Translation Series No Alterations in vacuum packaged smoked salmon, either in slices or fillets

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1 .. M-CHIVES, FISHERIES AND MARINE SERVICE Translation Series No Alterations in vacuum packaged smoked salmon, either in slices or fillets by S. DtAubert, P. Renon, P. Cattaneo, and A. Cremagnani Original title: Alterazioni del salmone affumicato in tranci o affettato e confezionato sotto vuoto From: Ind. Aliment. 14(11): 95-99, 1975 Translated by the Translation Bureau PM) Multilingual Services Division Department of the Secretary of State of Canada Department of the Environment Fisheries and Marine Service Vancouver Laboratory Vancouver, B.C. : pages typescript

2 t DEPARTMENT OF THE SECRETARY OF STATE TRANSLAT.ION BUREAU see ng fetti ' r SECRÉTARIAT D'ÉTAT BUREAU DES TRADUCTIONS MULTILIMGUAL SERVICES DIVISION ikete. CANADA DIVISION DES SERVICES MULTILINGUES 31i d TRANSLATED FROM - TRADUCTION DE Italian INTO - EN English AUTHOR - AUTEUR S. D'AUBERT et al. TITLE IN ENGLISH - TITRE ANGLAIS Alterations in vacuum packaged smoked salmon, either in slices or fillets. TITLE IN FOREIGN LANGUAGE (TRANSLITERATE FOREIGN CHARACTERS) TITRE EN LANGUE ÉTRANGÉRE (TRANSCRIRE EN CARACTÈRES ROMAINS) Alterazioni del s_alm.rmeaffumicato in tranci o affettato e confezionato sotto vuoto. REFERENCE IN FOREIGN LANGUAGE (NAME OF'BOOK OR PUBLICATION) IN FULL. TRANSLITERATE FOREIGN CFIARACTERS. RÉFÉRENCE EN LANGUE ÉTRANGÉRE (NOM DU LIVRE OU PUBLICATION), AU COMPLET, TRANSCRIRE EN CARACTÈRES ROMAINS. Industrie alimentari REFERENCE IN ENGLISH - RÉFÉRENCE EN ANGLAIS Food Industries PUBLISHER- ÉDITEUR Not stated PLACE OF PUBLICATION LIEU DE PUBLICATION Italy YEAR ANNÉE 1975 DATE OF PUBLICATION DATE DE PUBLICATION VOLUME 14 ISSUE NO. HUM ÉRO 11 PAGE NUMBERS IN ORIGINAL NUMÉROS DES PAGES DANS L'ORIGINAL NUMBER OF TYPED PAGES NOMBRE DE PAGES DACTYLOGRAPHIÉES 12 REQUESTING _ DEPARTMENT _ Environment V -LL U11111=14 I.- MINISTRE CLIENT TRANSLATION BUREAU NO NOTRE DOSSIER NO BRANCH OR DIVISION Fisheries and Marine/Office of Editor TRANSLATOR (INITIALS) MbIN DIRECTION OU DIVISION TRADUCTEUR (INITIALES) PERSON REQUESTING DEMANDÉ PAR NOt Stated YOUR NUMBER VOTRE DOSSIER NI) r 11, DATE OF REQUEST 17th August, DATE DE LA DEMANDE. 30S I5 (REV. 2/68)

3 sec 5-25T (6/76).'acretary 0 Secrétariat of State d'état TRANSLATION BUREAU MULTILINGUAL SERVICES DIVISION BUREAU DES TRADUCTIONS DIVISION DES SERVICES MULTILINGUES F^ Yn4 3R 14' CLIENT'S NO. NO OU CLIENT DEPARTMENT MINISTERE Environment SUREAU NO. NO DU BUREAU LANGUAGE LANGUE DIVISION/URANCH DIVISION/DIRECTION Fisheries & Marine/Office of the Editor TRANSLATOR(1NITIALS) TRADUCTEUR ( INITIALES) Italian MMH CITY VILLE Ottawa ALTERATIONS IN VACUUM PACKED SMOKED SALMON SLICES OR FILLETS by S. D'Aubert - P. Renan - P. Cattaneo - A. Cremagnani Alterations of packaged salmon sold in Italy are reported; these mainly consist in initial processes of oxidation and putrefaction. Some basic characteristics for salmon meats are advised and preservation techniques to avoid these changes are specified. At the present time, the greater part of the vacuum-packed smoked salmon slices or fillets consumed in Italy are produced by specialized firms. In the preparation of this product,they use imported frozen salmon, already gutted, which are thawed in boiling water, cut into sections and cleaned, salted, smoked and packaged. Sometimes alterations are observed in the finished product, the causes of which have been described in detail in a previous work (D'Aubert, Cattaneo, 1974). Thesein short, are caused by errors in smoking and consist in excessive humidity of the final product, and uneven concentrations of phenols and formaldehyde, compounds which are directly responsible for preservation. The excessive humidity, the limited presence or, indeed, the Ut rplii`1'.` ri ;':;. Y_. i' Iïi0 j\1 C... ;i lfl[af

