Abstract: Background and Objective: A global trend towards preserving food quality and minimizing deterioration, microbes and oxidation has led to the search for natural preservation materials to ensure food safety and quality without compromising their sensory properties to be used as alternatives. This analysis aims to study the effects of adding oil of oregano and basil on the shelf life of camel meat during cold storage. Materials and Methods: A total of seven treatments were prepared from camel meat burgers, without adding essential oils, with basil essential oil (A1, A2 and A3), with oregano essential oil (B1, B2 and B3). Moisture, PH, Ash, protein, fat and carbohydrate contents, thiobarbituric acid, Total Volatile Basic Nitrogen (TVB-N), Water Holding Capacity (WHC), cooking loss were determined. Results: Results showed that there were differences at p<0.05 in the TBA values between the basil oil, oregano oil and the control sample. Treated samples with basil EO at different concentrations showed increasing in TVB-N values than the untreated (control) samples, especially on the 9th day. The physicochemical analysis showed the addition of basil essential oils did not affect the evolution of the pH. The moisture content showed a drop for all samples during storage time (9 days). Conclusion: The study found that the shelf life of the camel meat burgers can be extended by using 0.05 μL/100 g for 9 days.
INTRODUCTION
In the last decades, consumers’ concern about the economic preservatives that were value-added to food has been inflated. That concern has LED researchers to have an interest in the development of natural alternatives that cut back consumers’ concerns. Within the method of looking for alternatives to the artificial preservatives or inhibitors, the Essential Oils (EOs) obtained from plants are studied like oregano and rosemary that are used as natural preservation alternatives in several merchandises1. Essential oils may also contribute to managing the expansion of each spoilage and unhealthful microorganisms. The antimicrobial activity and antioxidants of essential oils area unit the in consequence of the phenolic resin compound’s high concentrations like (Thymol, Carvacrol, Eugenol)2. The potency of thyme and oregano oil has been evidenced on microbes for his or her high content of carvacrol and thymic acid. The basil essential oil’s medication activity is attributed to its high content in essential oil and estragole, whereas the antimicrobial spectrum is restricted to staph and E. coli 3. Meat could be an alimentary, protein-rich food, that is extremely decayable and contains a short period unless preservation ways area unit used4. Meat contains a short period, that is sometimes daily or less at a temperature of (15-30°C) and several days at a cold temperature. Therefore, applying essential oils to meat and its merchandise is one in all the chances of prolonging their period5. A fat chemical reaction is that the explanation for deterioration within the quality of meat throughout the method of storing it and processing it. However, the fat chemical reaction produces several volatile compounds chargeable for flavour and may be stricken by chemical reaction of meat sensory quality like colour, texture and smell6. Within the last studies, essential oils have resulted in an impact of the impression of bearing a controlled sway against pathogens in meat and fish merchandise conjointly been found to own a pronounced effect on lipid chemical reaction7. Meat contaminated with antibiotic-resistant microbes like MRSA will be a significant threat to public health, so the analysis direction is to seek out natural antimicrobials to scale back the growing anxiety of microbic spoilage within the food8. It is acknowledged that packaging secures food and keep it safe from biological, chemical changes and extend the period. Packaging has become a necessity throughout the food process progress and it's a lot necessary to satisfy the food-packaging demand internationally9, the utilization of packaging beneath vacuum and preservation foods at low temperatures. As indicated by recent analysis within the technology of obstacles, that aim to mix many conservation ways to increase the period of meat and meat merchandise10. In this study, we tend to aim to explore the impact of essential oils of oregano and basil on the period of even-toed ungulate meat burgers throughout cold storage.
The objectives of this analysis are to study the effects of adding oregano and basil oils in numerous concentrations on the period of even-toed ungulate meat burgers also, to study Physico-chemical analysis of even-toed ungulate meat burgers as a result of its treatment by 2 essential oils throughout cold storage at 4°C.
MATERIALS AND METHODS
Study area: The study was carried out in the Laboratory of the Food Science and Department of Human Nutrition at Qassim University, from September, 2019-June, 2021.
Materials: Fresh lean camel meat muscle (shoulder, age 12 months) were purchased immediately after slaughter from the butcher shop in Buraidah, Gassim region. Fresh meat samples were directly mince using meat minced (home mincer) and minced meat was used for the processing of camel burgers. Chickpea’s flour, breadcrumbs and spices (black pepper, salt, onion and garlic powders) was purchased from the local market in Buraidah and used for the preparation of a camel burger.
