J. Sci. Food Agric. 1979, 30, 499-502
The Use of Mutton Tallow Fat in Fish Sausages Haluk Turguta, David Pearsonb and James Brennan National College of Food Technology, St George’s Avenue, Weybridge, Sicrrey (Manuscript received 10 July 1978)
This work studied the possibility of using mutton tallow fat as an ingredient in fish sausages as an alternative to pork fat. Mutton fat was found to produce an acceptable product. Addition of the fat at two different stages in the chopping cycle resulted in textural changes in the products. In the product containing the mutton fat variation in the time of addition of the fat also influenced the flavour of the product. 1. Introduction
This study is concerned with the conversion of fish of low acceptability into attractive forms for consumption. The material chosen is whiting (Merlangius rnerlangus) which has a low fat content and is readily available in large quantities. The aim is to compare fish sausages containing mutton tallow fat with those containing added pork fat, which is usually used in fish sausages manufactured in most parts of the world. The comparison is made on the basis of both flavour and texture of the products. Hansenl described the structure of meat emulsions and published photomicrographs of same. This work established that these products are mixtures in which finely divided meat constituents are dispersed throughout a fat-in-water emulsion. Much has been made of model systems to study the behaviour of such emulsions. In this way the influences of: pH; types of proteins and fats; the presence of sodium chloride and other ions; the presence of fillers and binders; temperature; type and degree of mechanical action; the use of fresh or frozen meat have been st~died.~-4 Edible mutton tallow fat is not used extensively in western foods, mainly because of the difficulty of complete removal of the strong odour and f l a ~ o u rHowever, .~ it is used for a variety of purposes in eastern countries. Very small chemical differences are found between pork fat and mutton tallow fat.6 2. Materials and methods
Fish (whiting) and edible mutton fat were bought in from retailers and frozen. Food grades of sodium chloride 2.5 %, sucrose 1.5 %, potato starch 8.0 %, peppers and spices 0.5 % and AR grades of potassium hydrogen phosphate 1.0%, sorbic acid 2.0% were used. Fish sausages were formulated and prepared according to the procedure reported in the literature.7-10 This was as follows: 250 g minced fish flesh at -2°C was washed with 500 cm3 distilled water, three times. The water was pressed out each time by hand through cheese cloth. The wash water was chilled during the second and third washings. At the end of the washing the temperature of the fish flesh was 2-3 “C. Two different chopping procedures were used in a pilot scale bowl chopper (Ward-Swift Co., knife speed 1700 rev min-1). In the first of these all the ingredients, including the fats, were chopped for 4 min. In the second procedure all the ingredients, except the fats were chopped for 3 min 45 s a Present address: Marmara Scientific and Industrial Research Institute, Department of Nutrition and Food Technology, P.K. 21, Gebze, Kocaeli, Turkey. b Deceased.
0022-5142/79/0500-0499 $02.00
01979 Society of Chemical Industry 499
H. Turgut et uI.
500
at which point the fats were added and chopping continued for a further 15 s. Samples for analysis were taken at various stages and frozen until required. At the end of the chopping the temperature of the mix was 12-13°C. The mixture was stuffed into Hypak PVDC casings, heat processed in a water bath at 90°C for 60 min and cooled quickly. Chemical, physical and organoleptic analyses were carried out on the samples. These included determination of protein by the Kjeldahl procedure, moisture by drying at 1OOf 1°C for 16 h, ash by ignition at 450f 10°C for 16 h and fat by Soxhlet extraction of the dried residue using light petroleum. The texture of fish sausages was measured using the General Foods Texturometer: (Tominaga and Co. Ltd, Tokyo, Japan). Fish sausage discs, 1.27 cm thick, were used. The parameter assessed was that reported as ‘hardness’ by Friedman et a/.” and expressed in the present study as chart units per unit voltage input Figure 1 .12
t
A Time
Figure 1. Typical texture profile curve obtained in the GFT (after Brennan et u/.l2)).H~=Hardness;A e / A l = cohesiveness; As=adhesiveness; (C-B)=elasticity; H e = brittleness; C = B for clay.
