Abstract
To identify the effect of sodium-alternative curing salts on the quality properties of salami through the ripening process, four salami treatments were prepared with different curing salts, T1 (-control, NaCl 1.9%), T2 (+control, NaCl 1.9%+NaNO2 0.01%), T3 (KCl 1.9%+NaNO2 0.01%), and T4 (MgCl2 1.9%+NaNO2 0.01%), under 40 days ripening conditions. Sodium-alternative salts (T3 or T4) showed characteristically different quality traits compared with T2. Especially, T3 had lower pH, water activity, volatile basic nitrogen, and lipid oxidation after 20 days of ripening period, compare with T2 or T4 (p<0.05). Sodium nitrite had critical impact on increased a* values, and T3 showed higher a* values compared with T2 or T4 (p<0.05). Sodium nitrite reduced initial growth of coliforms but sodium-alternative salts did not affect microbial growth patterns. T2–T4 containing sodium nitrite had higher content of umami nucleotide flavor compounds compared with T1, regardless of the chlorine salt species. The combined use of sodium-alternative curing salts and minimal sodium nitrite was found to be an applicable strategy on development of low sodium salami without a trade-off of the product quality.
Keywords: low sodium salami, sodium-alternative salt, sodium nitrite, physicochemical trait
Introduction
Sodium chloride (NaCl) not only provides microbial stability due to its capability to reduce water activity, but also helps solubilize myofibrillar proteins and imparts a pleasant salty taste as a flavor enhancer (Martin, 2001). Although NaCl is essential in the human diet, excess sodium intake which may raise the risk of cardiovascular disease with an increase of hypertension (WHO, 2010).
Therefore, possible effects have focused on reducing the level of sodium in meat products (Ruusunen and Puolanne, 2005). Diverse approaches for reducing the sodium level of meat products have been studied, in which sodium chloride was replaced by other chloride salts (KCl, CaCl2, and MgCl2) totally or in part. Especially, KCl was classified as Generally Recognized As Safe (GRAS) by the US FDA (2010) and is also approved by the international regulatory authorities and scientific bodies. The WHO recommended 3.5 g of daily dosage for potassium is to be advantageous on keeping blood pressure levels lower (Aburto et al., 2013). A previous study states that the most commonly used sodium-alternative salts, KCl, shows similar functional properties to NaCl. In fermented sausages, the replacement up to 40%–50% of NaCl with KCl was adequate to obtain an acceptable meat product, whereas an excessive addition of KCl can lead to flavor and textural defects (Guàrdia et al., 2008). NaCl replacers have their own different amounts of cations and chloride ions. The ionic strength of MgCl2 treatment was higher than that of NaCl, while KCl reduced the ionic strength (Kim et al., 2018).
Thus, the substitution of NaCl to the other chloride salts may delay the reduction of water activity and therefore increasing the post-salting time was needed to acquire similar water activities as compared to the traditional way (Laranjo et al., 2015). Despite the numerous studies in meat products, sodium reduction has been scarcely studied in the fermented meat products. The functions of non-sodium salts such as KCl or MgCl2 with different cations were not well difined in the fermented meat product of salamis.
Since sodium nitrite is indispensibly used in salamis without significantly affecting the sodium supply, this study was performed to examine the sodium-alternative effects of NaCl by KCl or MgCl2 for manufacturing low sodium salamis containing minimal sodium nitrite during the ripening and drying.
Materials and Methods
Salami manufacture
Refrigerated pork hind leg, beef topside round, and frozen pork backfat were purchased from a domestic meat supplier. After the raw materials were sliced, they stored frozen at –24°C for 2 days. The batters were made with various curing agents in triplicates (12 batches, in total). The mince of salami consisted of 46% pork hind leg, 30% beef topside round, 20% pork back fat and pork skin, 0.5% garlic, 0.1% monosodium glutamate, 0.4% glucose, and 0.2% starter culture. The added meat starter culture (Lyocarni RBL-73, SACCO, Italy) was containing Lactobacillus curvatus and Staphylococcus xylosus with 2.5×106 Log CFU/g and was used at a level of approximately 6 Log CFU/g. Four salami treatments were prepared with different curing salts, NaCl, KCl, or MgCl2 at 1.9% (w/w meat batter) with sodium nitrite (NaNO2) at 0.01%. The concentrations of additives were determined by preliminary studies. Only NaCl-added treatment without NaNO2 was prepared as negative control. Therefore, the treatments were T1 (-control, NaCl), T2 (+control, NaCl+NaNO2), T3 (KCl+NaNO2), and T4 (MgCl2+NaNO2).