Essential oils: The prepared-created flavorer oils of basil (Ocimum basilicum L.) and oregano (Origanum vulgare L.) utilized in this study at pure state, free from preservative were purchased from Mamlakataltabiea patrician Mahound bin Abdulaziz Street, Jeddah, Saudi Arabia. These oils were held on in amber coloured bottles at 4°C till use.
Packaging: Polyethylene bags size 178×203 mm were purchased from the local market in Buraidah and used to package a camel meat burger.
Chemicals: All Chemicals used in this study on a high degree of purity were purchased from Wateen Medical Company-Saudi Arabia.
Methods
Choosing the optimal concentrations of essential oils: The preliminary sensory study was conducted to select the ideal concentration of essential oils added to the camel burger for the last review. In the 1st session, 6 samples were evaluated (basil and oregano essential oils at 0.5, 1, 1.5% for each) in the second session, 6 samples were valued (oregano and basil essential oils at 0.01, 0.025, 0.05 μL/100 g).
| Table 1: Ingredients of camel meat burger samples (100 g) | |||||||
| Ingredients | Control |
A1 |
A2 |
A3 |
B1 |
B2 |
B3 |
| Minced camel meat | 70 |
70 |
70 |
70 |
70 |
70 |
70 |
| Camel fat | 15 |
15 |
15 |
15 |
15 |
15 |
15 |
| Salt | 2 |
2 |
2 |
2 |
2 |
2 |
2 |
| Black pepper powder | 1 |
1 |
1 |
1 |
1 |
1 |
1 |
| Onion powder | 1 |
1 |
1 |
1 |
1 |
1 |
1 |
| Garlic powder | 1 |
1 |
1 |
1 |
1 |
1 |
1 |
| Chickpea’s flour | 5 |
5 |
5 |
5 |
5 |
5 |
5 |
| Breadcrumbs | 5 |
5 |
5 |
5 |
5 |
5 |
5 |
| Basil essential oil | - |
10 μL |
25 μL |
50 μL |
- |
- |
- |
| Oregano essential oil | - |
- |
- |
- |
10 μL |
25 μL |
50 μL |
Control: Camel meat burger without additional essential oil, A1: Camel meat burger containing 10 μL/100 g basil essential oil, A2: Camel meat burger containing 25 μL/100 g basil essential oil, A3: Camel meat burger containing 50 μL/100 g basil essential oil, B1: Camel meat burger containing 10 μL/100 g oregano essential oil, B2: Camel meat burger containing 25 μL/100 g oregano essential oil, B3: Camel meat burger containing 50 μL/100 g oregano essential oil |
|||||||
Based on the results obtained, 2 essential oils were selected (oregano and basil) at a concentration of 0.01, 0.025 and 0.05 μL/100 g.
Preparation of camel burger samples: The camel meat burger samples were prepared as follows: mixing minced camel meat 70% with camel fat 20% by MOULINEX Odacio. After that added spices, breadcrumbs, chickpea’s flour until good homogenization, added oregano and basil essential oils. The burger (100 g) formed using a burger press after the preparation of each sample individually packaged under vacuum in polyethylene bags stored at 4°C (Table 1).
The camel burger samples are divided into 2 minor groups of treated and untreated (control). The treated groups were divided into 6 groups (100 g of each) that mixed with basil at concentrations (A1) 10, (A2) 25 and (A3) 50 μL/100 g and oregano at concentrations (B1) 10, (B2) 25 and (B3) 50 μL/100 g.
Cooking of camel meat burgers: According to Dreeling et al.11 burger samples were cooked on griddled for 10 min at medium heat (level 3 out of 5). Both sides of the burger were cooked and flipped for a few minutes until cooked well.
Chemical analysis: Fat, protein and ash determined in burger camel meat (after preparation burger at 0 days) and moisture content was also determined during storage period zero-time, 3, 6 and 9 days as described according to Yam et al.12.
