Optimization for Reduced-Fat / Low-NaCl Meat Emulsion Systems with Sea Mustard (Undaria pinnatifida) and Phosphate.

The effects of reducing fat levels from 30% to 20% and salt concentrations from 1.5% to 1.0% by partially substituting incorporated phosphate and sea mustard were investigated based on physicochemical properties of reduced-fat / low-NaCl meat emulsion systems. Cooking loss and emulsion stability, hardness, springiness, and cohesiveness for reduced-fat / low-NaCl meat emulsion systems with 20% pork back fat and 1.2% sodium chloride samples with incorporation of phosphate and sea mustard were similar to the control with 30% pork back fat and 1.5% sodium chloride. Results showed that reduced-fat / low-NaCl meat emulsion system samples containing phosphate and sea mustard had higher apparent viscosity. The results of this study show that the incorporation of phosphate and sea mustard in the formulation will successfully reduce fat and salt in the final meat products.

Introduction

Fat and salt are some of the main components of meat products. In recent years, we have seen a rapid expansion of knowledge about the influence of diet on health. Meat product based potential functional foods have been formulated both by reducing the fat and sodium contents and by promoting the presence of healthy compounds (Jimenez-Colmenero ).

The addition of fat to meat products has played important roles in stabilizing meat emulsions, reducing cooking loss, improving water holding capacity and providing juiciness and hardness (Choi ; Woo ). Some researchers have found that fats have considerable effects on the binding, rheological and structural properties of meat products (Bloukas ; Crehan ). However, high fat diets are linked to obesity, hypertension, cardiovascular diseases and coronary heart diseases (Choi ; Ozvural and Vural, 2008). Thus, the reduced fat content in meat products should result in healthier products.

Added salt in meat products has become a major issue for the processed meat industry (Desmond, 2006). Common salt has a flavor enhancing effect in meat products and one of the main functions of salt in processed meats is the solubilisation of the functional myofibrillar proteins in meat (Lee and Chin, 2010; Pappa ; Ruusunen ). This activates the proteins to increase hydration and water holding capacity, ultimately increasing the binding properties of proteins to improve texture. Salt is a critical component in contributing to the texture and shelf life of processed meat products (Ruusunen and Puolanne, 2005). However, excessive intake of sodium has been linked to hypertension. High blood pressure may in turn increase the risk of stroke and premature death from cardiovascular diseases (Jimenez-Colmenero ). Thus, salt reduction is a prime concern in meat industry.

Sea mustard (Undaria pinnatifida) is originally found in Korea and East Asian countries. It is a marine vegetable and the growing conditions depend on geography and temperature (Boulom ). In general, nutritional composition of sea mustard is varying depending with location and seasonal changes. Furthermore, Undaria pinnatifida is an excellent source of dietary fiber, vitamins, minerals, and phytosterols (MacArtain ). In particular, Undaria pinnatifida is a major source of dietary fiber such as alginic acid, fucoidan, and laminaran, all of which are beneficial to human health (Fung ; Urbano and Gorii, 2002). Dietary fiber has been added to different meat products to counteract the problems caused by fat and salt reduction (Kim ; Turhan ). Some studies have been carried out on low-fat or low-salt meat products with fat or salt partially replaced by dietary fiber, which helps to improve rheological properties and emulsion stability (Tobin ). However, application in meat products with dietary fiber both low-fat and low-salt have so far been limited research.

Sodium tripolyphosphate (STPP) is commonly used in the production of value added meat products (Detienne and Wicker, 1999) and it imparts improved sensory characteristics to the meat products. Also, STPP has demonstrated improved yield, tenderness, water holding capacity and extractable protein (Cannon ; Murphy and Zerby, 2004). A well known, but not well understood, interaction has been reported among NaCl, STPP and sea mustard. A clear understanding of this interaction could lead to more effective methods for commercial meat emulsion systems.

