Key findings:

Key findings from the study on using kluwek in beef marination include: no significant difference in bacterial count, water holding capacity, and cooking loss among different kluwek concentrations; significant effect on shelf life; and the best results with 10% kluwek concentration, 120 minutes marinating time, showing a bacterial count of 8.10 x 105CFU/g, water holding capacity of 23.64%, cooking loss of 35.71%, and shelf life of 1026.29 minutes (17 hours).

What is known and what is new?

The known aspect in this abstract is the use of kluwek, a traditional spice with antibacterial properties, as a natural preservative for beef to increase its shelf life. The new contribution is the specific evaluation of different kluwek concentrations (10%, 15%, 20%) in beef marination and their effects on bacterial count, shelf life, water holding capacity, and cooking loss, providing insights into optimizing the preservation of beef using this traditional method.

What is the implication, and what should change now?

The implication of this study on beef marination using kluwek suggests its potential as a natural preservative to increase shelf life without significantly affecting bacterial count, water holding capacity, or cooking loss. Changes needed include further research to optimize kluwek concentration and marinating time for maximum preservation while maintaining quality attributes of beef.

Beef is a source of animal protein originating from ruminant livestock which has quite complete nutritional content and is in great demand by the public. The fairly complete nutritional content in meat has excellent benefits for growth, repairing damaged body tissue, and regulating the process of providing energy for activities [1]. The shelf life of meat can be influenced by handling conditions, the environment, and the ingredients contained in the meat.

Damage caused by poor handling can result in the growth of spoilage microbes which can reduce the quality and shelf life of meat, so preservation efforts are needed. In general, meat preservation among the public is usually carried out through processing, freezing, or adding chemicals such as formalin, borax, and sodium nitrate which can endanger consumers' health if consumed continuously. Another effort that can be made to increase the shelf life of meat can be done through the marination process.

Marinating is the process of soaking meat before further processing in marinade which functions as a meat soaking agent which is used to increase meat yield, improve flavor, increase tenderness, reduce cooking losses, and extend shelf life [2] . The marination process can be done through the use of various types of spices, one of which is through the use of kluwek. Kluwek (Pangium edule) is another name for the picung plant which is used as a spice in cooking and traditional medicine which contains flavonoid compounds such as cyanide acid, hydrocarpic acid, khaulmogratic acid, gorlic acid and tannin. The role of the flavonoid content in kluwek is also that it is antibacterial against the bacteria Bacillus sp, Salmonella sp, Escherichia sp [3]. The aim of this research was to determine the effect of using different percentages of kluwek on the number of bacteria, shelf life, water holding capacity and cooking losses in marinated beef.

The marinating process uses 3600 grams of beef thigh, and 1 kg kluwek for 120 minutes (2 hours).
 

Kluwek preparation
The kluwek preparation procedure uses the method [4]. 1 kg of kluwek has its outer skin cracked to get the inner seed flesh. The kluwek meat seeds are washed clean and dried in the oven at 40oC for 24 hours. Then the dried kluwek seeds are ground using a blender until the size is 80 mesh. The refined kluwek is mixed using water with a ratio of kluwek and water respectively 1 : 2 (w/v) and boiled for 2 hours at a temperature of 70oC, then filtered and the filtrate obtained is evaporated in a vacuum evaporator at a temperature of 40oC.

Beef is marinated with different concentrations for each treatment (10%, 15%, 20%) then stored on a tray and wrapped in plastic wrap. The marination process was carried out at room temperature for 120 minutes (2 hours) and then tested for the number of bacteria, shelf life, water holding capacity and cooking loss.

Total Plate Count (TPC)
Measurement of the number of bacteria was calculated using the total plate count (TPC) method [5]. 5 grams of sample from each treatment was ground using a mortar then transferred to 45 mL of Physiological NaCl and homogenized for 90 seconds. Serial dilutions were prepared by mixing 1 mL of homogenized sample with 9 mL of Physiological NaCl. Total bacteria were counted by plating samples on Nutrient Agar after aerobic incubation at 37℃ for 24 hours. The colonies formed are counted and expressed as colony forming units of the suspension (CFU/g). The number of bacteria can be calculated using the formula:
 

N=C1 × n1+0.1 ×n2 ×(d)]

Shelf Life

Shelf life measurements are calculated using the H2S method [6]. 10 grams of sample was put into a petri dish which was then covered using Whatman filter paper and dripped with 1 - 2 drops of 10% Pb acetate, then the petri dish was closed using a lid. Calculation of shelf life is recorded based on the initial time of decay in the meat, marked by the formation of brown spots on the filter paper.

Water Holding Capacity
Water holding capacity (WHC) testing was determined using the Grau and Hamm method [7]. A sample of 0.3 g was placed on 2 glass plates covered with filter paper, pressed with a weight of 35 kg for 5 minutes and the wet area was calculated. Calculation of Water Holding Capacity (WHC) can be done using the formula:
 

Wet area = Area of ​​wet area – Area of ​​covered area

mg H2O = 100 - – 8.0Area Basah (cm2) 0.0948

Water Content = x 100%Berat sampel awal - Berat sampel akhir  Berat sampel awal

Water Holding Capacity = Water content -mgH²O 300x100

Reduce Cooking

Measuring cooking loss in meat uses the Suwiti, et al. (2017) [7] method. Samples were weighed and placed in closed polyethylene plastic before heating in a water bath at 80°C for 5 minutes. The sample was cooled to room temperature and weighed again as the final weight. Calculation of cooking loss can be calculated using the formula:

Cooking Loss (%) =Berat awal-berat akhirberat awal  ×100

Statistic analysis

This research was carried out using an experimental method, with an experimental design, namely a Completely Randomized Design (CRD), which consisted of 3 treatments using kluwek with concentrations of 10% (T1), 15% (T2), and 20% (T3) with 6 replications, so that 18 experimental units were obtained. Measurements were carried out quantitatively and the data obtained were analyzed using ANOVA and if there were differences, continued with the Duncan Range Test.

