Malcolm. — Composition of some .Yen: Zealand Foodstuffs. 267 



Qualitative Exam i nation . 



Protein. — As already mentioned, oysters contain a large amount of 

 nucleo-protein or similar body rich in phosphorus. Besides this a saline 

 extract of oysters contains a protein which coagulates about 75° C. 



Fat and Figment. — To the naked eye the ethereal extract of dried 

 oysters appears brown, as is generally the case with fats dried at high 

 temperatures. On spectroscopic examination this ethereal solution shows 

 a distinct absorption band near the red end of the spectrum — apparently 

 nearer that end than the characteristic band of methaemoglobin ; on 

 dilution the band approaches and fuses with the infra-red part of the 

 spectrum. It is probably a lipochrome, as it is absent from watery 

 extracts, and occurs only in extracts made by solvents of fat (ether, 

 chloroform, acetone, alcohol, amyl alcohol, &c). It was found in all the 

 samples examined. 



II. Frostfish (Lepidopus caudatus). 



This peculiar -looking fish, known in other parts of the English- 

 speaking world as " scabbard-fish," is found in the Mediterranean and 

 warmer parts of the Atlantic as well as around the Tasmanian and New 

 Zealand coasts. It derives its popular name from the fact that it is 

 thrown up by the sea in frosty weather, and is found dead or dying on 

 the beach. According to one view, it comes ashore voluntarily, as if 

 bent on self-immolation ; it has seldom, if ever, been caught alive, and 

 is generally believed to be a deep-water fish. In shape it is long and 

 ribbon-like, and has a bright scaleless skin. Unlike many New Zealand 

 food fishes, it has a distinctive flavour, and partly from this and partly 

 no doubt, from its comparative rarity it is regarded as a delicacy, and 

 sells at Is. 6d. to 3s. per pound. For the purposes of sale and for cook- 

 ing it is cut into slices across its long axis; all such cutlets include the 

 vertebral column, and some also include the abdominal cavity. There 

 is a considerable amount of waste matter in the cutlets; thus in an ordi- 

 nary slice as bought only 85 grm. out of a total of 134 grm. consisted 

 of edible flesh. The residue (36'5 per cent.) consisted of bone, skin, and 

 tough intermuscular septa, although the latter would probably form 

 gelatine during the process of cooking, and should not be considered 

 altogether as waste. 



Fat. — The flesh is obviously fatty, and an oily scum forms on the 

 water in which it is boiled ; but the fat is unequally distributed, there 

 being much more in the tissues immediately surrounding the abdominal 

 cavity than in the muscles of the sides. In the first sample examined the 

 fat of the dorsal portion or sides of the fish amounted to 4"55 per cent., 

 and that of the ventral to 16*77 per cent. In the second sample there 

 was 7'36 per cent, fat in the sides, and 20 per cent, in the ventral por- 

 tion. From the culinary point of view, therefore, the frostfish should 

 be reckoned as a fatty fish somewhat akin to turbot. The fat extracted 

 by ether is a yellow-coloured oil, half-fluid at room-temperature, and 

 possessing a smell which recalls that of cod-liver oil. It contains 1 per 

 cent, of nitrogen. 



Protein. — Owing to the presence of a considerable amount of non- 

 protein nitrogenous substance, it is not permissible in this case to use 

 the total nitrogen as the basis for calculating the percentage of protein. 

 The following procedure was therefore followed : The residue, after ex- 

 traction of the fat, etc., by chloroform and alcohol, was weighed and 

 sampled for nitrogen-estimation — thus 10967 grm. partly dried "sides ' 