Pork, beef, and pork backfat were chopped in a bowl chopper (Fujee, Seoul, Korea), and mixed for 4 min. Ingredients and starter culture were added and mixed in a mixer (Fujee). Using a stuffer (H20E, TALSA, Northampton, EU), the mince was stuffed into fibrous casings (55-mm diameter, Seoul, Korea) using a stuffer (H20E, TALSA, Northampton, EU). Then these were soaked in solution of Aspergillus spp. (obtained from the Korean Agricultural Culture Collection, RDA) for 2 min. The salami samples were streaked onto 18% Glycerol Agar (Dichloran DG18, Kisanbio, Seoul, Korea) and then incubated at 25°C for 7 days. The fungal colonies were diluted with distilled water for producing Aspergillus spp. solution. Samples were dried and aged in a dry-ripening room. The relative humidity and temperature were 80%–98% and 16°C–20°C during the ripening. Samples for physicochemical analyses were obtained from each treatment and after 20 and 40 days of ripening.
Physicochemical and microbial analysis
The pH of samples was measured by homogenizing a 10 g sample with 90 mL distilled water with a pH meter (PHM201, Radiometer, Villeurbanne, France). A water activity was measured using a water activity meter (Handheld HP23-AW-A, Rotronic AG, Bassersdorf, Switzerland). Volatile basic nitrogen (VBN) was estimated as the method reported by Conway (1950) then reported as mg/100 g. Lipid oxidation was analyzed in triplicate with minor modification of the method of Witte et al. (1970). The absorbance was measured on a spectrophotometer (X-MA 3000, Human, Seoul, Korea) at 530 nm. Water holding capacity (WHC) was measured using the modified method of Grau and Hamm (1953). Briefly, a sample weighing 300 mg was placed on Whatman No. 1 filter paper and compressed for 2 min. WHC was calculated as follows: WHC (%) = (1 − Total meat area / Meat film area) × 100.
Total plate counts, lactic acid bacteria counts, E. coli. counts of the samples were analyzed according to the guidelines specified in the Criteria and Ingredient Standard of Livestock Products (QIA, 2013). Color values were determined using a chromameter (CR-410, Minolta, Tokyo, Japan), at three replicates. A texture analyzer (TA-XT2, Stable Micro Systems, Godalming, UK) equipped with a load cell was (2,500 N) used on texture profile analysis (Bourne, 1978). The samples were reconstructed to 1.5 cm diameter and 1 cm height. Meat sample was compressed to 50% of their height at 1.0 mm/s, with a 50-mm-diameter plunger. The hardness, springiness, cohesiveness, gumminess, and chewiness values were measured. Shear force (kgf) was determined by the method described by the procedure of Bourne (1978).
Nucleotide-related compounds
Meat samples (4 g) were mixed with 20 mL of 0.7 M perchloric acid and homogenized (T25b, Ika Works, Malaysia) for 60 sec at 1,230 g to extract nucleic acids. The extracted nucleic acids were centrifuged (Union 32R, Hanil, Gimpo, Korea) for 14 min at 2,190 g (5°C) and filtered through Whatman No. 4 filter paper (Whatman, Maidstone, UK). The supernatant was then adjusted to pH 7 with 5 N KOH (SevenEasy, Mettler-Toledo Int., Switzerland). The pH-adjusted supernatant was placed in a volumetric flask and adjusted to a volume of 100 mL with 0.7 M perchloric acid (pH 7). After 25 min of cooling, the mixture was centrifuged (Union 32R) at 2,190×g (5°C) and the supernatant was filtered through a 0.2-μm PVDF syringe filter (Whatman). The filtrate was analyzed using a high-performance liquid chromatography (ACME 9000, Young-Lin, Korea) with a Waters-Atlantis C18 RP column (4.6×250 mm, 5 μm particles, Waters, Milford, MA, USA) and a mobile phase of 0.1 M triethylamine in 0.15 M acetonitrile (pH 7.0). The peaks of individual nucleotides were identified using standards of hypoxanthine, inosine, inosine-5-phosphate (IMP) (Sigma Chemical, St. Louis, MO, USA).
Statistical analysis
The experiment was designed and statistically analyzed in factorial (curing agents×ripening time). All the variables measured was analyzed on their variance using the General Linear Model (GLM) procedure. To determine the differences among the treatment means, the Duncan’s multiple range test was used with significance level of p<0.05. The SAS statistical software package was utilized (SAS, 2002).
