Research Article Received: 28 April 2014
Revised: 6 August 2014
Accepted article published: 23 August 2014
Published online in Wiley Online Library:
(wileyonlinelibrary.com) DOI 10.1002/jsfa.6885
The effect of salt replacers and flavor enhancer on the processing characteristics and consumer acceptance of turkey sausages Zeb Pietrasik* and Nicole J Gaudette Abstract BACKGROUND: Producing high-quality processed meats that contain reduced amounts of sodium chloride is a major challenge facing industry owing to the importance of sodium chloride toward the functional, microbial stability and sensory properties of these products. In order to create reduced sodium alternatives, a number of commercial salt replacers and flavor enhancers have entered the market; however, their ability to be applied in processed meats requires investigation. In this study, two salt replacers (Ocean’s Flavor – OF45, OF60) and one flavor enhancer (Fonterra™ Savoury Powder – SP) were evaluated for their ability to effectively reduce sodium while maintaining the functional and sensory properties of turkey sausages. Functionality via instrumental measures (yield, purge loss, pH, expressible moisture, proximate composition, sodium content, color, texture), safety (microbiological assessment) and consumer acceptability were obtained on all samples. RESULTS: All non-control treatments resulted in products with sodium chloride contents below Canada’s Health Check™ Program target for processed meats. There was no detrimental effect on water binding and texture in treatments when NaCl was substituted with OF60 sea salt replacers. Sodium reduction had no negative effect on the shelf life of the turkey sausages with up to 60 days of refrigerated storage. Consumer acceptability for all attributes did not differ significantly, except for aftertaste, which scored lowest for OF45 compared with the control (regular NaCl content). CONCLUSION: This work demonstrated that salt replacers could potentially substitute for NaCl in smoked turkey sausages; however, further flavor optimization may be required to suppress undesirable levels of bitterness elicited by some of these ingredients. © 2014 Society of Chemical Industry Keywords: salt replacer; flavor enhancer; turkey smokies; consumer acceptability; texture profile analysis; processed meats
INTRODUCTION Consumer interest in the availability of lower-sodium foods continues to be a major trend within the food industry. Such interest has primarily stemmed from health professionals who advocate the benefits of adopting a healthy lifestyle, which includes choosing low-sodium foods more often as part of the everyday diet. Since associations have been made between a diet high in sodium and an increased risk of certain conditions, including hypertension1 and cardiovascular disease,2 the response from some countries, including Canada, has been to adopt a national strategy toward sodium reduction.3 While sodium reduction in some foods is relatively straightforward, such an approach continues to be challenging for processed meats.4 Sodium content in processed meats is typically high in comparison with other foods owing to its important role in the functionality, microbial stability and sensory properties of these products. For example, sodium chloride plays a key role in waterand fat-binding characteristics, which contribute to the formation of stable gel structures within meat products. It also acts as a preservative by lowering the water activity and thus decreasing the opportunity for microbial growth. In addition, saltiness elicited by sodium chloride enhances the perception of meat flavor, which is an important factor in the overall acceptability of J Sci Food Agric (2014)
meat products.5 Thus sodium reduction in processed meats can negatively impact overall quality. Various alternative approaches have been used to create low-sodium meat options. For example, substitution of sodium chloride with potassium chloride can produce products with good functionality; however, at certain concentrations the potassium cation can elicit levels of bitterness that are undesirable.6 Therefore its use may be limited to certain products where lower levels of potassium can be added. Another approach is the use of compounds that elicit umami or savoriness, including monosodium glutamate (MSG).4 While a compound such as MSG can enhance the overall flavor and saltiness of certain products, its use within foods as an additive may be an undesirable approach, since some consumers remain concerned about its safety.7 Processed meats have been identified as a major source of sodium in the Western diet.8 As a national strategy implemented
∗
Correspondence to: Zeb Pietrasik, Food Processing Development Centre, Food and Bio Processing Division, Alberta Agriculture and Rural Development, Leduc, AB T9E 7C5, Canada. E-mail: [email protected] Food Processing Development Centre, Food and Bio Processing Division, Alberta Agriculture and Rural Development, Leduc, AB T9E 7C5, Canada
www.soci.org
© 2014 Society of Chemical Industry
www.soci.org to reduce the sodium intake of the population, the Health Check™ Program in Canada provides a target sodium level for the production of reduced sodium foods. In order to obtain these targets, the food industry has various options toward sodium reduction. For example, a number of commercial sodium replacers and flavor enhancers are now on the market to fully or partially replace sodium chloride in several products. While these ingredients exist, it is difficult to determine the best approach toward sodium reduction in specific products without their direct comparison in a model system. The objective of this study was to determine the impact of reduced sodium formulations on the functionality, quality, consumer acceptance and safety of turkey sausages.
