Exploring Natural Alternatives to Nitrites in Pork Meat Patty: A Study on the Effects of Gromwell Root Extract and Lettuce Powder as Substitutes

Lim, Youngho; Choi, Sumin; Park, Gyutae; Park, Yunhwan; Kim, Youngjin; Choi, Hyunsoo; Choi, Jungseok

doi:https://doi.org/10.1155/2023/4271840

Journal of Food Processing and Preservation

On this page

Abstract Introduction Materials and Methods Results and Discussion Conclusion Data Availability Conflicts of Interest Acknowledgments References Copyright Related Articles

Research Article | Open Access

Volume 2023 | Article ID 4271840 | https://doi.org/10.1155/2023/4271840

Exploring Natural Alternatives to Nitrites in Pork Meat Patty: A Study on the Effects of Gromwell Root Extract and Lettuce Powder as Substitutes

Youngho Lim,¹Sumin Choi,¹Gyutae Park,¹Yunhwan Park,¹Youngjin Kim,¹Hyunsoo Choi,¹and Jungseok Choi¹

Academic Editor: Slim Smaoui

Received24 Feb 2023

Revised08 May 2023

Accepted15 Jul 2023

Published16 Aug 2023

Abstract

The aim of this study was to assess the feasibility of substituting nitrite in pork meat patties with gromwell root extract and lettuce powder. We made pork patties with gromwell root extract and lettuce powder (control, no addition; positive control, addition of ; T1, 0.3% gromwell root extract; T2, 0.1% lettuce powder; T3, ) and investigated whether gromwell root extract and lettuce powder could serve as nitrite substitutes. Addition of gromwell root extract and lettuce powder improved WHC and CL and storage stability. Furthermore, addition of gromwell root extract reduced lightness and yellowness and increased redness. However, it had a negative effect on the sensory evaluation of flavor, bitterness, and off odor. In conclusion, gromwell root extract and lettuce powder showed positive potential as substitutes for nitrite in pork meat patties.

1. Introduction

Global meat consumption in Asia increased by 2.7 times between 1956 and 2006 [1]. From 1992 to 2016, global meat consumption increased by more than 500%, and steady growth is predicted [2]. Meat has a rich nutritional matrix that creates an environment favorable for the growth of meat deterioration bacteria and common foodborne diseases [3].

Processed pork meat products are vulnerable to oxidative reactions due to added heme iron, salt, and the relative plentiful of endogenous phospholipids [4]. Therefore, nitrite, with antioxidant and antimicrobial effects, is used in many meat products. Nitrite is an indispensable additive in meat product manufacturing as it plays a role in expressing and fixing meat color, the antioxidant effect of lipids, the flavor formation of unique cured meat, and antimicrobial action against Clostridium botulinum, the most important food-poisoning bacterium [5]. However, nitrites can react with amines at low pH in the body to form N-nitroso compounds, and many substances, including nitrosamine, are considered carcinogenic [6]. That is why many studies have measured residual nitrite in pork meat products [7, 8], and health concerns of using nitrite have increased consumer demand for organic and natural meat products; as a result, the meat industry is actively developing alternatives to nitrites [9].

Previous studies have reported using cherry tomato paste [10], drone pupa meal [11], red beet powder [12], polygoni multiflori radix [13], lemon seed essential oil and pitaya peel extract [8], and sage essential oil [14] as nitrite substitutes.

Gromwell (Lithospermum erythrorhizon Sieb. et Zucc.) is a perennial herbaceous plant with red pigment in the root integument and has been used as an herb for medication in eastern medicine [15, 16]. Gromwell contains a large amount of shikonin, a naphthoquinone-based compound, and its derivatives. This substance has a purple color and is known to be associated with the pharmacological effects of gromwell, such as antioxidant, antibacterial, anti-inflammatory, and immunomodulatory actions [15]. Also, gromwell has nitrite scavenging ability [17].

Lettuce (Lactuca sativa L.) is a 1- to 2-year-old herb belonging to Asteraceae and is cultivated nationwide in Korea. It contains vitamins A, B, C, and K, carotenoids, fiber, and polyphenolic compounds, so it exerts physiological activities, such as antibacterial and antioxidant effects [18]. In addition, lettuce contains nitrite and nitrate, and the contents of nitrite and nitrate were identified through several previous studies [19–21].

In this study, we added gromwell root extract, lettuce powder, and nitrite to pork patties and compared them to investigate their potential as nitrite replacements. There has been neither research to date on using gromwell as a substitute for nitrite, and no previous studies have investigated the combined use of gromwell and lettuce.

Our goal is to expand the range of potential substances that can replace nitrite in pork meat patties. This would benefit everyone, including those in the meat processing industry who are interested in health and public health issues.

2. Materials and Methods

2.1. Gromwell Root Extract

The gromwell root extract manufacturing method is shown in Figure 1. Gromwell root (herb and woodcutter, Dangjin-si, Korea) and 95% ethanol (Ethanol Supplies World Co., Ltd., Jeonju-si, Korea) were put into a bottle at a ratio of 100 g : 1000 ml and extracted at room temperature for 196 hours. The extract was filtered using Whatman no. 2 ∅ 150 mm (Korea Ace Scientific Co., Ltd., Seoul, Korea). The filtrate was concentrated in a vacuum rotary evaporator (N-1300E-W, EYELA, Tokyo, Japan) at 40°C and lyophilized (FDU-2100, EYELA, Tokyo, Japan).

2.2. Manufacturing of Patties

The material mixture of the patties is shown in Table 1. All patties had the same amount of ground pork meat, ice, salt, and pepper. 70 g of ground pork meat (Manpyeong Livestock Products, Cheongju, Korea) and 0.8 g of 99.0% sodium chloride (Samchun Chemicals, Pyeongtaek, Korea) were added first, followed by 0.16 g of pepper (Ottogi Co., Ltd., Anyang, Korea). Additives are added according to each treatment. Types of additives are gromwell root extract, lettuce powder (Baeksefood, Seoul, Korea), sodium nitrite (Junsei Chem. Co., Tokyo, Japan), and ascorbic acid (Sigma Aldrich, Darmstadt, Germany). The amount of additives added to each treatment is shown in Table 1.