Therefore, the objective of this study is to evaluate the effect of replacing fat and salt with various levels of sea mustard (Undaria pinnatifida) fiber and phosphate on optimized proximate composition, pH, color, cooking loss, emulsion stability, protein solubility, textural profile analysis and apparent viscosity of reduced-fat and reduced-salt meat emulsion systems.

Materials and Methods

Preparation and processing of sea mustard (Undaria pinnatifida)

The dietary fiber was extracted using the modified AOAC enzymatic-gravimetric method (AOAC, 2000). The sea mustard, purchased from a market in Seongnam-si, Gyeonggi-do, Korea, was ground in a mill and passed through a 25-mesh sieve. The sea mustard powder (moisture content: 8.54 g/100 g, protein content: 17.72 g/100 g, fat content: 1.42 g/100 g, ash content: 24.95 g/100 g, dietary fiber content: 54.32 g/100 g, salinity: 3.4%, pH: 6.43, lightness (L*-value): 41.37, redness (a*-value): −1.46, yellowness (b*-value): 1.35) was placed in polyethylene bags and vacuum-sealed using a vacuum packaging system (FJ-500XL, Fujee Tech., Korea). It was then stored at 4℃ until it was used for product manufacturing

Meat batter preparation and processing

Fresh pork ham (castrated boars; Landrace × Yorkshire × Duroc; approximately 110 kg, M. biceps femoris, M. semitendinosus, M. semimembranosus) and pork back fat (moisture 12.61%, fat 85.64%) were purchased from a local processor 48 h postmortem. All subcutaneous, intramuscular fat and visible connective tissue were removed from muscle. Lean materials and the pork fat were initially ground through an 8-mm plate. The ground tissue was then placed in polyethylene bags, vacuum sealed using a vacuum packaging system (FJ-500XL, Fujee Tech, Korea) and stored at 0℃ until required for product manufacturing. Seven different meat batters were produced and the experimental design and compositions are given in Table 1. The first meat batter served as the control and was prepared with 30% pork back fat and 1.5% sodium chloride. The second meat batter (T1) was prepared with 20% pork back fat and 1.2% sodium chloride. Meat batter T2 was prepared with 20% pork back fat, 1.2% sodium chloride and 0.1% sodium tripolyphosphate. Meat batter T3 was prepared with 20% pork back fat, 1.2% sodium chloride, 0.1% sodium tripolyphosphate, and 2.0% sea mustard. The concentration of the sea mustard was based on recommendations by Choi . The next three meat batters were prepared with 1.0% sodium chloride. The following combination of back fat, sodium chloride, sodium tripolyphosphate and sea mustard were used; T4: pork back fat 20% + sodium chloride 1.0%; T5: pork back fat 20% + sodium chloride 1.0%+ sodium tripolyphosphate 0.1%; T6: pork back fat 20% + sodium chloride 1.0% + sodium tripolyphosphate 0.1% + sea mustard 2%. Pork meat was homogenized, ground for 1 min in a silent cutter (Cutter Nr-963009, Hermann Scharfen GmbH & Co, Germany) then chilled in iced water (2℃). Sodium chloride and sodium tripolyphosphate were added to the meat and mixed for 1 min. 2% sea mustard was used for the samples and pork back fat was added after 3 min. The meat batters were homogenized for 6 min. A temperature probe (Kane-May, KM330, UK) was used to monitor the temperature of the emulsion, and the temperature was maintained below 10℃ during batter preparation. Meat batter processing was carried out thrice for each treatment (each meat batter was processed in a 10 kg batch). All analyses were carried out in triplicate for each meat batter formulation.

Table 1.