Measurement of thiobarbituric acid (TBA): According to Ahn et al.13, meat (5 g), 15 mL of Deionized Distilled Water (DDW) and 50 μL BHT (7.2%) were added to a 50 mL test tube and homogenized using a polytron for 15 sec at high speed. The meat homogenate (1 mL) with the solution (15 mL MTBA/15% TCA, 2 mL) was vortex-mixed and incubated in a boiling water bath for 15 min to develop colour. After refrigeration for 10 min in ice-water, the samples were mixed again and then centrifuged for 15 min at 2500 rpm/min×g at 4°C. The supernatant was collected and the absorbance read at 532 nm against a blank containing 1 mL of DDW and 2 mL of TBA/TCA solution. Thiobarbituric acid values expressed as mg of malondialdehyde per kg of meat.
Total volatile basic nitrogen (TVB-N): About 30 g of sample was weighed and mixed with 60 mL of trichloroacetic acid solution at 7.5% (w/v), centrifuged at 3000 rpm for 5 min, the supernatant was filtered through a Whatman No. 1 filter to add the extract of the sample. For determination of TVB-N, 5 mL of NaOH 10% (w/v) were added to 25 mL of the extract and it was subjected to steam distillation in an exceedingly Unit Pro Nitro M, SELECTA. The ammonia was collected in 15 mL of boric acid at 4% (w/v) and titrated with sulphuric acid 0.01 N. The results were expressed in mg N/100 g sample according to Malle and Tao14.
Physical analysis
Cooking loss: Cooking loss was determined by using the procedure carried out after cooking camel burger samples as described by Dreeling et al.11.
Cooking loss is calculated as follows:
Where:
| F | = | Fresh burger sample weight |
| G | = | Grilled burger sample weight |
Water holding capacity and plasticity: Diced meat samples (0.3 g) were placed on Whatman blotting paper and placed between 2 glasses, then pressed with a 1 kg weight for 10 min, 2 zones are formed in the blotting paper, a planimeter measures its outer zones, the outer zone, which is formed by the water separated from the pressed napkins, shows the value of the water retention capacity, the inner zone is due to the pressing of the meat shows only that malleability. The WHC is calculated by subtracting the area of the inner region from that of the outer zone according to Wierbicki and Deatherage15.
Statistical analysis: The data were analyzed using a two-way analysis of variance that was conducted on the experimental results and was multiple comparisons of the means were carried out by using Tukey's test with significance level p<0.05, employing the SPSS Statistical Software, v. 22.0. according to Hernández-Hernández et al.16.
RESULTS AND DISCUSSION
Chemical composition of a camel meat burger: The result of Fig. 1 indicates that the raw camel meat burger’s (cold for 9 days) protein, fat, ash, moisture content and carbohydrate. The camel meat moisture content was ranged between an hour to 64%, these results were less than which reported by Ahmed et al.17, who found that moisture content was 73.6% thanks to the meat cut change and in accept as true with Kadim et al.18, who found that moisture content was ranged between 63-79% counting on the sort of camel and therefore the muscle. Fat content was ranged between 17.7-19 attempts to the protein content was ranged between 14-16%, while ash content was ranged between 3-4.15% on a fresh 100 weight basis. A comparative study by Mohammed et al.19 described that among different meat sources camel meat (1.51%) was reported to have significantly lower fat content in comparison to beef (6.83%) and mutton (4.56%), while Kadim et al.18 stated that the protein content ranges from 20-23%. Ahmed et al.17 reported that the ash content in camel products was 4.13%. consistent with Yam et al.12, burger meat's moisture content is 70% and therefore the ash content must not increase than 3%.
Moisture content on meat burger during cold storage period: The results show that significant differences at p<0.05 in the moisture content percentages between samples treated by basil and oregano EOs and the control sample.
The data in Table 2 illustrates that the moisture contents of control samples were 62.6, 61.4, 61.3 and 60.8% at 0, 3rd, 6th and 9th day of the storage period, respectively.
The moisture contents of camel meat burger samples treated by adding basil EO in a concentration of 10 μL/100 g (A1) were 61.1, 61.1, 60.8 and 60.4% at 0, 3rd, 6th and 9th day of the storage period, respectively. On the other side moisture contents of camel meat burger which treated by adding basil EO in a concentration of 25 μL/100 g (A2) were 61.0, 62.0, 62.9 and 63.7% at 0, 3rd, 6th and 9th day of the storage period, respectively. The samples were treated by basil EO in a concentration of 50 μL/100 g (A3) the moisture contents were 63.0, 61.4, 61.6 and 62.1% at 0, 3rd, 6th and 9th day of the storage period, respectively. Moisture contents of the samples which treated by adding oregano essential oil in a concentration of 10 μL/100 g (B1) were 61.5, 61.6, 61.7 and 61.1% at 0, 3rd, 6th and 9th day of the storage period, respectively, while samples which treated by adding oregano EO in a concentration of 25 μL/100 g (B2) had moisture content 63.9, 62.7, 62.1 and 62.7% at 0, 3rd, 6th and 9th day of the storage period, respectively.