The meat was kneaded for a total of 3 minutes, and ice was added 5 times for 30 seconds each to add a total of 80 g. Ice was added to prevent denaturing by heat from the hands and kneading action. After that, it was molded into 80 g patties. Finally, 8 patties of 80 g per treatment were made. The 5 treatment groups are as follows: control (no addition), positive control (addition of 0.005% sodium nitrite and 0.1% ascorbic acid), T1 (addition of 0.3% gromwell root extract), T2 (addition of 0.1% lettuce powder), and T3 (addition of 0.3% gromwell root extract and 0.1% lettuce powder). All patties were refrigerated.

2.3. Proximate Analysis

Moisture, ash, fat, and protein components of the patties were determined prior to storage according to methods approved by AOAC [18, 22]. 1 g of the sample was dried overnight at 105°C in a forced air oven (SH-DO-100 FG, Samheung, Seoul, Korea) to a constant weight to determine the amount of moisture. To determine the ash content, a 1 g sample was placed in a porcelain dish and heated in a muffle furnace (MF2-12 GF, Jeio tech, Daejeon, Korea) at 540°C for 10 hours. To estimate crude fat, a 0.5 g sample was mixed with 25 ml of Folch solution, which is a combination of 99.5% chloroform (Samchun Chemicals, Pyeongtaek, Korea) and 99.5% methanol (Samchun Chemicals, Pyeongtaek, Korea) in a 2 : 1 ratio. The mixture was then refrigerated at 4°C for 24 hours, after which it was filtered using Whatman no. 2 paper and cleaned with 5 ml of the Folch solution. Next, 10 ml of deionized water was added to the filtrate, and the sample was centrifuged at 3000 rpm at room temperature for 20 minutes (Union 55R, Hanil Science Co., Ltd., Daejeon, Korea). The upper layer consisting of water and methanol was removed using a pipette, and the remaining mixture was left to evaporate overnight in a hood. Finally, the weight of the residue was measured. To measure proteins, the Kjeldahl method was used. A 0.5 g sample was mixed with 25 mL of 98% sulfuric acid (Merck, Darmstadt, Germany), and the mixture was heated in a flask. The flask was then connected to a distillation apparatus to adsorb the ammonia component of the sample using boric acid (Sigma Aldrich, Darmstadt, Germany) in the flask. Finally, titration with 0.05 M sulfuric acid was performed.

`

2.4. pH

Using a Stomacher (400 Lab Blender, London, England), homogenize 5 g of the material for 30 seconds with 50 ml of deionized water, and then measure it using a pH meter (Orion Star A211, Thermo Scientific, USA). Repeat 3 times and calculate the mean value.

2.5. Water-Holding Capacity (WHC)

Water-holding capacity was calculated according to the method of Laakkonen et al.’s measurement [23]. Weigh a 2 ml test tube with a small hole, and accurately weigh of sample into the test tube. The sample was subjected to a temperature of 80°C in a water bath (SW-90 MW, Sangwoo Scientific, Bucheon-si, Korea) for 20 minutes and then allowed to cool down to room temperature for 10 minutes. Following a 10 min, 2,000 rpm, 4°C centrifugation, the weight was recorded, and the water retention was calculated using the formula below.

2.6. Cooking Loss (CL)

CL was measured by referring to the method used by Park et al. [24]. Samples were cut into a steak shape of about 80 g and cooked in a water bath at 70°C for 40 min, and CL show the difference in weight before and after heating in percentage (%).

2.7. Color Measurements

Patty color was standardized using a spectrocolorimeter (JX-777, Color Techno System Co., Ltd., Tokyo, Japan), and whiteboard was measured (, 94.04; , 0.13; , −0.51). The present method involves using a white fluorescent lamp (D65) as the light source to measure the value for brightness, the value for red, and the value for yellow, according to the Hunter Laboratory color scheme. Repeat 3 times and calculate the mean value.

2.8. Texture Profile Analysis

Texture was analyzed using a rheometer (Model Compac-100, Sun Scientific Co., LTD. Tokyo, Japan). Samples were equilibrated to room temperature prior to texture mapping analysis. Two compression cycle measurements were used to generate force versus time graphs. The crosshead moves at 200 millimeters per minute, and the load cell weighs 10 kg. The Bourne-described curves [25] were used to calculate the characteristics of cohesiveness, chewiness, and hardness. To obtain the cohesiveness value, divide the area under the second compression curve by the area under the first compression curve. To calculate chewiness, multiply gumminess by springiness. And gumminess is hardness multiplied by cohesiveness. The maximum force of the first compression is defined as hardness.

2.9. Sensory Evaluation

Sensory evaluation was measured by referring to the method used by Kim et al. [26]. The sample was baked in a frying pan heated using a portable butane stove (DYC-3000, Daeyang, Busan, Korea) at the same intensity for 3 minutes and 30 seconds on each side and then cooled down at room temperature for 1 hour. Sensory evaluation was performed on samples shaped to () cm. Eight sensory inspectors who had received sensory test training evaluated 7 items, including color, flavor, bitterness, juiciness, off-odor, texture, and total preference. A 5-point scale was used. Redness was rated on a 5-point scale, with 5 points for red and 1 point for gray. The other tests were scored on a 5-point scale where a perfect score was 5 points, with 5 points indicating the best and 1 point indicating the worst.

2.10. 2-Thiobarbituric Acid Reactive Substance (TBARS)

TBARS was measured using Witte et al. method [27]. For the sample 5 g, homogenize 25 ml of deionized water and cold 10% perchloric acid which diluted 70% perchloric acid (Samchun Chemicals, Pyeongtaek, Korea) 15 ml in 20 seconds of homogenizing at 10,000 rpm to use homogenizer (AM-7, Nissei, Izumichom, Tokyo). The homogenate was filtered using Whatman no.2 filter paper, and 5 ml of 2-thiobarbituric acid (Sigma Aldrich, Darmstadt, Germany) solution with a concentration of 0.02 M and 5 ml of the filtrate were thoroughly mixed and placed in a cool, dark place for 16 hours. Blank used deionized water and 5 ml of 0.02 M 2-thiobarbituric acid solution. Thereafter, the absorbance at 529 nm was measured using a spectrophotometer (mobi, MicroDigital Co., Ltd., Seongnam, Korea). The TBA content is represented in mg of MDA per kg of sample (mg MDA/kg). The standard curve used at this time is (), , and value, and is calculated.