Reduced-fat meat emulsion systems formulation with varying sodium chloride, sodium tripolyphosphate and sea mustard levels (units: g/100 g)

Ingredients	Treatments1)
	Control	T1	T2	T3	T4	T5	T6
Pork meat	50	50	50	50	50	50	50
Back fat	30	20	20	20	20	20	20
Ice	20	30	30	30	30	30	30
Total	100	100	100	100	100	100	100
Sodium chloride	1.5	1.2	1.2	1.2	1.0	1.0	1.0
Sodium tripolyphosphate	-	-	0.1	0.1	-	0.1	0.1
Sea mustard	-	-	-	2.0	-	-	2.0

1)Control: pork back fat (30%) + sodium chloride (1.5%), T1: pork back fat (20%) + sodium chloride (1.2%), T2: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%), T3: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%) + sea mustard (2%), T4: pork back fat (20%) + sodium chloride (1.0%), T5: pork back fat (20%) + sodium chloride (1.0%) + sodium tripolyphosphate (0.1%), T6: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%) + sea mustard (2%).

Proximate composition

Compositional properties of the meat batters were performed using AOAC (2000) procedures. Moisture content (950.46B) was determined by weight loss after 12 h of drying at 105℃ in a drying oven (SW-90D, Sang Woo Scientific Co., Korea). Fat content (960.69) was determined by the Soxhlet method with a solvent extraction system (Soxtec® Avanti 2050 Auto System, Foss Tecator AB, Sweden) and protein content (981.10) was determined by the Kjeldahl method with an automatic Kjeldahl nitrogen analyzer (Kjeltec® 2300Analyzer Unit, Foss Tecator AB, Sweden). Ash was determined according to AOAC method 920.153 (muffle furnace).

Salinity

Mohr’s titration was carried out according to Chen . The salinity of the sample was calculated according to the amount of titrated chloride ion. Means with standard deviations of triplicate determinations were reported.

pH

The pH values of meat batters were measured in a homogenate prepared with 5 g of sample and distilled water (20 mL) using a pH meter (Model 340, Mettler-Toledo GmbH, Switzerland). All determinations were performed in triplicate.

Color measurements

The color of each meat batter was determined using a colorimeter (Minolta Chroma meter CR-210, Minolta Ltd., Osaka, Japan; illuminate C, calibrated with a white plate, L*=+97.83, a*=−0.43, b*=+1.98). Six measurements for each of five replicates were taken. Lightness (CIE L*- value), redness (CIE a*- value), and yellowness (CIE b*- value) values were recorded.

Cooking loss

The meat batters were stuffed into the casing (initial weight) and after heat processing at 75℃ for 30 min, cooked samples were cooled to room temperature at 21℃ for 3 h. After cooling, cooked meat batters were weighed and a cooking loss was calculated from the weights.

Cooking loss (g/100g) = [(weight of raw meat batter (g) − weight of cooked meat batter (g)) / weight of raw meat batter (g)] × 100

Emulsion stability

The meat batters were analyzed for emulsion stability using the method of Blouka and Honikel (1992) with the following modifications. At the middle of a 15 mesh sieve, pre-weighed graduated glass tubes were filled with batter. The glass tubes were closed and heated for 30 min in a boiling water bath to a core temperature of 75±1℃. After cooling to approximately 4±1℃ to facilitate fat and water layer separation, the total expressible fluid and fat separated in the bottom of each graduated glass tube were measured and calculated (Choi ).

Total expressible fluid separation (mL/g) = [(the water layer (mL) + the fat layer (mL)) / weight of raw meat batter (g)] × 100

Fat separation (mL/g) = [the fat layer (mL) / weight of raw meat batter (g)] × 100

Texture profile analysis

Texture profile analysis (TPA) was performed at room temperature with a texture analyzer (TA-XT2i, Stable Micro Systems Ltd., England). The meat batters were stuffed into casings followed by heating (75℃ for 30 min), and the cooked samples were cooled to room temperature at 21℃ for 3 h. Prior to analysis, samples were allowed to equilibrate to room temperature. Cooked meat batter samples were taken from the central portion of each meat batter. The conditions of texture analysis were as follows: pre-test speed 2.0 mm/s, post-test speed 5.0 mm/s, maximum load 2 kg, head speed 2.0 mm/s, distance 8.0 mm, force 5 g. The calculation of TPA values was obtained by graphing a curve using force and time plots. Values for hardness (kg), springiness, cohesiveness, gumminess (kg), and chewiness (kg) were determined as described by Bourne (1978).