| Fig. 1: | Chemical composition of a camel meat burger on wet basis (%) Control: Camel meat burger without additional essential oil, A1: Camel meat burger containing 10 μL/100 g basil essential oil, A2: Camel meat burger containing 25 μL/100 g basil essential oil, A3: Camel meat burger containing 50 μL/100 g basil essential oil, B1: Camel meat burger containing 10 μL/100 g oregano essential oil, B2: Camel meat burger containing 25 μL/100 g oregano essential oil, B3: Camel meat burger containing 50 μL/100 g oregano essential oil |
| Table 2: Mean moisture content of control and treated camel meat burger samples during storage period at 4°C | ||||||||
| Mean moisture content | ||||||||
| Treatments | ||||||||
| Storage (days) | Control |
10 μL (A1) |
25 μL (A2) |
50 μL (A3) |
Control |
10 μL (B1) |
25 μL (B2) |
50 μL (B3) |
| 0 | 62.6±0.44a |
61.1±0.10a |
61.0±0.00d |
63.0±0.00a |
62.6±0.44a |
61.5±0.10a |
63.9±0.10a |
63.8±0.20a |
| 3 | 61.4±0.35b |
61.1±0.01a |
62.0±0.01c |
61.4±0.35d |
61.4±0.40b |
61.6±0.10b |
62.7±0.20b |
62.2±0.20c |
| 6 | 61.3±0.36b |
60.8±0.08b |
62.9±0.10b |
61.6±0.10c |
61.3±0.40b |
61.7±0.10a |
62.1±0.00c |
62.7±0.20b |
| 9 | 60.8±0.20a |
60.4±0.01c |
63.7±0.20a |
62.1±0.10b |
60.8±0.20c |
61.1±0.20c |
62.7±0.20b |
62.6±0.10b |
| Within each column and for each property, mean values having the same lower-case letter are not significantly different (p<0.05) | ||||||||
| Table 3: Mean TBA values of control and treated camel meat burger samples during the storage period at 4°C | ||||||||
| Mean TBA values | ||||||||
| Treatments | ||||||||
| Storage (days) | Control |
10 μL (A1) |
25 μL (A2) |
50 μL (A3) |
Control |
10 μL (B1) |
25 μL (B2) |
50 μL (B3) |
| 0 | 1.40±0.2d |
1.04±0.04c |
0.45±0.05d |
1.39±0.01c |
1.40±0.20d |
0.50±0.01d |
1.10±0.01c |
1.10±0.10d |
| 3 | 1.58±0.08c |
1.06±0.05c |
1.04±0.04c |
1.40±0.10c |
1.60±0.08c |
0.84±0.04c |
1.10±0.09c |
1.40±0.20c |
| 6 | 6 2.66±0.01b |
2.03±0.01b |
1.26±0.06b |
1.61±0.01b |
2.70±0.01b |
1.92±0.02b |
1.63±0.03b |
1.50±0.30b |
| 9 | 2.90±0.1a |
2.62±0.02a |
2.11±0.01a |
2.47±0.01a |
2.90±0.10a |
2.40±0.01a |
2.11±0.01a |
1.73±0.03a |
| Within each column and for each property, mean values having the same lower-case letter are not significantly different (p<0.05) | ||||||||
Also, the moisture contents of camel meat burger samples, which were treated by adding oregano EO in a concentration of 50 μL/100 g (B3) were 63.8, 62.2, 62.7 and 62.6% at 0, 3rd, 6th day and 9th day of the storage period, respectively.
Results in Table 2 show that the control sample's moisture content dropped at the rate of 1.77 at the progression of cold storage (4°C) during 9 days. Also show that A1 and A3 samples' moisture content decreased with cold storage progression (4°C) during 9 days by 0.65 and 0.82%, respectively of its initial value. Also, Table 2 shows that moisture content at zero-time storage of A2 was 61%. However, moisture content raised at a rate of 2.70% in cold storage (4°C) to 9 days. Yam et al.12 found that the moisture content raised from 65.50% in raw camel meat to 78.8% in hamburgers containing 60% camel meat. The data in Table 2 shows that the moisture content of camel burger samples which treated by adding oregano EO (B1, B2, B3) dropped 1.18,1.18, 0.4, respectively at the progression of cold storage (4°C) at 9 days.
