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Practical use of surimi-like material made from porcine longissimus dorsi muscle for the production of low-fat pork patties
Meat Science 90 (2012) 292–296
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Meat Science j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / m e a t s c i
Practical use of surimi-like material made from porcine longissimus dorsi muscle for the production of low-fat pork patties Y.M. Choi, J.H. Choe, D.K. Cho, B.C. Kim ⁎ Division of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Korea University, 5-1 Anam-dong, Sungbuk-gu, Seoul 136-713, South Korea
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Article history: Received 25 February 2011 Received in revised form 11 July 2011 Accepted 16 July 2011 Keywords: Surimi-like material Fat replacer Low-fat meat products Pork patties
a b s t r a c t This study evaluates the effect of replacing fat with surimi-like material (SLM) made from the porcine longissimus dorsi muscle on the physicochemical and sensory characteristics of pork patties. Pork patties were produced with different levels of fat and SLM using a commercial method. Pork patties produced with 20% SLM had the lowest fat content (1.76%, P b 0.001), and had a higher cooking yield (87.41 vs. 78.57%, P b 0.05) and less shrinkage (4.01 vs. 9.02%, P b 0.001) than patties produced with 20% back-fat (control). Moreover, patties produced with SLM exhibited more acceptable organoleptic characteristics, including tenderness (P b 0.01) and overall acceptability (P b 0.001), than full-fat control patties. These results indicated that SLM cannot only be used as a fat replacer, but that it also improves the physicochemical and sensory characteristics of low-fat pork patties. © 2011 Elsevier Ltd. All rights reserved.
1. Introduction According to a report of the top 10 functional food trends in 2009 (Sloan, 2010), 58% of Americans consumed fortified foods last year to supplement their diet. Additionally, the report shows that most consumers read the nutritional facts on the labels of food products and wanted to know their overall fat content when they bought them for the first time, avoiding foods that contained higher levels of fat, sodium, and calories (Sloan, 2010). Because, many consumers believe that excessive consumption of meat and meat products is associated with obesity and various diseases due to their high fat content (Biesalski, 2005). In this sense, the demand for healthier food products, especially low-fat products, is rapidly increasing, with new low- and reduced-fat meat products being developed (Cierach, Modzelewska-Kapitula, & Szacilo, 2009), although the study of the association between meat consumption and the risk of developing cancer has produced inconsistent results, with some studies finding no association between dietary fat intake from meat products and colorectal cancer (Ferguson, 2010; Lin, Zhang, Cook, Lee, & Buring, 2004; Santarelli, Pierre, & Corpet, 2008; Webb & O'Neill, 2008). The amount of fat in meat products plays an important role in determining the organoleptic and quality characteristics, including stabilizing emulsions and improving their water-holding capacity (WHC) (Hughes, Confrades, & Troy, 1997; Keeton, 1994; Webb &
⁎ Corresponding author. Tel.: + 82 2 3290 3052; fax: + 82 2 925 1970. E-mail address: [email protected] (B.C. Kim). 0309-1740/$ – see front matter © 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.meatsci.2011.07.013
O'Neill, 2008). Thus, reduction of the fat content of these products can be detrimental to their overall quality (Khalil, 2000). The major problem of low-fat meat products is the resulting decline in palatability (Khalil, 2000; Serdaroglu, 2006). Other problems include reduced cooking yield, soft and mushy texture, and excessive purge in packages (Keeton, 1994). However, the production of low-fat meat products without loss of quality can be achieved through the use of various technologies and ingredients such as whey protein (Serdaroglu, 2006), corn flour (Serdaroglu & Degrimencioglu, 2004), konjac gel (Osburn & Keeton, 2004), and carrageenan (Cierach et al., 2009; Kumar & Sharma, 2004). Surimi is defined as a crude concentrate of myofibrillar proteins obtained after mincing, washing, and mechanical deboning fish muscle to remove its fat and sarcoplasmic proteins, including pigments and enzymes (Antonomanolaki, Vareltzis, Georgakis, & Kaldrymidou, 1999). Surimi is considered an intermediate product as it is usually further processed into various other products. Recently, the use of animal species for manufacturing surimi-like material (SLM) has increased (Antonomanolaki et al., 1999; Jin et al., 2007). Due to its functional properties, especially its unique gelling capacity (similar to that of the carrageenan and konjac gel) (Cierach et al., 2009), SLM can be a useful ingredient for the development of low-fat meat products. Some studies have used surimi from fish muscle to manufacture low-fat meat products (Cavestany, Jimenez Colmenero, Solas, & Carballo, 1994; Murphy, Gilroy, Kerry, Buckley, & Kerry, 2004). However, the effects of SLM on the perceived quality of low-fat meat products have not been studied. Therefore, the aim of this study was to determine the effect of SLM from porcine longissimus dorsi muscle, as a functional fat replacer, on the physicochemical and sensory characteristics of low-fat pork patties.
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2. Materials and methods 2.1. Samples Nine commercial crossbred (Yorkshire x Landrace x Duroc) gilt pigs were used. All animals were raised on the same farm, and were slaughtered at a similar live weight (110 ± 2 kg) at the same slaughterhouse. The abattoir used electrical stunning and a traditional scalding-singeing process. Twenty-four hours after slaughter, the left and right longissimus dorsi muscles (from the 8th to the 13th thoracic vertebra) and back-fat were removed from the carcass, and transported to the laboratory under refrigerated conditions (4 °C) within 1 h. The quality characteristics of the pork loins were reddish-pink, firm, and non-exudative (lightness of 42 to 50 and drip loss of 2 to 6%; Choi et al., 2010). Three pork loins were used to produce the SLM, and the rest were used for the production of the patties. All visible external fat and connective tissue were removed prior to processing. In Korea, most consumers prefer pork belly to pork loin because of their textural properties. Thus, pork bellies are imported from many countries including France and Denmark, while the total stock of pork loin has increased (Jin et al., 2007). Therefore, low-fat pork patties using SLM made from porcine longissimus dorsi muscle was used. 2.2. Surimi-like material and pork patty production The SLM was produced using a traditional method (Antonomanolaki et al., 1999; Jin et al., 2007; Park, Brewer, Novakofski, Bechtel, & McKeith, 1996). Three pork loins were mixed and minced through a 5 mm plate. Minced samples were then homogenized using a Polytron homegenizer (T25B, IKA Ltd., Germany) at 8000 rpm for 30 s with iced water in a water/mince ratio of 5:1 (v/w). Water was then added to the washed mince at a 2.5:1 ratio (water/washed mince, v/w) in the final washing step. The slurry was filtered through a 2.0 and 0.5 mm mesh metal screen to remove connective tissues, and then was centrifuged at 1510 × g for 15 min at 4 °C (CR-21 G, Hitachi Co., Japan). The supernatant was discarded. This washing procedure was performed three times. Next, cryoprotectants (5% sorbitol and 0.3% phosphate) and 0.2% sodium chloride were added to the washed mince and mixed well. The SLM was stored at 4 °C for no longer than 1 day. The average production yield was approximately 40%. The different formulations of pork patty were as follows: (control) basic formulation with 20% back-fat; (T1) basic formulation with 15% back-fat and 5% SLM; (T2) basic formulation with 10% back-fat and 10% SLM; (T3) basic formulation with 20% SLM. The pork loins and fat were initially ground through a 1.9 cm plate grinder. Mixtures of the lean and fat sources to represent the various fat and SLM levels were mixed and ground through a 3 mm plate grinder. Batches of 2 kg of each formulation were prepared, and the resulting preparations used a petri dish (70 mm × 15 mm, each weighing 60 ± 2 g) to produce the patties. Pork patties were placed on plastic trays and wrapped with polyethylene film, and then were frozen at −18 °C until further analysis. The production of pork patties was repeated six times, and the average of six replications was used. 2.3. Proximate composition Following the standard procedures of Association of Official Analytical Chemists (AOAC, 2000), the moisture (950.46B, oven airdrying method), protein (981.10, Kjeldahl nitrogen), fat (960.39, ether extractable component), and ash (920.153, muffle furnace) contents of the pork patties were determined. 2.4. Color and cooking properties The color of the cooked pork patties was measured using a Minolta chromameter (CR-300, Minolta Camera Co., Japan). The average of