Apparent viscosity

Meat batter viscosity was measured in triplicate with a rotational viscometer (HAKKE Viscotester® 550, Thermo Electron Corporation, Germany) set at 10 rpm. The standard cylinder sensor (SV-2) was positioned in a 25 mL metal cup filled with batter and allowed to rotate under a constant share rate (s−1) for 60 s before each reading was taken. Apparent viscosity values in centipoises were obtained. The temperature of each sample at the time (18±1℃) of viscosity testing was also recorded.

Statistical analysis

All tests were done at least three times for each experimental condition and mean values were reported. An analysis of variance was performed on all the variables measured using the general linear model (GLM) procedure of the SAS statistical package (2008). Duncan’s multiple range test (p<0.05) was used to determine the differences among treatments.

Results and Discussion

Proximate composition and salinity

The proximate composition and salinity of reduced-fat/low-salt meat emulsion systems formulated with different amounts of phosphate and sea mustard are given in Table 2. The differences in moisture, fat and ash contents of the reduced-fat/low-salt cooked meat emulsion systems are shown to be significant statistically compared to control (p<0.05), but protein content shows no statistically significant difference (p>0.05). The moisture content of the control was lower than that of the treatment samples, due to the fact that the treatment samples had 10% more water added to make up for the replaced back fat (Table 2). The moisture contents of emulsion systems with same sodium chloride were higher for treatments with sodium tripolyphosphate and sea mustard than for treatment without (p<0.05). The control had higher fat content than the treatment samples (p<0.05) and the fat levels for the reduced-fat/low-salt meat batters were close to the target value of 20%. The highest ash content for the reduced-fat/low-salt cooked meat emulsion systems were obtained for sea mustard treatment samples (p<0.05). The sea mustard used for the treatment contained mineral and vitamin. Similar trends of proximate composition were observed in studies by Choi when different amounts of Laminaria japonica were added to reduced-fat pork patties. These results agree with Jimenez-Colmenero who reported similar quality characteristics for reduced/low-fat, low-salt frankfurters supplemented with konjac and seaweed. Differences in proximate analysis are likely due to differences in formulation conditions.

Table 2.

Proximate composition of cooked reduced-fat meat batters formulation with varying sodium chloride, sodium tripolyphosphate and sea mustard levels

Treatments1)	Moisture (g/100 g)	Protein (g/100 g)	Fat (g/100 g)	Ash (g/100 g)	Salinity (%)
Control	53.71±1.26e	12.19±0.53	31.65±0.99a	1.80±0.15b	1.54±0.04a
T1	61.40±1.23b	12.79±0.67	23.93±0.91b	1.61±0.27c	1.30±0.03d
T2	64.09±0.69a	11.58±0.62	21.94±0.98b	1.78±0.10b	1.36±0.03c
T3	64.15±0.83a	11.44±0.75	22.18±0.83b	1.98±0.11a	1.42±0.05b
T4	57.84±0.36d	12.19±0.78	20.48±1.11b	1.44±0.12d	1.15±0.02e
T5	60.53±1.26c	11.46±0.72	21.20±0.98b	1.62±0.10c	1.17±0.03e
T6	63.98±1.21ab	11.91±0.85	20.55±1.05b	1.97±0.11a	1.28±0.02d

All values are mean±standard deviation of three replicates (n=9).

a-eMeans within a column with different letters are significantly different (p<0.05).

1)Control: pork back fat (30%) + sodium chloride (1.5%), T1: pork back fat (20%) + sodium chloride (1.2%), T2: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%), T3: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%) + sea mustard (2%), T4: pork back fat (20%) + sodium chloride (1.0%), T5: pork back fat (20%) + sodium chloride (1.0%) + sodium tripolyphosphate (0.1%), T6: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%) + sea mustard (2%).