Thiobarbituric acid (TBA) on meat burger during cold storage period: Thiobarbituric acid (TBA) values of prepared camel burger samples were followed up during cooling storage for nine days at 4°C. Results in Table 3 shows that at control samples TBA values were 1.40, 1.58, 2.66 and 2.90 mg kg–1 at 0, 3rd, 6th and 9th day of the storage period, respectively. The samples treated by basil EO at a concentration of 10 μL/100 g (A1), the TBA values were 1.04,1.06, 2.03 and 2.62 malondialdehyde/kg at 0, 3rd, 6th and 9th day of the storage period, respectively, while on camel burger samples treated by the concentration 25 μL/100 g (A2), TBA values were 0.45, 1.04, 1.26 and 2.11 mg kg–1 at 0, 3rd, 6th and 9th day of the storage period, respectively. On the other hand, TBA values of camel burger which contained basil EO in a concentration of 50 μL/100 g (A3) were 1.39,1.40,1.61 and 2.47 mg kg–1 at 0, 3rd, 6th and 9th day of storage period, respectively. However, results showed that, by using oregano EO, the TBA values were at a concentration of 10 μL/100 g (B1) were 0.50,0.84,1.92 and 2.40 mg kg–1 at 0, 3rd, 6th and 9th day of the storage period, respectively, while the camel meat burger contained oregano EO in a concentration of 25 μL/100 g (B2) TBA values were 1.10, 1.10,1.63 and 2.11 mg kg–1 at 0, 3rd, 6th and 9th. The TBA values of camel burger samples treated by oregano EO in a concentration of 50 μL/100 g (B3) were1.10, 1.40, 1.50 and 1.73 mg kg–1, at 0, 3rd, 6th and 9th day of the storage period, respectively.
The treated samples with basil EO at different concentrations showed rising in TBA values especially at the 6th and 9th of the storage period this result agreed with that reported by Sharafati-Chaleshtori et al.20, who found the highest TBA values in the beef burger treated by basil EO (0.25%) after day 1 of the storage period and the samples treated by oregano EO at different concentrations indicated increasing in TBA values especially at 6th and 9th of storage period. On another hand, the camel meat burger which was treated with 10 μL/100 g (B1) showed the highest values of TBA than other concentrations this result agreed with that reported by Ünal et al.21, who found that the TBA values of samples increased slightly throughout minced beef's storage time. The results showed that we have a difference in the thiobarbituric acid between all concentrations.
The results showed that there were differences at p<0.05 in the TBA values between the basil oil, oregano oil and the control sample. TBA values were different between the camel meat burger treated by basil EO and the control sample. Simultaneously, there was a difference in the TBA values between the control sample and the camel meat burger was treated by oregano EO and that samples contained basil oil. Also, there was a difference in the TBA values between the different concentration levels for the essential oil as it is significant at p<0.05, in addition to having a difference in the TBA value according to the days.
Total volatile basic nitrogen (TVB-N) on meat burgers during the cold storage period: Results obtained in Table 4 showed that at concentration 50 μL/100 g (A3) TVN values were 17.00, 18.00, 22.00 and 31.00 mg N/100 at 0, 3rd, 6th and 9th day of the storage period, respectively, while camel meat burger with oregano EO at a concentration of 10 μL/100 g (B1) TVN values was 17.00, 19.00, 22.00 and 32.00 mg N/100 at 0, 3rd, 6th and 9th day of the storage period, respectively. At concentration 25 μL/100 g (B2), TVN values were 17.00, 18.00, 25.00 and 35.00 mg N/100 at 0, 3rd, 6th and 9th day of the storage period, respectively. Also, at concentration 50 μL/100 g (B3) TVN values were 16.00, 17.00, 23.00 and 35.00 mg N/100 at 0, 3rd, 6th and 9th day of storage period, respectively.