MATERIALS AND METHODS Sausage processing For each of three replications, boneless turkey thigh meat was purchased from a local processor (Lilydale Inc., Edmonton, AB, Canada) and delivered to the Food Processing Development Centre (FPDC), Leduc, AB, Canada. Turkey thighs were trimmed of skin, all visible fat and connective tissue, then ground in a grinder through a plate with 6 mm diameter orifices. The skin and fat were ground through plates with 3 mm openings. Five different turkey sausage formulations were processed on the same day at the FPDC: regular salt 18 g kg−1 NaCl (control), low-salt sausages containing 9 g kg−1 NaCl (LS), sausages formulated to contain 18 g kg−1 Ocean’s Flavor sea salts (OF45 or OF60) and LS sausages (9 g kg−1 salt) formulated to contain 7.5 g kg−1 Savoury Powder (SP). All treatments were formulated to contain 150 g kg−1 protein and 70 g kg−1 fat. The turkey sausages (16 kg treatments) were prepared by mixing ground thigh meat, ground skin with spices (Smokie Seasoning, Newly Weds, Edmonton, AB, Canada) and water until a homogeneous mass was obtained (∼5 min). After mixing, the meat mixtures were transferred to a cooler and allowed to cure overnight at 4 ∘ C. Each meat mixture was then stuffed into 32 mm hog casings (UniPac, Edmonton, AB, Canada) using a VF80 vacuum stuffer (Handtmann, Waterloo, ON, Canada) and ∼6 inch links were formed. The sausage treatments were heat processed in a Maurer smokehouse (Maurer & Söhne, Insel Reichenau, Germany) using a standard cooking protocol to a final internal temperature of 74 ∘ C and then cooled in running water for 15 min and stored at 2 ∘ C until use. Following overnight storage, each sausage treatment was weighed to determine cook yield, calculated as a percentage of raw stuffed weight before cooking. Total cook yield was calculated as a percentage based on the weight of the raw meat for each treatment. The sausages were vacuum packaged (four links per package) in high-barrier mylar/polyethylene pouches in a TF Supra packaging machine (Ulma CyE,S Coop Ltd, Onati, Spain) for later use in instrumental and consumer testing. Samples were then randomly allocated to storage time subgroups (0, 4, 8 weeks), placed in boxes and stored in a dark, walk-in cooler at 2 ∘ C until evaluation. Physical characteristic measurements Proximate analysis, sodium content and pH Proximate analysis (total moisture, protein, fat) was done using a FoodScan Lab Type 78800 analyzer (Foss, Hillerød, Denmark). pH measurements of cooked products were performed in duplicate
wileyonlinelibrary.com/jsfa
Z Pietrasik, NJ Gaudette with a Hanna Instruments FC240 pH meter (Canadawide Scientific, Ottawa, ON, Canada) on a homogenate of 20 g of sample in 80 mL of deionized water. Sodium content was measured in duplicate as described previously.9 Sodium ion concentration (mg · L−1 ) was read directly from the adjusted homogenate. Water activity Water activity was measured at ambient temperature using an Aqualab CX-2 water activity meter (Decagon Devices Inc., Pullman, WA, Inc.) according to the manufacturer’s specifications. Expressible moisture Three core samples (12.7 mm × 15 mm) of known weight (3.0 ± 0.5 g) were placed in 50 mL centrifuge tubes fitted with a thimble consisting of Whatman No. 3 filter paper folded around Whatman No. 50 filter paper, centrifuged (Rotor #11457, MPW Med Instruments, Warsaw, Poland) at 963 × g for 10 min and then reweighed. Expressible moisture (EM, %) was calculated as the ratio of the weight lost after centrifugation to the initial sample weight. Texture profile analysis (TPA) Textural properties were measured using a previous TPA procedure10 and an Instron Universal Testing System (Model 5565, Instron Corporation, Burlington, ON, Canada) fitted with a 100 N load cell. Five core samples (20 mm diameter, 15 mm height) were prepared and compressed twice to 30% of their original height at a constant crosshead speed of 60 mm min−1 . The TPA parameters hardness (peak force on first compression (N)), cohesiveness (ratio of active work done under the second force–displacement curve to that done under the first compression curve (dimensionless)), springiness (distance the sample recovered after the first compression (mm)) and chewiness (hardness × cohesiveness × springiness (N mm)) were computed. Bind strength Bind strength was determined using the three-point break test. The breaking force of four (15 mm × 15 mm × 50 mm) samples cut from the center of each sausage was determined for each treatment using an Instron Universal Testing System (Model 5565, Instron Corporation) fitted with a 100 N load cell. Samples were placed on an adjustable two-point base at 25 mm apart and penetrated with a flat blade attachment at a constant speed of 60 mm min−1 . Maximum peak force recorded during the test indicates bind strength (N). Instrumental color Color was measured using a Minolta CM-2500C handheld spectrophotometer (Konica-Minolta, Osaka, Japan) with a 10∘ observer angle and illuminant A, calibrated against a white tile immediately before readings were taken. Internal color (CIE L* (lightness), a* (redness), b* (yellowness)) was measured on fresh sausages by taking observations from four different cut surfaces of the same sausage. In addition, color measurements were made through intact packages 2 days after processing and after 4 and 8 weeks of storage either in a retail display case (4.0 ± 1.0 ∘ C) under 24 h fluorescent lighting with an average intensity of 1630 lx or in the dark. All measurements were taken in quadruplicate. Hue angle was calculated as tan−1 (b*/a*) and saturation index (chroma) as [(a*)2 + (b*)2 ]1/2 .
© 2014 Society of Chemical Industry
J Sci Food Agric (2014)
Salt replacement in turkey sausages
www.soci.org
Purge loss during storage Purge accumulation from vacuum-packaged products was determined on three vacuum-packaged bags from each treatment. After packaging, the bags were stored in a dark, walk-in cooler (2 ∘ C) for up to 8 weeks. Purge loss was determined by reweighing blotted sausages from the three packages following storage and expressed as a percentage of the initial weight. Microbiological testing Microbiological testing was conducted by the Agri-Food Laboratories Branch of Alberta Agriculture and Rural Development. At 1 day post-packaging and at 4 and 8 weeks post-processing, two packages of each sample were shipped in a chilled state to the lab, where duplicate samples were prepared for aerobic plate, lactic acid bacteria (LAB) and coliform counts according to Health Canada11 protocols. Sensory testing – consumer panel assessment Consumer sensory analysis was performed on all treatments at the Consumer Product Testing Centre (CPTC), Edmonton, AB, Canada. Consumers over 18 years of age were screened for allergies and were required to consume smokie sausages at least once every month (n = 87). Evaluations were collected using Compusense Five Release 5.2 software (Compusense Inc., Guelph, ON, Canada). A completely randomized design was used.12 Panelists were provided with half smokie sausages. Samples were presented monadically on 6 inch foam plates and labeled with three-digit randomized codes. During each session, consumers sampled all five treatments ad libitum and performed evaluations on overall acceptability and acceptability of appearance, color, saltiness, flavor, texture and aftertaste. Ratings were collected using a nine-point hedonic scale where 1 = dislike extremely, 2 = dislike very much, 3 = dislike moderately, 4 = dislike slightly, 5 = neither like/dislike, 6 = like slightly, 7 = like moderately, 8 = like very much and 9 = like extremely. In order to reduce carryover, a 30 s forced break with two water rinses and a bite of cracker was enforced between samples. Data analyses All data were analyzed using the PROC MIXED procedure of SAS (SAS Institute Inc., Cary, NC, USA). For processing and instrumental data, the model included both fixed (formulation treatment) and random (processing replication) effects. For sensory data, panelist and treatment were independent variables (random and fixed variables respectively) and consumer hedonic scores corresponding
to individual sensory attributes served as the dependent variable. Least squares means were calculated for the main effect of formulation, and means were separated using the probability of difference option with a Tukey’s honestly significant difference (HSD) adjustment when the respective F tests were significant (P ≤ 0.05).