4 2 absence of these compounds with an antibacterial action, cause the appearance of abnormal odoum3from sulphurated hydrogen, methyl mercaptan and ammonia, which are produced by the action of bacteria and enzymes. Recently, in addition to this type of alteration, the causes of which are readily understandable, the appearance of a totally new alteration has been noted, which takes the form of an unusual odour, that is to say a "fruity" aroma, in the samples of salmon slices packaged under vacuum. Fruity aromas in other food.;products, like Cheddar cheese for example, have been known for some time and have been described by Bills et al. (1958); the formation mechanism has been studied in detail by Pereira et al. (1958), Perry (1961), Reddy et al. (1968, 1970), by Singh (1970), by Vedamuthu et al. (1966), Yano et al. (1970) and Hosano et al. (1974). The fruity aroma seems to be due to esters, especially ethyl butyrate and ethylhexanoate, produced by the action of lactic bacteria (Streptococcus diacetilactis, S. lactis, S. cremoris, Lactobacillus spp and Pseudomonas). All these strains esterify the butyric and caproic acids with the ethanol giving rise to the esters mentioned above. While all these results were obtained working with Cheddar, this alteration had never been mentioned for preserved products and especially not for salmon. For the purposes of preservability of salmon fillets or slices, and the maintaining of essential organoleptic qualities, if we are to explain the causes of the. various types of alterations encountered, we require certain data, not only on the correct processing technqiue, but also on the quality of the salmon meat undergoing processing.

5 3 The research dealt with in this note, of which the results are reported in detail, was therefore conducted with a view to establishing: a) the importance of certain factors (chemical and bacteriological) for the purpose- of controlling the quality and suitability of the raw material (the salmon) before processing; b) some preservability indices of the products ready for use; c) identification of the causes of the alteration consisting in the appearance of the fruity aroma in the sliced salmon pouches. In order to establish the quality of the meats and their suitabilitÿ for processing, the following were determined: peroxides, ph, TVN, humidity and bacterial content of the muscle tissue of the skin of the frozen salmon before processing; to establish suitability for consumption and preservation, we proceeded to determine the same parameters, plus the phenol and formaldehyde concentrations, in samples ready-for consumption. Tô identify the compound responsible for'l.the fruity aroma, we undertook more detailed research, consisting of a gas chromatographic analysis of the gases present in pouches of sliced salmon, altered or in a normal state of preservation, and an evaluation of the esters and aldehydes contained in the fat of normal and altered samples. Since, initially, we could not exclude the possibility that the abnormal aroma was a component of the pouch (plastic film consisting of cellophane/ saran wrap/polethylene) which had migrated to the contents, we also analyzed the pouch and the sheet of plasticmaterial placed between the salmon slices, in order to determine the composition in solvents.