Results and Discussion
Physicochemical characteristics
The effect of different sodium-alternative curing agents on the physicochemical traits of salamis during ripening is presented in Table 1. After 20 d of ripening of salamis, pH was the highest in T1 but the lowest in T3 (p<0.05). The pH values were higher in KCl treatment and lower in MgCl2 than that of NaCl treatments during the ripening period (p<0.05). These results are consistent with results of previous report (Kim et al., 2018). This difference was related to the inhibitory action of NaCl substitution by KCl towards the growth of coliforms, which metabolized basic nitrogen compounds leading to pH changes in dry-cured bacons (Alinõ et al., 2010). Gimeno et al. (1999) also reported that NaCl was replaced by a mixture of 44.5% NaCl, 24.5% KCl, 20.6% CaCl2, and 10.4% MgCl2, and a more decrease in pH on the mixture than NaCl-only formulation. A pattern similar to this was reported for a partial NaCl decrease by a chloride salts mixture (NaCl 10 g/kg and KCl 5.5 g/kg) (Gimeno et al., 2001). During aging and drying of salamis, their pH significantly declined at 20 and 40 days compared to 0 day. After 20 days of ripening, all treatments had pH below 4.9. This rapid decline in pH is vital for inhibiting pathogenic microorganisms, increasing the safety of fermented sausages (Leroy et al., 2006).
Table 1. Effect of different curing salts on pH and water activity (Aw) of salamis during ripening.
| Variable | Days of ripening | ||||
|---|---|---|---|---|---|
| 0 | 20 | 40 | SEM | ||
| pH | T11) | 5.35Aa | 4.78Ab | 4.87Ab | 0.01 |
| T2 | 5.36Aa | 4.75Bb | 4.78Bb | 0.01 | |
| T3 | 5.36Aa | 4.42Db | 4.43Db | 0.01 | |
| T4 | 5.26Ba | 4.60Cb | 4.68Cb | 0.01 | |
| SEM | 0.01 | 0.01 | 0.01 | 0.01 | |
| AW | T11) | 0.99A | 0.85b | 0.84b | 0.01 |
| T2 | 0.98A | 0.83b | 0.84b | 0.01 | |
| T3 | 0.98A | 0.83b | 0.84b | 0.01 | |
| T4 | 0.98A | 0.87b | 0.86b | 0.01 | |
| SEM | 0.02 | 0.03 | 0.02 | ||
Standard error of the means (n=16).
T1, NaCl 1.9%; T2, NaCl 1.9%+NaNO2 0.01%; T3, KCl 1.9%+NaNO2 0.01%; T4, MgCl2 1.9%+NaNO2 0.01%.
Figures with different letters within a same row differ significantly (p<0.05).
Figures with different letters within a same column differ significantly (p<0.05).
As shown in Table 1, there were no significant differences of water activities among the treatments, even though T4 had higher Aw than the others at 20 and 40 d. Initial Aw was reduced from around 0.98–0.99 to 0.84–0.86 during the process of ripening and drying. Aw gradually declined during the ripening of the salamis (p<0.05). These Aw results coincide with the results in salami (Horita et al., 2014).
During ripening and drying, T3 had significantly lower VBN than the other treatments during ripening (p<0.05) (Table 2). These results may be due to the replacement of NaCl by KCl, since the replacement was found to decrease the quantity of salt-tolerant flora and inhibit the growth of coliforms (Alinõ et al., 2010). During the ripening time, the VBN of salamis continuously increased (p<0.05). Our study showed that T3 samples containing KCl and NaNO2 had a positive effect on VBN in salamis during aging.
Table 2. Effect of different curing salts on the physicochemical traits of salamis during ripening.
| Variable | Days of ripening | ||||
|---|---|---|---|---|---|
| 0 | 20 | 40 | SEM | ||
| VBN (mg%) | T11) | 6.13Ac | 19.57Cb | 31.88Ca | 0.17 |
| T2 | 4.93Bc | 20.62Bb | 34.97Ba | 0.15 | |
| T3 | 3.72Cc | 19.61Cb | 31.95Ca | 0.21 | |
| T4 | 4.55Bc | 21.61Ab | 40.26Aa | 0.12 | |
| SEM | 0.01 | 0.21 | 0.10 | ||
| TBARS (mg MDA/kg) | T11) | 0.67Ac | 1.17Cb | 1.37Ca | 0.01 |
| T2 | 0.55Cc | 1.90Ab | 2.01Aa | 0.01 | |
| T3 | 0.60Bc | 1.03Db | 1.15Da | 0.01 | |
| T4 | 0.55Cb | 1.56Ba | 1.47Ba | 0.01 | |
| SEM | 0.01 | 0.01 | 0.01 | 0.01 | |
| WHC (%) | T11) | 95.08Aa | 49.32Ab | 42.20 Ac | 4.02 |
| T2 | 87.01Ba | 36.46Bb | 29.26 Bb | 15.99 | |
| T3 | 92.34Aa | 34.60Bb | 30.07 Bb | 6.35 | |
| T4 | 96.69Aa | 30.78Cb | 28.74 Bb | 3.27 | |
| SEM | 5.22 | 1.82 | 3.69 | ||
| Total plate counts (Log CFU/g) | T11) | 7.21c | 7.81b | 7.93a | 0.19 |
| T2 | 7.24c | 7.35b | 7.56a | 0.05 | |
| T3 | 7.12b | 7.13b | 7.26a | 0.08 | |
| T4 | 7.15b | 7.14b | 7.29a | 0.06 | |
| SEM | 0.22 | 0.80 | 0.78 | ||
| Lactic acid bacteria (Log CFU/g) | T11) | 7.02b | 8.19a | 8.43a | 0.65 |
| T2 | 7.04b | 8.47a | 8.21a | 0.57 | |
| T3 | 7.09b | 8.43a | 8.18a | 0.67 | |
| T4 | 7.01b | 8.09a | 8.10a | 0.63 | |
| SEM | 0.26 | 0.58 | 0.51 | ||
| Coliforms (Log CFU/g) | T11) | 1.25A | 1.76 | <0.1 | - |
| T2 | 0.94B | <0.1 | <0.1 | - | |
| T3 | 0.85B | <0.1 | <0.1 | - | |
| T4 | 0.98B | <0.1 | <0.1 | - | |
| SEM | 0.15 | - | - | ||
Standard error of the means (n=16).