RESULTS AND DISCUSSION Functional characteristics of turkey sausages Reducing formulated salt from 18 g kg−1 in the control formulation to 9 g kg−1 in the LS treatment resulted in a 44% reduction in sodium content. This reduction allowed for formulation of a product with a per serving sodium content 13% lower than the Health Check™ Program limit (Table 1). Use of each of the salt replacer ingredients (OF45, OF60, SP) was also successful in terms of meeting Health Check™ Program requirements, with sodium level in the OF60 formulation being significantly lower than in the other alternative products (19% less sodium than required by the Health Check™ Program). The pH values (Table 1) of the cooked products ranged from 6.41 to 6.49. In general, none of the experimental treatments had any effect on pH of the cooked products. Proximate composition was not statistically different (P > 0.05) among treatments (Table 1). Fat content ranged from 69.1 to 71.6 g kg−1 and only varied slightly from the target value of 70 g kg−1 . Moisture levels in the cooked products varied from 687.6 to 700.7 g kg−1 , while protein content ranged from 191.8 to 198.9 g kg−1 . In all formulations the amount of meat and fat was held constant, so any variation in overall moisture, fat or protein content would potentially be the result of differences in cooking losses among sausage treatments. However, there was no significant (P > 0.05) effect of formulation on cook yield of turkey sausages. Lack of significantly important variations in proximate composition is consistent with similar cook yields of the cooked sausages. Although cook yield and moisture content were not different across formulations, the ability of the different meat systems to retain moisture under stress due to centrifugation was affected by formulation. The expressible moisture in control treatments and those containing OF60 was significantly lower as compared with LS, OF45 and SP formulations. Results indicated that the matrix formed in those sausages had a greater ability to entrap water than that of other treatments. It is well known that a lower concentration of NaCl is associated with less capacity to solubilize protein, which generally means that heat-induced gels have poorer water- and fat-binding properties.4,5 Salt disrupts the myofibrillar structure within muscle
Table 1. Mean values for functional parameters and proximate composition of turkey sausages processed with salt replacers and flavor enhancer Formulationa
pH
Control LS OF45 OF60 SP P value
6.41 6.49 6.44 6.44 6.44 0.11
Cook yield (%) 79.9 80.6 80.5 80.6 78.6 0.33
aw 0.979c 0.989a 0.985b 0.984b 0.985b
Revised: 6 August 2014
Accepted article published: 23 August 2014
Published online in Wiley Online Library:
(wileyonlinelibrary.com) DOI 10.1002/jsfa.6885
The effect of salt replacers and flavor enhancer on the processing characteristics and consumer acceptance of turkey sausages Zeb Pietrasik* and Nicole J Gaudette Abstract BACKGROUND: Producing high-quality processed meats that contain reduced amounts of sodium chloride is a major challenge facing industry owing to the importance of sodium chloride toward the functional, microbial stability and sensory properties of these products. In order to create reduced sodium alternatives, a number of commercial salt replacers and flavor enhancers have entered the market; however, their ability to be applied in processed meats requires investigation. In this study, two salt replacers (Ocean’s Flavor – OF45, OF60) and one flavor enhancer (Fonterra™ Savoury Powder – SP) were evaluated for their ability to effectively reduce sodium while maintaining the functional and sensory properties of turkey sausages. Functionality via instrumental measures (yield, purge loss, pH, expressible moisture, proximate composition, sodium content, color, texture), safety (microbiological assessment) and consumer acceptability were obtained on all samples. RESULTS: All non-control treatments resulted in products with sodium chloride contents below Canada’s Health Check™ Program target for processed meats. There was no detrimental effect on water binding and texture in treatments when NaCl was substituted with OF60 sea salt replacers. Sodium reduction had no negative effect on the shelf life of the turkey sausages with up to 60 days of refrigerated storage. Consumer acceptability for all attributes did not differ significantly, except for aftertaste, which scored lowest for OF45 compared with the control (regular NaCl content). CONCLUSION: This work demonstrated that salt replacers could potentially substitute for NaCl in smoked turkey sausages; however, further flavor optimization may be required to suppress undesirable levels of bitterness elicited by some of these ingredients. © 2014 Society of Chemical Industry Keywords: salt replacer; flavor enhancer; turkey smokies; consumer acceptability; texture profile analysis; processed meats