2.11. Peroxide Value (POV)

POV was measured by referring to the method of Folch [28] and Park [29]. After finely chopping the sample, take 1.0 g of the sample into an Erlenmeyer flask with a stopper. After completely dissolving the sample by adding 10 ml of chloroform, 15 ml of CH₃COOH was added and mixed. A saturated KI solution was prepared by dissolving 99.5% potassium iodide (Samchun Chemicals, Pyeongtaek, Korea) and deionized water in a ratio of 7 : 3. After adding 1 ml of saturated KI solution, stoppering, and homogenizing for about 1 minute, it was left in the dark for 10 minutes at room temperature. After homogenizing again with 30 ml of deionized water, 1 ml of a 1% starch solution (BIOZOA Biological Supply, Seoul, Korea) indicator was added, and titration was performed with Na₂S₂O₃ (Samchun Chemicals, Pyeongtaek, Korea) solution with a concentration of 0.01 M until it became colorless. A blank test was conducted in parallel with this experiment.

2.12. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) Radical Scavenging Capacity

DPPH radical scavenging capacity was measured using Brand-Williams et al.’s [30] method. To obtain samples, blanks, and references, the mixture of 45 ml of methanol and 5 g of patties was homogenized and then subjected to filtration using Whatman no. 2 filter paper. After that, each sample was prepared: sample, homogenate solution (0.2 mM DPPH solution, BIOZOA Biological Supply, Seoul, Korea) 2 ml; blank, 99% methanol 5 ml; reference, DPPH 4 ml. Cover with aluminum foil to prevent exposure to light, and let it sit at room temperature in a dark environment for a duration of 20 to 30 minutes and then take measurements at a wavelength of 517 nm. After averaging the obtained values, they were substituted into the formula to obtain the value of the capacity of radical scavenging.

2.13. Total Microbial Count (TMC)

TMC was measured by referring to the method used by Park et al. [24]. TMC uses a serial dilution method. Combine 5 g of the sample with 45 ml of a peptone (Bacto^tm Peptone solution, Becton, Dickinson and Company, New Jersey, USA) solution with a concentration of 0.1% then use a stomacher bag to homogenize the mixture for 30 seconds. Afterwards, plate count agar (Difco^tm Plate Count Agar, Becton, Dickinson and Company, New Jersey, USA) medium was added with serially diluted samples, and the mixture was incubated for 48 hours at 37°C. Following incubation, count the colonies. Log cfu/g is the unit used to indicate the overall plate count.

2.14. Volatile Basic Nitrogen (VBN)

The VBN was determined using Pearson’s method [31]. A 5 g sample was mixed with 45 ml of deionized water. After homogenization at 10,000 rpm for approximately 20 seconds, filter the homogenate through Whatman no.2 filter paper. Introduce 1 ml of boric acid solution with a concentration of 0.01 M and 3 drops of Conway solution, which is a mixture of 0.066% bromocresol green (Samchun Chemicals, Pyeongtaek, Korea) and 0.066% methyl red (Samchun Chemicals, Pyeongtaek, Korea), into the inside of the Conway unit. Then, add 3 ml of filtrate outside the Conway unit. Following this, 1 ml of K2CO3 (Samchun Chemicals, Pyeongtaek, Korea) with a concentration of 50% is added to the outside of the Conway unit, and it is then incubated for 120 minutes at 37°C. After the incubation period, the boric acid solution inside the Conway unit is titrated using sulfuric acid with a concentration of 0.01 M. The resulting value for VBN is expressed in milligrams per 100 grams of the sample (mg%).

The variables used are , which represents the volume of sulfuric acid added in milliliters (ml); , which denotes the quantity of sulfuric acid added to the blank sample in ml; and , which represents the amount of necessary to react with 1 ml of 0.01 M H2SO4.

2.15. Statistical Analysis

Statistical analysis was performed using GLM (general linear model) of the SAS 9.4 program (statistics analytical system). For comparison between treatment averages, a significance test () was conducted through Duncan’s multiple tests.

3. Results and Discussion

3.1. Proximate Analysis

Table 2 shows the proximate analysis of patties with added gromwell root extract and lettuce powder. In the control group, ash and fat contents were lower than other treatments (). The T3 group was higher fat content than the control, positive control, and T1 groups ().

The composition of typical lettuce, excluding moisture, is about 28% of crude protein, 6% of crude fat, 11% of crude fiber, 43% of nitrogen-free extract, and 11% of crude ash [32]. Since the lettuce powder used in this experiment was a dried product, the moisture content was excluded. The ash content of gromwell was 9.61% [33]. The control group was thought to have a low ash content because it was not treated with gromwell root extract, lettuce powder, nitrite, or ascorbic acid.

The reason for the lower fat content of the control group is thought to be due to the moisture content. Moisture loss occurs due to the physical force applied when manufacturing the patties. Lettuce powder was added to groups T2 and T3, and the WHC of meat increased as the strength of the protein network increased [34]. However, the addition of dietary fiber may have interfered with the gel network formed by protein-water or protein-protein, resulting in a reduction in the strength of the gel in the product [35]. The positive control group had a lower pH than the control group due to the addition of ascorbic acid (Table 3). Moisture loss increased as the lattice-shaped space between myofibrils became smaller when the pH approached the isoelectric point (pH 5 for pork meat) [5, 36]. Moisture in meat is divided into bound water, combined water, and free water based on the binding pattern with protein [5]. Free water accounts for about 75% of the water in meat and can easily be exuded to the surface of the meat in response to external shock due to its free thermodynamic movement [5]. The excessive exudation of free water can cause protein loss because free water contains water-soluble proteins [5]. Most of the juiciness of meat is due to free water [5]. The sensory evaluation results of juiciness in the T1 group were not significant, but it was evaluated as lower than the other treatments (Table 4). This finding could have been due to the escape of more free water in this treatment group compared to the other groups. Therefore, the control group tended to have higher moisture and protein contents than the other treatments. Accordingly, the proportion of fat was relatively low. Lettuce excluding moisture contains about 6% of crude fat [32]. Therefore, it is considered that the T3 group, with lettuce powder added, showed a higher fat content than the control, positive control, and T1 groups.