6 4 MATERIALS AND METHODS A) Criteria and methods used to establish what characteristics of the meats were necessary to guarantee correct processing and preservability. Working on 10 frozen salmon, we determined the bacterial content of the meats and skins during processing, as well as the TVN, the peroxides, the ph and the humidity. The methods used for the bacteriological analyses were those recommended by Cantoni and Gervasini (1965), while the chemical analyses were conducted according to Pearson (1974). B) Criteria and methods used to determine the state of preservation of salmon fillets or sliced salmon packaged under vacuum. The same determinations described above were carried out on 50 samples ready for consumption. In addition, the concentrations of formaldehyde and phenols were determined according to Snell and Snell (1967). C) Identification of the "fruity" aroma. The gases obtained from the affected pouches were analyzed by gas chromatography. The technique used was the following: A small rubber disk 1 cm in diameter is attached to the pouch under examination with adhesive. Once the disk was secured, we introduced approximately 10 ml of 99.5% research nitrogen into the pouch, piercing the disc with a hypodermic needle. The needle was removed and after approximately one hour at ambient temperature, the gas contained in the pouch (gas + aromas or solvents) was removed with a gas syringe and was analyzed by gas chromatography, injecting it into an evaporation chamber and using the following gaschromatographic parameters:

7 4 x 2 mm stainless steel column containing 20e polyethylene glycol At 10% on W chromosorb 60'i. 80 mesh washed with acids Length of column: 4 m Temperature of column: 90 C Carrier gas: nitrogen: 1.5K/m 2 Combustible gas: hydrogen: 0.45K/m 2 2 Comburent gas: alr: 1.0KM Flame ionization detector Detector temperature: 210 o C Evaporator temperature: 230 C Paper velocity: 10 mm/minute In order to confirm or to refute that the unusual odour came from the covering pouch or from the sheets inside the pouch ) the materials were analyzed by gas chromatography using the following technique: 50 x 10 mm strips are removed from the outer pouches or from the inner plastic sheets, and, following cleaning and cold drying, they are inserted into the special sample holder coil; the whole thing (coil + strips) is placed in the oven of the C. Erba pyrolysis apparatus and completely airsealed. The sample remains in the oven chamber for approximately 15 min at a temperature of 140 C. This temperature was selected so as not to char the plastic under examination or chemically alter the compounds present in it. At this point, the gas which has now formed in the oven chamber is introduced into the gas chromatograph using the gas chromatographic parameters reported above. N.B. The gases in the pouches, to which inert nitrogen was added, could be analyzed in two ways: either by introducing the gas into the separation chamber or by introducing the gas into the oven chamber of the pyrolysis apparatus.

8 6 Both methods were used in order to confirm the nature of the gases present, varying the retention times of same depending on the method of introduction. D) Colorimetric Reactions To identify the compounds responsible for the aroms, specific colour reactions were induced on the contents and on the'pduches; as recommended by Perez et al (1966), as follows: a) Esters: Areas of 50 cm2 were extracted with. 10 ml of Et.OH for 45 min at ambient temperature. The reaction of the esters is obtained on 1 ml according to Perez et al (1966). b) Carbonyl compounds: Areas of 50 cm2 are extracted in a test tube with 10 ml of benzene for 45 minutes. The reaction is obtained on 4 ml according to the method of Snell and Snell (1967). E) Analysis of the ester and carbonyl compound contents of salmon meat. a) Esters: 20 g of meat are extracted in a mixer or a mortar with Et.OH up to a total of 100 ml. It is filtered on paper. The ester reaction is obtained on 1 ml of filtrate according to Perez et al (1966). b) Carbonyl compounds: 20 g of meat are extracted with benzene in a mortar up to 100 ml. It is filtered on paper. The carbonyl reaction according to Snell and Snell (1967) is obtained on a known quantity appropriately diluted. RESULTS The results are shown in tables 1, 2, 3, 4, and 5, and are expressed as averages of the values obtained.

9 CONSIDERATIONS AND CONCLUSIONS Shown in table 1 are the counts of ph, humidity, TVN (basic volatile nitrogen (sic)), (total volatile nitrogen), peroxides and microbial flora of salmon meats before processing. On the basis of the data obtained and the result of the processing of meats with these characteristics, it is possible to establish that salmon meat, in order not to show alterations of the organoleptic characteristics during processing and preservation, must have: a) TVN concentrations below 30 milligrams of N/100 g; b) No peroxide; C) Humidity of 72/74%, and therefore equal to natural humidity; d) A microorganism count below 103 g/g (in the skin the b.acterial count is slightly higher, but must not exceed 10 5 g/g); e) The bacteria present must be mainly or exclusively sarcinae and cocci. Table 1 - ph, humidity, TVN, peroxide and microbial flora of salmon meats, before and during processing TVN Perox- Humid- Samplesexamined ph (mg of N/Kg) ides ity Germs/gr ' meq/kg % Meat Skin NaCl Frozen Salmon 6.2/6.3 20/ / D3.sqe,cte.d Salmon - 6.2/6.3 20/ / Salted Salmon 6.2/6.3 20/ / _OS 4.3% Smoked Salmon 6.1/6.2 25/ / %