The ranking method was used to evaluate the texture and flavour. Four samples were presented to 20 panelists. The latter were selected from college personnel and included male and female members of varying ages. No special training was given. The first question related to the flavour of sausages and the second to texture. Latin square design was used for the above ranking. The grading and analysis of results were calculated as described by Larmond.l3 3. Results and discussion The results of the chemical analyses are shown in Table 1. From these results it can be seen that washing the minced fish flesh increased its water content by 3-4%. The moisture contents of the two sausage products did not differ significantly. Washing also had the effect of reducing the ash content of the minced flesh indicating a considerable loss of soluble minerals into the washings. Washing also resulted in a reduction in the fishy
Mutton tallow fat in fish sausages
501
Table 1. Composition of fish flesh and fish sausages
Water (%) Ash ( % I Protein (%) N x 6 . 1 Fat (%) Fish flesh in dried mix (‘Kj
MFF
MWFF
PFAFS
MTFAFS
81 .o 1.20 16.8 0.1
84.1 0.25 14.3 0.1
69.5 3.40 11.1 6.9 62.4
68.3 3.40 11.6 7.6 66.3
M F F = Mincedfishflesh; MWFF=minced-washedfishflesh;PFAFS=pork fat added fish sausages ; MTFAFS = mutton tallow fat added fish sausages. Table 2. Texture of fish sausages as determined using the General Foods Texturometer
PI PS MI
Mz
HI
Hi volt-’
A1 cm2
Az cm2
AzlAi
42.3 44.3 61.7 59.5
28.2 29.5 40.2 39.7
9.86 9.95 14.75 13.77
4.32 4.59 7.02 7.62
0.43 0.45 0.47 0.55
P ~ = P o r kfat chopped with slurry for 4 min; P?=pork fat chopped with slurryfor 15 s (fat added after 3 min 45 s); Mi = mutton tallow fat chopped with slurry for 4 rnin; M Z= mutton tallow fat chopped with slurry for 15 s (fat added after 3 min 45 sj.
odour of the flesh suggesting that some of the odour compounds were water soluble and hence lost during washing. The high ash content of the sausage products relative to the minced fish flesh arises from the high ash content of the other ingredients included in the formulations (spices and salt mainly). The protein content of the minced fish flesh also fell as a result of washing presumably due to the leaching out of water soluble protein material. Fish flesh is known to contain some non-protein nitrogen and this was calculated as protein.14 The protein contents of the two sausage products were very similar in the range 11 .4-12.0 %. Nominally 8 % of added fat was included in both sausage formulations. The actual fat content, determined by extraction was in the range 5.5-7.5 %, being higher in the product containing mutton fat as compared with the pork-only recipe. This is probably due to the presence of moisture in the raw fats, the pork fat containing more than the mutton fat. The results of the texture measurements using the General Foods Texturometer are shown in Table 2. These figures represent the mean of ten replicates. Hardness of the products are shown under HI and also HI volt-l as chart units and this is a good index of firmness of sausages. The difference between PI and PZ is not significant at 5 % level according to the ‘t’ test. In all cases sausages containing mutton tallow fat were harder than those containing pork fat. The ‘cohesiveness’ of sausages (A2/A1) is also shown in Table 2. There is a considerable difference between M I and M.2 while the others were more or less the same. Adhesiveness was not measured as an area (the negative peak obtained when the plunger withdraws from the the sample in the first cycle) and it was thought that the height of the negative peak can be used instead. The addition of fat at different times effects this characteristic of the sausages. Fat chopped for 4 min gave more adhesive product than fat chopped only for 15 s. Looking at the texturometer curves, examples of which are shown in Figure 2, it was observed that the broken, multipeak feature in the first curve of each cycle changes location from the ‘downstream’ side of the peak to the ‘upstream’ side as the chopping time is reduced from 4 min to 15 s. The fat particles in PZ and M Z sausages were relatively large while in P I and M I were evenly distributed and of smaller size. The taste panel could detect n o significant differences in texture between the four samples. It
H. Turgut ef ol.
502
Figure 2. Multipeak shapes of texturorneter curves for fish sausages.
would appear that the differences detected instrumentally were masked by the other organoleptic properties to the extent that panelists failed to notice them. Results on flavour indicated a different picture. The panel results showed that M I is significantly ( 5 % level) less acceptable than PI,Pz,and M z . The addition of pork fat at different times ( P I ,Pz)did not give a different flavour but the addition of mutton tallow fat at different times gave different results. This means that longer chopping time of mutton tallow fat produced an undesirable flavour note. The panel did not report a fishy taste in the sausages. Although the college panel objected to the mutton tallow flavour in the M I sample such a flavour could be attractive to Asian consumers. In fact the Asian diet includes large amounts of mutton and therefore the tendency is to like such a flavour, so a longer chopping time with mutton tallow fat may yield a product with better acceptance in Asian countries.