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triplicate measurements was recorded, and the results were expressed in terms of lightness (L⁎), redness (a⁎), and yellowness (b⁎) as advised by the Commission Internationale de l'Eclairage (C.I.E., 1978). For the analyses of the cooking properties, frozen samples were thawed at 4 °C overnight, and patties were roasted in a convection oven with fan and steam cooking functions (MCS312CF4, Electrolux, Sweden) set at 180 °C. Patties were turned every 3 min, and cooked to an internal temperature of 75 °C, which was monitored using a thermometer with a handheld probe (TES-1300, TES Electrical Electronic Co., Taiwan). The cooking properties were determined using standard procedures. The cooking yield, water retention, and fat retention of the pork patties were calculated as reported by to Alakali, Irtwange, and Mzer (2010). The diameter and thickness of raw and cooked patties were determined using a stainless steel Vernier caliper (Mitutoyo, Japan). The percentage decrease in diameter, increase in thickness, and shrinkage were calculated (Murphy, Criner, & Gray, 1975). 2.5. Texture profile analysis A texture profile analysis (TPA) was performed with a texture analyzer (TA-XT2i, Stable Micro System, England). Cooked samples were cut into 2.0 × 2.0× 1.5 cm3 pieces after removal of the cooked surface. A cylindrical 10 mm diameter probe of ebonite was used for all TPA tests, thus it was a puncture not a compression test. Samples were placed under the probe, which moved downward at constant speeds of 3.0 mm/s (pre-test), 1.0 mm/s (test), and 3.0 mm/s (post-test). When the probe first came into contact with the sample, the thickness of the sample was automatically recorded by the software. The probe continued downward to a pre-fixed percentage of the sample thickness (75%), returned to the initial point of contact with the sample, and then stopped for a set period of time (2 s) before the second compression cycle started (Ruiz de Huidobro, Miguel, Blazquez, & Onega, 2005). A TPA of each sample was performed using 8 cubes. The force-by-time data from each test were used to calculate the mean values for the TPA parameters. Hardness, cohesiveness, springiness, gumminess, and chewiness were determined as described by Bourne (1978). 2.6. Sensory evaluation A total of 24 cooked pork patties were evaluated, with each sample being evaluated twice. A total of 6 evaluation sessions were conducted, with four samples per session and 12 panelists (20–40 years, seven females and five males). The panelists were previously untrained but had some experience with sensory evaluation of various food products. Before testing, all panelists were trained for 4 weeks (3 times per week) and for up to 1 h in each training session. All training and testing was conducted at Korea University. The 12 trained panelists were selected to take part in the sensory trial based on their interest and availability. Panelist training was performed according to published procedures (Meilgaard, Civille, & Carr, 1991). The preparation of the cooked pork patties for the evaluation of their sensorial characteristics was similar to the procedure described for the evaluation of their cooking properties and TPA. The cooked patties were cut into 1.0 × 1.0 × 1.5 cm 3 pieces without surface, which were subsequently randomly selected to minimize bias. The samples were placed into 1-ounce lidded glass jars labeled with random threedigit codes and held in a water bath (54 °C) until presented to the panelists. During the sensorial evaluation, the panelists were in private booths under incandescent lighting. Water (at room temperature) and unsalted soda crackers were provided to purge the palate of residual flavor between samples. The following characteristics were evaluated: appearance (1 = very unacceptable, 9 = very acceptable), flavor (1 = very unacceptable, 9 = very acceptable), tenderness (1 = very tough, 9 = very tender), juiciness (1 = very dry, 9 = very juicy), and overall acceptability (1 = very unacceptable, 9 = very acceptable).
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2.7. Statistical analysis
3.2. Cooking properties and texture profile analysis
The statistical analysis was performed using the SAS software (SAS Institute, 2004). An analysis of variance was used to evaluate potential differences (P b 0.05) between the different treatments. The results are presented as means for each group, together with their standard deviations.
Table 2 shows the effects of adding SLM on the cooking properties of pork patties. Control patties exhibited a lower cooking yield than T3 patties (78.57 vs. 87.41%, P b 0.05), whereas no significant differences were detected among control, T1, and T2 patties. The formulation and processing methodology employed in the production of emulsified meat products are key determinants of moisture and fat retention during cooking (Serdaroglu, 2006). In general, the cooking yield of a meat product is influenced by its ability to retain water and fat during cooking (Suman & Sharma, 2003). In the current study, pork patties with 20% SLM exhibited a higher cooking yield, showing higher water (T3 N T2= T1N control) and fat retention (T3 = T2 = T1N control) than patties with 20% back-fat and no SLM. The decrease in the diameter and increase in thickness of the patties differed significantly depending on the percentage of SLM added. Control patties showed significantly higher changes in diameter (P b 0.001) than those in SLM-added patties, however no statistical differences were observed between the T2 and T3 groups. Moreover, control patties had higher changes in thickness (17.94 vs. 5.65%, P b 0.05) than those in the T3 group, but there were no significant differences among the T1, T2, and T3 groups. Correspondingly, the highest percentage shrinkage was observed in control patties when compared to those patties with 20% SLM (9.02 vs. 4.01%, P b 0.001). However, no statistical differences in the extent of shrinkage were found between the T2 and T3 groups. Alakali et al. (2010) reported that patties shrunk after cooking due to the denaturation of muscle proteins and partly from the evaporation of water and loss of melted fat and juice. These structural alterations influence the textural characteristics of cooked patties (Alakali et al., 2010). Regarding textural characteristics (Table 3), TPA-hardness was higher in T2 than control or T1 samples (9.00 vs. 5.92 or 6.84 N, P b 0.001), and T3 samples showed the highest value (13.02 N). No significant differences were observed between control and treatments with respect to springiness. T1 samples had significantly higher cohesiveness (0.40 vs. 0.34, P b 0.001) and gumminess (2.72 vs. 2.00, P b 0.001) than the control samples. In terms of chewiness, T3 patties were characterized by a higher value than control patties (7.93 vs. 2.42, P b 0.05). Thus, the treatment samples had a harder texture than the control samples. Since fat positively influences the binding capacity and textural properties of meat products, reduction of fat levels can lead to unacceptable textures, especially in emulsified sausages and patties (Miles, 1996). Aleson-Carbonell, Fernandez-Lopez, Perez-Alvarez, and Kuri (2005) suggested that the textural properties of a meat product
3. Results and discussion 3.1. Proximate composition and color As expected, the treatments differed significantly with respect to their levels of moisture, protein, fat, and ash (Table 1). The moisture content was higher in the treatment with 20% SLM (T3) than in the treatment with 10% SLM (T2) or the treatment with 20% back-fat (Control) (73.83 vs. 67.55 or 60.38%, P b 0.001). All treatments had a significantly higher protein (P b 0.01) and ash content (P b 0.001) than the control group, with the exception of the level of protein in T1 (19.46 vs. 18.51% in the T1 and control, respectively; P N 0.05). In the case of fat, the T3 group had the lowest content (1.76%), with the content of fat decreasing with the increase in the percentage of SLM added (P b 0.001). Patties in T3 and T2 had a significantly higher lightness values (66.30 and 64.77, respectively) than control patties (61.63, P b 0.05), whereas the measured redness and yellowness were similar in the T3 and control samples. Naturally, these results reflect the composition and color of SLM, with SLM being characterized by high moisture (79.13 ± 0.97%) and protein (18.09 ± 0.84%) contents, and a low fat content (0.41 ± 0.08%) (data not shown). SLM has typically high whiteness and lightness values due to the removal of pigments, including myoglobin (Jin et al., 2007). The lightness and whiteness of SLM were 73.82 and 57.53, respectively (data not shown). Moreover, all treatments had a higher salt and phosphate content than the control, because SLM contained 0.2% salt and 0.3% phosphate. However, there were no significant differences pH among the control and treatments, and pH values being in the range 5.8 to 6.1 (data not shown). According to the United States Department of Agriculture (USDA, 2010), a low-fat food product is strictly defined as a product containing 3 g or less of fat per Recommended Amount Customarily Consumed (RACC), per serving size, and per 100 g of product. A reduced-fat product must contain at least 25% less fat per RACC. Hence, the patties produced in T3 and T2 can be defined as low- and reduced-fat meat products, respectively.