10 8 Table 2 - ph, peroxide$,tvn, NaC1, humidity, formaldehyde, phenol of sliced salmon packaged'under vacuum. -- TVN Lot No. ph NaC1 PeroxidesHumidity Formal- Phenols. * (mg 100 of11/ g) T i. mg/100 % dehyde mg/kg mg/kg 1 6.2/6.3 25/30 4/5 0/1.4 54/ /6.3 25/30 3/4 1/5 69/ absent 3 6.2/6.3 30/40 2/4 0 64/68 traces traces 4 6.2/6.3 25/35 4/ /6.3 30/54 2/4 1.5/2 60/ absent. Table 3 - Esters, carbonyl compounds and peroxides of salmon meats and.- -.-poucheer.of-normal:salmon fillets and those-with "fruity" aroma.. ' Normal Sliced Pouch Used Fillets Sliced Fillets with "Fruity" Aroma Do Esters at 530 millimicrons 0.205/ / /0.315 DO Carbonyl Compounds at 430 millimicrons 0.260/ / /1.400 Peroxides mg 0 11/20 Table 4 - Basic volatile nitrogen (TVN) and microorganisms (g/gr) of normal sample's of sliced salmon packaged under vacuum and those with "fruity" odour. Normal Sliced Salmon Sliced Salmon with "Fruity" Aroma TVN mg N/100 g Germs (g/gr) 25/30. 50/79 4 '

11 .. 9 During the various phases of processing, the TVN must be kept below. the limit of 30 mg of N/100 g, the peroxides must not exceed 7/8 meq/kg and the bacteria must not reach concentrations higher than g/g. The saline concentration must reach a limit of 4%. Particular attention should be paid, during processing, to drying, smoking and salting. In fact, an examination of the results reported in Table 2 reveals considerable variations in humidity percentages in the various lots examined and just as many variations in the concentrations of sodium chloride, formaldehyde and phenols. In particular, these compounds are completely absent from certain samples. In fact, these variations, as already indicated by D'Aubert et al (1974), affect the preservability of the products and their importance is clearly revealed by the TVN count which, in some samples examined, greatly exceeds the limit value of 30 mg of N per 100 g.. At present, the preservability limits of salmon-based food products (both the fillets and the sliced salmon) cannot be established with certainty, although the commercial life sometimes required of products can be as much as 90 days at C. In our opinion, since this time limit seems to us excessive, it would be advisable to establish an exact time limit, to avoid lawsuits and con- siderable financial loss, as well as alterations of the organoleptic - characteristics. The preservability limit should be established experimentally based on the variations in TVN, peroxides and bacterial count at different storage temperatures and indeed we are presently working towards this end.

12 10 Table 5 --Gas-chromatographic analysis of the gases present in pouches of normal sliced salmon packaged under vacuum and those with a "fruity" odour, and of the plastic materials used for packaging. Presumed Components Indicative percentages based on the height of the peaks Salmon in a good state. Salmon with "fruity" of preservation odour Gas FZ B+1 Gas PZ B+1,...8. m..e.* Acetaldehyde 25.1 <5 <2 8.2 <5 <5 Pentaneeexane < Heptane+Octaiw < Octane (+x ) Acetone X <5 - <5 2. Xl <2 2.6<5 <5 <5 Eely1 cetate < < Methyl ethyl ketone <2 < Methanol+Isopropyl Acetate <2 <2 <2 <2 <2 <2 Ethanoi < Benzene. 2.6 <5 <5 <2 <5.<5 Propyl Acetate - ' <5 - <2 <5 <5 Tertiary Amyl (Alcohol) < <2 Methyl.isobutylketone+Tertiary <5 <2 <2 Butanol Propanol. 3.7 <2 < <5 Toluene. 4.1 <2 <2 <2' 11.9 <5 X - - <2 <2 - <2 Isobutanol 4 < <5 <2 Butyl acetate <2 - <2 <2 <5 <2. X <2 - - <2 - - X <2 <5 <2 6 5 Iscalleacetate < Butanol <2 - <2. <2 <2 <2 Xylol (Xylene) tr <2 - - <2 - X <2 < <2 X 7 <2 - <2 ' Amyl 8 acetate - <i <2 <2 - <2 X - -z.- <2. - <2 9 Legend: GAS =112+ gaseous odours FZ = inner plastic sheet B +1 =inked outer pouch

