FRUIT-GROWING AND PRESERVING. 67 



version of insoluble pectin compound into soluble pectin has 

 reached. Two such methods have been recently worked out, 

 and there is good promise that they may be found to answer all 

 requirements of the chemist, and thus facilitate considerably the 

 investigations into methods of storage. The pectin content of 

 the apple is, however, influenced by a number of factors, and an 

 intensive study of them is necessary in order to find out the 

 best conditions for the preservation of the fruit in cold storage 

 or by other methods. It may here be stated that under an 

 arrangement with the Department of Scientific and Industrial 

 Research a cold store has been installed at the Institute, and in 

 that are being conducted experiments on methods of storage of 

 fruit at low temperatures. This subject of cold storage is also 

 being dealt with at the Imperial College of Science, London, and 

 the work there is briefly mentioned in the chapter on Plant 

 Physiology. 



Investigations into methods of fruit and vegetable preserva- 

 tion are conducted at the Experimental Station at Campden ; 

 but research at this centre has only lately become possible 

 through the establishment of a smaU laboratory at the Station 

 within the past year. The main problems which have been 

 undertaken within this short period have dealt with the common- 

 est t5^e of preservation, i.e., jam-making. In this connection, 

 special attention has been paid to certain points which are of 

 paramount importance in the making of a good and economic 

 preserve, namely, the minimum sugar content required, the 

 obtaining of a " set " or gel, and the retention of flavour and 

 colour. It is not generaUy known that there are three essential 

 features necessary in order to obtain a good preserve with suffi- 

 cient "set" to overcome an often noticed " runny " condition — 

 usually very difficult to counteract in certain varieties of fruits ; 

 or alternatively, to prevent crystallisation of the sugar at the 

 surface of, and sometimes right through, the jam. These three 

 essentials are pectin, acid, and sugar, in the correct propor- 

 tions. Most fruits contain some of each, but by no means always 

 in the proportions essential to a successful result. Data are 

 gradually being built up at Campden which should throw con- 

 siderable light on this hitherto little-known subject. 



In regard to the retention of flavour, much work has yet to be 

 done, but it may be mentioned that the flavours contained in the 

 different fruits are extremely volatile, especially under the appHca- 

 tion of heat. The necessity therefore arises for the improvement 

 of means whereby this volatile flavour can be prevented from 

 escaping in the large proportion usual under ordinary conditions 

 of preserving, and this point is under investigation. The question 



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