Table 1 Effect of surimi-like material (SLM) addition on the composition and color of cooked pork patties. Treatments
Levels of significance
Control
T1
T2
T3
Proximate composition Moisture (%) Protein (%) Fat (%) Ash (%)
60.38d ± 0.39 18.51c ± 0.69 18.64a ± 0.40 2.47c ± 0.10
64.14c ± 0.42 19.46bc ± 0.09 13.76b ± 0.43 2.63b ± 0.06
67.55b ± 0.29 20.52ab ± 0.75 9.20c ± 0.83 2.74b ± 0.04
73.83a ± 0.46 21.42a ± 0.79 1.76d ± 0.34 2.97a ± 0.04
*** ** *** ***
Patty color Lightness (L⁎) Redness (a⁎) Yellowness (b⁎)
61.63b ± 0.95 4.22 ± 0.49 12.93 ± 0.51
63.58ab ± 1.99 4.08 ± 0.44 12.12 ± 0.94
64.77a ± 2.01 3.95 ± 0.21 12.21 ± 0.44
66.30a ± 1.04 3.70 ± 0.24 11.63 ± 0.68
* NS NS
Results are expressed as means ± SD. Levels of significance: NS, not significant; * P b 0.05; ** P b 0.01; *** P b 0.001. a–d Means with different superscripts within a row are significantly different (P b 0.05). Abbreviations: Control = 20% back-fat; T1 = 15% back-fat and 5% SLM; T2 = 10% back-fat and 10% SLM; T3 = 0% back-fat and 20% SLM.
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Table 2 Effect of surimi-like material (SLM) addition on the cooking properties of cooked pork patties. Treatments
Cooking yield (%) Water retention (%) Fat retention (%) Diameter decrement (%) Thickness increment (%) Shrinkage (%)
Control
T1
T2
T3
78.57b ± 2.12 71.04c ± 1.69 69.10b ± 1.84 14.61a ± 1.49 17.94a ± 5.33 9.02a ± 0.46
81.75b ± 1.42 76.09b ± 1.77 84.55a ± 3.56 11.32b ± 2.26 13.26ab ± 5.85 7.18b ± 1.08
83.27ab ± 2.97 74.52b ± 2.45 85.61a ± 6.85 8.02c ± 1.23 10.33ab ± 3.59 4.99c ± 0.64
87.41a ± 1.42 83.12a ± 1.64 85.61a ± 6.92 5.99c ± 0.26 5.65b ± 1.90 4.01c ± 0.16
Levels of significance * *** ** *** * ***
Results are expressed as means ± SD. Levels of significance: * P b 0.05; ** P b 0.01; *** P b 0.001. a–c Means with different superscripts within a row are significantly different (P b 0.05). Abbreviations: Control = 20% back-fat; T1 = 15% back-fat and 5% SLM; T2 = 10% back-fat and 10% SLM; T3 = 0% back-fat and 20% SLM.
Table 3 Effect of surimi-like material (SLM) addition on the texture profile analysis of cooked pork patties. Treatment
Hardness (N) Cohesiveness Springiness Gumminess Chewiness
Control
T1
5.92c ± 0.75 0.34c ± 0.02 1.19 ± 0.04 2.00d ± 0.12 2.42b ± 0.19
6.84c ± 0.32 0.40b ± 0.06 1.15 ± 0.10 2.72c ± 0.12 3.09b ± 0.21
T2 9.00b ± 1.09 0.44a ± 0.03 1.36 ± 0.37 3.79b ± 0.16 5.22ab ± 1.04
T3 13.02a ± 1.53 0.45a ± 0.01 1.35 ± 0.34 5.85a ± 0.69 7.93a ± 3.10
Levels of significance *** *** NS *** *
Results are expressed as means ± SD. Levels of significance: NS, not significant; * P b 0.05; *** P b 0.001. a–d Means with different superscripts within a row are significantly different (P b 0.05). Abbreviations: Control = 20% back-fat; T1 = 15% back-fat and 5% SLM; T2 = 10% back-fat and 10% SLM; T3 = 0% back-fat and 20% SLM.
Table 4 Effect of surimi-like material (SLM) addition on the sensory evaluation of cooked pork patties. Treatments
Appearance1 Flavor1 Tenderness2 Juiciness3 Overall acceptability1
Control
T1
T2
T3
4.98d ± 0.10 4.32c ± 0.31 4.38c ± 0.63 5.28 ± 0.27 4.32c ± 0.18
5.64c ± 0.10 5.28b ± 0.27 5.34b ± 0.45 5.40 ± 0.65 5.22b ± 0.18
6.42a ± 0.21 5.58ab ± 0.18 5.88ab ± 0.58 5.76 ± 0.18 5.94a ± 0.54
6.06b ± 0.27 5.94a ± 0.48 6.54a ± 0.27 5.82 ± 0.27 6.54a ± 0.42
Levels of significance *** ** ** NS ***
Results are expressed as means ± SD. Levels of significance: NS, not significant; ** P b 0.01; *** P b 0.001. a–d Means with different superscripts within a row are significantly different (P b 0.05). Abbreviations: Control = 20% back-fat; T1 = 15% back-fat and 5% SLM; T2 = 10% back-fat and 10% SLM; T3 = 0% back-fat and 20% SLM. 1 Scale: 1 = very unacceptable; 9 = very acceptable. 2 Scale: 1 = very tough; 9 = very tender. 3 Scale: 1 = very dry; 9 = very juicy.