13 11 It is however essential that during storage, transport and sale, these products be kept at 0+50 C and not at ambient temperature, as is presently the case. Passing now to the second aspect of the problem, that is to say the alterations which occurs with the appearance of the "fruity " arom a in the pouches of sliced salmon, it may be maintained, on the basis of the experimental tests, that the aroma is the result of processes of fat oxidation, which translate into the formation of hydroperoxides and then of aldehydes. In particular (see Table No. 5), both in the pouches of normal salmon and in those with the "fruity" aroms, we find a good 34 components present. Some of these are solvents which migrate from the pouch. Other compounds are produced by the hydrolytic and oxidative processes, through the action of bacteria present in the various components of the meats. Based on the results of the gas-chromatographic analyses and the specific colorimetric tests, the compound responsible for the aroms is a carbpnyl (probably an aldehyde). In Table No. 5, it has been indicated as X8. Its production could be the result of an oxidative process caused by bacterial respiratory processes, during growth in an environment with low oxygen pressure as happens in this type of pouch made of combinations of plastic material, of which the permeability is between 5 and 10 cm3 of oxgen per cm2/atm in 24 hours. In confirmation of this hypothesis, a high count ( g/g) of bacteria (mainly Corynebacteria) was found in pouches containing salmon slices and the expe'rimental tests conducted using salmon artificially contaminated with a mixture of strains isolated from the altezéd salmon,

14 e k I. 12 reproduced it faithfully. In this regard, however, other research is necessary to gain an understanding of the exact mechanism of the-formation of the abnormal odour. Above all, it is necessary to thoroughly study the importance of the type of salmon used and its state of preservation. S. D'Aubert - P. Renon - P. Cattaneo A. Cremagnani, Institute for the Inspection of Foodstuffs, University of Milan, Italy. BIBLIOGRAPHY 1) Bills D.D., Morgan Ri.E., Libbey L.M. & Day E.A. (1965) J. Dairy Sci. 48, ) Cantoni C., Gervasini C. (1965) A4anrrale d'analisi delle carni /resche e conservate. Ed. Cuem - Milano. 3) D'Aubert S. & Cattaneo P. (1974) Arch. Vet. Ital. 25, ) D'Aubert S., Renon P., Cremagnani A. & Cattaneo P. ( 1975) Industrie Alimentari. In stampa. 5) Hosono A., Elliott J.A. & Mc Gugan W.A. ( 1974) J. Dairy Sci. 57, ) Hosono A. & Elliott J.A. (1974) J. Dairy Sci. 57, ) Pereira J.N. & Morgan M.E. (1958) J. Dairy Sci. 41, ) Pesez M., Poirier-P. & Bartos ( 1966) Pratique de l'analyse organique colorimetrique. Ed. Masson Parigi. 9) Reddy M.C., Bills D.D., Lindsay R.C., Libbey L.M., Miller A. & Morgan M.E. ( 1968) J. Dairy Sci. 51, ) Rgddy M.C., Lindsay R.C. & Montgomery M.W. (1970) Appl. Microbiol. 20, ) Singh S., Kristoffersen T. (1970) J. Dairy Sci. 53, ) Snell F.D. & Snell C.T. (1967) Colorivretric methods of analysis. Ed. Van Nostrand, New Yersey. 13) Vedamuthu E.R., Sandine W.E. & Elliker P.R. (1966) J. Dairy Sci. 49, ) Yano N. & Morichi T. (1970) 18 Int. Congr. Dairy Sci. IE : 107. ITALIAN BIBLIOGRAPHIC ITEMS 2) Manual of analysis of fresh and preserved meats.

15 .., Date Due A U G AOUT I 5 $g6 BRODART. CO. Cat. No Printed in U.S.A.