The differences in salinity of reduced-fat/low-salt meat emulsion systems with phosphate and sea mustard are shown to be significant (Table 2). The salinity for the control with 1.5% NaCl was the highest. By decreasing the sodium chloride levels from 1.5% to 1.0%, the salinity of reduced-fat/low-salt meat emulsion systems significantly decreased (p<0.05). Also, the treatments adding the phosphate and sea mustard increased salinity, due to phosphate and sea mustard contains sodium components. Thus, the salinity of reduced-fat/low-salt meat emulsion systems is shown to be positive related to the amount of salt, phosphate and sea mustard added.

pH and color

Table 3 gives the pH, L*-value (lightness), a*-value (redness), and b*-value (yellowness) values for uncooked and cooked reduced-fat/low-salt meat emulsion systems formulated with incorporated phosphate and sea mustard. Increasing sodium chloride levels yielded lower pH values for both uncooked and cooked meat emulsion systems (p<0.05). Also, the pH values for uncooked and cooked reduced-fat/low-salt meat emulsion systems were higher for batters formulated with phosphate and sea mustard. According to Puolanne , the pH of cooked sausages tended to decrease when phosphate or salt level was increased. Jimenez-Colmenero reported that the pH of low-fat frankfurters with konjac gel were higher than the control with regular fat and salt. Detienne and Wicker (1999) observed that the pH of pork loin injected with 0.5% NaCl increased with increasing sodium tripolyphosphate levels. Jung and Lee (2011) reported that the pH of cookies containing sea mustard decreased as the sea mustard powder level increased. Puolanne reported similar results for the combined effects of NaCl and phosphate in cooked sausage.

Table 3.

Effects of pH and color (CIE L*-, a*- and b*-values) of reduced-fat meat batters formulated with varying sodium chloride, sodium tripolyphosphate and sea mustard levels

Treatments1)	Uncooked				Cooked
	pH	L*-value	a*-value	b*-value	pH	L*-value	a*-value	b*-value
Control	5.93±0.03d	73.23±2.13a	7.90±0.52d	11.68±0.46b	6.08±0.02e	73.91±0.65c	4.19±0.16a	10.44±0.23b
T1	5.95±0.05c	68.20±2.12b	10.02±0.35b	11.84±0.83b	6.14±0.03d	74.50±0.87bc	4.50±0.25a	10.63±0.10b
T2	6.06±0.03b	67.01±1.16b	8.17±0.46c	11.06±0.81b	6.17±0.03c	75.95±0.45b	3.25±0.23b	9.89±0.28c
T3	6.10±0.02ab	50.71±1.69d	−8.14±0.31e	20.02±0.96a	6.23±0.04b	58.12±0.82d	−9.04±0.23c	19.91±0.32a
T4	5.97±0.02c	65.91±1.23bc	10.42±0.38a	11.27±0.88b	6.16±0.03c	75.86±0.28b	4.20±0.22a	10.91±0.15b
T5	6.12±0.02a	61.20±2.03c	7.65±0.48d	11.56±0.65b	6.26±0.03a	77.44±0.36a	2.92±0.18b	10.29±0.13b
T6	6.14±0.03a	50.86±0.98d	−8.72±0.29f	20.79±0.87a	6.27±0.02a	59.59±0.94d	−9.13±0.15c	20.24±0.19a

All values are mean±standard deviation of three replicates (n=9).

a-fMeans within a column with different letters are significantly different (p<0.05).

1)Control: pork back fat (30%) + sodium chloride (1.5%), T1: pork back fat (20%) + sodium chloride (1.2%), T2: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%), T3: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%) + sea mustard (2%), T4: pork back fat (20%) + sodium chloride (1.0%), T5: pork back fat (20%) + sodium chloride (1.0%) + sodium tripolyphosphate (0.1%), T6: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%) + sea mustard (2%).