Acknowledgement This work formed part of a project for the degree of M S c . in the University of Reading, National College of Food Technology. H. Turgut is grateful for the award of a CENT0 Fellowship. References 1. Hansen L. J. Food Technol. 1960, 14, 565. 2. Swift, G. E.; Locker, C.; Fryer, A. J. Food Technol. 1961, 15, 468. 3. Hogarty, G . R.; Bratzler, L. S.; Pearson, A. M. J. Food Sci. 1963, 28, 663. 4. Carpenter, J. A.; Saffle, R. L. J . Food Sci. 1964, 29, 774. 5. Kirschenbauer, H. G. Futs and Oils; An Outline of their Chemistry and Technoiogy Reinhold Pub. Corp., London, 1960. 6. Hilditch, T. P; Williams, P. N. The Chemical Constitution of Nutural Fats Chapman and Hall, London, 1969, 4th edn. 7. Ueno, S . Ind. of Fish Sausage and Meat Sausage in Japan Kureka Chemical Ind. Co. Ltd, Lab. of Food Proc. No. 2, 3-3, Chome, Kichdaki, Chuo-ku, Tokyo, Japan, 1968. 8. Amano, K. In Fish us Food Vol. 3 (Borgstrom, G., Ed.), Academic Press, London, 1965. 9. McLay, R. Torry Adv. Note, No. 43 Torry Res. Station, Aberdeen, 1969. 10. Krishnawarny, M. A.; Pastel, J. D.; Dhanora, J. S.; Govindurajan, V. S.; Yunus Ahmet, S. J. Food Sci. Techno[. (Myrose) 1968, 5 (4), 186. 11. Friedman, H. H.; Whitney, J. E.; Szczesniak, A. S. J. Food Sci. 1963, 28, 390. 12. Brennan, J. G.; Jowitt, R.; Mughsi, 0. A. J. Texture Stud. 1970, 1, 167. 13. Larmond, E. Methods for Sensory Evaluation of Food Food Research Inst. Central Experimental Farm, Canada Dept. of Agric., Ottawa, 1967. 14. Pimentel, H. R. Texture inadifcations of coinininutedfish muscle systems Ph.D. Thesis, University of Reading, 1971.
The Use of Mutton Tallow Fat in Fish Sausages Haluk Turguta, David Pearsonb and James Brennan National College of Food Technology, St George’s Avenue, Weybridge, Sicrrey (Manuscript received 10 July 1978)
This work studied the possibility of using mutton tallow fat as an ingredient in fish sausages as an alternative to pork fat. Mutton fat was found to produce an acceptable product. Addition of the fat at two different stages in the chopping cycle resulted in textural changes in the products. In the product containing the mutton fat variation in the time of addition of the fat also influenced the flavour of the product. 1. Introduction
This study is concerned with the conversion of fish of low acceptability into attractive forms for consumption. The material chosen is whiting (Merlangius rnerlangus) which has a low fat content and is readily available in large quantities. The aim is to compare fish sausages containing mutton tallow fat with those containing added pork fat, which is usually used in fish sausages manufactured in most parts of the world. The comparison is made on the basis of both flavour and texture of the products. Hansenl described the structure of meat emulsions and published photomicrographs of same. This work established that these products are mixtures in which finely divided meat constituents are dispersed throughout a fat-in-water emulsion. Much has been made of model systems to study the behaviour of such emulsions. In this way the influences of: pH; types of proteins and fats; the presence of sodium chloride and other ions; the presence of fillers and binders; temperature; type and degree of mechanical action; the use of fresh or frozen meat have been st~died.~-4 Edible mutton tallow fat is not used extensively in western foods, mainly because of the difficulty of complete removal of the strong odour and f l a ~ o u rHowever, .~ it is used for a variety of purposes in eastern countries. Very small chemical differences are found between pork fat and mutton tallow fat.6 2. Materials and methods
Fish (whiting) and edible mutton fat were bought in from retailers and frozen. Food grades of sodium chloride 2.5 %, sucrose 1.5 %, potato starch 8.0 %, peppers and spices 0.5 % and AR grades of potassium hydrogen phosphate 1.0%, sorbic acid 2.0% were used. Fish sausages were formulated and prepared according to the procedure reported in the literature.7-10 This was as follows: 250 g minced fish flesh at -2°C was washed with 500 cm3 distilled water, three times. The water was pressed out each time by hand through cheese cloth. The wash water was chilled during the second and third washings. At the end of the washing the temperature of the fish flesh was 2-3 “C. Two different chopping procedures were used in a pilot scale bowl chopper (Ward-Swift Co., knife speed 1700 rev min-1). In the first of these all the ingredients, including the fats, were chopped for 4 min. In the second procedure all the ingredients, except the fats were chopped for 3 min 45 s a Present address: Marmara Scientific and Industrial Research Institute, Department of Nutrition and Food Technology, P.K. 21, Gebze, Kocaeli, Turkey. b Deceased.