Total bacteria (TPC), Shelf life, Water Holding Capacity (WHC), and Cooking Loss

The results of the effect of using kluwek with different percentages on total bacteria (TPC), shelf life, water holding capacity (WHC), and cooking losses can be seen in Table 1.

                  Table 1. Effect of using kluwek on TPC, shelf life, water holding capacity (WHC), cooking loss

Different superscripts in the same column represent significant differences (p<0.05).

T1 = addition of 10% kluwek, T2 = addition of 15% kluwek, T3 addition of 20% kluwek.
 

 Based on table 1, the results show that the number of bacteria in beef that has been marinated in kluwek with a concentration of 10% - 20% shows results that are not significantly different (p>0.05) and is in the range 7.32 - 8.10 x 10⁵ CFU /gram. The results show that bacterial contamination in meat is below the threshold for bacterial contamination in meat set by SNI (2009) [8], which states that the maximum microbial contamination in meat is 1 x 10⁶ CFU/gram.

The results show that the higher the concentration of kluwek used, the smaller the number of bacteria, this can happen because kluwek contains alkaloids, flavonoids, saponins, triterprnoids and steroids. According to (Ismanto et al., 2013) [1] stated that the active substance saponin contained in kluwek leaves which is used as a preservative in pork works like a detergent by damaging bacterial cell membranes and reducing the surface of bacterial cell walls. Saponin will diffuse with the cytoplasmic membrane which can disrupt the stability of the membrane and leak the cytoplasm, resulting in bacterial cell death [9].

The shelf life of meat is closely related to meat spoilage. The better the quality of the meat or the protective components in the meat, the more the spoilage process will be delayed and the shelf life will increase. Bacteria that can cause spoilage in meat include Aeromonas, Enterococcus, Acinetobacter, Moraxella, Chromobacterium, and Pseudomonas [10].

The use of kluwek in marinating beef on shelf life showed significantly different results from using a concentration of 15% kluwek for 803.07 minutes or the equivalent of 13 hours. The use of kluwek concentration in marinating beef can inhibit the growth of pathogenic bacteria which can accelerate the spoilage process in meat, this can happen because kluwek contains tannin which is toxic to fungi, yeast and bacteria [11], in addition to its Tannin content according to (Paramitasari et al., 2021) [3] kluwek seeds contain flavonoids which can act as an antibacterial against Bacillus s, Salmonella sp, Eschericia sp. The flavonoid content can inhibit the growth of gram-positive and gram-negative bacteria [11]. The use of kluwek with a concentration of 10% showed the longest results for the shelf life of meat at 1026 minutes or the equivalent of 17 hours.

Water holding capacity is the ability of the inner flesh binding water or adding water as a result of external influences such as cutting, heating or pressure. The results show that the use of kluwek in marinating beef is not significantly different (p>0.05) in each treatment, this can happen because the strong muscle fibers in the meat can cause the binding force of water to change the water molecules inside and out. The results show that the value of water holding capacity in meat marination is in the range of 22.12% – 25.33%. The decrease in water holding capacity can be caused by changes in the pH of the actin and myosin proteins which approach the isoelectric point after post rigor, therefore the distance between the protein filaments decreases and reduces the ability of the protein to bind water so that the water holding capacity of meat decreases [2].

Cooking loss in meat marinated in kluwek showed results that were not significantly different in all treatments (p>0.05). The addition of kluwek with different concentrations showed that the cooking loss values ​​were not much different for each treatment, consisting of 35.71 (T1), 35.47 (T2), 35.73 (T3) and were still within normal limits, according to Filla, et al (2022) [6] the normal range for cooking loss values ​​for meat is 15 – 40%.

Cooking loss values ​​which do not differ much between treatments can be influenced by the temperature and time used during the boiling process. According to Filla, et al (2022) [6], muscle fibers in meat, weight of meat samples, temperature, cooking time, and cross-section of meat are factors that influence the value of cooking loss in meat. The cooking loss value is related to the shrinkage of meat during the cooking process. Meat with a high water holding capacity value during the cooking process will cause the nutrient fluid to decrease so that the weight of the meat will decrease [12].

The use of kluwek with different concentrations in marinating beef showed no significant difference in the number of bacteria, water holding capacity and cooking losses. However, it has a significant effect on the shelf life of meat. The use of kluwek with a concentration of 10% on beef with a marinating time of 120 minutes showed the best results with a bacterial count of 8.10 x 10⁵ CFU/g, water holding capacity of 23.64%, cooking loss of 35.71%, and shelf life of 1026.29 minutes (17 hours).

Funding: No funding sources.

Conflict of interest: None declared.

Ethical approval: The study was approved by the Institutional Ethics Committee of Padjadjaran University.

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