T1, NaCl 1.9%; T2, NaCl 1.9%+NaNO2 0.01%; T3, KCl 1.9%+NaNO2 0.01%; T4, MgCl2 1.9%+NaNO2 0.01%.
Figures with different letters within a same row differ significantly (p<0.05).
Figures with different letters within a same column differ significantly (p<0.05).
VBN, volatile basic nitrogen; TBARS, TBA-reactive substance; WHC, water holding capacity.
TBA-reactive substance (TBARS) level is used to set an acceptable limit for rancidity for fresh meat (Ockerman, 1985). As presented in Table 2, T3 had significantly lower TBA than the other treatments at 20 and 40 days (p<0.05). On the other hand, T2 had significantly higher TBA at 20 and 40 days. In general, TBA can be affected by salt concentration (Choi et al., 2016). Low salt concentration tended to reduce lipid oxidation and had a less pro-oxidant effect during aging (Andrés et al., 2004). In this case, it appears that KCl induced slower lipid oxidation than the other curing salts. The TBARS levels increased throughout ripening (p<0.05), which is related to the oxidation by the salt that can be favored by the metallic ions contained as impurities in added curing salts (Lorenzo et al., 2015). KCl may have less impurities acerbating lipid oxidation, which could affect the shelf-life of the salami.
WHC of samples continuously decreased during the ripening and drying phases (Table 2). At 20 and 40 days, T1 showed higher WHC than that of the other samples (p<0.05). The result is supported by Kim et al. (2018) finding highest water-holding capacity could be expected at ionic strength 1.0–1.5 with high pH and the substitution by KCl reduced the ionic strength. As the level of NaCl was reduced, the amount of soluble myofibrillar proteins decreased (Gordon and Barbut, 1992). As a results of reducing ionic strength or changing in charge density by using different salts, the water-holding capacity and the gel strength could be changed (Whiting, 1984).
The microbiological characteristics using different curing agents are presented in Table 2. No significant differences among treatments were observed regarding total plate counts, lactic acid bacteria counts (p>0.05). These reports are in agreement with Alinõ et al. (2010) and Aaslyng et al. (2014) who did not find significant differences among the chloride salts used. LAB showed a strong increase above 8.0 Log CFU/g after 20 days without changes until the end of manufacturing. This result was similar to that reported by Campagnol et al. (2011). Coliforms were not detected in the sodium nitrite-added treatment groups in comparison of the only sodium-added treatments at 0 day, which was because the bacteria have low resistance to acidification (González-Fernández et al., 2006). From this result, the growths of total plate count and LAB were not affected by use of sodium-alternative curing salts.
The influence of curing agents on the salami meat color during ripening is shown in Table 3. T3 samples showed a higher redness value (a*) than the other samples, while T1 showed lowest value (p<0.05). Treatments with sodium-nitrite had higher redness value (a*) compared with T1 (only NaCl-added). Thus, sodium nitrite showed more favorable red color in salami.
Table 3. Effect of different curing salts on color values of salamis during ripening.
| Variable | Days of ripening | ||||
|---|---|---|---|---|---|
| 0 | 20 | 40 | SEM | ||
| L* | T11) | 56.71a | 46.68b | 43.71b | 0.05 |
| T2 | 53.69a | 45.98b | 44.14b | 0.14 | |
| T3 | 55.28a | 44.06b | 41.33b | 0.14 | |
| T4 | 53.04a | 41.83b | 40.84b | 0.08 | |
| SEM | 0.02 | 0.13 | 0.16 | ||
| a* | T11) | 2.37Da | 2.04Db | 0.47Dc | 0.01 |
| T2 | 6.35Ba | 4.09Bb | 2.75Bc | 0.01 | |
| T3 | 7.78Aa | 5.78Ab | 2.99Ac | 0.01 | |
| T4 | 4.59Ca | 3.22Cb | 1.40Cc | 0.01 | |
| SEM | 0.01 | 0.01 | 0.01 | 0.01 | |
| b* | T11) | 9.96Aa | 5.57Ab | 4.51Ac | 0.01 |
| T2 | 8.27Ca | 3.85Cb | 1.41Cc | 0.01 | |
| T3 | 8.89Ba | 4.94Bb | 1.81Bc | 0.01 | |
| T4 | 7.59Da | 3.18Db | 1.27Dc | 0.01 | |
| SEM | 0.02 | 0.01 | 0.01 | ||
Standard error of the means (n=16).
