Chemical Characteristics of Kavurma with Selected Condiments

Abstract

A traditional meat product, kavurma, was prepared with the addition of various condiments (sage, thyme, ginger). The effects of condiments and storage time on thiobarbutiric acid (TBA) value, color attributes, pH, moisture, protein and fat contents of kavurma samples were investigated. Also, the effect of condiments on the sensory properties of samples was determined. The TBA values of condiments added samples were significantly lower than that of control. Ginger had a highest antioxidative activity and sensory scores compared to others samples. Color attributes generally decreased during storage and the additives differently affected the color of sample. The moisture content of samples was significantly affected from the condiments and storage period. Although sensory scores of the sample with condiments were higher than control, the difference was not statistically significant. It could be concluded that natural condiments could be used in kavurma production to improve quality characteristics of the product.

Keywords:

• Kavurma
• Fried meat
• Antioxidant activity
• Natural antioxidants

INTRODUCTION

Kavurma is a traditional cooked or fried meat product prepared as follows. Beef or lamb is cut into pieces smaller than 7 cm³ and placed in a boiler for cooking. Salt, beef fat, tallow or tailed fat are added to the meat and all are collectively cooked. Spices or other flavor-giving ingredients may be incorporated to the mix while the product is still warm and then it is filled into natural or artificial cases.[1] The shelf life of kavurma is the highest among the ready-to-eat meat products.

Kavurma has been known for many years in Anatolia, and it was an important meat product when the food technology and preservation was not as advanced as today. It was mainly produced to satisfy the need of meat products in winters where meat supply was low. Parallel to the advances in food preservation technology, the methods for the preservation of meat and meat products improved that provided meat products to be kept longer time with no spoilage or a minimum quality loss. In addition, the new techniques enabled the production of novel meat products possessing different appearance, taste and flavor.

Tallow used in the production of kavurma increases the stability of the product; however, they play an important role in the quality deterioration due to oxidation.[2] The research on kavurma is currently limited in the literature. Vural and Öztan[3] investigated the effect of tocopherol and potassium sorbate on the stability of kavurma during storage. Çetin[4] isolated and identified the microorganisms present in kavurma in addition to determining some chemical properties of the product. Yetim and Kesmen[5] studied the effect of nitrite addition on some properties of kavurma and determined that TBA values and percent acidity decreased while redness value of samples increased with the addition of nitrite. Besides, they concluded that sensory panel preferred the nitrite-added samples over control.

Herbs and spices are used in meat products for various purposes. In addition to enhancing taste properties of meat products, the condiments may serve functional such as reducing rancidity. The consumers’ conscience has been increasing as more people become concerned about what they eat. The recent focus of consumers is on healthy eating,[6] and they prefer food with no artificial additives. In addition, the food manufacturers and researchers are exploring the possible use of natural sources for antioxidative effect due to the safety concerns of synthetic antioxidants.[7] Therefore, the use of natural substances for their antioxidative properties in the place of synthetic antioxidants became more important. The use of natural condiments for their antioxidative effects in meat and meat products have received considerable attention and a number of studies have been carried out with the aim of finding natural antioxidants to be used in meat products.[8,9,10,11,12,13] It was reported that rosemary, sage and α‐tocopherol had antioxidant activity in meat products. In addition to those, several other natural extracts have been reported to possess antioxidative activity; for example, black pepper and oriental herbs were effective in retarding lipid oxidation in meat products. Karpinska et al.[14] studied the effect of garden sage and a spice blend of garden sage, red pepper, garlic and marjoram on the oxidation of turkey meat. They added 1% sage and 1.5% spice blend and they observed that both delayed the oxidation process of the meat. Mansour and Khalil[15] produced the extracts of potato peel, fenugreek seeds and ginger rhizomes by freezing and investigated their antioxidative properties by adding them to the beef patties. They reported that ginger roots and stalks had the greatest antioxidant activity that was as much as that of commercial antioxidants. The objectives of this study were to evaluate the use of various condiments in kavurma production and to determine the effectiveness of these natural condiments in preventing or reducing lipid oxidation, rancid odor and color changes in kavurma.