The differences in lightness, redness and yellowness values of uncooked and cooked reduced-fat/low-salt meat emulsion systems are shown to be significant (Table 3). The highest lightness value for uncooked reduced-fat/low-salt meat emulsion systems was obtained for the control sample (p<0.05), due to affect by adding salt and phosphate levels, and sea mustard. By adding sea mustard, the redness of uncooked and cooked reduced-fat/low-salt meat emulsion systems decreased significantly when compared to treatments without sea mustard (p<0.05). The yellowness of uncooked and cooked reduced-fat/low-salt meat emulsion systems with added sea mustard was significantly higher than that for treatments without sea mustard (p<0.05). Jung and Lee (2011) reported that yellowness of cookies prepared significantly increased, while lightness and redness decreased with higher sea mustard levels. These results were also in agreement with Jimenez-Colmenero who reported that reduced/low-fat, low-salt frankfurters prepared with added konjac and seaweed had similar color values. Also, by decreasing the sodium chloride levels from 1.5% to 1.0%, the lightness and redness of uncooked reduced-fat/low-salt meat emulsion systems significantly decreased (p<0.05), while the lightness of cooked reduced-fat/low-salt meat emulsion systems increased. However, the redness of cooked reduced-fat/low-salt meat emulsion systems was not affected by sodium chloride levels. Similar results of decreased lightness as a function of reducing salt levels were reported by O’Flynn for reduced-phosphate breakfast sausages. Thus, the color of reduced-fat/low-salt meat emulsion systems is shown to be affected by the amount of salt and phosphate levels, and sea mustard added.

Cooking loss and emulsion stability

The effects of incorporated phosphate and sea mustard on the cooking loss and emulsion stability of the reduced-fat/low-salt meat emulsion systems are shown in Table 4. The cooking loss for the control, T3 and T6 samples had the lowest values (p<0.05). Decreasing the sodium chloride from 1.5% to 1.0% significantly increased the cooking loss and significant differences in cooking loss were observed among the treatments with sodium tripolyphosphate and sea mustard added (p<0.05). Tobin indicated that lowering the salt and fat levels increased the cooking loss of frankfurter. Jimenez-Colmenero reported that cooking loss in reduced-fat or low-fat frankfurter samples having only konjac gel was similar to that of the control samples, while reduced/low-fat and low-salt frankfurters samples with konjac gel had higher cooking loss than the control. Kim reported that the most difficult challenge to reducing salt addition is the technological function of salt, contributing to water and fat retention and impacting cooking loss of meat products. They reported that reduced-salt frankfurter with glasswort caused the increased cooking loss. According to O’Flynn , salt content decreased cooking loss, and the decrease was directly related to salt concentrations up to 2%. These results agree with Detienne and Wicker (1999) who showed that sodium chloride and tripolyphosphate levels in meat product samples resulted in cooking loss. Therefore, the cooking loss of reduced-fat/low-salt meat emulsion systems can be similar to the control by adding phosphate and sea mustard.

Table 4.

Effects of cooking loss and emulsion stability of reduced-fat meat batters formulated with varying sodium chloride, sodium tripolyphosphate and sea mustard levels

Treatments1)	Cooking loss (g/100 g)	Emulsion stability
		Total expressible fluid (mL/100 g)	Fat loss (mL/100 g)
Control	15.97±0.81d	10.23±0.66e	1.71±0.25e
T1	35.11±0.84b	19.21±0.92b	3.28±0.35b
T2	29.58±1.08c	16.08±0.98c	1.75±0.09de
T3	16.54±0.15d	9.89±0.86e	1.68±0.12e
T4	40.55±1.20a	24.86±1.09a	3.82±0.16a
T5	36.71±1.08b	19.96±0.99b	2.69±0.19c
T6	16.92±1.64d	11.92±0.87d	1.98±0.08d

All values are mean±standard deviation of three replicates (n=9).

a-eMeans within a column with different letters are significantly different (p<0.05).