3.2. pH, WHC, and CL

Table 3 shows the pH, WHC, and CL of patties with added gromwell root extract and lettuce powder. The positive control group showed a lower pH value than the control group (). The T1, T2, and T3 groups which added gromwell root extract, lettuce powder, or both had higher pH value than the control and positive control groups ().

The positive control group had a lower pH than the control group because ascorbic acid was added. Natural color mainly causes color fading and discoloration due to the interaction between the ingredients in the food itself. In the case of gromwell root extract pigments, it is orange in acidic conditions but changes from red to purple as the pH increases [35]. The gromwell root extract used in the experiment had high redness and low yellowness values in the patty color measurements (Table 5) and showed a deep red color to the naked eye. The pH of cut lettuce according to the storage days was 6.0 on day 1 and 6.5 on day 15 [37]. Therefore, it is considered that the T1, T2, and T3 groups showed higher pH values than the control and positive control groups.

The T1, T2, and T3 groups had higher WHC value than the control group (). And WHC measurements of patties generally showed a tendency that the higher the pH, the higher the WHC. This result was due to the WHC decreased as the lattice-shaped space between myofibrils became smaller as the pH approached the isoelectric point (pH 5 for pork meat) [5, 36].

The cooking loss of patties in the T1 and T3 groups with added gromwell root extract had lower than the control, positive control, and T2 groups (), indicating a negative correlation with WHC. Cooking loss increases as the pH decreases and the surface-to-weight ratio of meat increases [38], and moisture loss occurs as the binding force between protein and water molecules weakens. When the pH is high, the ability to retain water increases, so CL also decreases. However, when the pH is low, protein approaches the isoelectric point, making it easier to release water, so CL also increases [5, 38, 39]. This is the reason why the T1 and T2 groups had lower CL value than the control and positive control groups. In general, dietary fiber absorbs and stores moisture. However, during the heating process, some of the soluble dietary fiber can be hydrolyzed and lost, while the molecular structure of some of the insoluble dietary fiber may also be broken, leading to a decrease in the overall amount of dietary fiber [40]. As an example of this, the CL value of sausages with 3% spinach powder was significantly lower than that of sausages without anything added [41]. The crude fiber content of lettuce excluding moisture is 11% [32]. It is thought that T2 with lettuce powder added showed a higher CL value than T1 for this reason, and T3 also showed a higher tendency than T1 in CL value.

In conclusion, when gromwell root extract was added, pH and WHC increased, and CL decreased. Furthermore, while adding lettuce powder increased pH and WHC, it did not have a significant effect on CL.

3.3. Color Measurements

Table 5 shows the color of patties with added gromwell root extract and lettuce powder. The T1 and T3 groups, which added gromwell root extract, show low lightness and yellowness values and a higher redness value than the control, positive control, and T2 groups (). The T2 group, which added lettuce powder, showed high redness and yellowness value than the control group (). But there was no difference between T2 and positive control groups.

Gromwell root is known to contain shikonin and its derivatives, which are red-purple pigments [15, 42]. Therefore, the high red color of the T1 and T3 groups’ patties was due to shikonin, which also resulted in low lightness and yellowness values in T1 and T3 groups. The T2 group supplemented with lettuce powder showed significantly greater redness than the control group, but there was no significant difference compared to the positive control group, according to the results. Redness of meat can be increased by inhibiting metmyoglobin formation using ascorbic acid, which acts as a reducing agent [43]. Lettuce is known to contain ascorbic acid [18], so it is possible that the result was due to the ascorbic acid present in the lettuce powder.

Thus, when gromwell root extract is added to the pork patty, the redness is significantly increased, while the brightness and yellowness are reduced. On the other hand, adding lettuce powder to the pork patties results in an increase in both redness and yellowness.

3.4. Texture Profile Analysis

Table 6 shows the texture profile analysis of patties with added gromwell root extract and lettuce powder. The T3 group had lower values in hardness and chewiness than other treatments.

The addition of dietary fiber may have caused interfered with the gel network formed by protein-water or protein-protein, resulting in a reduction in the strength of the gel in the product [35]. Moreover, hardness was negatively correlated with fiber content [44]. The lettuce powder added to the T3 group contains dietary fiber, and the fiber of the lettuce powder destabilized the patty which may have contributed to the lower hardness value. The degree of chewiness is a secondary characteristic that is influenced by the level of hardness [45, 46]. Therefore, if the hardness is low, chewiness is also low. Since the hardness of the T3 group was low, it is considered that the chewiness was also low.

The higher the moisture content, the higher the springiness [47]. Texture profile analyses were measured after cooking the patties. Since the CL value of the T3 group was lower than that of the T2 and positive control groups, it can be inferred that it has a high water content, and thus, a high springiness value was obtained (Tables 3 and 6, ).

3.5. Sensory Evaluation

Table 4 shows the sensory evaluation of patties with added gromwell root extract and lettuce powder. The T1 and T3 groups which added gromwell root extract had higher meat color values than control, positive control, and T2 groups (), because gromwell root contains a large amount of red-colored shikonin and its derivatives [15]. In terms of flavor, bitterness, and off-odor, the T1 and T3 groups with added gromwell root extract received lower scores than control, positive control, and T2 groups ().Gromwell’s unique flavor in the patty was perceived negatively. However, adding gromwell to gangjeong did not adversely affect the taste or overall acceptability [48], suggesting that the preference for gromwell-added patties can be increased depending on the cooking method. While the T2 group showed significantly lower color scores than the other treatment groups, there were no significant differences between the T2 group and the control group in terms of the other characteristics, particularly overall preference. Therefore, it can be said that the addition of 0.1% lettuce powder did not decrease the preference for the patties.

Thus, the addition of gromwell root extract to the pork patty had a positive effect on color but had a negative effect on flavor, bitterness, and off odor. The addition of lettuce powder did not affect sensory evaluation.