MATERIALS AND METHODS

Materials

Cow large intestine used as the package material of cooked kavurma and meat for the production of kavurma were obtained from Manisa Slaughterhouse belonged to the Meat and Fish Products Company. Spice and herbs in dry form (ginger, sage and thyme) were purchased from a local market.

Kavurma Preparation

Kavurma was produced according to the procedure described in Kavurma Standard of Turkish Standard Institute[1,16] and guideline for manufacturing of meat products.[17] First of all, beef was trimmed from fat and connective tissue and was cut into pieces of 3–6 cm³. Table salt (refined and ground) in the amount of 2% of meat weight was added to meat pieces. After that, tallow (31% of beef weight) was added to the salty meat and slow cooking at 55.5° C was started in an open-cover boiler. After 30 minutes of this slow cooking the rest of the tallow required for kavurma production was incorporated into mix and the temperature increased to 105° C at 4–5 atm pressure. After temperature and pressure reached the proper cooking conditions, the meat was cooked for 3–4 hours. Meat pieces were stirred time to time for homogeneous cooking. When the inside of meat color turned from red to dark gray, elasticity of meat was lost and meat become easy to fracture by hand, the cooking process was finished.

Each trial containing 15.2 Kg cooked kavurma was divided into six groups; the first group named control did not contain any condiments. Treatments separately contained 1.8% sage, 1.2% thyme and 1.2% ginger. After cooked meat and herbs were mixed, 420 g of each sample were filled in cow large intestine. Total of 36 samples were held at 0 to 4° C of cold storage up to 4 months. Samples were taken on the 1st, 15th, 30th, 60th, 90th and 120th day of storage for analysis. Three trials with 2 replications for each were conducted.

Proximate Analysis

Moisture, protein and fat (ether-extractable) contents of samples were determined according to standard AOAC procedures.[18] pH was measured from a homogenate prepared by mixing 10 g of kavurma with 90 ml of distilled water for 30 s. Readings were taken with a WTW, model pH 521, digital pH-meter and a WTW, type E56 combination electrode (WTW-Wissensehaftlich-Technische Werkstaetten GmbH, Weilheim, Germany).

Rancidity Determination

The rancidity of samples was determined by 2-thiobarbituric acid (TBA) test. A modified Tarladgis-Watts-Younathan-Dugan[19] method was used to ascertain the TBA values of samples on the 1st, 15th, 30th, 60th, 90th, and 120th day of storing. Samples were prepared according to the procedure and readings were taken at 530 nm on spectrophotometer (Shimadzu UV-1601, Japan).

Color Measurements

Color measurements (L*, a*, b* values) were taken with a Hunterlab model Minolta CR 300 (Osaka, Japan) chromometer. The samples were homogenized and filled into petri dishes before taking readings. It was ensured that there was no gap between the sample and the petri lid. As the Hunter colorimeter was taking readings, the lenses directly touched the lid of the petri dish. Six readings were taken and averaged for each of three replications.

Sensory Evaluation

Sensory evaluation was carried out according to the procedure described in the Kavurma Standard of Turkish Standard Institute[1] by a nine-member semi-trained panel. Panel members with ages ranging from 20 to 45 were either professors or graduate students of Food Engineering Department of Celal Bayar University and all were experienced with sensory evaluation of various food products. Panelists were asked to evaluate the samples of each treatment for appearance, texture and taste. The descriptions of sensory properties and how to rate a sample for the particular sensory property were on the evaluation form. Panelists were first familiarized with the samples through pre-trials during which the description of sensory attributes and how to rate a sample was instructed. Panel evaluated a slice of kavurma from each one of the five treatments and control sample at the same time. Kavurma samples were presented to panel after they were warmed up for 5 minutes. According to the importance of a particular sensory attribute, a whole number was given to sample by the panel: 1–20 for appearance; 1–20 for texture and 1–60 for taste (total of 100). Higher numbers indicated preference for the sensorial quality of the sample. Samples stored for 21 days were tested for sensory characteristics, and the sensory evaluation was completed under artificial light, and the room temperature was approximately ambient.

