fat sausages
Dawn B. Homer
Kim R. Matthews and
Chris C. Warkup
For many years the Meat and Livestock Commission (MLC) has been encouraging and assisting the UK meat industry to reduce the fat content of pig, sheep and beef carcases produced in the UK. More recently the fat content of meat products has come under scrutiny. Meat products are an important source of fat in the UK human diet which, on average, is said to contain excessive fat. One of the targets of theHealth of the Nation Initiative(Department of Health, 1991) is that the percentage dietary energy originating from fat should fall from approximately 40 per cent to 35 per cent. In the UK (in particular Scotland and Northern Ireland) death rates from coronary heart disease (CHD) in both men and women exceed those in most other countries (BNF, 1992). A high incidence of CHD, and some other diseases, has for some time been linked, in both the scientific and lay press, to a high intake of saturated fat (Sanders, 1994). Meat products can have relatively high fat content compared to many other foods and because of this are criticised by health professionals.
There is a commonly held viewthat lowfat meat products generally have poorer eating quality but Mandigo and Elbert (1994), in a reviewof US literature, felt that significant yet relatively small reductions in fat would not be objectionable to most consumers. Such products have not proved successful in the UK. In one study (LFRA, 1995) it was found that lowfat meat products made up only 2 per cent of the meat market.
Sausages form a significant part of the meat product market in the UK. The National Food Survey (1998) estimates that the consumption of sausages in the home has remained relatively stable over the past few years at approximately 62 grams per person per week. In addition those in the lowest income groups consume twice as much as those in the highest income groups. Reductions in the fat content of sausages could have a large impact on the contribution of the meat industry to fat in the UK diet.
Much of the published research on reduced fat sausages has been carried out in the USA and Canada where fat replacers or water have been used to reduce the fat content of sausages (Ahmedet al., 1990; Barbut and Mittal, 1995; Krahlet al., 1995; Skelly et al., 1994). The situation in the UK is different.
The authors
Dawn B. Homeris a Statistician,Kim R. Matthewsis a Meat Scientist andChris C. Warkupis head of Livestock and Meat Science, all at the Meat and Livestock Commission, PO Box 44, Winterhill House, Snowdon Drive, Milton Keynes, UK.
Keywords
Taste, Food, Meat
Abstract
Sausages from three major retail outlets producing their own label pork and reduced fat sausages were sampled over a period of four weeks. A branded product was also purchased from the stores. A trained sensory panel evaluated the sausages and found that, although the overall acceptability differed between retailers, one of the low fat products matched the equivalent standard product in terms of acceptability. The overall acceptability of the branded product was within the range of the own label standard products but below the most acceptable low fat product. It was concluded that, whilst the successful production of low fat sausages is possible, a wider range would be encouraged by the adoption of modified compositional standards.
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Nutrition & Food Science
Volume 30 . Number 2 . 2000 . pp. 67±72
UK sausages must have a minimum meat content (consisting of lean and fat). Fat must be replaced with other meat, rather than a fat replacer or water, to keep the recipe within the legal requirements for a sausage (50 per cent meat) or pork sausage (65 per cent meat). This may have implications for the price, texture and flavour. Several major retail chains offer a lowfat alternative to their standard product. This study was set up to evaluate the eating quality of some of these lowfat products.
Materials and methods
Three national retail outlets were identified that produced their own label, chilled sausages that carried a lowfat claim as an alternative to their standard product. In addition a widely consumed branded standard sausage was included in the study.
Local retail stores were visited once per week for four weeks to ensure that purchases were from a range of manufacturing batches. On each purchase occasion six packs (454g or 1lb) of each product (reduced fat and the matched standard) were purchased. The branded product was purchased from more than one of the retail stores. After purchasing the samples were blast frozen to ±208C within three hours of purchase and stored until needed.
Samples purchased during the first week were used to develop a standard cooking methodology and for training of sensory panellists. Training was carried out in two phases. In the first phase panellists tasted samples and were asked to list descriptors perceived in each sample and then share their observations in group discussions. After several such sessions the following reference list was constructed from the list of attributes panellists found most useful to discriminate between samples:
During phase 2 panellists were asked to evaluate samples using these descriptors. Their performance was monitored by comparing results from sausages of the same recipe.