3.6. TBARS, POV, and DPPH Radical Scavenging Capacity

TBARS, POV, and DPPH radical scavenging capacity were measured to confirm the antioxidant capacity of gromwell root extract and lettuce powder in pork patties. Figure 2 shows the TBARS, POV, and DPPH radical scavenging capacity of patties with added gromwell root extract and lettuce powder.

TBARS measurements on 1 day of storage showed that the T2 group had lower values than control group (). On 3 days of storage, the T3 group had lower values than the control and positive control groups (). On 7 days of storage, T1 had lower values than the control and positive groups (). Also, the T1, T2, and T3 groups were lower than control groups ().

POV measurements did not show any differences between the treatment groups on days 1 and 3 of storage. On day 7 of storage, the T1 and T3 groups had lower values than the T2 group (), but no significant differences were found between the T2, control, and positive control groups. However, on day 7, the T1 and T3 groups exhibited lower POV values compared to the other treatment groups ().

On DPPH radical scavenging capacity measurement, during all storage days, it was higher in the order of positive control, T1, T2, T3, and control groups ().

Since phenolic compounds have a phenolic hydroxyl group capable of accepting free radicals, they can bind to proteins and other macromolecules, providing antioxidant properties [49]. Gromwell root contained phenolic compounds and exhibits high antioxidant activity [50]. Also, gromwell contained 1.7 times more polyphenols than ginseng and 2.6 times more than sealwort [51]. Furthermore, shikonin from gromwell has been shown to scavenge reactive oxygen species [52]. Acetylshikonin, β, β-dimethylacrylshikonine, and shikonin in gromwell acted as antioxidants in lard [53].

Lettuce contained 22-48 mg/kg of nitrite at ambient temperature (25°C) and 21-40 mg/kg when refrigerated (10°C), depending on storage time (0-48 hours) [54]. Lettuce contains nitrates and nitrites [19], and ascorbic acid present in lettuce acts as a reducing agent that promotes nitrite reduction [55]. In addition, lettuce contains fat-soluble antioxidants such as lutein and tocopherol, as well as water-soluble antioxidants such as phenolic acid, anthocyanidin, caffeic, caftaric, and chicoric acid [56–58]. Thus, these factors may explain the observed antioxidant effect in patties that have been supplemented with gromwell root extract and lettuce powder.

Based on the results of TBARS and DPPH radical scavenging measurements, it was shown that gromwell root extract and lettuce powder have antioxidant abilities in pork patties. In addition, the antioxidant effect was better in the treatment group added separately than in the combination of gromwell root extract and lettuce powder.

3.7. TMC and VBN

To investigate the antimicrobial properties of gromwell root extract and lettuce powder on pork patties, TMC and VBN were confirmed. Figure 3 shows the TMC and VBN of patties with added gromwell root extract and lettuce powder.

On TMC measurements, in all storage days, the positive control group showed lower values than all other treatments (). The T1 and T2 groups showed lower values than the control group on all storage days (). The T3 group showed a higher value than the T1 and T2 groups on day 1 (). Also, the T3 group showed a lower value than the control group on the 3rd day ().

On VBN measurements, on days 1 and 7, the T1, T2, and T3 groups were lower than the control group (). Also on day 7, there was no difference between the T1 and T2 groups and the positive control group, and the T3 group was greater than the positive control group ().

Gromwell contains a large amount of shikonin, a naphthoquinone-based compound with antimicrobial properties [15]. Shikonin has bactericidal properties [59]. Shikonin showed antibacterial effect against food-poisoning bacteria, such as E. coli, B. cereus, S. aureus, and V. parahaemolyticus, as well as antimicrobial effects against both gram-negative and positive bacteria [60]. Lettuce contains nitrate and nitrite [19], as well as ascorbic acid, which is a reducing agent that can promote nitrite reduction to NO [18]. Nitrite and NO can interfere with heme transport by impairing cyt c maturation E, resulting in impaired cytochromes c biosynthesis, resulting in antibacterial action [61]. Lettuce’s phenolic acid is effective in either killing or preventing the growth of microorganisms through multiple mechanisms, such as modifying the permeability of the bacteria plasma membrane, directly impacting microbial metabolism, and depriving them of the necessary substrates for growth [62]. The T1 and T2 groups added with gromwell root extract and lettuce powder through these materials showed lower values than the control group in TMC measurement ().

The VBN values of the treatments showed a similar trend to the TMC values. Microbes break down meat proteins into amines, ammonia, and other alkaline nitrogenous substances that can be measured by the VBN measurement [63]. Additionally, as spoilage bacteria and endogenous enzyme activities increased, the VBN value also increased [8]. Therefore, VBN values in meat are highly correlated with microbial counts. For fresh meat, the Korean Food Code specifies a VBN value of less than 20 mg/% [64].

TMC and VBN measurements confirmed that gromwell root extract and lettuce powder have antimicrobial effects on pork patties. The antimicrobial effect was found to be better when gromwell root extract and lettuce powder were used separately rather than used together.

4. Conclusion

The addition of gromwell root extract to pork patties (T1) had positive effects on WHC, CL, and meat color. Furthermore, in the storage experiments measuring TBARS, DPPH radical scavenging capacity, TMC, and VBN, it was shown to improve storage stability with antioxidant and antimicrobial effects. However, it had a negative effect on flavor, bitterness, and off-odor of sensory evaluation. This disadvantage could potentially be solved by adding spices or seasoning or changing the cooking method. When lettuce powder was added to pork patties (T2), WHC and storage stability were improved, and there was no difference in sensory evaluation compared to the control group. The addition of gromwell root extract and lettuce powder to pork patties (T3) had a positive effect on WHC, CL, and meat color. However, in storage experiments, it tended to be less effective than patties with separately added gromwell root extract and lettuce powder (T1 and T2). And it had a bad effect on flavor, bitterness, and off-odor of sensory evaluation.