are determined by the ability of its protein matrix to retain water and bind fat. To enhance WHC and cooking yield, carrageenan and konjac gel can be added to meat products as a fat replacer (Cierach et al., 2009; Osburn & Keeton, 2004). These ingredients have high gelling powers and can thus improve the textural properties and cooking yield of low-fat meat products (Cofrades, Hughes, & Troy, 2000; Kumar & Sharma, 2004). The results suggest that the addition of SLM to low-fat pork patties can improve their cooking properties and texture due to the ability of the SLM gel to keep moisture and fat in the patty matrix. 3.3. Sensory evaluation The effect of SLM addition on the sensory characteristics of pork patties is shown in Table 4. With the exception of juiciness (P N 0.05), the scores of sensory quality attributes were higher in SLM-added treatments compared to the control. T2 samples showed the highest appearance score (6.42), and T3 samples scored significantly higher in
terms of appearance (6.06 vs. 5.64, P b 0.001) and flavor (5.94 vs. 5.28, P b 0.01) than T1 samples. Moreover, panelists judged T3 patties to be more tender than control or T1 patties (6.54 vs. 4.38 or 5.34, P b 0.01). The overall acceptability of cooked patties is evaluated by considering all sensory attributes. Here, T3 samples showed a higher overall acceptability value than the control (6.54 vs. 4.32, P b 0.001), but there were no significant differences between T3 and T2 samples (5.94, P N 0.05). The maintenance of acceptable palatability standards is an important consideration in the development of low-fat meat products. Miles (1996) reported that less than 20% fat in ground meat products can lead to unacceptable product palatability. Several studies have found similar results for low- and reduced-fat products. In Turkish type meatballs, meatballs with 20% fat (control) were more tender than those with 5% fat; however, there were no differences in overall acceptability between control meatballs and those with 10% fat and 2% corn flour (Serdaroglu & Degrimencioglu, 2004). According to Cierach et al. (2009), a significantly higher taste score was observed in frankfurter sausages produced with 10% fat and 0.7% carrageenan
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than in control sausages produced with 10% fat or sausages with 20% fat. Murphy et al. (2004) reported that there were no significant differences in sensory acceptability between full-fat pork sausage with 30% fat and low-fat pork sausage produced with 25.3% surimi and 6.3% fat. Hence, many studies have developed low- and reducedfat meat products using various ingredients, achieving improved cooking and textural properties without impairment of palatability as compared to full-fat meat products. However, only a few studies have shown improved palatability in low-fat meat products (Osburn & Keeton, 2004; Serdaroglu & Degrimencioglu, 2004; Suman & Sharma, 2003). In the present study, the reduced- and low-fat pork patties produced with 10% and 20% SLM presented higher palatability scores compared to patties with 20% back-fat. 4. Conclusion SLM made from the porcine longissimus dorsi muscle can be used as a fat replacer, improving the physicochemical and sensory quality characteristics of low- and reduced-fat pork patties. Specifically, pork patties produced with 20% SLM had a lower fat content (1.76%), and exhibited higher cooking yields and overall acceptability than pork patties produced with 20% back-fat. These results may be useful in developing low-fat meat products. Acknowledgments This research was supported by iPET (the Korea Institute of Planning and Evaluation for Technology of Food, Agriculture, Forestry, and Fisheries). The authors thank the Korea University Food Safety Center for the use of their equipment and facilities. References Alakali, J. S., Irtwange, S. V., & Mzer, M. T. (2010). Quality evaluation of beef patties formulated with Bambara groundnut (Vigna subterranean L.) seed flour. Meat Science, 85, 215–223. Aleson-Carbonell, L., Fernandez-Lopez, J., Perez-Alvarez, J. A., & Kuri, V. (2005). Characteristics of beef burger as influenced by various types of lemon albedo. Innovative Food Science and Emerging Technologies, 6, 247–255. Antonomanolaki, R. E., Vareltzis, K. P., Georgakis, S. A., & Kaldrymidou, E. (1999). Thermal gelation properties of surimi-like material made from sheep meat. Meat Science, 52, 429–435. AOAC (2000). Official methods of analysis (17th ed.). Gaithersburgh, Maryland: Association of Official Analytical Chemists. Biesalski, H. K. (2005). Meat as a component of a healthy diet — are there any risks or benefits if meat is avoided in the diet? Meat Science, 70, 509–524. Bourne, M. C. (1978). Texture profile analysis. Food Technology, 33, 62–66. C.I.E. (1978). Recommendations on uniform color spaces — Color differences equations, psychrometic color terms. Supplement No. 2, CIE Publication No. 15 (E1.3.1). Cavestany, M., Jimenez Colmenero, F., Solas, M. T., & Carballo, J. (1994). Incorporation of sardine surimi in bologna sausage containing different fat levels. Meat Science, 38, 27–37. Choi, Y. M., Lee, S. H., Choe, J. H., Rhee, M. S., Lee, S. K., Kim, B. C., & Joo, S. T. (2010). Protein solubility is related to myosin isoforms, muscle fiber types, meat quality
traits, and postmortem protein changes in porcine longissimus dorsi muscle. Livestock Science, 127, 183–191. Cierach, M., Modzelewska-Kapitula, M., & Szacilo, K. (2009). The influence of carrageenan on the properties of low-fat frankfurters. Meat Science, 82, 295–299. Cofrades, S., Hughes, E., & Troy, D. J. (2000). Effects of oat fiber and carrageenan of the texture of frankfurters formulated with low and high fat. European Food Research and Technology, 211, 19–26. Ferguson, L. R. (2010). Meat and cancer. Meat Science, 84, 308–313. Hughes, E., Confrades, S., & Troy, D. J. (1997). Effects of fat level, oat fiber and carrageenan on frankfurters formulated with 5, 12 and 30% fat. Meat Science, 45, 273–281. Jin, S. K., Kim, I. S., Kim, S. J., Jeong, K. J., Choi, Y. J., & Hur, S. J. (2007). Effect of muscle type and washing times on physico-chemical characteristics and qualities of surimi. Journal of Food Engineering, 81, 618–623. Keeton, J. T. (1994). Low-fat meat products — Technological problems with processing. Meat Science, 36, 261–276. Khalil, A. H. (2000). Quality characteristics of low-fat beef patties formulated with modified corn starch and water. Food Control, 68, 61–68. Kumar, M., & Sharma, B. D. (2004). The storage stability and textural, physico-chemical and sensory quality of low-fat ground pork patties with carrageenan as fat replacer. International Journal of Food Science and Technology, 39, 31–42. Lin, J., Zhang, S. M., Cook, N. R., Lee, I. M., & Buring, J. E. (2004). Dietary fat and fatty acids and risk of colorectal cancer in women. American Journal of Epidemiology, 160, 1011–1022. Meilgaard, M., Civille, G. V., & Carr, B. T. (1991). Affective tests: Consumer tests and inhouse panel acceptance tests. Sensory evaluation techniques (pp. 211–222). (3rd ed). Boca Ranton, FL: CRC Press Inc. Miles, R. S. (1996). Processing of low fat meat products. In 49th reciprocal meat conference proceedings (pp. 17–22). Chicago, IL: American Meat Science Asoociation. Murphy, E. W., Criner, P. E., & Gray, B. C. (1975). Comparison