T1, NaCl 1.9%; T2, NaCl 1.9%+NaNO2 0.01%; T3, KCl 1.9%+NaNO2 0.01%; T4, MgCl2 1.9%+NaNO2 0.01%.
Figures with different letters within a same row differ significantly (p<0.05).
Figures with different letters within a same column differ significantly (p<0.05).
T1 samples exhibited a higher yellowness (b*) value than the other samples, while T4 showed a significantly lower value. Choi et al. (2016) showed KCl-added sausages were redder than those made with NaCl. The L*, a*, and b* values in all samples continuously declined during the aging (p<0.05), and the results were same as that from another study (Papadima and Bloukas, 1999). A reduction in a* values of the sausages can be attributed to the oxidation of nitrosylmyoglobin to nitrate and brown metmyoglobin (Gøtterup et al., 2008).
Texture profiles
T1 samples had a lower shear force than the other samples (p<0.05, Table 4). In addition, T1 showed lower springiness, cohesiveness, and gumminess values, whereas T4 showed a significantly higher values. The higher texture parameters might be partly attributed to the reduction of bound water during aging (Horita et al., 2014). In addition, NaCl reduction in sausages could destroy the texture-profile of sausages due to the reduced ionic strength and charge density, which causes a decrease in the soluble myofibrillar proteins (Toldrá, 1998). Previous researches have indicated that MgCl2 or CaCl2 can increase hardness because of negative attribution of divalent salt (Ca2+) to water-binding capacity (Horita et al., 2014). The present study showed an similar trend in texture profiles at the end of aging. Campagnol et al. (2011) reported that the NaCl replacement or reduction could decrease the textural properties of salamis. Lücke (1998) attributed this to the ability of NaCl to solubilize and diffuse muscle myofibrillar proteins forming gel between the meat and fat particles, thus favoring slicing and improving the juiciness and texture of the product. All texture parameters in all samples increased continuously and steadily during the ripening (p<0.05), by the lower moisture content. This findings was similar to that reported by Lorenzo et al. (2015) who reported that shear force showed a marked rise during aging.
Table 4. Effect of different curing salts on texture profiles of salamis during ripening.
| Variable | Days of ripening | ||||
|---|---|---|---|---|---|
| 0 | 20 | 40 | SEM | ||
| Shear force (kg) | T11) | 0.07Bc | 0.27Bb | 1.93Ba | 0.01 |
| T2 | 0.09Ac | 1.29Ab | 3.46Aa | 0.08 | |
| T3 | 0.09Ac | 1.09Ab | 3.44 Aa | 0.07 | |
| T4 | 0.10Ac | 1.33Ab | 2.92Aa | 0.18 | |
| SEM | 0.01 | 0.05 | 0.14 | ||
| Hardness (kg) | T11) | 0.22Ac | 0.74Cb | 4.24Ca | 0.01 |
| T2 | 0.22Ac | 2.63Ab | 4.82Ca | 0.16 | |
| T3 | 0.20Bc | 1.79Bb | 9.45Ba | 0.09 | |
| T4 | 0.16Cc | 1.48Bb | 12.12Aa | 0.37 | |
| SEM | 0 | 0.08 | 0.86 | ||
| Springiness | T11) | 0.31Cb | 0.34Cb | 0.42Ca | 0.01 |
| T2 | 0.36Bb | 0.52Ba | 0.47Ba | 0.01 | |
| T3 | 0.37Bb | 0.51Ba | 0.50Ba | 0.01 | |
| T4 | 0.42Ab | 0.60Aa | 0.57Aa | 0.01 | |
| SEM | 0.01 | 0.01 | 0.01 | ||
| Cohesiveness | T11) | 0.27Cb | 0.32Ca | 0.33Ca | 0 |
| T2 | 0.44Ab | 0.46Aa | 0.46ABa | 0 | |
| T3 | 0.35Bb | 0.39Ba | 0.40BCa | 0 | |
| T4 | 0.45Ac | 0.48Ab | 0.50Aa | 0 | |
| SEM | 0 | 0 | 0 | ||
| Gumminess | T11) | 0.17Bc | 0.24Cb | 1.34Ba | 0 |
| T2 | 1.03Ac | 1.38Bb | 1.46Ba | 0.02 | |
| T3 | 0.61ABb | 3.85Aa | 3.80Aa | 0.07 | |
| T4 | 1.02Ac | 3.14Ab | 3.69Aa | 0.12 | |
| SEM | 0.06 | 0.19 | 0.05 | ||
| Chewiness | T11) | 0.05Cc | 0.09Cb | 0.13Ca | 0 |
| T2 | 0.53Bb | 0.53Bb | 0.63Ba | 0.01 | |
| T3 | 0.72Ab | 0.81Ab | 1.32Aa | 0.02 | |
| T4 | 0.44Bc | 0.70Ab | 1.42Aa | 0.03 | |
| SEM | 0.01 | 0 | 0.03 | ||
Standard error of the means (n=16).