INTRODUCTION Consumer interest in the availability of lower-sodium foods continues to be a major trend within the food industry. Such interest has primarily stemmed from health professionals who advocate the benefits of adopting a healthy lifestyle, which includes choosing low-sodium foods more often as part of the everyday diet. Since associations have been made between a diet high in sodium and an increased risk of certain conditions, including hypertension1 and cardiovascular disease,2 the response from some countries, including Canada, has been to adopt a national strategy toward sodium reduction.3 While sodium reduction in some foods is relatively straightforward, such an approach continues to be challenging for processed meats.4 Sodium content in processed meats is typically high in comparison with other foods owing to its important role in the functionality, microbial stability and sensory properties of these products. For example, sodium chloride plays a key role in waterand fat-binding characteristics, which contribute to the formation of stable gel structures within meat products. It also acts as a preservative by lowering the water activity and thus decreasing the opportunity for microbial growth. In addition, saltiness elicited by sodium chloride enhances the perception of meat flavor, which is an important factor in the overall acceptability of J Sci Food Agric (2014)
meat products.5 Thus sodium reduction in processed meats can negatively impact overall quality. Various alternative approaches have been used to create low-sodium meat options. For example, substitution of sodium chloride with potassium chloride can produce products with good functionality; however, at certain concentrations the potassium cation can elicit levels of bitterness that are undesirable.6 Therefore its use may be limited to certain products where lower levels of potassium can be added. Another approach is the use of compounds that elicit umami or savoriness, including monosodium glutamate (MSG).4 While a compound such as MSG can enhance the overall flavor and saltiness of certain products, its use within foods as an additive may be an undesirable approach, since some consumers remain concerned about its safety.7 Processed meats have been identified as a major source of sodium in the Western diet.8 As a national strategy implemented
∗
Correspondence to: Zeb Pietrasik, Food Processing Development Centre, Food and Bio Processing Division, Alberta Agriculture and Rural Development, Leduc, AB T9E 7C5, Canada. E-mail: [email protected] Food Processing Development Centre, Food and Bio Processing Division, Alberta Agriculture and Rural Development, Leduc, AB T9E 7C5, Canada
www.soci.org
© 2014 Society of Chemical Industry
www.soci.org to reduce the sodium intake of the population, the Health Check™ Program in Canada provides a target sodium level for the production of reduced sodium foods. In order to obtain these targets, the food industry has various options toward sodium reduction. For example, a number of commercial sodium replacers and flavor enhancers are now on the market to fully or partially replace sodium chloride in several products. While these ingredients exist, it is difficult to determine the best approach toward sodium reduction in specific products without their direct comparison in a model system. The objective of this study was to determine the impact of reduced sodium formulations on the functionality, quality, consumer acceptance and safety of turkey sausages.
MATERIALS AND METHODS Sausage processing For each of three replications, boneless turkey thigh meat was purchased from a local processor (Lilydale Inc., Edmonton, AB, Canada) and delivered to the Food Processing Development Centre (FPDC), Leduc, AB, Canada. Turkey thighs were trimmed of skin, all visible fat and connective tissue, then ground in a grinder through a plate with 6 mm diameter orifices. The skin and fat were ground through plates with 3 mm openings. Five different turkey sausage formulations were processed on the same day at the FPDC: regular salt 18 g kg−1 NaCl (control), low-salt sausages containing 9 g kg−1 NaCl (LS), sausages formulated to contain 18 g kg−1 Ocean’s Flavor sea salts (OF45 or OF60) and LS sausages (9 g kg−1 salt) formulated to contain 7.5 g kg−1 Savoury Powder (SP). All treatments were formulated to contain 150 g kg−1 protein and 70 g kg−1 fat. The turkey sausages (16 kg treatments) were prepared by mixing ground