0022-5142/79/0500-0499 $02.00
01979 Society of Chemical Industry 499
H. Turgut et uI.
500
at which point the fats were added and chopping continued for a further 15 s. Samples for analysis were taken at various stages and frozen until required. At the end of the chopping the temperature of the mix was 12-13°C. The mixture was stuffed into Hypak PVDC casings, heat processed in a water bath at 90°C for 60 min and cooled quickly. Chemical, physical and organoleptic analyses were carried out on the samples. These included determination of protein by the Kjeldahl procedure, moisture by drying at 1OOf 1°C for 16 h, ash by ignition at 450f 10°C for 16 h and fat by Soxhlet extraction of the dried residue using light petroleum. The texture of fish sausages was measured using the General Foods Texturometer: (Tominaga and Co. Ltd, Tokyo, Japan). Fish sausage discs, 1.27 cm thick, were used. The parameter assessed was that reported as ‘hardness’ by Friedman et a/.” and expressed in the present study as chart units per unit voltage input Figure 1 .12
t
A Time
Figure 1. Typical texture profile curve obtained in the GFT (after Brennan et u/.l2)).H~=Hardness;A e / A l = cohesiveness; As=adhesiveness; (C-B)=elasticity; H e = brittleness; C = B for clay.
The ranking method was used to evaluate the texture and flavour. Four samples were presented to 20 panelists. The latter were selected from college personnel and included male and female members of varying ages. No special training was given. The first question related to the flavour of sausages and the second to texture. Latin square design was used for the above ranking. The grading and analysis of results were calculated as described by Larmond.l3 3. Results and discussion The results of the chemical analyses are shown in Table 1. From these results it can be seen that washing the minced fish flesh increased its water content by 3-4%. The moisture contents of the two sausage products did not differ significantly. Washing also had the effect of reducing the ash content of the minced flesh indicating a considerable loss of soluble minerals into the washings. Washing also resulted in a reduction in the fishy
Mutton tallow fat in fish sausages
501
Table 1. Composition of fish flesh and fish sausages
Water (%) Ash ( % I Protein (%) N x 6 . 1 Fat (%) Fish flesh in dried mix (‘Kj
MFF
MWFF
PFAFS
MTFAFS
81 .o 1.20 16.8 0.1
84.1 0.25 14.3 0.1
69.5 3.40 11.1 6.9 62.4
68.3 3.40 11.6 7.6 66.3
M F F = Mincedfishflesh; MWFF=minced-washedfishflesh;PFAFS=pork fat added fish sausages ; MTFAFS = mutton tallow fat added fish sausages. Table 2. Texture of fish sausages as determined using the General Foods Texturometer
PI PS MI
Mz
HI
Hi volt-’
A1 cm2
Az cm2
AzlAi
42.3 44.3 61.7 59.5
28.2 29.5 40.2 39.7
9.86 9.95 14.75 13.77
4.32 4.59 7.02 7.62
0.43 0.45 0.47 0.55
P ~ = P o r kfat chopped with slurry for 4 min; P?=pork fat chopped with slurryfor 15 s (fat added after 3 min 45 s); Mi = mutton tallow fat chopped with slurry for 4 rnin; M Z= mutton tallow fat chopped with slurry for 15 s (fat added after 3 min 45 sj.