From the results it appears that the treated samples with basil EO at different concentrations showed increasing in TVB-N values than the untreated (control) samples especially on the 9th day, these results agree with IRIMIA et al.22, who found that the values of TVB-N for chicken breasts samples treated by black caraway oil were 22.2-24.9 mg N/100 after 3-5 days of refrigerated storage. Karoui and Hassoun23 found that the TVB-N values of the rosemary and basil groups remained below the upper limit of acceptability until the 10th day in fish samples treated by rosemary and basil EOs. Tang et al.24 found that the TVB-N values on 0 days are about 14 mg N/100 and it increases during the storage period after 3 days to 19 mg/100 g in chicken meat.
Physical analysis
pH on meat burger during cold storage period: The result of Table 5 illustrates that the pH values of untreated camel meat burger samples were 5.65, 5.11, 5.46 and 5.95 at 0, 3rd, 6th and 9th day of the storage period, respectively on the control sample. Results show that the pH values of camel meat burger samples which treated by adding basil EO in a concentration of 10 μL/100 g (A1) were 5.58, 5.47, 5.71 and 6.24 at 0, 3rd, 6th and 9th day of the storage period, while the pH values of camel meat burger samples which treated by adding basil EO in a concentration of 25 μL/100 g (A2) were 5.57, 5.84, 5.61 and 6.41 at 0, 3rd, 6th and 9th day of storage period. On the other hand, the pH values of camel meat burger samples treated by adding basil EO in a concentration of 50 μL/100 g (A3) were 5.39, 5.2, 5.84 and 5.95 at 0, 3rd, 6th and 9th day of the storage period, respectively.
| Table 4: Mean TVB-N values of control and treated camel meat burger samples during storage period at 4°C | ||||||||
| Mean TVB-N values | ||||||||
| Treatments | ||||||||
| Storage (days) | Control |
10 μL (A1) |
25 μL (A2) |
50 μL (A3) |
Control |
10 μL (B1) |
25 μL (B2) |
50 μL (B3) |
| 0 | 15.00±0.10d |
16.00±1.73d |
16.00±1.73d |
17.00±1.73d |
15.00±0.10d |
17.00±1d |
17.00±2d |
16.00±2d |
| 3 | 18.00±0.95c |
17.00±1c |
18.00±1c |
18.00±1c |
18.00±0.95c |
19.00±1c |
18.00±1c |
17.00±1c |
| 6 | 28.00±2b |
21.00±1ab |
23.00±3b |
22.00±2b |
28.00±2b |
22.00±2b |
25.00±5b |
23.00±3b |
| 9 | 37.00±1a |
30.00±1a |
34.00±4a |
31.00±1a |
37.00±1a |
32.00±2a |
35.00±5a |
35.00±2a |
| Within each column and for each property, mean values having the same lower-case letter are not significantly different (p<0.05) | ||||||||
| Table 5: Mean pH values of control and treated camel meat burger samples during storage period at 4°C | ||||||||
| Treatments | ||||||||
| Storage (days) | Control |
10 μL (A1) |
25 μL (A2) |
50 μL (A3) |
Control |
10 μL (B1) |
25 μL (B2) |
50 μL (B3) |
| 0 | 5.65±0.01b |
5.58±0.03c |
5.57±0.06d |
5.39±0.03c |
5.70±0.012b |
5.04±0.04d |
5.40±0.14d |
5.34±0.10c |
| 3 | 5.11±0.09d |
5.47±0.04d |
5.84±0.06c |
5.20±0.07d |
5.11±0.10d |
5.74±0.10b |
5.90±0.10b |
5.20±0.10d |
| 6 | 5.46±0.16c |
5.71±0.02b |
5.61±0.10b |
5.84±0.12b |
5.50±0.20c |
5.70±0.10c |
5.74±0.12c |
5.92±0.20b |
| 9 | 5.95±0.03a |
6.24±0.05a |
6.41±0.13a |
5.95±0.15a |
5.95±0.04a |
5.83±0.10a |
6.21±0.30a |
6.30±0.30a |
| Within each column and for each property, mean values having the same lower-case letter are not significantly different (p<0.05) | ||||||||
| Table 6: Cooking loss of control and treated camel meat burger samples during storage period at 4°C | ||||||||
| Mean cook loss | ||||||||
| Treatments | ||||||||
| Storage (days) | Control |
10 μL (A1) |
25 μL (A2) |
50 μL (A3) |
Control |
10 μL (B1) |
25 μL (B2) |
50 μL (B3) |
| 0 | 13.00±1.73a |
14.00±3a |
13.00±a |
7.00±1a |
13.00±1.7a |
15.00±3a |
16.00±3a |
11.00±3a |
| 9 | 12.00±1b |
13.00±0.00b |
11.00±b |
5.00±1b |
12.00±1b |
14.00±3b |
10.00±0.0b |
10.00±0.0b |
| Within each column and for each property, mean values having the same lower-case letter are not significantly different (p<0.05) | ||||||||