Statistical Analysis

The statistical evaluation of the results was performed using the Statistical Analysis System.[20] Data collected for sensory evaluation of products were analyzed by one-way analysis of variance in order to test for significant differences between treatments. Data collected for all other parameters were analyzed by a two-factor factorial analysis in a completely randomized design. The two factors were (1) the four treatments and (2) the processing time. Means were compared using Duncan's test.

RESULTS AND DISCUSSION

Chemical Composition

The moisture content of samples was significantly affected from the storage period, incorporated condiments and their interaction (Table 1). Fig. 1a illustrates the change in moisture content of samples during the storage period. If all samples were considered for the determination of the effect of storage time on moisture content, it was observed that the average moisture content of samples was initially 20.44% and increased to 25.15% after 15 days of storage, but then it gradually decreased and the lowest moisture was obtained at the end of the storage period. On the other hand, when the moisture content of sample averaging over storage time is considered, statistical analysis revealed that there was a significant (p < 0.05) differences among treatments. Moisture content of samples with sage was higher than the control; on the other hand, the addition of ginger reduced the moisture content. Thyme addition did not affect the moisture content. The moisture results were higher than the results for the same kind of meat product determined by some researchers[2,3,21] but were similar to those of others.[22]

Table 1 Analysis of variance on the effect of treatment and storage time on physico-chemical parameters and TBA values of kavurma samples (F-values of independent variables and interactions).

	Source of variance
Parameters	A	B	A*B
Moisture	13.72*	97.40*	24.84*
pH	38.12*	1190*	14.00*
TBA
unheated	18.68*	153.6*	24.59*
heated	97.93*	410.5*	31.94*
Color
L*	19.52*	204.0*	4.452*
a*	68.90*	77.24*	7.291*
b*	37.70*	219.7*	10.02*
A: treatments. B: Storage time.

Figure 1 The effect of condiments during storage on (a) moisture content (b) pH (c) TBA value (d) L* value (e) a* value (f) b* value.

The protein and fat contents of kavurma samples were illustrated in Table 2. One-way ANOVA revealed that the addition of herbs and spices did not affect the protein or fat content of samples (p < 0.05). Since any change in protein and fat content with respect to storage time was not expected, those values were obtained for only in the beginning of storage. On the other hand, pH of samples gradually increased with time, and the increase in pH became more evident towards to the end of storage (Fig. 1b). Except for the ginger-added sample, the pH increased up to 90 days then decreased; for example, pH of the control sample was initially 6.23 and increased to 6.67 at 90th of storage, but it went down to 6.49 at the end of storage. It was also found that the addition of condiments caused an increase in pH of samples and the lowest pH value was obtained for control sample whose pH was significantly (p < 0.05) lower than any of the sample with condiments. Highest pH values were observed for samples with thyme and sage.

Table 2 Average chemical properties and TBA values for each treatment.

Treatment	Fat content	Protein content
Control	36.8 ± 3.30	38.6 ± 5.08
Sage	34.2 ± 3.61	36.0 ± 1.82
Thyme	33.3 ± 5.35	38.1 ± 4.92
Ginger	38.8 ± 6.97	39.8 ± 4.92

TBA

TBA of kavurma samples were affected from storage time and the antioxidant treatment. TBA values of samples were illustrated in Fig. 1c. It was found that TBA values of all samples were significantly (p < 0.05) lower than that of the control. As it was expected beforehand, the use of condiments reduced the rancidity in the samples and the highest TBA values occurred in control sample. Among all treatments, ginger was the best in reducing lipid oxidation since the sample with ginger generally had the lowest TBA value. This occurrence was observed for heated samples on 4 out of 6 storage times. The effect of treatments was particularly evident at the 120th day of storage. It was determined that TBA values generally increased with storage time however, it was noticeable that the TBA value of heated sample at the 90th day and unheated samples at the 60th and 90th days were higher than that of respected sample at the 120th day. The difference was also statistically significant. As seen in the Fig. 1c the highest TBA result (2.32 mg malonaldehyde/kg) was obtained for control sample at the 90th day of storage. The effect of condiments on the TBA value showed variability. If those additives were lined up in terms of antioxidative effect considering the TBA values of samples, ginger > sage > thyme sequence was obtained. TBA values of control sample rapidly increased during storage period; on the other hand, the increase in TBA was slower for samples with natural condiment addition. Many researchers stated that the lipid oxidation could be controlled with the use of natural or synthetic antioxidants in meat products.[7,10,11,23]

