AGKICrULTUEAL CHEMISTBY AGROTECHNT. 13 



Some effects of refrig'eration on sulphured and unsulphured hops, W. W. 

 Stockbergee and F. Rabak ( U. S. Dept. Agr., Bur. Plant Indus. Bui. 271, pp. 21). — 

 The purpose of this work was to determine the effect of refrigeration on the 

 quality of sulphured and unsulphured hops grown on the same field in the 

 Sacramento Valley, Cal. The green hops were divided into 2 lots, one of which 

 was sulphured during the process of drying. Bales from each lot were placed 

 in cold and in ordinary storage, and samples examined from time to time with 

 respect to physical condition and certain chemical constituents. 



At intervals of 7 and 18 months, respectively, from the time the hops were 

 placed in storage, samples were drawn and submitted to trade experts for 

 rating according to their relative quality. 



The results show that both cold storage and sulphuring delayed undesirable 

 chemical changes and, furthermore, that the usual trade judgment can not be 

 relied upon to give an accurate idea of the changes which have occurred in 

 such goods, as opinions vary widely on the same sample. All of the experts 

 agreed, however, that the sulphured hops in cold storage were the best in 

 quality. 



During the storage period determinations of the acid, ester, and resin con- 

 tents were made. The conclusions drawn from these analyses are that both 

 sulphuring and cold storage retard changes in the hops leading to an Increase 

 in acidity and ester content of the oUs. Cold storage is apparently more 

 effective than sulphuring in retarding the increase in acidity, but is less effi- 

 cient than sulphuring in retarding increase in ester content. Cold storage and 

 sulphuring combined are much more effective in retarding changes in acidity 

 and ester content than either alone. 



" The percentage of decrease in the content of soft resins was less in the 

 cold-stored hops than in those in ordinary storage. The evidence from the 

 analyses goes to show that the sulphuring tends to retard changes in the 

 content of soft resins only when combined with cold storage." 



The utilization of waste raisin seeds, F. Rabak ( U. S. Dept. Agr., Bur. 

 Plant Indus. Bui. 276, pp. 36, figs. S). — This investigation deals with the utiliza- 

 tion of this by-product hitherto disregarded, from the raisin-seeding and wine 

 and grape juice industries. 



It is shown that 4 commodities, sirup, fixed oU, tannin extract, and meal can 

 be made from grape and raisin seeds, of which from 3,000 to 4,000 tons are 

 available annually. The sirup produced from the saccharin matter which 

 adheres to the seeds was clear and transparent, and had the characteristic, 

 pleasant taste of the raisin. It had a specific gravity of 1.384 at 22° C, con- 

 tainetl 61 per cent of reducing sugars calculated as dextrose, and 2.94 per cent 

 of saccharose. The acidity of the sirup corresponded to 1.06 per cent of tar- 

 taric acid. Approximately 18.5 per cent of sirup is obtainable, or from 96,000 

 to 128,000 gal. of sirup. If fermented this amount of sirup would yield ap- 

 proximately from 41,000 to 54,000 gal. of alcohol (U. S. Pharmacopceia). 



The fixed oil, which is extracted after removing the sugary pulp and screen- 

 ing and drying the seeds, is pale, golden-yellow in color, has a slight fatty 

 odor, and a bland, nut-like taste. The specific gravity of the oil obtained by 

 extracting with ether is 0.922, at 24°, and it has a refractive index of 1.4702 

 at 25°. The yield was 14.5 per cent of the dried seeds. The saponification 

 value was 188, the iodin number (Hiibl's) 131, the volatile acids (Reichert- 

 Meissl figure) 0.64, acids soluble in water 0.394 per cent, insoluble acids 94.4 

 per cent, acetyl value 16, and unsaponifiable matter 0.78 per cent. 



A detailed chemical examination of the oil showed it to be composed of 

 linolein 54 per cent, olein 34.48, palmitin 7.87, stearin 0.94, and free acids 

 (calculated as oleic acid) 0.62 per cent As the fixed oU contains constituents 



