PART III NOTES, ABSTRACTS AND NEWS NOTE : I FATTY ACID COMPOSITION OF ANCHOVIELLA AND THRISSOCLEUS Anchoviella and thrissocleus constitute as reported earlier (Gopakumar and two species of good food fish of India . Both Rajendranathan Nair, 1972) . belong to the family of clupeidae . Their phospholipid composition was reported earlier (Gopakumar & Rajendranathan The results of the study show that Nair, 1971) . , It was also reported the polyunsaturated fatty acids, eicosapen- (Gopakumar & Rajendranathan Nair, taenoic acid and docosahexaenoic acid, are 1967) that polyunsaturated fatty acids occur the two major fatty acids in the phosph- predominantly in the phospholipid fraction olipid fraction of both anchoviella and of a number of Indian marine fish . Fatty thrissocleus . This was the pattern seen for acid and phospholipid composition of oil both phospholipids of mackerel and sardine, another notable member of the pomfret (Gopakumar and Rajendrana- family of clupeidae was extensively invest- than Nair, 1967) . Myristic, palmitic and igated earlier (Gopakumar and stearic acids in the nonphosphorylated Rajendranathan Nair, 1966) . Hence, this fraction constitute the major constituents work was undertaken with a purpose to (thrissocleus, 47 .5%, anchoviella, 43 .5%) . iavestig_ite tha fatty acid composition of In the nonphosphorylated lipids C 1 ,s acids these two species and to bring out their (palmitic and palmitoleic) levels were possible similarities with the other members significantly high but polyunsaturated fatty of the family of clupeidae . acids levels were low compared to phos- pholipids, a pattern also seen for South The fish samples were beheaded, de- African abalone (De Koning, 1966 IV), scaled and deboned . The muscle was taken hake (De Koning and Me Mullan 1966) . for analysis . Lipids were extracted from Of the odd numbered acids C l , : () and the muscle by the method of Bligh and C15 were only detected . But C, 5 : o acid Dyer (1959) . The chloroform extract was is present to a significant level only in the washed twice following washing procedure phospholipid fractions. C2 .a : a acid was of Folch, Lees and Sloane Stanley (1957) . the major constituent of unsaturated fatty The lipids were saponified by the official acids in ' the phospholipids (thrissocleus method of A. O . C. S. Fatty acids were 21 .0%, anchoviella 22 .7%). C 20 ; s was the converted to methyl esters by methanol- principal component in the non-phosphory- HCl reagent. Fatty acid composition was lated lipids (thrissocleus 7.7%, anchoviella, determined by gas-liquid chromatography 3.0%). VOL 12 No. 1 1975 75 Gopakumar & Rajendranathan Nair : Fatty acid composition of Ancliooiella and Ikrissocleus FATTY ACID COMPOSITION OF LIPIDS OF THRISSOCLEUS AND ANCHOVIELLA Fatty acid designation Thrissocleus Anchoviella PL* NL** PL NL 7.0 C14 :0 2.9 9.0 1 .2 C14 :1 1 .4 0.5 1 .0 1 .3 C15 :0 1 .6 - 0.7 1 .5 C16:0 18.2 32.5 20.'5 30.9 016:1 4.0 7 .0 8 .0 11 .0 017:0 2 .0 3 .0 2.9 3 .0 C18 :0 5.0 6.0 6.2 5 .6 C18:1 18.7 24.2 19.6 27.8 0 18:2 1 .6 2.9 0.9 2.0 C18:3 0.9 1 .0 - 1 .7 C18 :4 3.2 0.8 3.2 0.7 020 :1 0.9 2 .1 0.5 0.8 C20:5 12.6 7.7 9.0 3 .0 C22:1 1 .2 0.4 - 1 .4 C22:4 0.9 1 .10 C22 :5 2.0 - 2.2 C22 :6 21 .0 2.9 22.7 2.3 C24:1 1 .9 - 0.5 *PL - Phospholipids, **NL - Nonphosphorylated lipids. ACKNOWLEDGEMENT De Koning A . J. and K. B . Mc Mullan The authors wish to express the deep 1966 . J. Sci. Fd. Agric., 17 : 385. sense of gratitude to Dr. R . V. Nair, Folch, J . Lees, M. and Sloane Stanley G . H. Director for his permission to publish this 1957. J. Biol. Chem., 226: 497 . paper. Gopakumar K . and Rajendranathan Nair M. 1966. Fish. Technol. 3, 1 : 21 . REFERENCES Gopakumar K . & Rajendranathan Nair M . Bligh E. G. and Dyer W . J. 1959 . Can . J. 1967. Indian J. Biochem ., 4: 229. Biochern . Physiol. 37:911 . De Koning A. J . 1966. I. J. Sci. Fd. Agric. Gopakumar K . & Rajendranathan Nair M . 17 : 112. 1971 . Fish . Technol. 8, 2 : 171 . De Koning A. J. 1966.IV. J . Sci Fd . Agric . Gopakumar K . & Rajendranathan Nair M . 17 : 460. 1972 . J. Sci. Fd. Agric. 