of methods for calculating retentions of nutrients in cooked foods. Journal of Agricultural and Food Chemistry, 23, 1153–1157. Murphy, S. C., Gilroy, D., Kerry, J. F., Buckley, D. J., & Kerry, J. P. (2004). Evaluation of surimi, fat and water content in a low/no added pork sausage formulation using response surface methodology. Meat Science, 66, 689–701. Osburn, W. N., & Keeton, J. T. (2004). Evaluation of low-fat sausage containing desinewed lamb and konjac gel. Meat Science, 68, 221–233. Park, S., Brewer, M. S., Novakofski, J., Bechtel, P. J., & McKeith, F. K. (1996). Process and characteristics for a surimi-like material made from beef or pork. Journal of Food Science, 61, 422–427. Ruiz de Huidobro, F., Miguel, E., Blazquez, B., & Onega, E. (2005). A comparison between two methods (Warner-Bratzler and texture profile analysis) for testing either raw meat or cooked meat. Meat Science, 69, 527–536. Santarelli, R. L., Pierre, F., & Corpet, D. E. (2008). Processed meat and colorectal cancer: A review of epidemiologic and experimental evidence. Nutrition and Cancer, 60, 131–144. SAS Institute (2004). SAS user's guide, version 9.1.3. Cary, NC: SAS Institute Inc. Serdaroglu, M. (2006). Improving low fat meatball characteristics by adding whey powder. Meat Science, 72, 155–163. Serdaroglu, M., & Degrimencioglu, O. (2004). Effects of fat level (5%, 10%, 20%) and corn flour (0%, 2%, 4%) on some properties of Turkish type meatballs (koefte). Meat Science, 68, 291–296. Sloan, A. E. (2010). Top 10 functional food trends. Food Technology, 64, 23–41. Suman, S. P., & Sharma, B. D. (2003). Effects of grind size and fat levels on the physicochemical and sensory characteristics of low-fat ground buffalo meat patties. Meat Science, 65, 973–976. USDA (2010). Nutrient content claims for fat, fatty acids, and cholesterol content of meat products. In Electronic Code of Federal Regulations. Title 9, Part 317.362., National Archives and Records Administration. http://ecfr.gpoaccess.gov accessed December 2010. Webb, E. C., & O'Neill, H. A. (2008). The animal fat paradox and meat quality. Meat Science, 80, 28–36.
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Meat Science j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / m e a t s c i
Practical use of surimi-like material made from porcine longissimus dorsi muscle for the production of low-fat pork patties Y.M. Choi, J.H. Choe, D.K. Cho, B.C. Kim ⁎ Division of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Korea University, 5-1 Anam-dong, Sungbuk-gu, Seoul 136-713, South Korea
a r t i c l e
i n f o
Article history: Received 25 February 2011 Received in revised form 11 July 2011 Accepted 16 July 2011 Keywords: Surimi-like material Fat replacer Low-fat meat products Pork patties
a b s t r a c t This study evaluates the effect of replacing fat with surimi-like material (SLM) made from the porcine longissimus dorsi muscle on the physicochemical and sensory characteristics of pork patties. Pork patties were produced with different levels of fat and SLM using a commercial method. Pork patties produced with 20% SLM had the lowest fat content (1.76%, P b 0.001), and had a higher cooking yield (87.41 vs. 78.57%, P b 0.05) and less shrinkage (4.01 vs. 9.02%, P b 0.001) than patties produced with 20% back-fat (control). Moreover, patties produced with SLM exhibited more acceptable organoleptic characteristics, including tenderness (P b 0.01) and overall acceptability (P b 0.001), than full-fat control patties. These results indicated that SLM cannot only be used as a fat replacer, but that it also improves the physicochemical and sensory characteristics of low-fat pork patties. © 2011 Elsevier Ltd. All rights reserved.
1. Introduction According to a report of the top 10 functional food trends in 2009 (Sloan, 2010), 58% of Americans consumed fortified foods last year to supplement their diet. Additionally, the report shows that most consumers read the nutritional facts on the labels of food products and wanted to know their overall fat content when they bought them for the first time, avoiding foods that contained higher levels of fat, sodium, and calories (Sloan, 2010). Because, many consumers believe that excessive consumption of meat and meat products is associated with obesity and various diseases due to their high fat content (Biesalski, 2005). In this sense, the demand for healthier food products, especially low-fat products, is rapidly increasing, with new low- and reduced-fat meat products being developed (Cierach, Modzelewska-Kapitula, & Szacilo, 2009), although the study of the association between meat consumption and the risk of developing cancer has produced inconsistent results, with some studies finding no association between dietary fat intake from meat products and colorectal cancer (Ferguson, 2010; Lin, Zhang, Cook, Lee, & Buring, 2004; Santarelli, Pierre, & Corpet, 2008; Webb & O'Neill, 2008). The amount of fat in meat products plays an important role in determining the organoleptic and quality characteristics, including stabilizing emulsions and improving their water-holding capacity (WHC) (Hughes, Confrades, & Troy, 1997; Keeton, 1994; Webb &
⁎ Corresponding author. Tel.: + 82 2 3290 3052; fax: + 82 2 925 1970. E-mail address: [email protected] (B.C. Kim). 0309-1740/$ – see front matter © 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.meatsci.2011.07.013
O'Neill, 2008). Thus, reduction of the fat content of these products can be detrimental to their overall quality (Khalil, 2000). The major problem of low-fat meat products is the resulting decline in palatability (Khalil, 2000; Serdaroglu, 2006). Other problems include reduced cooking yield, soft and mushy texture, and excessive purge in packages (Keeton, 1994). However, the production of low-fat meat products without loss of quality can be achieved through the use of various technologies and ingredients such as whey protein (Serdaroglu, 2006), corn flour (Serdaroglu & Degrimencioglu, 2004), konjac gel (Osburn & Keeton, 2004), and carrageenan (Cierach et al., 2009; Kumar & Sharma, 2004). Surimi is defined as a crude concentrate of myofibrillar proteins obtained after mincing, washing, and mechanical deboning fish muscle to remove its fat and sarcoplasmic proteins, including pigments and enzymes (Antonomanolaki, Vareltzis, Georgakis, & Kaldrymidou, 1999). Surimi is considered an intermediate product as it is usually further processed into various other products. Recently, the use of animal species for manufacturing surimi-like material (SLM) has increased (Antonomanolaki et al., 1999; Jin et al., 2007). Due to its functional properties, especially its unique gelling capacity (similar to that of the carrageenan and konjac gel) (Cierach et al., 2009), SLM can be a useful ingredient for the development of low-fat meat products. Some studies have used surimi from fish muscle to manufacture low-fat meat products (Cavestany, Jimenez Colmenero, Solas, & Carballo, 1994; Murphy, Gilroy, Kerry, Buckley, & Kerry, 2004). However, the effects of SLM on the perceived quality of low-fat meat products have not been studied. Therefore, the aim of this study was to determine the effect of SLM from porcine longissimus dorsi muscle, as a functional fat replacer, on the physicochemical and sensory characteristics of low-fat pork patties.