T1, NaCl 1.9%; T2, NaCl 1.9%+NaNO2 0.01%; T3, KCl 1.9%+NaNO2 0.01%; T4, MgCl2 1.9%+NaNO2 0.01%.
Figures with different letters within a same row differ significantly (p<0.05).
Figures with different letters within a same column differ significantly (p<0.05).
Nucleotide-related compounds
A further basic taste sensation called ‘umami’ has been expressed as the taste of monosodium-glutamate (MSG), guanosine 5-monophosphate (GMP), and IMP (Mateo et al., 1996). The role of IMP for the generation of meat odor and flavor has been demonstrated in sensory studies (Aristoy and Toldrá, 2009). As shown in Table 5, treatments with sodium-nitrite had lower contents of GMP and IMP compared with T1 (only NaCl-added) (p<0.05). Thus, sodium nitrite showed desirable umami flavor-enhancing activities in salami ripening. The results show that sodium nitrite might possibly affect more directly the formation of nucleotides-related flavor compounds rather than chloride salts. However, little effect was found on the nucleotides and nucleotides degradation products in cured meat products owing to the antioxidant effect of sodium nitrite (Feng et al., 2017).
Table 5. Effect of different curing salts on the nucleotide contents (mg/100 g) of salamis during ripening.
| Variable | GMP | AMP | IMP | Inosine | Hypoxanthine |
|---|---|---|---|---|---|
| T11) | 1.44b | 0.18 | 1.89b | 0.72 | 73.78 |
| T2 | 2.44a | 0.20 | 2.22a | 1.23 | 87.70 |
| T3 | 2.36a | 0.15 | 2.22a | 1.91 | 80.22 |
| T4 | 2.54a | 0.16 | 2.39a | 2.88 | 79.49 |
| SEM | 0.10 | 0.02 | 0.24 | 0.50 | 4.91 |
Standard error of the means (n=16).
T1, NaCl 1.9%; T2, NaCl 1.9%+NaNO2 0.01%; T3, KCl 1.9%+NaNO2 0.01%; T4, MgCl2 1.9%+NaNO2 0.01%.
Figures with different letters within a same column differ significantly (p<0.05).
GMP, guanosine 5-monophosphate; AMP, adenosine monophosphate; IMP, inosine 5-monophosphate.
Conclusion
Sodium-alternative salts (KCl or MgCl2) replacing NaCl strongly influenced the quality traits of salami throughout the ripening processing. Addition of KCl or MgCl2 showed different patterns at certain meat quality attributes. In case of salami texture, MgCl2 showed greater hardness due to the formation of relatively hard skin coat surrounding salami circumferences. Although it is not easy to select an appropriate sodium-alternative curing salts for manufacturing low-sodium salamis, a sodium-alternative salt can be used considering targeted meat quality traits of the meat products. From result of the present study, KCl can be used for the purpose of sodium reduction in salamis with improved physicochemical characteristics. Especially, the substitution of NaCl to KCl had advantages in maintaining relatively high pH, low protein degradation, and low lipid oxidation during the 40 days of ripening. Besides, KCl showed more favorable red color in salami. Sodium nitrite showed its own characteristic impact on especially color and microbiological safety of fermented salamis. Therefore, combined use of sodium-alternative curing salts with minimal amounts of sodium nitrite can be used for the development of lower sodium salami products without adverse effects on the physicochemical traits.
Acknowledgements
This study was supported by Golden Seed Project (No. 213010-05-1-SB420, PJ01282202), Ministry of Agriculture, Food and Rural Affairs, Ministry of Oceans and Fisheries, Rural Development Administration.
Conflicts of Interest
The authors declare no potential conflicts of interest.
Author Contributions
Conceptualization: Nam KC. Data curation: Yim DG. Formal analysis: Yim DG, Jo C. Methodology: Yim DG, Nam KC. Validation: Shin DJ, Jo C. Writing - original draft: Yim DG. Writing - review & editing: Yim DG, Shin DJ, Jo C, Nam KC.
Ethics Approval
This article does not require IRB/IACUC approval because there are no human and animal participants.