23 : 493 . Central Institute of Fisheries Technology, K. Gopakumar Cochin - 682011 . M. Rajendranathan Nair 76 Fish . Technol. NOTE II STUDIES ON SMOKE CURING OF TROPICAL FISHES In spite of the tremendous progress prejudice among the local processors engaged made by our freezing and canning industries, in fish curing against chemical preservatives, curing still continues to be a very important it has not yet become very popular . So, method of fish preservation in our coun- as an alternative, a well known natural try . This is especially so for our internal preservative and food additive viz ; turm- market, since our freezing and canning eric was tried as preservative for such industries are compl--tley export oriented . products. This treatment is found to But surprisingly, smoke curing, a simple increase the storage life of the final smoked and efficient method, is not yet very products, besides imparting an attractive popular among our fish curers. Smoking appearance . is a favourite method of curing in the Far East and Continental countries, where a Fresh fish [mackerel (Rastrelliger veriety of smoked products like Bloater, kanagurta) cat fish (Tachisurus dussunieri) Kipper, Red herring, Buckling, pale cure and sole (Cynoglossus dubis)] were pro- Finnan, Golden cutlets, Scotch fillets, Smo- cured from local fish landing centres. kies etc . are prepared . Extensive studies They were gutted, cleaned and washed . In have also been conducted there on th° the case of sole the upper hard skin was various aspects of this method of curing removed before washing . The cleaned fish (Shewan 1945, 1949 ; House and Cutting, were first brined for uniform salt uptake. 1956 ; Cutting 1951 ; Simpson 1961 ; Foster In pale cures, salt is used mainly for the and Simpson 1961 ; Simpson and Campbell formation of a surface pellicle and also as 1962 ; Linton and French 1945) . However a condiment. Though it contributes to the very little attention has been given in quality of the smoked products, salt does India to develop this method of fish not appear to prevent bacterial growth or curing (Moorjani et al. 1972 ; Solanki et al. spoilage at low concentrations (Weekel 1970). This note reports results of a study and Wosje 1966, F A 0 Report) . But in on smoke curing of some of our common heavily salted products salt is found to food fishes . have a definite preservative action. The effet of pH and temperature on the action The relatively shorter storage life of of salt has already been reviewed by smoke cured products when compared to Ingram and Kitchell (1967). The salt dry cured products, and the early onset uptake. during brining depends on various of fungus and mites are the main reasons factors like age and size of fish, concen- for their lesser popularity. The use of tration of brine, temperature of brine, sodium propionate has been found to be duration of brining, ratio of the weight very effective in enhancing their storage of fish brined to the weight of brine etc . life. But because of the difficulty in pro- It was found from experiments that brin- curing this chemical and also due to the ing by dipping the fish in an equal amount VOL 12 No. 1 1975 77 Deoadasar, Muruleedlaran & George 7osepei : Studies on smoke curing of tropical fishes TABLE I Initial Analysis of smoked samples 1. Control 2. Propionate treated 3 . Turmeric treated Moisture 21 .94 15 .54 15 .32 - 21 .98 13 .95 13.64 15.14 16.82 16.14 Chloride DWB 11 .50 12.82 11 .98 10.28 11 .93 10.92 10.98 11 .12 11 .88 (W/V) of saturated brine for 15 minutes conducted at regular intervals to follow at room temperature, prior to smoking, is the course of their spoilage . Moisture and quite satisfactory for reasonably uniform chloride were estimated according to A . and sufficiently high salt uptake . 0 . A. C. (1960) procedures and total vo- latile nitrogen by the method of Conway The control sample was dipped in (1947) . saturated brine and the experimental sam- ples were dipped in (1) saturated brine containing 3% sodium propionate, (2) a In all the three cases, smoked products saturated extract of turmeric in water of good appearance and taste were obta- containing salt to saturation . The turme- ined. The turmeric trated samples had a ric extract was prepared by boiling sufficient very attractive appearance especially in the turmeric powder in water, cooling it to case of sole . The samples had a moisture room temperature and then saturating it content of 15-20% and salt content of with solid refined salt . All these dip 10 - 12% (Table I) . The course of spoilage treated samples were then drained well . in these products -as followed by changes in the total volatile nitrogen content is given The well drained fish were then smoked in Table II. In all cases the control samples in a laboratory model smoke kiln, in which were spoiled within 3 months. But the turme- the fish were hung from hooks . Smoke ric and propionate treated samples remained was generated by burning coconut husks in good condition for over 6 months . The and saw dust . The smoking was continued products had a high salt content which is for about 5 hrs.