1)Control: pork back fat (30%) + sodium chloride (1.5%), T1: pork back fat (20%) + sodium chloride (1.2%), T2: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%), T3: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%) + sea mustard (2%), T4: pork back fat (20%) + sodium chloride (1.0%), T5: pork back fat (20%) + sodium chloride (1.0%) + sodium tripolyphosphate (0.1%), T6: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%) + sea mustard (2%).

The differences in emulsion stability of reduced-fat/low-salt emulsion systems formulated with incorporated phosphate and sea mustard at different concentrations were significant (Table 4). The reduced-fat/low-salt emulsion systems with control and T3 resulted in lower total expressible fluid and fat loss compared to other treatment samples (p<0.05). Total expressible fluid and fat loss also exhibited similar trends to cooking loss. Jimenez-Colmenero reported that emulsion stability of the different meat batters was affected by the formulation. Their results showed that the effect of substituting konjac gel for back fat was dependent on the level of substitution. O’Flynn reported similar results that increasing the salt content added to breakfast sausages decreased the total expressible fluid and fat loss. According to O’Flynn , the phosphates are employed in the manufacture of breakfast sausages to increase the extraction and solubilisation of proteins. Thus, a stable gel matrix leads to a smaller release of water and fat and helps to improve the binding properties of emulsion systems. Cofrades reported that incorporation of sea spaghetti and wakame led to a decrease in total fluid and fat release in the gel/emulsion systems and in general, the emulsion stability of these samples was improved when the amount of added seaweed was increased.

Textural properties are the most important factor in the arrangement of emulsion meat products. The effects of incorporated phosphate and sea mustard on the textural properties of reduced-fat/low-salt meat emulsion systems are presented in Table 5. The control with general fat and sodium chloride had the highest value for all textural parameters (p<0.05), and a reduction in fat and sodium chloride levels led to decreased hardness, cohesiveness, gumminess and chewiness. Also, the addition of phosphate and sea mustard to the reduced-fat/low-salt meat emulsion systems led to significant increases in all textural parameters (p<0.05). This is in agreement with the results reported by O’Flynn where textural properties were affected when salt contents in frankfurters were reduced from 2.5 to 0.5%. Kim reported that sausage batters with lower salt concentrations implies less solubilized protein and decreased water holding capacity, and hence there may be enough protein aggregation to form a strong protein network. According to related studies, Jimenez-Colmenero , the seaweed and/or konjac is largely responsible for the increase in the hardness and chewiness of low-fat/reduced-salt frankfurter. Also, Cofrades showed that low-salt gel/emulsion meat systems with edible seaweed added have improved textural properties and this may be due to the enhanced binding capacity of the emulsion systems. O’Flynn found that the effect of phosphate levels on the texture profile attributes of breakfast sausages was not affected by reductions in the range of 0.5 to 0%. Thus, this study showed that utilizing dietary fiber from sea mustard and phosphate in systems with worsening texture profiles due to reduced fat and salt levels results in significant improvements in the textural profiles.

Table 5.

-Effects of the textural attributes of cooked meat batters formulated with varying sodium chloride, sodium tripolyphosphate and sea mustard levels-

Treatments1)	Hardness (kg)	Springiness	Cohesiveness	Gumminess (kg)	Chewiness (kg)
Control	2.51±0.12a	0.92±0.03a	0.42±0.02a	1.05±0.12a	0.97±0.12a
T1	1.63±0.12de	0.79±0.04d	0.34±0.03d	0.56±0.14e	0.44±0.13e
T2	2.26±0.28b	0.83±0.04c	0.41±0.03ab	0.94±0.27b	0.78±0.19c
T3	2.32±0.32ab	0.89±0.03ab	0.41±0.04ab	0.96±0.19b	0.85±0.20b
T4	1.10±0.29e	0.81±0.04c	0.32±0.03e	0.35±0.21f	0.28±0.20f
T5	1.83±0.12d	0.86±0.02b	0.38±0.04c	0.70±0.15d	0.60±0.16d
T6	2.06±0.19c	0.91±0.03a	0.40±0.03b	0.82±0.17c	0.74±0.14c

All values are mean±standard deviation of three replicates (n=9).

a-fMeans within a column with different letters are significantly different (p<0.05).