For the main analysis a single sensory session comprised the seven sausage types. One pack of each product was used from the same week's purchase. In total 15 packs of each product were panelled. Packs were removed from the freezer 24 hours before panelling and were thawed in a fridge at +48C. They were cooked for ten minutes under a Stott Benham commercial grill, adapted with a rotating turntable on the grill plates, with a low heat and were turned once. Although it was recognised that a standard cooking time for products differing in composition may not be ideal, cooking to fixed end point temperature was not logistically possible. Sausages were cut into three and samples were presented to panellists wrapped in foil and kept warm on heated plate stands. The order of tasting by panellists within a session was rotated using a partial Latin square design to ensure that any ordering effects were minimised.
Between nine and 12 panellists assessed each sample on a 24-point pseudo-line scale for the descriptors listed above.
One pack of each product from purchase weeks two, three and four was used for chemical analysis. Sausages were thawed and half the pack was cooked as for the sensory analysis. Both halves were then refrozen and transported to the Department of Food Animal Science at the University of Bristol where they were analysed for protein, fat, moisture, carbohydrate and ash. All sausages were skinned before blending and were analysed by the following methods:
. Moisture and fat by CEM according to
Crosland and Bratchell (1988).
. Total nitrogen by Kjeldahl distillation
using Buchi nitrogen distillation apparatus and values obtained were multiplied by 6.25 to give crude protein.
. Ashing to a constant weight was carried
out overnight at 5508C.
. Carbohydrate was obtained by
Statistical analysis
Panellist scores were averaged for each descriptor and sample, so for every sample a mean score for each descriptor was used in an analysis of variance with terms for:
. session;
. fatness ± standard, low;
. source ± A, B, C, D,
and the interaction between fatness and source.
Results
The declared composition, pack size and price of the product panelled are presented in Table I. All declared compositional data were for the rawproduct except for product D which was for cooked. Composition was not declared to the same detail on all products. The rawfat content of the standard products ranged from 26-30 per cent and for the reduced fat product 10-12 per cent. The reduction in fat between the standard and reduced fat product from the same source was always greater than 50 per cent. The protein content of the lower fat products was declared higher than the standard, perhaps due to a higher lean meat content. Lean meat content was highest for source C standard pork sausage and the lowest was for source C lower fat sausage at 60 per cent ± which at this level means it cannot be labelled a pork sausage. Generally as the fat decreased and protein increased the cost of the sausages increased, due to the need to replace fat with other meat. Differences in carbohydrate and
fibre content were not consistent across source. The Table also shows the purchase price at the time of sampling; not surprisingly within supplier the low fat products were always more expensive than the standard product.
The results of the chemical analysis generally confirmed those stated by the supplier (Table II). The relationship between the fat in the rawproduct and the cooked product was linear (Figure 1). The line of best fit suggests that, whilst at least 3.5 per cent fat will remain in the cooked product, the rest of the fat reduces by approximately 60 per cent (i.e. a sausage with an uncooked fat content of 10 per cent will have a predicted cooked fat content of (10 ± 3.5)*0.6 + 3.5 = 7.4 per cent). Perhaps surprisingly there was no strong relationship between cooking loss (by weight) and fat content.
Least square means for the sensory
attributes are shown in Table III. Overall the standard product was significantly more acceptable than the lowfat versions (figures not shown); however, there were also large differences both within the standard product and within the low fat versions. Supplier A's lowfat product matches its standard although both have a relatively lowacceptability mean. The lowfat product from supplier B had a poorer acceptability mean than the standard from the same supplier, although the mean was higher than the other two low fat products, the standard product from source A and the branded sausage. Supplier C's lowfat product was poor compared to all of the other products. Supplier B's and C's standard product matched the branded product for overall acceptability.