References
- Aaslyng MD, Vestergaard C, Koch AG. The effect of salt reduction on sensory quality and microbial growth in hotdog sausages, bacon, ham and salami. Meat Sci. 2014;96:47–55. doi: 10.1016/j.meatsci.2013.06.004. [DOI] [PubMed] [Google Scholar]
- Aburto NJ, Hanson S, Gutierrez H, Hooper L, Elliott P, Cappuccio FP. Effect of increased potassium intake on cardiovascular risk factors and disease: Systematic review and meta-analyses. Br Med J. 2013;346:1378. doi: 10.1136/bmj.f1378. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Aliño M, Grau R, Toldrá F, Blesa E, Pagán MJ, Barat JM. Physicochemical properties and microbiology of dry-cured loins obtained by partial sodium replacement with potassium, calcium and magnesium. Meat Sci. 2010;85:580–588. doi: 10.1016/j.meatsci.2010.03.009. [DOI] [PubMed] [Google Scholar]
- Andrés AI, Cava R, Ventanas J, Muriel E, Ruiz J. Lipid oxidative changes throughout the ripening of dry-cured Iberian hams with different salt contents and processing conditions. Food Chem. 2004;84:375–381. doi: 10.1016/S0308-8146(03)00243-7. [DOI] [Google Scholar]
- Aristoy MC, Toldrá F. Nucleotides and its derived compounds. In: Nollet ML, Toldrá F, editors. In Handbook of muscle foods analysis. CRC Press; Boca Raton, FL, USA: 2009. pp. 279–288. (ed) [DOI] [Google Scholar]
- Bourne MC. Texture profile analysis. Food Technol. 1978;32:62–66. [Google Scholar]
- Campagnol PCB, Dos Santos BA, Morgano MA, Terra NN, Pollonio MAR. Application of lysine, taurine, disodium inosinate and disodium guanylate in fermented cooked sausages with 50% replacement of NaCl by KCl. Meat Sci. 2011;87:239–243. doi: 10.1016/j.meatsci.2010.10.018. [DOI] [PubMed] [Google Scholar]
- Choi YS, Jeong TJ, Hwang KE, Song DH, Ham YK, Kim YB, Jeon KH, Kim HW, Kim CJ. Effects of various salts on physicochemical properties and sensory characteristics of cured meat. Korean J Food Sci Anim Resour. 2016;36:152–158. doi: 10.5851/kosfa.2016.36.2.152. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Conway EJ. Microdiffusion analysis and volumetric error. Crosby Lockwood & Son; London, UK: 1950. [Google Scholar]
- Feng X, Moon SH, Lee HY, Ahn DU. Effect of irradiation on the degradation of nucleotides in turkey meat. Animal Industry Report, No. ASL R3129. Iowa State University; Ames, IA, USA: 2017. [DOI] [Google Scholar]
- Gimeno O, Astiasarán I, Bello J. Influence of partial replacement of NaCl with KCl and CaCl2 on texture and color of dry fermented sausages. J Agric Food Chem. 1999;47:873–877. doi: 10.1021/jf980597q. [DOI] [PubMed] [Google Scholar]
- Gimeno O, Astiasarán I, Bello J. Influence of partial replacement of NaCl with KCl and CaCl2 on microbiological evolution of dry fermented sausages. Food Microbiol. 2001;18:329–334. doi: 10.1006/fmic.2001.0405. [DOI] [PubMed] [Google Scholar]
- González-Fernández C, Santos EM, Rovira J, Jaime I. The effect of sugar concentration and starter culture on instrumental and sensory textural properties of chorizo-spanish dry-cured sausage. Meat Sci. 2006;74:467–475. doi: 10.1016/j.meatsci.2006.04.019. [DOI] [PubMed] [Google Scholar]
- Gordon A, Barbut S. Effect of chloride salts on protein extraction and interfacial protein film formation in meat batters. J Sci Food Agric. 1992;58:227–238. doi: 10.1002/jsfa.2740580211. [DOI] [Google Scholar]
- Gøtterup J, Olsen K, Knøchel S, Tjener K, Stahnke LH, Møller JKS. Colour formation in fermented sausages by meat-associated staphylococci with different nitrite-and nitrate-reductase activities. Meat Sci. 2008;78:492–501. doi: 10.1016/j.meatsci.2007.07.023. [DOI] [PubMed] [Google Scholar]
- Grau R, Hamm R. Eine einfache methode zur bestimmung der wasserbindung im muskel. Naturwissenschaften. 1953;40:29–30. doi: 10.1007/BF00595734. [DOI] [Google Scholar]
- Guàrdia MD, Guerrero L, Gelabert J, Gou P, Arnau J. Sensory characterisation and consumer acceptability of small calibre fermented sausages with 50% substitution of NaCl by mixtures of KCl and potassium lactate. Meat Sci. 2008;80:1225–1230. doi: 10.1016/j.meatsci.2008.05.031. [DOI] [PubMed] [Google Scholar]