1)Control: pork back fat (30%) + sodium chloride (1.5%), T1: pork back fat (20%) + sodium chloride (1.2%), T2: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%), T3: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%) + sea mustard (2%), T4: pork back fat (20%) + sodium chloride (1.0%), T5: pork back fat (20%) + sodium chloride (1.0%) + sodium tripolyphosphate (0.1%), T6: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%) + sea mustard (2%).

Fig. 1 shows the apparent viscosity for reduced-fat/low-salt meat emulsion systems formulated with incorporated phosphate and sea mustard. All the reduced-fat/low-salt meat emulsion systems samples exhibited thixotropic behavior with apparent values that decreased with an increase in rotation time. According to some researchers, the meat emulsion samples had significantly decreased apparent viscosity with increased rotation time (Choi ; Lee ; Sariçoba ; Yapar ). The significant changes in higher apparent viscosity that were observed for reduced-fat/low-salt meat emulsion systems were due to the lower fat and salt concentrations found in the T3 and T6 samples with incorporated phosphate and sea mustard compared to control. The reduced-fat/low-salt meat emulsion systems without phosphate and sea mustard (T1 and T4) had the lowest values for apparent viscosity. This result agrees with the results of Choi that showed the effects of dietary fiber extracted form rice bran on the apparent viscosity of low-fat meat batters. Similar results were found by Yapar who reported that increasing emulsion viscosity is desirable in high-fat emulsion meat products since the higher emulsion viscosity imparts increased elasticity to emulsion meat products. Sariçoba et al. (2008) showed that an increase in viscosity of samples at different rotation speeds with respect to albedo levels proves that the albedo effect increases emulsion viscosity. Also, Kim reported that effects of apparent viscosity of meat batter formulated with reduced salt (a half) and added glasswort powder resulted in an increase in apparent viscosity. Terrell (1983) reported that salt reduction reduced the apparent viscosity of meat batters. Normally, the increase in the apparent viscosity of meat emulsion is one of the reasons for the attributed stable emulsion (Choi ; Kim , Lee ; Shand, 2000). Thus, viscosity is an indicator of the valuable criteria of quality characteristics in emulsion meat products. In this study, increasing the apparent viscosity of reduced-fat/low-salt meat emulsion systems contributed to the observed improvements resulting from incorporating phosphate and sea mustard into the systems.

Fig. 1.

Change of apparent viscosity on reduced-fat meat batters formulated with varying sodium chloride, sodium tripolyphosphate and sea mustard levels stirred for 100 s. (□) Control: pork back fat (30%) + sodium chloride (1.5%), (■) T1: pork back fat (20%) + sodium chloride (1.2%), ( △ ) T2: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%), ( ▲ ) T3: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%) + sea mustard (2%), ( ○ ) T4: pork back fat (20%) + sodium chloride (1.0%), ( ● ) T5: pork back fat (20%) + sodium chloride (1.0%) + sodium tripolyphosphate (0.1%), ( ◇ ) T6: pork back fat (20%) + sodium chloride (1.2%) + sodium tripolyphosphate (0.1%) + sea mustard (2%).

Conclusion

In this study we showed that the combination of reduced fat levels (from 30% to 20%), reduced salt concentrations (from 1.5% to 1.0%) and the addition of phosphate and sea mustard has an important effect on the quality of reduced-fat/low-salt meat emulsion systems. The results of this study showed that reducing pork back fat and salt with incorporated phosphate and sea mustard in reduced-fat/low-salt meat emulsion system formulations results in optimized food characteristics. The incorporation of phosphate and sea mustard in the formulation successfully reduced fat and salt in reduced-fat/low-salt meat emulsion systems.