Table IDeclared composition of sausage products
Supplier A Supplier B Supplier C Brand
Pork Pork
Raw Lower fat Pork Lower fat Pork Lower fat Cooked Protein 10.5 13.9 10.3 10.8 11.0 12.7 14.0
Carbohydrate 11.9 10.5 8.3 11.3 9.8 9.4 16.0
Sugars 2.2 0.7 1.4 2.1 1.7 0.3 1.7
Starch 9.7 9.8
Fat 26.8 9.9 30.4 12.3 28.3 12.0 18.0
Saturates 10.6 3.8 12.5 4.4 11.3 4.7 11.0
Monos 13.4 5.2
Poly 3.6 1.8 3.4 2.2 0.4
Fibre 1.3 2.1 0.3 0.2 2.4 0.0 1.4
Sodium 0.8 0.8 0.8 0.5 1.0 0.5 1.4
Min. meat content 65.0 65.0 68.0 60.0 65.0 65.0 65.0
The correlations between the attributes and overall acceptable scores are shown in Table IV (after correction for session). There were high, positive correlations for meatiness and pork flavour with overall acceptability and high, negative correlations for breadiness and off flavour. The scores for these four
attributes are reflected in the overall acceptability scores. Both the standard and lowfat products from supplier A had high abnormal flavour scores and relatively high breadiness scores with relatively low meatiness scores.
The lowfat product from supplier C had the highest breadiness and off flavour scores and the lowest meatiness and pork flavour scores. The branded product, product D, had means in the middle of the range for the four important attributes and overall
acceptability.
Discussion
Perhaps surprisingly acceptability was more related to flavour traits than textural ones. Fats may serve as a depot for naturally occurring flavour compounds and these may be released on chewing (Rhee, 1989). When interpreting these results the standardised cooking methodology should be recognised. All of the lower fat sausages had a higher water content than the standard equivalents and may not have cooked quite so much due to a greater specific heat capacity. However, the cooked water content of all lower fat sausages was similar and this cannot therefore explain the large differences in acceptability between the retail sources.
Results from the sensory analysis indicate that it is possible to manufacture an
acceptable lowfat sausage, although for two of the three retailers surveyed consumers switching from the standard to the lower fat product may detect a deterioration in acceptability. It is clear that, although the successful production of lowfat sausages is possible, a wider range would be encouraged by the adoption of modified compositional standards. Added water increases tenderness of sausages to the extent that an equivalent or
better product can be produced (Ahmedet
al., 1990; Barbut and Mittal, 1995; Frederick
et al., 1994). In fact the viewimplicit in the American literature is clearly expressed by Claus (1991) and is worth quoting: ``Without
Table IIChemical analysis of sausage products
Supplier A Supplier B Supplier C Brand Pork Lower fat Pork Lower fat Pork Lower fat Pork Moisture
Raw 48.6 63.5 47.1 59.4 47.0 61.5 47.6
Cooked 50.5 59.7 49.2 57.7 50.5 59.6 51.6
Fat
Raw 26.4 8.8 28.9 14.0 27.2 11.1 26.3
Cooked 19.4 8.2 24.2 12.7 18.4 10.4 16.6
Ash
Raw 2.6 2.5 2.5 2.6 2.9 2.2 3.1
Cooked 3.3 2.7 2.7 2.9 3.6 2.3 3.8
Protein
Raw 9.1 13.2 9.2 10.9 10.2 10.9 10.2
Cooked 11.1 14.7 10.9 11.9 11.9 12.4 12.4
Carbohydrates
Raw 13.3 12.0 12.2 13.2 12.8 14.2 12.8
Cooked 15.8 14.7 13.0 14.8 15.6 15.2 15.6
Cooking loss (%) 10.2 8.7 12.1 7.3 13.9 8.1 14.2
[the] added flexibility provided by the [rule allowing additional added water] the reduction in fat in processed meats would result in products that are tougher, more rubbery, less juicy and more expensive than high fat products.'' A general change in the standards such that the requirement for a total meat content was replaced by a total lean meat content would allow fat to be replaced with other ingredients (including water). Alternatively, a separate ruling could be made for lowfat products to allowtheir
development. This would protect the quality of standard products but the requirement to identify the lower fat product as different
would not allow healthier products to be sold under standard labels.
In the light of consumers' attitude to fat and the evidence relating fat intake to human disease, industry should continue, or even accelerate, its efforts to reduce the fat content of sausages. With care and attention lower fat products can be achieved with little detriment to sensory properties.