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2. Materials and methods 2.1. Samples Nine commercial crossbred (Yorkshire x Landrace x Duroc) gilt pigs were used. All animals were raised on the same farm, and were slaughtered at a similar live weight (110 ± 2 kg) at the same slaughterhouse. The abattoir used electrical stunning and a traditional scalding-singeing process. Twenty-four hours after slaughter, the left and right longissimus dorsi muscles (from the 8th to the 13th thoracic vertebra) and back-fat were removed from the carcass, and transported to the laboratory under refrigerated conditions (4 °C) within 1 h. The quality characteristics of the pork loins were reddish-pink, firm, and non-exudative (lightness of 42 to 50 and drip loss of 2 to 6%; Choi et al., 2010). Three pork loins were used to produce the SLM, and the rest were used for the production of the patties. All visible external fat and connective tissue were removed prior to processing. In Korea, most consumers prefer pork belly to pork loin because of their textural properties. Thus, pork bellies are imported from many countries including France and Denmark, while the total stock of pork loin has increased (Jin et al., 2007). Therefore, low-fat pork patties using SLM made from porcine longissimus dorsi muscle was used. 2.2. Surimi-like material and pork patty production The SLM was produced using a traditional method (Antonomanolaki et al., 1999; Jin et al., 2007; Park, Brewer, Novakofski, Bechtel, & McKeith, 1996). Three pork loins were mixed and minced through a 5 mm plate. Minced samples were then homogenized using a Polytron homegenizer (T25B, IKA Ltd., Germany) at 8000 rpm for 30 s with iced water in a water/mince ratio of 5:1 (v/w). Water was then added to the washed mince at a 2.5:1 ratio (water/washed mince, v/w) in the final washing step. The slurry was filtered through a 2.0 and 0.5 mm mesh metal screen to remove connective tissues, and then was centrifuged at 1510 × g for 15 min at 4 °C (CR-21 G, Hitachi Co., Japan). The supernatant was discarded. This washing procedure was performed three times. Next, cryoprotectants (5% sorbitol and 0.3% phosphate) and 0.2% sodium chloride were added to the washed mince and mixed well. The SLM was stored at 4 °C for no longer than 1 day. The average production yield was approximately 40%. The different formulations of pork patty were as follows: (control) basic formulation with 20% back-fat; (T1) basic formulation with 15% back-fat and 5% SLM; (T2) basic formulation with 10% back-fat and 10% SLM; (T3) basic formulation with 20% SLM. The pork loins and fat were initially ground through a 1.9 cm plate grinder. Mixtures of the lean and fat sources to represent the various fat and SLM levels were mixed and ground through a 3 mm plate grinder. Batches of 2 kg of each formulation were prepared, and the resulting preparations used a petri dish (70 mm × 15 mm, each weighing 60 ± 2 g) to produce the patties. Pork patties were placed on plastic trays and wrapped with polyethylene film, and then were frozen at −18 °C until further analysis. The production of pork patties was repeated six times, and the average of six replications was used. 2.3. Proximate composition Following the standard procedures of Association of Official Analytical Chemists (AOAC, 2000), the moisture (950.46B, oven airdrying method), protein (981.10, Kjeldahl nitrogen), fat (960.39, ether extractable component), and ash (920.153, muffle furnace) contents of the pork patties were determined. 2.4. Color and cooking properties The color of the cooked pork patties was measured using a Minolta chromameter (CR-300, Minolta Camera Co., Japan). The average of
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triplicate measurements was recorded, and the results were expressed in terms of lightness (L⁎), redness (a⁎), and yellowness (b⁎) as advised by the Commission Internationale de l'Eclairage (C.I.E., 1978). For the analyses of the cooking properties, frozen samples were thawed at 4 °C overnight, and patties were roasted in a convection oven with fan and steam cooking functions (MCS312CF4, Electrolux, Sweden) set at 180 °C. Patties were turned every 3 min, and cooked to an internal temperature of 75 °C, which was monitored using a thermometer with a handheld probe (TES-1300, TES Electrical Electronic Co., Taiwan). The cooking properties were determined using standard procedures. The cooking yield, water retention, and fat retention of the pork patties were calculated as reported by to Alakali, Irtwange, and Mzer (2010). The diameter and thickness of raw and cooked patties were determined using a stainless steel Vernier caliper (Mitutoyo, Japan). The percentage decrease in diameter, increase in thickness, and shrinkage were calculated (Murphy, Criner, & Gray, 1975). 2.5. Texture profile analysis A texture profile analysis (TPA) was performed with a texture analyzer (TA-XT2i, Stable Micro System, England). Cooked samples were cut into 2.0 × 2.0× 1.5 cm3 pieces after removal of the cooked surface. A cylindrical 10 mm diameter probe of ebonite was used for all TPA tests, thus it was a puncture not a compression test. Samples were placed under the probe, which moved downward at constant speeds of 3.0 mm/s (pre-test), 1.0 mm/s (test), and 3.0 mm/s (post-test). When the probe first came into contact with the sample, the thickness of the sample was automatically recorded by the software. The probe continued downward to a pre-fixed percentage of the sample thickness (75%), returned to the initial point of contact with the sample, and then stopped for a set period of time (2 s) before the second compression cycle started (Ruiz de Huidobro, Miguel, Blazquez, & Onega, 2005). A TPA of each sample was performed using 8 cubes. The force-by-time data from each test were used to calculate the mean values for the TPA parameters. Hardness, cohesiveness, springiness, gumminess, and chewiness were determined as described by Bourne (1978). 2.6. Sensory evaluation A total of 24 cooked pork patties were evaluated, with each sample being evaluated twice. A total of 6 evaluation sessions were conducted, with four samples per session and 12 panelists (20–40 years, seven females and five males). The panelists were previously untrained but had some experience with sensory evaluation of various food products. Before testing, all panelists were trained for 4 weeks (3 times per week) and for up to 1 h in each training session. All training and testing was conducted at Korea University. The 12 trained panelists were selected to take part in the sensory trial based on their interest and availability. Panelist training was performed according to published procedures (Meilgaard, Civille, & Carr, 1991). The preparation of the cooked pork patties for the evaluation of their sensorial characteristics was similar to the procedure described for the evaluation of their cooking properties and TPA. The cooked patties were cut into 1.0 × 1.0 × 1.5 cm 3 pieces without surface, which were subsequently randomly selected to minimize bias. The samples were placed into 1-ounce lidded glass jars labeled with random threedigit codes and held in a water bath (54 °C) until presented to the panelists. During the sensorial evaluation, the panelists were in private booths under incandescent lighting. Water (at room temperature) and unsalted soda crackers were provided to purge the palate of residual flavor between samples. The following characteristics were evaluated: appearance (1 = very unacceptable, 9 = very acceptable), flavor (1 = very unacceptable, 9 = very acceptable), tenderness (1 = very tough, 9 = very tender), juiciness (1 = very dry, 9 = very juicy), and overall acceptability (1 = very unacceptable, 9 = very acceptable).
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2.7. Statistical analysis
3.2. Cooking properties and texture profile analysis
The statistical analysis was performed using the SAS software (SAS Institute, 2004). An analysis of variance was used to evaluate potential differences (P b 0.05) between the different treatments. The results are presented as means for each group, together with their standard deviations.