In summary, gromwell root extract and lettuce powder have the potential to replace nitrites in pork meat patties. Gromwell is a good option when antioxidant, antimicrobial, WHC, CL, and red meat color effects are required, while lettuce is a good option when antioxidant and antimicrobial effects are required without affecting its organoleptic properties. Adding gromwell root extract and lettuce powder together tends to have lower antioxidant and antimicrobial effects than adding them separately. Therefore, when using gromwell and lettuce as nitrite substitutes, it is recommended to use either 0.3% gromwell root extract or 0.1% lettuce powder alone, rather than combining both.

Data Availability

The data used to support the findings of this study are available from the corresponding author upon reasonable request.

Conflicts of Interest

The authors declare that they have no conflicts of Interest.

Acknowledgments

This work was supported by the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) through the High Value-added Food Technology Development Program, funded by the Ministry of Agriculture, Food and Rural Affairs (MAFRA) (321028-5). This research was supported by the “Regional Innovation Strategy (RIS)” through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (MOE) (2021RIS-001).

References

K.-C. Nam, C. Jo, and M. Lee, “Meat products and consumption culture in the east,” Meat Science, vol. 86, no. 1, pp. 95–102, 2010.
View at: Publisher Site | Google Scholar
B. Katare, H. H. Wang, J. Lawing, N. Hao, T. Park, and M. Wetzstein, “Toward optimal meat consumption,” American Journal of Agricultural Economics, vol. 102, no. 2, pp. 662–680, 2020.
View at: Publisher Site | Google Scholar
T. Aymerich, P. A. Picouet, and J. M. Monfort, “Decontamination technologies for meat products,” Meat Science, vol. 78, no. 1-2, pp. 114–129, 2008.
View at: Publisher Site | Google Scholar
J. Jiang and Y. L. Xiong, “Natural antioxidants as food and feed additives to promote health benefits and quality of meat products: a review,” Meat Science, vol. 120, pp. 107–117, 2016.
View at: Publisher Site | Google Scholar
Korean Society for Meat Science Research, Meat Science, Sunjin Printing, 2018.
World Health Organization, Guidelines for Drinking-Water Quality: Incorporating the First and Second Addenda, World Health Organization, 2022.
K.-E. Hwang, H.-W. Kim, D.-H. Song et al., “Application of Ganghwa Mugwort in combination with ascorbic acid for the reduction of residual nitrite in pork sausage during refrigerated storage,” Korean Journal for Food Science of Animal Resources, vol. 34, no. 2, pp. 178–184, 2014.
View at: Publisher Site | Google Scholar
K.-q. Xin, X.-y. Ji, Z. Guo, L. Han, Q.-l. Yu, and B. Hu, “Pitaya peel extract and lemon seed essential oil as effective sodium nitrite replacement in cured mutton,” LWT, vol. 160, article 113283, 2022.
View at: Publisher Site | Google Scholar
A. U. Alahakoon, D. D. Jayasena, S. Ramachandra, and C. Jo, “Alternatives to nitrite in processed meat: up to date,” Trends in Food Science & Technology, vol. 45, no. 1, pp. 37–49, 2015.
View at: Publisher Site | Google Scholar
J.-H. Hong, S.-H. Lee, and H.-Y. Kim, “Effect of cherry tomato paste for nitrite replacement on emulsion-type pork sausage,” Journal of the Korean Society of Food Science and Nutrition, vol. 50, no. 5, pp. 506–514, 2021.
View at: Publisher Site | Google Scholar
S. M. Kang, A. R. Maeng, P.-N. Seong et al., “Effect of drone pupa meal added as replacement of sodium nitrite and vitamin C on physico-chemical quality characteristics of emulsion-type sausage,” The Korean Journal of Food And Nutrition, vol. 31, no. 6, pp. 802–810, 2018.
View at: Google Scholar
S.-R. Ha, J.-S. Choi, and S.-K. Jin, “The physicochemical properties of pork sausages with red beet powder,” Journal of Life Science, vol. 25, no. 8, pp. 896–902, 2015.
View at: Publisher Site | Google Scholar
J. I. Pak, J.-G. Lim, J. W. Jhoo, G. Y. Kim, and S. M. Kang, “Antioxidant activity of a fraction from polygoni multiflori radix as an alternative to nitrite in cured-ground pork,” Journal of the Korean Society of Food Science and Nutrition, vol. 49, no. 3, pp. 253–261, 2020.
View at: Publisher Site | Google Scholar
B. Šojić, V. Tomović, J. Savanović et al., “Sage (Salvia officinalis L.) essential oil as a potential replacement for sodium nitrite in dry fermented sausages,” PRO, vol. 9, no. 3, p. 424, 2021.
View at: Publisher Site | Google Scholar
J. Song, “Study on biological functions and utilizations of Shikonin and it's derivatives in Lothospermum erythrohizon,” in Food Engineering, Graduate School of Mokpo National University, 2008.
View at: Google Scholar
G.-S. Kim, C.-G. Park, K.-H. Lee et al., “Investigation of shikonin pigments and antioxidant activity of the roots from Lithospermum erythrorhizon according to the different growth stages and areas of cultivation,” Korean Journal of Medicinal Crop Science, vol. 19, no. 6, pp. 435–440, 2011.
View at: Publisher Site | Google Scholar
H.-O. Boo, J.-S. Shin, S.-J. Hwang, C.-S. Bae, and S.-H. Park, “Antimicrobial effects and antioxidative activities of the cosmetic composition having natural plant pigments,” Korean Journal of Plant Resources, vol. 25, no. 1, pp. 80–88, 2012.
View at: Publisher Site | Google Scholar
S. Jang, E. Lee, and W. Kim, “Analysis of research and development papers on lettuce in Korea,” Korean Journal of Horticultural Science & Technology, vol. 25, no. 3, pp. 295–303, 2007.
View at: Google Scholar