References
Ahmed, P.O., Miller, M.F., Lyon, C.E., Vaughters, H.M. and Reagan, J.O. (1990), ``Physical and sensory characteristics of low-fat fresh pork sausages processed with various levels of added water'', J. Food Sci., Vol. 55 No. 3, pp. 625-8.
Barbut, S. and Mittal, G.S. (1995), ``Physical and sensory properties of reduced fat breakfast sausages'', J. Musc. Foods, Vol. 6, pp. 47-62.
BNF, B. N. F. (1992),Unsaturated Fatty Acids ± Nutritional and Physiological Significance, Chapman & Hall, London.
Claus, J.R. (1991),Fat Reduction in Comminuted Meat Systems, 44th Annual Reciprocal Meat Conference, Kansas State University, National Livestock and Meat Board, Chicago, IL.
Crosland, A.R. and Bratchell, N. (1988), ``An evaluation and comparison of the CEM meat analysis system with official standard methods for the
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Department of Health (1991),The Health of the Nation, HMSO, London.
Table IVCorrelations with overall acceptability (after correction for session)
Table IIILeast square means for sensory attributes
Supplier A Supplier B Supplier C Brand
Pork Tenderness 17.4 16.9 ns 17.7 16.7 * 18.1 19.0 * 18.3
Particle size 14.8 12.7 *** 11.7 11.4 ns 11.6 11.8 ns 11.3
Firmness 12.1 14.8 *** 13.3 15.4 ** 11.8 8.2 *** 9.9
Juiciness 14.0 13.7 ns 15.6 14.4 * 14.5 12.3 *** 13.1
Greasiness 14.7 13.2 ** 15.9 13.7 *** 14.4 13.7 ns 14.3
Breadiness 12.5 13.2 ns 9.4 10.5 * 11.7 15.3 *** 12.5
Springiness 11.3 12.7 ns 13.1 14.2 ** 11.4 9.3 *** 9.7
Graininess 9.6 11.1 *** 8.2 9.4 ** 9.3 10.9 *** 8.9
Meatiness 14.1 13.6 ns 16.3 15.4 ns 15.2 11.3 *** 14.5
Pork flavour 12.7 12.2 ns 15.4 13.8 ** 14.2 10.3 *** 14.1
Spiciness 10.6 12.8 *** 12.9 14.6 ** 12.9 12.3 ns 13.4
Saltiness 10.9 10.3 ns 11.2 10.8 ns 11.9 9.3 *** 13.0
Herbiness 7.7 10.3 *** 9.1 11.0 *** 9.3 9.3 ns 8.9
Off flavour 5.6 7.1 * 3.5 4.5 ns 4.2 9.3 *** 3.5
Acceptability 12.2 12.3 ns 15.8 14.3 ** 15.1 9.4 *** 13.9
Notes
Frederick, T.L., Miller, M.F., Tinney, K.S., Bye, L.R. and Ransey, C.B. (1994), ``Characteristics of 95% lean beef German sausage varying in phosphate and added water'',J. Food Sci., Vol. 59 No. 3, pp. 153-455.
Krahl, L.M., Rhee, K.S., Lin, K.W., Keeton, J.T. and Ziprin, Y.A. (1995), ``Sodium lactate and sodium
tripolyphosphate effects on oxidative stability and sensory properties of precooked reduced fat pork sausage with carrageenan'',J. Musc. Foods, Vol. 6, pp. 243-56.
LFRA (1995),Fat Substitutes, Leatherhead Food Research Association.
Mandigo, R.W. and Elbert, S. (1994), ``Strategies for reduced-fat processed meats. Low-fat meats'', in Hafs, H.D. and Zimbleman, R.G. (Eds),Design
Strategies and Human Implications, Academic Press, San Diego, CA, pp. 145-66.
National Food Survey 1997 (1998), Ministry of Agriculture Fisheries and Food, HMSO.
Rhee, K.S. (1989), ``Chemistry of meat flavour'', in Min, D.B. and Smouse, T.H. (Eds),Flavour Chemistry of Lipid Foods, American Oil Chemists' Society, Champaign, IL, pp. 166-89.
Sanders, T. (1994),Dietary Fats, Health Education Authority.