thigh meat, ground skin with spices (Smokie Seasoning, Newly Weds, Edmonton, AB, Canada) and water until a homogeneous mass was obtained (∼5 min). After mixing, the meat mixtures were transferred to a cooler and allowed to cure overnight at 4 ∘ C. Each meat mixture was then stuffed into 32 mm hog casings (UniPac, Edmonton, AB, Canada) using a VF80 vacuum stuffer (Handtmann, Waterloo, ON, Canada) and ∼6 inch links were formed. The sausage treatments were heat processed in a Maurer smokehouse (Maurer & Söhne, Insel Reichenau, Germany) using a standard cooking protocol to a final internal temperature of 74 ∘ C and then cooled in running water for 15 min and stored at 2 ∘ C until use. Following overnight storage, each sausage treatment was weighed to determine cook yield, calculated as a percentage of raw stuffed weight before cooking. Total cook yield was calculated as a percentage based on the weight of the raw meat for each treatment. The sausages were vacuum packaged (four links per package) in high-barrier mylar/polyethylene pouches in a TF Supra packaging machine (Ulma CyE,S Coop Ltd, Onati, Spain) for later use in instrumental and consumer testing. Samples were then randomly allocated to storage time subgroups (0, 4, 8 weeks), placed in boxes and stored in a dark, walk-in cooler at 2 ∘ C until evaluation. Physical characteristic measurements Proximate analysis, sodium content and pH Proximate analysis (total moisture, protein, fat) was done using a FoodScan Lab Type 78800 analyzer (Foss, Hillerød, Denmark). pH measurements of cooked products were performed in duplicate
wileyonlinelibrary.com/jsfa
Z Pietrasik, NJ Gaudette with a Hanna Instruments FC240 pH meter (Canadawide Scientific, Ottawa, ON, Canada) on a homogenate of 20 g of sample in 80 mL of deionized water. Sodium content was measured in duplicate as described previously.9 Sodium ion concentration (mg · L−1 ) was read directly from the adjusted homogenate. Water activity Water activity was measured at ambient temperature using an Aqualab CX-2 water activity meter (Decagon Devices Inc., Pullman, WA, Inc.) according to the manufacturer’s specifications. Expressible moisture Three core samples (12.7 mm × 15 mm) of known weight (3.0 ± 0.5 g) were placed in 50 mL centrifuge tubes fitted with a thimble consisting of Whatman No. 3 filter paper folded around Whatman No. 50 filter paper, centrifuged (Rotor #11457, MPW Med Instruments, Warsaw, Poland) at 963 × g for 10 min and then reweighed. Expressible moisture (EM, %) was calculated as the ratio of the weight lost after centrifugation to the initial sample weight. Texture profile analysis (TPA) Textural properties were measured using a previous TPA procedure10 and an Instron Universal Testing System (Model 5565, Instron Corporation, Burlington, ON, Canada) fitted with a 100 N load cell. Five core samples (20 mm diameter, 15 mm height) were prepared and compressed twice to 30% of their original height at a constant crosshead speed of 60 mm min−1 . The TPA parameters hardness (peak force on first compression (N)), cohesiveness (ratio of active work done under the second force–displacement curve to that done under the first compression curve (dimensionless)), springiness (distance the sample recovered after the first compression (mm)) and chewiness (hardness × cohesiveness × springiness (N mm)) were computed. Bind strength Bind strength was determined using the three-point break test. The breaking force of four (15 mm × 15 mm × 50 mm) samples cut from the center of each sausage was determined for each treatment using an Instron Universal Testing System (Model 5565, Instron Corporation) fitted with a 100 N load cell. Samples were placed on an adjustable two-point base at 25 mm apart and penetrated with a flat blade attachment at a constant speed of 60 mm min−1 . Maximum peak force recorded during the test indicates bind strength (N). Instrumental color Color was measured using a Minolta CM-2500C handheld spectrophotometer (Konica-Minolta, Osaka, Japan) with a 10∘ observer angle and illuminant A, calibrated against a white tile immediately before readings were taken. Internal color (CIE L* (lightness), a* (redness), b* (yellowness)) was measured on fresh sausages by taking observations from four different cut surfaces of the same sausage. In addition, color measurements were made through intact packages 2 days after processing and after 4 and 8 weeks of storage either in a retail display case (4.0 ± 1.0 ∘ C) under 24 h fluorescent lighting with an average intensity of 1630 lx or in the dark. All measurements were taken in quadruplicate. Hue angle was calculated as tan−1 (b*/a*) and saturation index (chroma) as [(a*)2 + (b*)2 ]1/2 .