J.-H. Shin, M.-J. Kang, S.-M. Yang, H.-S. Kim, and N.-J. Sung, “Contents of nitrate and nitrite in vegetables and fruits,” Journal of Food Hygiene and Safety, vol. 17, no. 2, pp. 101–105, 2002.
View at: Google Scholar
M. Iammarino, A. Di Taranto, and M. Cristino, “Monitoring of nitrites and nitrates levels in leafy vegetables (spinach and lettuce): a contribution to risk assessment,” Journal of the Science of Food and Agriculture, vol. 94, no. 4, pp. 773–778, 2014.
View at: Publisher Site | Google Scholar
Y. M. Ko, J. H. Park, and K. S. Yoon, “Nitrite formation from vegetable sources and its use as a preservative in cooked sausage,” Journal of the Science of Food and Agriculture, vol. 97, no. 6, pp. 1774–1783, 2017.
View at: Publisher Site | Google Scholar
AOAC, Official Methods of Analysis, The Association of Official Analytical Chemists, Gaithersburg, MD, USA, 17th edition, 2000.
E. Laakkonen, G. Wellington, and J. Sherbon, “Low-temperature, long-time heating of bovine muscle 1. Changes in tenderness, water-binding capacity, pH and amount of water-soluble components,” Journal of Food Science, vol. 35, no. 2, pp. 175–177, 1970.
View at: Publisher Site | Google Scholar
G. Park, S. Oh, S. Park et al., “Physicochemical characteristics and storage stability of hybrid beef patty using shiitake mushroom (Lentinus edodes),” Journal of Food Quality, vol. 2023, Article ID 7239709, 10 pages, 2023.
View at: Publisher Site | Google Scholar
M. C. Bourne, “Texture profile analysis,” Food Technology, vol. 32, pp. 62–66, 1978.
View at: Google Scholar
Y.-A. Kim, S. Park, Y. Park, G. Park, S. Oh, and J. Choi, “Effect of addition of fermented soy sauce on quality characteristics of pork patties during refrigerated storage,” Food, vol. 11, no. 7, p. 1004, 2022.
View at: Publisher Site | Google Scholar
V. C. Witte, G. F. Krause, and M. E. Bailey, “A new extraction method for determining 2-thiobarbituric acid values of pork and beef during storage,” Journal of Food Science, vol. 35, no. 5, pp. 582–585, 1970.
View at: Publisher Site | Google Scholar
M. Lees and G. Sloanestanley, “A simple method for the isolation and purification of total lipides from animal tissues,” The Journal of Biological Chemistry, vol. 226, no. 1, pp. 497–509, 1957.
View at: Publisher Site | Google Scholar
G. Park, S. Jin, and J. Choi, “Effects of physicochemical characteristics and storage stability of porcine albumin protein hydrolysates in pork sausage,” Current Research in Nutrition and Food Science Journal, vol. 10, no. 3, pp. 1007–1019, 2022.
View at: Publisher Site | Google Scholar
W. Brand-Williams, M.-E. Cuvelier, and C. Berset, “Use of a free radical method to evaluate antioxidant activity,” LWT-Food science and Technology, vol. 28, no. 1, pp. 25–30, 1995.
View at: Publisher Site | Google Scholar
D. Pearson, “Application of chemical methods for the assessment of beef quality. II. Methods related to protein breakdown,” Journal of the Science of Food and Agriculture, vol. 19, no. 7, pp. 366–369, 1968.
View at: Publisher Site | Google Scholar
H.-Y. Kim, K.-B. Lee, and H.-Y. Lim, “Contents of minerals and vitamins in organic vegetables,” Korean Journal of Food Preservation, vol. 11, no. 3, pp. 424–429, 2004.
View at: Google Scholar
J. S. Kim, H. J. Park, S. M. Yoo, G. J. Han, Y. S. Han, and M. H. Kang, A Study on Funtionality and Utilization from Lithospermum Erythrohizon, National Institute of Agricultural Sciences, 2002.
L. Morin, F. Temelli, and L. McMullen, “Interactions between meat proteins and barley (Hordeum spp.) β-glucan within a reduced-fat breakfast sausage system,” Meat Science, vol. 68, no. 3, pp. 419–430, 2004.
View at: Publisher Site | Google Scholar
M. Han and H. C. Bertram, “Designing healthier comminuted meat products: effect of dietary fibers on water distribution and texture of a fat-reduced meat model system,” Meat Science, vol. 133, pp. 159–165, 2017.
View at: Publisher Site | Google Scholar
S. Ju, “Let's get right to know pork(4)-water holding capacity of pork,” Korea Swine Journal, vol. 20, no. 4, pp. 163–165, 1998.
View at: Google Scholar
A. King Jr., J. Magnuson, T. Török, and N. Goodman, “Microbial flora and storage quality of partially processed lettuce,” Journal of Food Science, vol. 56, no. 2, pp. 459–461, 1991.
View at: Publisher Site | Google Scholar
M. Flores, V.-J. Moya, M.-C. Aristoy, and F. Toldrá, “Nitrogen compounds as potential biochemical markers of pork meat quality,” Food Chemistry, vol. 69, no. 4, pp. 371–377, 2000.
View at: Publisher Site | Google Scholar
E. C. HaeKyung Yim, “The effect of medicinal plants with additives on storage characteristics of sausage,” The East Asian Society of Dietary Life, vol. 12, no. 3, pp. 249–257, 2002.
View at: Google Scholar
E.-Y. Lee and Y.-A. Kim, “Effects of heat treatment on the dietary fiber contents of soybean sprout and spinach,” Korean Journal of Food and Cookery Science, vol. 10, no. 4, pp. 381–385, 1994.
View at: Google Scholar
J.-A. Lee, M.-Y. Choi, S.-Y. Choo, D.-B. Hwang, and H.-Y. Kim, “Antioxidant activity and quality characteristics of the pork emulsion sausage added with spinach powder,” Resources Science Research, vol. 1, no. 1, pp. 24–31, 2019.
View at: Publisher Site | Google Scholar
W. J. JaeCheol Song, “Natural plants and food coloring,” Bulletin of Food Technology, vol. 10, no. 2, pp. 55–61, 1997.
View at: Google Scholar
A. Sánchez-Escalante, D. Djenane, G. Torrescano, J. A. Beltrán, and P. Roncalés, “The effects of ascorbic acid, taurine, carnosine and rosemary powder on colour and lipid stability of beef patties packaged in modified atmosphere,” Meat Science, vol. 58, no. 4, pp. 421–429, 2001.