Also, by using oregano essential oil, the pH values of a concentration of 10 μL/100 g (B1) were 5.04, 5.74, 5.70 and 5.83 at 0, 3rd, 6th and 9th day of the storage period, while camel meat burger samples which treated by adding a concentration of 25 μL/100 g (B2), pH values were 5.40, 5.90, 5.74 and 6.21 at 0, 3rd, 6th and 9th day of storage period. The camel burger samples which were treated by adding oregano EO in a concentration of 50 μL/100 g (B3) pH values were 5.34, 5.20, 5.92 and 6.30, at 0, 3rd, 6th and 9th day of the storage period, respectively. pH values of the samples treated with basil EO were lower than pH values of untreated (control) samples during the period of storage these may be due to the activity effect of basil oil as an antimicrobial agent. Also, camel meat burger samples that contained basil EO in a concentration of 50 μL/100 g has a higher pH value than those samples that contained basil oil (10 and 25 μL/100 g), there was a steady pH percentages pattern, which is increases during a period of storage increases. This result was different from that reported by Karoui and Hassoun23, who found significantly lower pH values for the samples treated by basil EO in mackerel compared to the untreated (control) sample, suggesting that the basil EO treatment may delay pH probably due to antimicrobial effects. There was increasing in pH values on samples treated by oregano EO this result disagreed with that reported by Hulankova et al.25. The pH of the control sample (untreated) increased from 5.38-5.53 by the end of storage, while the pH values of the treated samples of camel burgers with oregano essential oil did not change noticeably during storage.
The results show that there were no differences at p<0.05 in the pH percentages between the camel meat burger treated with basil and oregano essential oils and the untreated (control) sample.
Cooking loss on meat burgers during cold storage period: The result of Table 6 shows the effect of oregano essential oil concentrations on cooking loss during the storage period. Cooking loss of the prepared camel burger (control) at zero time 13 and 12% at 9th storage. Results showed that cooking loss of camel meat burger sample treated by basil EO at concentration 10 μL/100 g (A1) was 15% at zero-time storage and 14% at 9-day storage, at concentration 25 μL/100 g (A2) cooking loss was 16% at zero-time storage and 10% at 9th storage and concentration 50 μL/100 g (A3) cooking loss was at 0 day 11% and 10 at 9th day during the cold storage period, respectively, while, cooking loss of the prepared camel burger with additives oregano oil at concentration 10 μL/100 g (B1) was 14% at zero-time and 13% at 9-day storage, at concentration 25 μL/100 g (B2) cooking loss was 13% at zero-time storage and 11% at 9th storage and at concentration 50 μL/100 g (B3) cooking loss was at 0 days 7% and 5 at 9th day during the cold storage period, respectively. Loss of weight occurred during cooking mostly due to moisture content. This result agrees with Ibrahim and Nour26, who found the decrease in cooking loss was not significant. The A2 burger sample which contained 25 μL/100 g basil essential oil had the best cooking loss among the samples, probably because more fluid was lost during cooking due to the upper-fat content, this result accepted with that reported by Yam et al.12 which found a decrease in cooking loss was significant.
The results showed no difference in the cooking loss factor between the basil oil, oregano oil and the control sample and showed a difference in the cooking loss factor between the different concentration levels for each oil. In contrast, there was no difference in the cooking loss factor according to the days and the differences only between (A1 and B3) since the cooking loss factor in A1 was more than the cooking loss factor in B3 5.33 while there was no difference in the cooking loss factor in the other concentration pairs.
Water holding capacity and plasticity on meat burgers during cold storage period: Water Holding Capacity (WHC) of control and samples were determined during cold storage at 4°C for 9 days and results in Table 7 shows that the area of water released from camel burger samples (control) were 4.50, 4.43, 4.07 and 4.67 at zero-time, 3rd, 6th and 9th day during the cold storage period, respectively.