Table 2 shows the effects of adding SLM on the cooking properties of pork patties. Control patties exhibited a lower cooking yield than T3 patties (78.57 vs. 87.41%, P b 0.05), whereas no significant differences were detected among control, T1, and T2 patties. The formulation and processing methodology employed in the production of emulsified meat products are key determinants of moisture and fat retention during cooking (Serdaroglu, 2006). In general, the cooking yield of a meat product is influenced by its ability to retain water and fat during cooking (Suman & Sharma, 2003). In the current study, pork patties with 20% SLM exhibited a higher cooking yield, showing higher water (T3 N T2= T1N control) and fat retention (T3 = T2 = T1N control) than patties with 20% back-fat and no SLM. The decrease in the diameter and increase in thickness of the patties differed significantly depending on the percentage of SLM added. Control patties showed significantly higher changes in diameter (P b 0.001) than those in SLM-added patties, however no statistical differences were observed between the T2 and T3 groups. Moreover, control patties had higher changes in thickness (17.94 vs. 5.65%, P b 0.05) than those in the T3 group, but there were no significant differences among the T1, T2, and T3 groups. Correspondingly, the highest percentage shrinkage was observed in control patties when compared to those patties with 20% SLM (9.02 vs. 4.01%, P b 0.001). However, no statistical differences in the extent of shrinkage were found between the T2 and T3 groups. Alakali et al. (2010) reported that patties shrunk after cooking due to the denaturation of muscle proteins and partly from the evaporation of water and loss of melted fat and juice. These structural alterations influence the textural characteristics of cooked patties (Alakali et al., 2010). Regarding textural characteristics (Table 3), TPA-hardness was higher in T2 than control or T1 samples (9.00 vs. 5.92 or 6.84 N, P b 0.001), and T3 samples showed the highest value (13.02 N). No significant differences were observed between control and treatments with respect to springiness. T1 samples had significantly higher cohesiveness (0.40 vs. 0.34, P b 0.001) and gumminess (2.72 vs. 2.00, P b 0.001) than the control samples. In terms of chewiness, T3 patties were characterized by a higher value than control patties (7.93 vs. 2.42, P b 0.05). Thus, the treatment samples had a harder texture than the control samples. Since fat positively influences the binding capacity and textural properties of meat products, reduction of fat levels can lead to unacceptable textures, especially in emulsified sausages and patties (Miles, 1996). Aleson-Carbonell, Fernandez-Lopez, Perez-Alvarez, and Kuri (2005) suggested that the textural properties of a meat product
3. Results and discussion 3.1. Proximate composition and color As expected, the treatments differed significantly with respect to their levels of moisture, protein, fat, and ash (Table 1). The moisture content was higher in the treatment with 20% SLM (T3) than in the treatment with 10% SLM (T2) or the treatment with 20% back-fat (Control) (73.83 vs. 67.55 or 60.38%, P b 0.001). All treatments had a significantly higher protein (P b 0.01) and ash content (P b 0.001) than the control group, with the exception of the level of protein in T1 (19.46 vs. 18.51% in the T1 and control, respectively; P N 0.05). In the case of fat, the T3 group had the lowest content (1.76%), with the content of fat decreasing with the increase in the percentage of SLM added (P b 0.001). Patties in T3 and T2 had a significantly higher lightness values (66.30 and 64.77, respectively) than control patties (61.63, P b 0.05), whereas the measured redness and yellowness were similar in the T3 and control samples. Naturally, these results reflect the composition and color of SLM, with SLM being characterized by high moisture (79.13 ± 0.97%) and protein (18.09 ± 0.84%) contents, and a low fat content (0.41 ± 0.08%) (data not shown). SLM has typically high whiteness and lightness values due to the removal of pigments, including myoglobin (Jin et al., 2007). The lightness and whiteness of SLM were 73.82 and 57.53, respectively (data not shown). Moreover, all treatments had a higher salt and phosphate content than the control, because SLM contained 0.2% salt and 0.3% phosphate. However, there were no significant differences pH among the control and treatments, and pH values being in the range 5.8 to 6.1 (data not shown). According to the United States Department of Agriculture (USDA, 2010), a low-fat food product is strictly defined as a product containing 3 g or less of fat per Recommended Amount Customarily Consumed (RACC), per serving size, and per 100 g of product. A reduced-fat product must contain at least 25% less fat per RACC. Hence, the patties produced in T3 and T2 can be defined as low- and reduced-fat meat products, respectively.
Table 1 Effect of surimi-like material (SLM) addition on the composition and color of cooked pork patties. Treatments
Levels of significance
Control
T1
T2
T3
Proximate composition Moisture (%) Protein (%) Fat (%) Ash (%)
60.38d ± 0.39 18.51c ± 0.69 18.64a ± 0.40 2.47c ± 0.10
64.14c ± 0.42 19.46bc ± 0.09 13.76b ± 0.43 2.63b ± 0.06
67.55b ± 0.29 20.52ab ± 0.75 9.20c ± 0.83 2.74b ± 0.04
73.83a ± 0.46 21.42a ± 0.79 1.76d ± 0.34 2.97a ± 0.04
*** ** *** ***
Patty color Lightness (L⁎) Redness (a⁎) Yellowness (b⁎)
61.63b ± 0.95 4.22 ± 0.49 12.93 ± 0.51
63.58ab ± 1.99 4.08 ± 0.44 12.12 ± 0.94
64.77a ± 2.01 3.95 ± 0.21 12.21 ± 0.44
66.30a ± 1.04 3.70 ± 0.24 11.63 ± 0.68
* NS NS
Results are expressed as means ± SD. Levels of significance: NS, not significant; * P b 0.05; ** P b 0.01; *** P b 0.001. a–d Means with different superscripts within a row are significantly different (P b 0.05). Abbreviations: Control = 20% back-fat; T1 = 15% back-fat and 5% SLM; T2 = 10% back-fat and 10% SLM; T3 = 0% back-fat and 20% SLM.
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Table 2 Effect of surimi-like material (SLM) addition on the cooking properties of cooked pork patties. Treatments
Cooking yield (%) Water retention (%) Fat retention (%) Diameter decrement (%) Thickness increment (%) Shrinkage (%)
Control
T1
T2
T3
78.57b ± 2.12 71.04c ± 1.69 69.10b ± 1.84 14.61a ± 1.49 17.94a ± 5.33 9.02a ± 0.46
81.75b ± 1.42 76.09b ± 1.77 84.55a ± 3.56 11.32b ± 2.26 13.26ab ± 5.85 7.18b ± 1.08
83.27ab ± 2.97 74.52b ± 2.45 85.61a ± 6.85 8.02c ± 1.23 10.33ab ± 3.59 4.99c ± 0.64
87.41a ± 1.42 83.12a ± 1.64 85.61a ± 6.92 5.99c ± 0.26 5.65b ± 1.90 4.01c ± 0.16
Levels of significance * *** ** *** * ***
Results are expressed as means ± SD. Levels of significance: * P b 0.05; ** P b 0.01; *** P b 0.001. a–c Means with different superscripts within a row are significantly different (P b 0.05). Abbreviations: Control = 20% back-fat; T1 = 15% back-fat and 5% SLM; T2 = 10% back-fat and 10% SLM; T3 = 0% back-fat and 20% SLM.