odour of the flesh suggesting that some of the odour compounds were water soluble and hence lost during washing. The high ash content of the sausage products relative to the minced fish flesh arises from the high ash content of the other ingredients included in the formulations (spices and salt mainly). The protein content of the minced fish flesh also fell as a result of washing presumably due to the leaching out of water soluble protein material. Fish flesh is known to contain some non-protein nitrogen and this was calculated as protein.14 The protein contents of the two sausage products were very similar in the range 11 .4-12.0 %. Nominally 8 % of added fat was included in both sausage formulations. The actual fat content, determined by extraction was in the range 5.5-7.5 %, being higher in the product containing mutton fat as compared with the pork-only recipe. This is probably due to the presence of moisture in the raw fats, the pork fat containing more than the mutton fat. The results of the texture measurements using the General Foods Texturometer are shown in Table 2. These figures represent the mean of ten replicates. Hardness of the products are shown under HI and also HI volt-l as chart units and this is a good index of firmness of sausages. The difference between PI and PZ is not significant at 5 % level according to the ‘t’ test. In all cases sausages containing mutton tallow fat were harder than those containing pork fat. The ‘cohesiveness’ of sausages (A2/A1) is also shown in Table 2. There is a considerable difference between M I and M.2 while the others were more or less the same. Adhesiveness was not measured as an area (the negative peak obtained when the plunger withdraws from the the sample in the first cycle) and it was thought that the height of the negative peak can be used instead. The addition of fat at different times effects this characteristic of the sausages. Fat chopped for 4 min gave more adhesive product than fat chopped only for 15 s. Looking at the texturometer curves, examples of which are shown in Figure 2, it was observed that the broken, multipeak feature in the first curve of each cycle changes location from the ‘downstream’ side of the peak to the ‘upstream’ side as the chopping time is reduced from 4 min to 15 s. The fat particles in PZ and M Z sausages were relatively large while in P I and M I were evenly distributed and of smaller size. The taste panel could detect n o significant differences in texture between the four samples. It
H. Turgut ef ol.
502
Figure 2. Multipeak shapes of texturorneter curves for fish sausages.
would appear that the differences detected instrumentally were masked by the other organoleptic properties to the extent that panelists failed to notice them. Results on flavour indicated a different picture. The panel results showed that M I is significantly ( 5 % level) less acceptable than PI,Pz,and M z . The addition of pork fat at different times ( P I ,Pz)did not give a different flavour but the addition of mutton tallow fat at different times gave different results. This means that longer chopping time of mutton tallow fat produced an undesirable flavour note. The panel did not report a fishy taste in the sausages. Although the college panel objected to the mutton tallow flavour in the M I sample such a flavour could be attractive to Asian consumers. In fact the Asian diet includes large amounts of mutton and therefore the tendency is to like such a flavour, so a longer chopping time with mutton tallow fat may yield a product with better acceptance in Asian countries.
Acknowledgement This work formed part of a project for the degree of M S c . in the University of Reading, National College of Food Technology. H. Turgut is grateful for the award of a CENT0 Fellowship. References 1. Hansen L. J. Food Technol. 1960, 14, 565. 2. Swift, G. E.; Locker, C.; Fryer, A. J. Food Technol. 1961, 15, 468. 3. Hogarty, G . R.; Bratzler, L. S.; Pearson, A. M. J. Food Sci. 1963, 28, 663. 4. Carpenter, J. A.; Saffle, R. L. J . Food Sci. 1964, 29, 774. 5. Kirschenbauer, H. G. Futs and Oils; An Outline of their Chemistry and Technoiogy Reinhold Pub. Corp., London, 1960. 6. Hilditch, T. P; Williams, P. N. The Chemical Constitution of Nutural Fats Chapman and Hall, London, 1969, 4th edn. 7. Ueno, S . Ind. of Fish Sausage and Meat Sausage in Japan Kureka Chemical Ind. Co. Ltd, Lab. of Food Proc. No. 2, 3-3, Chome, Kichdaki, Chuo-ku, Tokyo, Japan, 1968. 8. Amano, K. In Fish us Food Vol. 3 (Borgstrom, G., Ed.), Academic Press, London, 1965. 9. McLay, R. Torry Adv. Note, No. 43 Torry Res. Station, Aberdeen, 1969. 10. Krishnawarny, M. A.; Pastel, J. D.; Dhanora, J. S.; Govindurajan, V. S.; Yunus Ahmet, S. J. Food Sci. Techno[. (Myrose) 1968, 5 (4), 186. 11. Friedman, H. H.; Whitney, J. E.; Szczesniak, A. S. J. Food Sci. 1963, 28, 390. 12. Brennan, J. G.; Jowitt, R.; Mughsi, 0. A. J. Texture Stud. 1970, 1, 167. 13. Larmond, E. Methods for Sensory Evaluation of Food Food Research Inst. Central Experimental Farm, Canada Dept. of Agric., Ottawa, 1967. 14. Pimentel, H. R. Texture inadifcations of coinininutedfish muscle systems Ph.D. Thesis, University of Reading, 1971.
