FISHERIES AND MARINE SERVICE. Translation Series No Physicochemical characteristics of fish frozen in Freon712 'using a contact Method

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1 XÉCHIVE9 FISHERIES AND MARINE SERVICE Translation Series No Physicochemical characteristics of fish frozen in Freon712 'using a contact Method by V. V. Koneva. - Original title: Fiziko-khimicheskaya kharakteristika ryby zamorozhennoi vo Freone-12 kontaktnym sposobom From: Izv. Vyssh. Uchebn. Zaved. Pishch. Tekhnol. (1): 83-85, 1977 Translated by the Translation Bureau (ne) Multilingual Services Division Department of the Secretary of State of Canada Department of Fisheries and the Environmant Fisheries and Marine Service Halifax Laboratory Halifax, N.S pages typescript

2 Frct- r DEPARTMENT OF THE SECRETARY OF STATE TRANSLATION BUREAU SECRÉTARIAT D'ÉTAT BUREAU DES TRADUCTIONS MULTILIMGUAL SERVICES DIVISION CANADA DIVISION DES SERVICES MULTILINGUES TRANSLATED FROM - TRADUCTION DE Russian AUTHOR AUTEUR V.V. Koneva INTO - EN English TITLE IN ENGLISH - TITRE ANGLAIS Physicochemical characteristics of fish frozen in Freon-12 using a contact method TITLE IN FOREIGN LANGUAGE (TRANSLITERATE FOREIGN CHARACTERS) TITRE EN LANGUE ÉTRANGÉRE (TRANSCRIRE EN CARACTÈRES ROMAINS) Fiziko-khimicheskaya kharakteristika ryby zamorozhennoi vo Freone- 12 kontaktnym sposobom REFERENCE IN FOREIGN LANGUAGE (NAME OF BOOK OR PUBLICATION) IN FULL. TRANSLITERATE.FOREIGN CHARACTERS. RÉFÉRENCE EN LANGUE ÉTRANGÈRE (NOM DU LIVRE OU PUBLICATION), AU COMPLET, TRANSCRIRE EN CARACTÈRES ROMAINS. Izvestiya vysshykh uchebnykh zavedeniy, Pishchevaya tekhnologiya REFERENCE IN ENGLISH - RÉFÉRENCE EN ANGLAIS Bulletin of Higher Educational Establishments, Food Technology PUBLISHER - ÉDITEUR PLACE OF PUBLICATION LIEU DE PUBLICATION not available USSR YEAR ANNÉE 197? DATE OF PUBLICATION DATE DE PUBLICATION VOLUME ISSUE NO. NUMÉRO 1 PAGE NUMBERS IN ORIGINAL NUMÉROS DES PAGES DANS L'ORI GINAL NUMBER OF TYPED PAGES NOMBRE DE PAGES DACTYLOGRAPHIÉES 6 Tn--- TRANSLATION BUREAU NO. minvironment REQUESTING DEPARTMENT MINISTÈRE-CLIENT NOTRE DOSSIER 11 0 BRANCH OR DIVISION DIRECTION OU DIVISION Fisheries TRANSLATOR (INITIALS) TRADUCTEUR (INITIALES) N. De. PERSON REQUESTING DEMANDÉ PAR Dr. R.G. Ackman YOUR NUMBER VOTRE DOSSIER N 0 DATE OF REQUEST DATE DE LA DEMANDE February 27, 1978 For cc C^) 1 only TRADUCTiON NON Information :-.7,r,u':cr;I:.:nt SOS (REV. 2/68)

3 Seeretary Secrétariat of State d'état TRANSLATION BUREAU MULTILINGUAL SERVICES DIVISION BUREAU DES TRADUCTIONS DIVISION DES SERVICES MULTILINGUES.ci-mpe9) co Erivs NO. DEpARTMENT MMION/BRANCN CITY NO OU CLIENT MINISTCRE OIVMON/OMECTION VILLE Environment Fisheries Halifax, N.S. muluau NO. LANGUAGE.._ TR...MU...MI ( imn...ls) No u BUREAU LANGUE umentm (Imnucs) Russian N. De. MAR Izvestiya vysshykh uchebnykh zavedeniy, Pishchevaya tekhnologiya, 1977, No. l e pp z e - r: U LLI ità.> Z?: (. 1 F C; Physicochemical characteristics of fish frozen in Freon-12 using a contact method by V.V. Koneva Leningrad Sanitation and Hygiene Medical Institute The method of freezing food products in liquid Freon-12 is presently under study in the USSR. (83 ) This is an effective and economical method, as it ensures freezing in less than 40 min, requires a small amount of refrigerant (1.5 kg per 100 kg of the frozen product), and Freon can be used several times over. ides that, Freon units are small and can be used directly on fishing vessels. However, the effect of this method of freezing on the physicochemical characteristics of the fish has not been studied, which has made it necessary to conduct multi-purpose investigations. Freezingwas carried out in the following way: Be- fish placed E Q whole into containers measuring 800 x 250 x 60 mm (weight of the 0 r: block kg)was conveyed into the freezing chamber and immersed (,).7.) 0 into liquid Freon-12. When the fish came into contact with the The numbers in the right-hand margin are the pages of the Russian text - translator SEC 5-25T (6/76)

4 Freon, it froze rapidly as a result of a high heat transfer coefficient, after which the temperature in the centre of the block reached -18 C. The control fish was also frozen in blocks in a "Nema" refrigerator by means of cold air supplied by a system of pipes containing a refrigerant,to a temperature of -18 o C which was attained after 3 hrs. The temperature level inside the block was controlled in both cases by a thermocouple during freezing. After 7 days of storage in an ordinary freezer, the fish was subjected to exhaustive analysis. Considering the fact that the thermal conductivity of fish depends on its chemical composition, particularly the content of fat, we analyzed fish of lean and fat species, i.e. cod and mackerel respectively (two experimental and two control groups of fish samples). In all the cases, analysis included testing of the organoleptic qualities of the fish when frozen, after defrosting and after cooking. We conducted 368 experiments with evaluation of the organoleptic indices using the method of pair compari- son. The best indices were observed in the frozen fish from the cold-air freezer.. The fish frozen in Freon-12 had a slight whitish coating and a more lusterless surface due to the formation of hydrates. The experimental fish analyzed after defrosting also showed low indices in comparison with:the control. (84) However, the organoleptic indices of cooked fish and broth were considerably higher in the fish frozen in Freon-12 as compared * translated literally - transl.

