1925, li»'2(), and li)27, on llu- ilu-in- 

 ic-al composition of the fruit as well as the heat-extracted juiie. Tahle 1 

 shows no striking changes in composition from year to year. Similarly Tahic 

 13 presents only minor differences in the heat-extracted juices from ajipies 

 harvested during three successive years. Despite varying ratios of fruit to 

 extraction water, tiie range of soluble solids obtained by a single 15-minute 

 extraction was narrow, 47.9 to 59.6, and for the second extraction 22.2 to 27.7. 

 Similarly, the amounts of extracted pectin and also malic acid varied l)ut 

 little. In general, both jelly yields and jelly strengths were higher in the 3:2 

 ratio than in the 3:3 or 3:4 ratios. 



STUDIES OF JELLY 



Jelly Yields per Unit Weight of Apples 



In Table 14 is summarized the average jelly yields from two extractions at 

 100°C. for the 8 varieties already mentioned. Additional data also are found 

 in Tables 10, 11 and 13. In interpreting these data, the method of making 

 the jelly must be kept in mind. That is, to 18 ounces (511 grams) of juice 

 composed of proportionate parts of the first and second extracts, was added 

 sufficient sugar in addition to that already present in the juice, to make 12 

 ounces (341 grams). The juice was then rapidly concentrated until the jelly 

 sheeted or, in the absence of a satisfactory jelly test, until the sugar content 

 reached 69 to 70 per cent. In general jellies containing over 70 or under 64 

 per cent of sugar were abnormally soft in consistency or were otherwise of 

 poor qualitj'. 



Had the sugar been proportioned exactly to the pectin actually present, 

 the increase in jelly yields in columns 3, 8 and 13, Table 14, would not be as 

 marked, though the general trend would have been the same. This may be 

 .shown by a simple calculation using the pectin content of the juice or jelly 

 as tabulated respectively in Tables 2 and 3. The pectin content of jellies 

 made from a 3:2 ratio of fruit to extraction water was higher than where 

 the ratio was 3:3 or 3:4. 



The effect of pectin content of the juice upon jelly strength is clearly pre- 

 sented in Table 14. Other things being equal, for short extractions the jelly 

 strength increased as the pectin content of the jelly increased. Most of the 

 jellies made from the 3:2 ratio of fruit to extraction water were tough, i. e., 

 over 100 Bloom grams, while those made from a 3:3 ratio were of medium 

 firnmess, and those from the 3:4 ratio were considerably softer in consist- 

 ency. The grade of jelly depended upon several factors such as flavor, color, 

 texture, consistency, stickiness, syneresis and ability to withstand storage. 



Two 15-minute extraction periods using equal parts of fruit and water, gave 

 high yields of juice containing sugar, acid and jellifying-pectin in suitable 

 amounts to produce in turn high yields of well flavored, higli grade jelly. 

 Normally, this procedure gave best results. In some cases it was possibly 

 more economical to use a ratio of apple to extraction water of 3:2 but the 

 danger of scorching, difficulty of separating the juice from the pulp and the 

 lower yields of solids, pectin and jelly usually outweighed the advantage 

 gained by having only a small amount of relatively concentrated juice. If 

 the sugar was properly proportioned to the amount of jellifying i)ectin 