Table 3 Effect of surimi-like material (SLM) addition on the texture profile analysis of cooked pork patties. Treatment
Hardness (N) Cohesiveness Springiness Gumminess Chewiness
Control
T1
5.92c ± 0.75 0.34c ± 0.02 1.19 ± 0.04 2.00d ± 0.12 2.42b ± 0.19
6.84c ± 0.32 0.40b ± 0.06 1.15 ± 0.10 2.72c ± 0.12 3.09b ± 0.21
T2 9.00b ± 1.09 0.44a ± 0.03 1.36 ± 0.37 3.79b ± 0.16 5.22ab ± 1.04
T3 13.02a ± 1.53 0.45a ± 0.01 1.35 ± 0.34 5.85a ± 0.69 7.93a ± 3.10
Levels of significance *** *** NS *** *
Results are expressed as means ± SD. Levels of significance: NS, not significant; * P b 0.05; *** P b 0.001. a–d Means with different superscripts within a row are significantly different (P b 0.05). Abbreviations: Control = 20% back-fat; T1 = 15% back-fat and 5% SLM; T2 = 10% back-fat and 10% SLM; T3 = 0% back-fat and 20% SLM.
Table 4 Effect of surimi-like material (SLM) addition on the sensory evaluation of cooked pork patties. Treatments
Appearance1 Flavor1 Tenderness2 Juiciness3 Overall acceptability1
Control
T1
T2
T3
4.98d ± 0.10 4.32c ± 0.31 4.38c ± 0.63 5.28 ± 0.27 4.32c ± 0.18
5.64c ± 0.10 5.28b ± 0.27 5.34b ± 0.45 5.40 ± 0.65 5.22b ± 0.18
6.42a ± 0.21 5.58ab ± 0.18 5.88ab ± 0.58 5.76 ± 0.18 5.94a ± 0.54
6.06b ± 0.27 5.94a ± 0.48 6.54a ± 0.27 5.82 ± 0.27 6.54a ± 0.42
Levels of significance *** ** ** NS ***
Results are expressed as means ± SD. Levels of significance: NS, not significant; ** P b 0.01; *** P b 0.001. a–d Means with different superscripts within a row are significantly different (P b 0.05). Abbreviations: Control = 20% back-fat; T1 = 15% back-fat and 5% SLM; T2 = 10% back-fat and 10% SLM; T3 = 0% back-fat and 20% SLM. 1 Scale: 1 = very unacceptable; 9 = very acceptable. 2 Scale: 1 = very tough; 9 = very tender. 3 Scale: 1 = very dry; 9 = very juicy.
are determined by the ability of its protein matrix to retain water and bind fat. To enhance WHC and cooking yield, carrageenan and konjac gel can be added to meat products as a fat replacer (Cierach et al., 2009; Osburn & Keeton, 2004). These ingredients have high gelling powers and can thus improve the textural properties and cooking yield of low-fat meat products (Cofrades, Hughes, & Troy, 2000; Kumar & Sharma, 2004). The results suggest that the addition of SLM to low-fat pork patties can improve their cooking properties and texture due to the ability of the SLM gel to keep moisture and fat in the patty matrix. 3.3. Sensory evaluation The effect of SLM addition on the sensory characteristics of pork patties is shown in Table 4. With the exception of juiciness (P N 0.05), the scores of sensory quality attributes were higher in SLM-added treatments compared to the control. T2 samples showed the highest appearance score (6.42), and T3 samples scored significantly higher in
terms of appearance (6.06 vs. 5.64, P b 0.001) and flavor (5.94 vs. 5.28, P b 0.01) than T1 samples. Moreover, panelists judged T3 patties to be more tender than control or T1 patties (6.54 vs. 4.38 or 5.34, P b 0.01). The overall acceptability of cooked patties is evaluated by considering all sensory attributes. Here, T3 samples showed a higher overall acceptability value than the control (6.54 vs. 4.32, P b 0.001), but there were no significant differences between T3 and T2 samples (5.94, P N 0.05). The maintenance of acceptable palatability standards is an important consideration in the development of low-fat meat products. Miles (1996) reported that less than 20% fat in ground meat products can lead to unacceptable product palatability. Several studies have found similar results for low- and reduced-fat products. In Turkish type meatballs, meatballs with 20% fat (control) were more tender than those with 5% fat; however, there were no differences in overall acceptability between control meatballs and those with 10% fat and 2% corn flour (Serdaroglu & Degrimencioglu, 2004). According to Cierach et al. (2009), a significantly higher taste score was observed in frankfurter sausages produced with 10% fat and 0.7% carrageenan
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than in control sausages produced with 10% fat or sausages with 20% fat. Murphy et al. (2004) reported that there were no significant differences in sensory acceptability between full-fat pork sausage with 30% fat and low-fat pork sausage produced with 25.3% surimi and 6.3% fat. Hence, many studies have developed low- and reducedfat meat products using various ingredients, achieving improved cooking and textural properties without impairment of palatability as compared to full-fat meat products. However, only a few studies have shown improved palatability in low-fat meat products (Osburn & Keeton, 2004; Serdaroglu & Degrimencioglu, 2004; Suman & Sharma, 2003). In the present study, the reduced- and low-fat pork patties produced with 10% and 20% SLM presented higher palatability scores compared to patties with 20% back-fat. 4. Conclusion SLM made from the porcine longissimus dorsi muscle can be used as a fat replacer, improving the physicochemical and sensory quality characteristics of low- and reduced-fat pork patties. Specifically, pork patties produced with 20% SLM had a lower fat content (1.76%), and exhibited higher cooking yields and overall acceptability than pork patties produced with 20% back-fat. These results may be useful in developing low-fat meat products. Acknowledgments This research was supported by iPET (the Korea Institute of Planning and Evaluation for Technology of Food, Agriculture, Forestry, and Fisheries). The authors thank the Korea University Food Safety Center for the use of their equipment and facilities. References Alakali, J. S., Irtwange, S. V., & Mzer, M. T. (2010). Quality evaluation of beef patties formulated with Bambara groundnut (Vigna subterranean L.) seed flour. Meat Science, 85, 215–223. Aleson-Carbonell, L., Fernandez-Lopez, J., Perez-Alvarez, J. A., & Kuri, V. (2005). Characteristics of beef burger as influenced by various types of lemon albedo. Innovative Food Science and Emerging Technologies, 6, 247–255. Antonomanolaki, R. E., Vareltzis, K. P., Georgakis, S. A., & Kaldrymidou, E. (1999). Thermal gelation properties of surimi-like material made from sheep meat. Meat Science, 52, 429–435. AOAC (2000). Official methods of analysis (17th ed.). Gaithersburgh, Maryland: Association of Official Analytical Chemists. Biesalski, H. K. (2005). Meat as a component of a healthy diet — are there any risks or benefits if meat is avoided in the diet? Meat Science, 70, 509–524. Bourne, M. C. (1978). Texture profile analysis. Food Technology, 33, 62–66. C.I.E. (1978). Recommendations on uniform color spaces — Color differences equations, psychrometic color terms. Supplement No. 2, CIE Publication No. 15 (E1.3.1). Cavestany, M., Jimenez Colmenero, F., Solas, M. T., & Carballo, J. (1994). Incorporation of sardine surimi in bologna sausage containing different fat levels. Meat Science, 38, 27–37. Choi, Y. M., Lee, S. H., Choe, J. H., Rhee, M. S., Lee, S. K., Kim, B. C., & Joo, S. T. (2010). Protein solubility is related to myosin isoforms, muscle fiber types, meat quality
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