- Horita CN, Messias VC, Morgano MA, Hayakawa FM, Pollonio MAR. Textural, microstructural and sensory properties of reduced sodium frankfurter sausages containing mechanically deboned poultry meat and blends of chloride salts. Food Res Int. 2014;66:29–35. doi: 10.1016/j.foodres.2014.09.002. [DOI] [Google Scholar]
- Kim GD, Hur SJ, Park TS, Jin SK. Quality characteristics of fat-reduced emulsion-type pork sausage by partial substitution of sodium chloride with calcium chloride, potassium chloride and magnesium chloride. LWT-Food Sci Technol. 2018;89:140–147. doi: 10.1016/j.lwt.2017.10.033. [DOI] [Google Scholar]
- Laranjo M, Agulheiro-Santos AC, Potes ME, Cabrita MJ, Garcia R, Fraqueza MJ, Elias M. Effects of genotype, salt content and calibre on quality of traditional dry-fermented sausages. Food Control. 2015;56:119–127. doi: 10.1016/j.foodcont.2015.03.018. [DOI] [Google Scholar]
- Leroy F, Verluyten J, De Vuyst L. Functional meat starter cultures for improved sausage fermentation. Int J Food Microbiol. 2006;106:270–285. doi: 10.1016/j.ijfoodmicro.2005.06.027. [DOI] [PubMed] [Google Scholar]
- Lorenzo JM, Bermúdez R, Domínguez R, Guiotto A, Franco D, Purriños L. Physicochemical and microbial changes during the manufacturing process of dry-cured lacón salted with potassium, calcium and magnesium chloride as a partial replacement for sodium chloride. Food Control. 2015;50:763–769. doi: 10.1016/j.foodcont.2014.10.019. [DOI] [Google Scholar]
- Lücke FK. Fermented sausages. In: Wood BJB, editor. In Microbiology of fermented foods. Springer; Boston, MA, USA: 1998. pp. 441–483. (ed) [DOI] [Google Scholar]
- Martin M. Meat curing technology. In: Hui YH, editor. In Meat science and applications. CRC Press; Boca Raton, FL, USA: 2001. pp. 491–508. (ed) [DOI] [Google Scholar]
- Mateo J, Domínguez MC, Aguirrezábal MM, Zumalacárregui J. Taste compounds in chorizo and their changes during ripening. Meat Sci. 1996;44:245–254. doi: 10.1016/S0309-1740(96)00098-8. [DOI] [PubMed] [Google Scholar]
- Ockerman HW. Quality control of post-mortem muscle tissue. Ohio State University; Columbus, OH, USA: 1985. [Google Scholar]
- Papadima SN, Bloukas JG. Effect of fat level and storage conditions on quality characteristics of traditional greek sausages. Meat Sci. 1999;51:103–113. doi: 10.1016/S0309-1740(98)00103-X. [DOI] [PubMed] [Google Scholar]
- QIA . Livestock processing standards and ingredient specifications No. 2012-118. Animal Plant and Fisheries Quarantine and Inspection Agency; Korea: 2013. [Google Scholar]
- Ruusunen M, Puolanne E. Reducing sodium intake from meat products. Meat Sci. 2005;70:531–541. doi: 10.1016/j.meatsci.2004.07.016. [DOI] [PubMed] [Google Scholar]
- SAS . SAS/STAT Software for PC. Release 6.11. SAS institute; Cary, NC, USA: 2002. [Google Scholar]
- Toldrá F. Proteolysis and lipolysis in flavour development of dry-cured meat products. Meat Sci. 1998;49:S101–S110. doi: 10.1016/S0309-1740(98)00077-1. [DOI] [PubMed] [Google Scholar]
- US Food and Drug Administration [US FDA] [Accessesd at 10 May, 2020];Code of federal regulations. 2010 https://www.govinfo.gov/app/collection/cfr/2010/ Available from.
- Whiting RC. Stability and gel strength of frankfurter batters made with reduced NaCl. J Food Sci. 1984;49:1350–1354. doi: 10.1111/j.1365-2621.1984.tb14988.x. [DOI] [Google Scholar]
- WHO [World Health Organization] Strategies to monitor and evaluate population sodium consumption and sources of sodium in the diet. Report of a Joint Technical Meeting Convened by Who and the Government of Canada. WHO; Geneva, Switzerland: 2010. [Google Scholar]
- Witte VC, Krause GF, Bailey ME. A new extraction method for determining 2‐thiobarbituric acid values of pork and beef during storage. J Food Sci. 1970;35:582–585. doi: 10.1111/j.1365-2621.1970.tb04815.x. [DOI] [Google Scholar]