Color

L*, a*, and b* values of samples generally declined with progressing storage time. Figure 1d shows the effect of herbs/spice addition on L* value of kavurma samples during storage. It was determined that thyme, and ginger that were added to kavurma for the determination of their antioxidative effect influenced the color of the sample differently. Ginger caused an increase on L*, a*, b* values, and only b* value increased with sage addition; on the other hand, color attributes decreased with the use of other herbs/spice. The color characteristics were also affected by the storage period. Redness of samples did not change in the first 30 days but it decreased noticeably after 60 days (Fig. 1e). Sage was not generally effective on redness, while ginger increased and thyme diminished the redness of samples. Considering both color and TBA values, it could be stated that ginger was an effective antioxidant for kavurma at the same time, it provides a color stability of the sample. The stability of color could be achieved by additives with prevention of oxide myoglobin formation. b* values of samples were significantly (p < 0.05) affected from treatments, storage time and their interaction. As can be seen in Fig. 1f, the b* value of sample at the beginning of storage was higher than those of other storage times, and it decreased with time progressing; the only exception was observed for samples at the 60th day. Statistical results on the effect of treatments on yellowness revealed that b* value of ginger and sage added samples were higher than that of control. On the other hand thyme did not affect the yellowness of samples.

Sensory Properties

Sensory properties of samples were illustrated in Table 3. The appearance, taste and texture scores of control were lower than those of any kavurma sample with condiments. The highest total score was observed for the sample with ginger that was in accordance with TBA scores as ginger was found to have a highest antioxidative effect among condiments. However, the statistical results revealed that addition of condiments to the kavurma had no significant effect (p < 0.05) on each of the sensory attributes of samples.

Table 3 Sensory scores of kavurma samples.

Treatments	Appearance	Taste	Texture	Total
Control	14.1 ± 1.91	35.6 ± 14.60	10.2 ± 5.80	59.9 ± 19.76
Sage	15.2 ± 3.94	37.8 ± 11.82	12.3 ± 4.13	65.3 ± 20.09
Thyme	13.4 ± 3.17	38.0 ± 16.85	11.9 ± 3.84	63.3 ± 16.38
Ginger	15.1 ± 3.60	40.9 ± 11.30	12.1 ± 4.67	68.1 ± 21.72

CONCLUSION

All condiments used in the study, except for marjoram, lowered the TBA values of the samples, indicating that they can be used in kavurma making for their antioxidative effects. Ginger had the highest antioxidative effect among investigated condiments, and the sample prepared with ginger received the highest preference from sensory panel. Although it was not statistically significant, the sensory scores of samples with condiments were higher than those of control. It could be concluded that the condiments, particularly ginger, could be used in kavurma making to improve quality characteristics of the product.

Notes

*p < 0.05.

1. TS 978. Turkish Standards Institute, Kavurma, 1996 (Turkish).

4. Çetin, B. Identification of microorganisms present in kavurma samples sold in Erzurum market by using fatty acid composition method and some properties of kavurma. M.Sc. thesis. Atatürk University (Turkish), 2000.

16. TS 8962. Turkish Standards Institute, Kavurma Making Procudeures, 1991. (Turkish).

17. Anonymous. Guideline for manufacturing of meat products, Meat and Fish Products Company. (Turkish), 1973.

21. Dinç, I Chemical, microbiological and organoleptic quality of kavurma produced from healthy meat and meat with tuberculosis. Ph.D Thesis. (Turkish) Konya, 1997.

22. Sarigöl, C. Technological, microbiological and chemical investigation of canned and ordinary kavurma obtained from Elaziğ region (Turkish). Thesis (unpublished), Firat University, Veterinary Faculty, Technology of Animal Foods and Food Quality Control Section, 1978.