5 with the fish from the air freezer: the broth was clearer and more aromatic, and the meat was more tender and tastier. The water-retaining-capacity of the,fish was determined by the press-method /2/. Indices Water-retaining capacity of muscle tissue, % Peroxide number, Acid number, mg KOH Dry residue, g W e found that the method of freezing did not have any significant effect on the water-retaining capacity of the fish tissue (see table). No. of Frozen fish fish lean fat samples Freon-12 cold-air Freon-12.cold-air frcm each M±m freezer M±m freezer group M±m Mém ± ± ± ±0.8 t=1.4, P>0.05 t=1.4, P> C2±O é0.00C2 t= P> ± ±0.05" t=0.3 1 P> ± ±0.2 t=2.5 1 P< ± ±0.009 t=0.7, P> e t0.11 t=0.1, P> ± ±0.7 t=6.7, P<0.001 No differences in freshness were observ d.between the fish frozen in Freon-12 and the control samples. The acid and peroxide numbers of the corresponding species were similar both in the Freon-frozen fish, and in the control. The content of fat was determined by the Soxhlet method in 68 samples of fish (17 samples from each group). We established that freezing in Freon-12 reduced the content of fat in the lean and fat fish, as had been indicated by data regarding the capacity of Freon-12 to dissolve fats /1/. The fat content diminished from 0.37 to 0.26 g per 100 g in the lean fish, and from 11.9 to 7.9 g in the fat fish as compared with the control.

6 -4- The dry residue was determined by drying to a constant weight in 80 samples (20 samples from each group). As indicated in the table, the dry residue was significantly lower in the lean (Pe:. 0.05) and fat fish (P<0.001) frozen in Freon-12, which correlated with the data on the lower fat content of fish samples. the corresponding Since freezing in Freon-12 brings the product into direct contact with the refrigerant, in order to eliminate the possibility of the fluorine ion passing into the product we determined the content of the fluorine ion in the muscle tissue using the method described in reference /3/. The fluorine-ion content amounted to 1 mg/kg in cod and 1.95 mg/kg in mackerel; however, we did not observe any differences that could be attributed to the method of freezing. Organofluoric volatile compounds were determined in lean and fat fish frozen with cold air and in Freon-12. The tests were carried out by means of a group method /4/ adapted for biosubstrates /5/. The sensitivity of fluorine determination amounted to mg per 5 ml of an aqueous solution. A total 136 samples of fish were analyzed (68 frozen in Freon-12 and 68 control samples). the 68 samples of lean and fat fish frozen in Freon-12, 14 of the frozen samples were found to contain organofluoric compounds: from (85) 0.04 to 0.08 mg% in seven samples of fat fish, and from 0.04 to 0.09 mg% in seven samples of lean fish. The fish samples containing residual amounts of organofluoric comppunds were defrosted, cooked and analyzed again. No organofluoric volatile compounds were found in the defrosted and cooked fish, or in the fish broth. Of

7 Besides analyzing fish stored in frozen blocks for seven days and in order to obtain comparative data, we proceeded to determine the effect of lengthy storage on the -content of the fluorine ion and volatile organofluoric compounds. Analysis of fish frozen in Freon-12 and stored for longer periods (2, 6 and 9 months) has shown that volatile organofluoric compounds are not contained in fish stored for such lengths of time. The content of the fluorine ion was at the same level as in the fish stored for seven days. CONCLUSIONS 1. Fish frozen in Freon-12 is organoleptically superior to air-frozen fish when cooked. 2. Freezing in Freon-12 does not affect the water-retaining capacity of the tissue, the freshness of the fat, or the content of fluorine in the fish. 3. Residual amounts of volatile organofluoric compounds were detected in individual specimens of fish frozen in Freon-12, both in lean and fat species. The same samples of fish contained no organofluoric compounds when cooked or defrosted. Organofluoric compounds were not found in s 'amples stored for 2, 6 and 9 months. 4. Freezing in Freon-12 reduces the fat content and, therefore, the content of dry residue in the fish, as compared with the control. References 1. Badyl'kes I.S. Kholodil'naya tekhnika (Refrigeration technology). 1. Izd. "Gostorgizdat", Leningradll Volovinskaya V., Kerman B. Myasnaya industriya SSSR, 1960, No. 6, p. 47.

8 3. Kornakova A.A. Voprosy gigieny truda, professional'noi patologii, promyshlennoi toksikologii i sanitarnoi khimii (Problems of labour hygiene, occupational pathology, industrial toxicology and sanitation chemistry). Izd. NIGT i PZ. Gorky, Peregud Ye.A., Gernet Ye.V. Khimicheskiy analiz vozdukha promyshlennykh predpriyatiy (Chemical analysis of the air of industrial enterprises). Izd. "Khimiya". Moscow-Leningrad, Frolova A.D. Gigiena truda i professional'nykh zabolevaniy, 1969, No. 4, p. 48. Department of Nutritional Hygiene with the Clinic of Nutritional Diseases Received April 28, 1976