View at: Publisher Site | Google Scholar
M. Kaur, N. Singh, and N. S. Sodhi, “Physicochemical, cooking, textural and roasting characteristics of chickpea (Cicer arietinum L.) cultivars,” Journal of Food Engineering, vol. 69, no. 4, pp. 511–517, 2005.
View at: Publisher Site | Google Scholar
M. Selgas, E. Cáceres, and M. García, “Long-chain soluble dietary fibre as functional ingredient in cooked meat sausages,” Food Science and Technology International, vol. 11, no. 1, pp. 41–47, 2005.
View at: Publisher Site | Google Scholar
N. Ktari, S. Smaoui, I. Trabelsi, M. Nasri, and R. B. Salah, “Chemical composition, techno-functional and sensory properties and effects of three dietary fibers on the quality characteristics of Tunisian beef sausage,” Meat Science, vol. 96, no. 1, pp. 521–525, 2014.
View at: Publisher Site | Google Scholar
J.-H. Choe and H.-Y. Kim, “Effects of swelled pig skin with various natural vinegars on quality characteristics of traditional Korean blood sausages (sundae),” Food Science and Biotechnology, vol. 25, no. 6, pp. 1605–1611, 2016.
View at: Publisher Site | Google Scholar
J.-S. Kim and Y.-S. Han, “Quality characteristics of Kangjung with added gromwell (Lithospermum erythrorhizon Sieb. et Zucc.) extracts,” Korean Journal of Food and Cookery Science, vol. 21, no. 6, pp. 908–918, 2005.
View at: Google Scholar
J.-S. Kim and M.-H. Kang, “Antioxidant activity of solvent fractions from cultivated and wild gromwell,” Journal of the Korean Society of Food Science and Nutrition, vol. 39, no. 6, pp. 789–795, 2010.
View at: Publisher Site | Google Scholar
M.-H. Jung, S.-S. Lee, S.-H. Park, and H.-J. Hwang, “The antioxidative effect of ethanol extracts from Lithospermum erythrorhizon Siebold & Zucc., Xanthium strumarium Linn, and Lonicera japonica,” Journal of Life Science, vol. 23, no. 5, pp. 643–649, 2013.
View at: Publisher Site | Google Scholar
S. Seo, “Antioxidant and anti-aging activities of Lithospermi radix extracts,” Journal of Investigative Cosmetology, vol. 12, no. 4, pp. 339–346, 2016.
View at: Publisher Site | Google Scholar
L. S. Yoshida, S. Kohri, S. Tsunawaki et al., “Evaluation of radical scavenging properties of shikonin,” Journal of Clinical Biochemistry and Nutrition, vol. 55, no. 2, pp. 90–96, 2014.
View at: Publisher Site | Google Scholar
X. Weng, G. Xiang, A. Jiang et al., “Antioxidant properties of components extracted from puccoon (Lithospermum erythrorhizon Sieb. et Zucc.),” Food Chemistry, vol. 69, no. 2, pp. 143–146, 2000.
View at: Publisher Site | Google Scholar
J. Silalahi, A. F. Nasution, N. Ginting, and Y. Silalahi, “The effect of storage condition on nitrite and nitrate content in lettuce (Lactuca sativa L.),” International Journal of PharmTech Research, vol. 9, pp. 422–427, 2016.
View at: Google Scholar
J. Y. Jeong, “Alternative curing technology in meat products,” Livestock Food Science and Industry, vol. 5, no. 2, pp. 77–84, 2016.
View at: Google Scholar
C. Nicolle, N. Cardinault, E. Gueux et al., “Health effect of vegetable-based diet: lettuce consumption improves cholesterol metabolism and antioxidant status in the rat,” Clinical Nutrition, vol. 23, no. 4, pp. 605–614, 2004.
View at: Publisher Site | Google Scholar
A. Galieni, C. Di Mattia, M. De Gregorio et al., “Effects of nutrient deficiency and abiotic environmental stresses on yield, phenolic compounds and antiradical activity in lettuce (Lactuca sativa L.),” Scientia Horticulturae, vol. 187, pp. 93–101, 2015.
View at: Publisher Site | Google Scholar
N. Nikzad and H. Parastar, “Evaluation of the effect of organic pollutants exposure on the antioxidant activity, total phenolic and total flavonoid content of lettuce (Lactuca sativa L.) using UV-Vis spectrophotometry and chemometrics,” Microchemical Journal, vol. 170, article 106632, 2021.
View at: Publisher Site | Google Scholar
V. P. Papageorgiou, A. N. Assimopoulou, E. A. Couladouros, D. Hepworth, and K. Nicolaou, “The chemistry and biology of alkannin, shikonin, and related naphthazarin natural products,” Angewandte Chemie International Edition, vol. 38, no. 3, pp. 270–301, 1999.
View at: Publisher Site | Google Scholar
U.-Y. Park, D.-S. Chang, and H.-R. Cho, “Antimicrobial effect of Lithospermi radix (Lithospermum erythrorhizon) extract,” Journal of the Korean Society of Food Science and Nutrition, vol. 21, no. 1, pp. 97–100, 2015.
View at: Google Scholar
W. Wang, J. Wang, X. Feng, and H. Gao, “A common target of nitrite and nitric oxide for respiration inhibition in bacteria,” International Journal of Molecular Sciences, vol. 23, no. 22, p. 13841, 2022.
View at: Publisher Site | Google Scholar
J. Liu, C. Du, H. T. Beaman, and M. B. B. Monroe, “Characterization of phenolic acid antimicrobial and antioxidant structure–property relationships,” Pharmaceutics, vol. 12, no. 5, p. 419, 2020.
View at: Publisher Site | Google Scholar
X. He, R. Liu, S. Nirasawa, D. Zheng, and H. Liu, “Effect of high voltage electrostatic field treatment on thawing characteristics and post-thawing quality of frozen pork tenderloin meat,” Journal of Food Engineering, vol. 115, no. 2, pp. 245–250, 2013.
View at: Publisher Site | Google Scholar
Ministry of Food and Drug Safety, Food Code (No. 2021-54), 2021.

Copyright

Copyright © 2023 Youngho Lim et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

PDF Download Citation

Download other formats

Order printed copies

Views

313

Downloads

239

Citations