© 2014 Society of Chemical Industry
J Sci Food Agric (2014)
Salt replacement in turkey sausages
www.soci.org
Purge loss during storage Purge accumulation from vacuum-packaged products was determined on three vacuum-packaged bags from each treatment. After packaging, the bags were stored in a dark, walk-in cooler (2 ∘ C) for up to 8 weeks. Purge loss was determined by reweighing blotted sausages from the three packages following storage and expressed as a percentage of the initial weight. Microbiological testing Microbiological testing was conducted by the Agri-Food Laboratories Branch of Alberta Agriculture and Rural Development. At 1 day post-packaging and at 4 and 8 weeks post-processing, two packages of each sample were shipped in a chilled state to the lab, where duplicate samples were prepared for aerobic plate, lactic acid bacteria (LAB) and coliform counts according to Health Canada11 protocols. Sensory testing – consumer panel assessment Consumer sensory analysis was performed on all treatments at the Consumer Product Testing Centre (CPTC), Edmonton, AB, Canada. Consumers over 18 years of age were screened for allergies and were required to consume smokie sausages at least once every month (n = 87). Evaluations were collected using Compusense Five Release 5.2 software (Compusense Inc., Guelph, ON, Canada). A completely randomized design was used.12 Panelists were provided with half smokie sausages. Samples were presented monadically on 6 inch foam plates and labeled with three-digit randomized codes. During each session, consumers sampled all five treatments ad libitum and performed evaluations on overall acceptability and acceptability of appearance, color, saltiness, flavor, texture and aftertaste. Ratings were collected using a nine-point hedonic scale where 1 = dislike extremely, 2 = dislike very much, 3 = dislike moderately, 4 = dislike slightly, 5 = neither like/dislike, 6 = like slightly, 7 = like moderately, 8 = like very much and 9 = like extremely. In order to reduce carryover, a 30 s forced break with two water rinses and a bite of cracker was enforced between samples. Data analyses All data were analyzed using the PROC MIXED procedure of SAS (SAS Institute Inc., Cary, NC, USA). For processing and instrumental data, the model included both fixed (formulation treatment) and random (processing replication) effects. For sensory data, panelist and treatment were independent variables (random and fixed variables respectively) and consumer hedonic scores corresponding
to individual sensory attributes served as the dependent variable. Least squares means were calculated for the main effect of formulation, and means were separated using the probability of difference option with a Tukey’s honestly significant difference (HSD) adjustment when the respective F tests were significant (P ≤ 0.05).
RESULTS AND DISCUSSION Functional characteristics of turkey sausages Reducing formulated salt from 18 g kg−1 in the control formulation to 9 g kg−1 in the LS treatment resulted in a 44% reduction in sodium content. This reduction allowed for formulation of a product with a per serving sodium content 13% lower than the Health Check™ Program limit (Table 1). Use of each of the salt replacer ingredients (OF45, OF60, SP) was also successful in terms of meeting Health Check™ Program requirements, with sodium level in the OF60 formulation being significantly lower than in the other alternative products (19% less sodium than required by the Health Check™ Program). The pH values (Table 1) of the cooked products ranged from 6.41 to 6.49. In general, none of the experimental treatments had any effect on pH of the cooked products. Proximate composition was not statistically different (P > 0.05) among treatments (Table 1). Fat content ranged from 69.1 to 71.6 g kg−1 and only varied slightly from the target value of 70 g kg−1 . Moisture levels in the cooked products varied from 687.6 to 700.7 g kg−1 , while protein content ranged from 191.8 to 198.9 g kg−1 . In all formulations the amount of meat and fat was held constant, so any variation in overall moisture, fat or protein content would potentially be the result of differences in cooking losses among sausage treatments. However, there was no significant (P > 0.05) effect of formulation on cook yield of turkey sausages. Lack of significantly important variations in proximate composition is consistent with similar cook yields of the cooked sausages. Although cook yield and moisture content were not different across formulations, the ability of the different meat systems to retain moisture under stress due to centrifugation was affected by formulation. The expressible moisture in control treatments and those containing OF60 was significantly lower as compared with LS, OF45 and SP formulations. Results indicated that the matrix formed in those sausages had a greater ability to entrap water than that of other treatments. It is well known that a lower concentration of NaCl is associated with less capacity to solubilize protein, which generally means that heat-induced gels have poorer water- and fat-binding properties.4,5 Salt disrupts the myofibrillar structure within muscle
Table 1. Mean values for functional parameters and proximate composition of turkey sausages processed with salt replacers and flavor enhancer Formulationa
pH
Control LS OF45 OF60 SP P value
6.41 6.49 6.44 6.44 6.44 0.11
Cook yield (%) 79.9 80.6 80.5 80.6 78.6 0.33
aw 0.979c 0.989a 0.985b 0.984b 0.985b