Though Table 7 also shows that WHC of camel burger samples with basil EO at concentration 10 μL/100 g (A1) were 4.37, 4.23, 4.13 and 4,37 at zero-time, 3rd, 6th and 9th day, at concentration 25 μL/100 g (A2) were 4.20, 4.17,4.17 and 4.20 and at concentration 50 μL/100 g (A3) was 5.43, 4.17, 4.33 and 4.20 at zero-time, 3rd, 6th and 9th day during the cold storage period, respectively.
| Table 7: Mean WHC values of control and treated camel meat burger samples during storage period at 4°C | ||||||||
| Mean WHC values | ||||||||
| Treatments | ||||||||
| Storage (days) | Control |
10 μL (A1) |
25 μL (A2) |
50 μL (A3) |
Control |
10 μL (B1) |
25 μL (B2) |
50 μL (B3) |
| 0 | 4.50±0.00b |
4.37±0.12a |
4.20±0.20a |
5.43±0.20a |
4.50±0.00b |
5.70±0.10a |
5.10±0.01a |
4.43±0.12c |
| 3 | 3 4.43±0.15c |
4.23±0.16b |
4.17±0.21b |
4.17±0.31d |
4.43±0.15c |
5.10±0.17b |
4.60±0.25b |
4.50±0.20b |
| 6 | 4.07±0.06d |
4.13±0.06c |
4.17±0.20b |
4.33±0.06b |
4.10±0.10d |
4.60±0.21d |
4.50±0.10c |
4.43±0.10c |
| 9 | 9 4.67±0.12a |
4.37±0.12a |
4.20±0.20a |
4.20±0.20c |
4.70±0.12a |
4.73±0.21c |
4.60±0.30b |
4.60±0.30b |
| Within each column and for each property, mean values having the same lower-case letter are not significantly different (p<0.05) | ||||||||
Also, Table 7 shows that WHC of camel burger sample with oregano EO at concentration 10 μL/100 g (B1) were 5.70, 5.10, 4.60 and 4.73 at concentration 25 μL/100 g (B2) were 5.10, 4.60, 4.50 and 4.60 and at concentration 50 μL/100 g (B3) were 4.43, 4.50, 4.43 and 4.63 at zero-time, 3rd day, 6th day and 9th day during the cold storage period, respectively. Low WHC during storage due to the loss of water content in the meat in refrigeration. Basil and oregano oil decrease WHC values, which reflect increasing meat protein's ability to hold water. The results showed a difference in the water holding capacity between the basil oil, oregano oil and the control sample as the significant value equal 0.000, which is less than 0.05. Also, that there was no difference in the water holding capacity between the oregano oil and the control sample. However, the water holding capacity differs from the difference between the control sample and A1, A2 and A3. Simultaneously, it is clear that there was no difference in the water holding capacity between the control and B1, B2 and B3. Though the water holding capacity was different between A1 and all the other concentrations except A2, while the water holding capacity is different between A3 and all the other concentrations. Also, the water holding capacity was no different between B1 and each of B2 and B3, while there was a difference between B1 and the other concentrations. The water holding capacity in B2 and B3 has the same as with the B1 situation.
Plasticity of the control sample and samples with basil and oregano EOs were determined during cold storage at 4°C for 9 days.
This study results showed that the red colour intensity decreased with storage ("a*" value) in camel burgers with basil and oregano essential oil during cold storage for 9 days at 4°C. Also, by increasing storage time for camel burgers, pH values increased in all treatments. While the decrease in cooking loss was non-significant for all treated sample's, except A2 (25 μL basil oil) which showed the highest cooking loss. The study showed that the moisture content of burger samples was affected by adding basil or oregano EOs.
CONCLUSION
The utilization of essential oils affects the characteristics of the meat, therefore, it can be useful to maintain the quality of the meat, extend the shelf life of camel meat, prevent economic losses and provide the consumer with foods containing natural additives, in particular, oregano and basil (10, 25 and 50 μL/100 g). To improve the shelf life of fish and seaweed burgers, the concentration of both essential oils should be increased.
SIGNIFICANCE STATEMENT
This study discovers that, using concentrations 10. 25 and 50 μL/100 g of basil and oregano essential oils have an impact on increasing the shelf life of camel meat burger when stored at 4°C for 9 days, for which the study will help the researchers to study the effects of basil and oregano essential oils as antioxidants to prevent deterioration in the quality of raw meat and during storage time.