Accelerated shelf life test method with arrhenius approach for shelf life estimation of tongkol ‘euthynnus affinis’ balado in cans

Many people in Indonesia consumed tongkol fish by processing it into balado tongkol. The process carried out to extend the shelf life of the product is by packing it in cans. Information related to shelf life was needed for canned food, so that it can guarantee that the food was still good for consumption. This study aims to determine the shelf life of balado tongkol in cans from TEFA Fish Canning with the Arrhenius method. Arrhenius is the method of estimating shelf life used was ASLT (Accelerated Shelf Life Test). The ASLT method requires a relatively short testing time with an acceptable level of accuracy. This research was conducted at the TEFA Fish Canning and Food Processing Laboratory of Politeknik Negeri Jember in March – July 2021. Estimating the shelf life used the reaction approach that increases the TBA number as a critical parameter. The kinetic reaction of increasing the TBA number in canned balado tongkol followed the ordo 0 reaction. The results showed that the shelf life of balado tongkol in cans at room temperature was 24,6 weeks.


Introduction
Food is the most important basic of human need and its fulfillment is also part of human rights [1]. Food can be interpreted as derived from both treated and untreated biological sources and water. [2]. Public protection from unsafe food circulation is a guarantee that must be obtained by the community as consumer. Shelf life is directly related to the safety of the product and product quality assurance so as not to endanger the health of consumers. The fisheries sub-sector is the main source of food and nutrition for the people of Indonesia. Besides being a source of protein, fish is also recognized as a 'functional food' which has important meaning for health since it contains long-chain unsaturated fatty acids (especially those belonging to omega-3 fatty acids), macro and micro minerals, and vitamins. During the storage process, fish and processed fish products can undergo unwanted changes so as to limit storage time. These changes include protein oxidation ( [3]; [4]) and lipid oxidation ( [5]; [6]). One of the most commonly consumed fish is tongkol.
Tongkol is a commodity that rapidly declines in quality, in other words, it is easy to decompose because its high level of protein and water is easier to spoilage bacteria to grow [7]. One way to extend the shelf life of tongkol is by the canning process. Canning is one way of preserving food through a processing method that is packaged hermitically or using a very tight, watertight, airtight cover so as to  [8]. This study aims to determine the shelf life of a product from TEFA Fish Canning with the Arrhenius method.

Research methods
This research done in the Food Processing Laboratory and TEFA Fish Canning, Jember State Polytechnic for 6 months, from February to July 2021. The production process of balado tongkol in can is first carried out by the fish sorting process, followed by the exhausting process. After this, the process of filling the balado seasoning into the tongkol which will be canned is carried out. After the can is closed then the sterilization process is done. The research completed in several stages, (1) testing the production process; (2) identification of critical quality parameters and determination of shelf life.
The expiry date of the Balado Tongkol in can is determined by the accelerated method (Accelerated Shelf-life Testing or ASLT) with the Arrhenius model. Model selection is based on the consideration that the damage of balado seasoning tongkol is suspected to be caused by chemical changes in the food components during storage which could be triggered by storage temperature.
There are 30 cans of Balado tongkol in cans, where each can contains 115gr of Balado tongkol. Storage is carried out at three temperatures, which are 35ºC, 45ºC, and 55ºC. There are 10 cans for each storage temperature. Observations during storage is carried out at the beginning of storage or day 0, within an interval of 1 week in along 1 month. Each observation is conducted on two cans (2 replicates) per each can and storage temperature. Observations are made on the critical parameters of TBA number using the distillation method.

Principle of estimating shelf life
The method of determining shelf life can be done by putting away the product until it is damaged under normal storage condition. This method produces the most valid information, but it takes time and impractical for industrial application. Therefore, an accelerated shelf-life testing or ASLT method was developed for estimating shelf life, where the product is kept under extreme storage conditions that can accelerate its deterioration. Shelf life is estimated using a mathematical model, where the factors that can affect product damage are included in the mathematical model [9]. The ASLT method requires a relatively short testing time with an acceptable level of accuracy. The more valid the mathematical model used, the more valid the prediction will be.
ASLT method oftenly used for estimating shelf life are the critical moisture content model and the Arrhenius model. The critical moisture content model is applied to estimate the shelf life of damaged food product by the water absorption of the product. The Arrhenius model is applied to foods that are easily damaged by chemical reactions such as fat oxidation, protein denaturation, Maillard reaction, etc.
The Arrhenius model is carried out by storing food product in final packaging stage at least of three extreme storage temperatures. Experiment with the Arrhenius method aims to determine the reaction rate constant (k) at several extreme storage temperatures, extrapolation then carried out to calculate the reaction rate constant (k) at the desired storage temperature using the Arrhenius equation

Determination of the critical point
Determination of critical parameters used in estimating shelf life is specific for each product. In canned balado tongkol, the critical quality parameter of TBA number is used as an approach in estimating shelf life. Degradation of polyunsaturated fatty acids (PUFA) during storage leads to the formation of volatile components combined with rancidification [10]. A high percentage of unsaturated fatty acids means that fish tissue is easily pre-oxidized and quickly degraded. Oxidative changes are mainly related to the taste and texture of the fish. Changes in color, nutritional value or secondary product of lipid will be observed at an advanced stage of the lipid peroxidation process [11]. Oxidation of fish lipids is usually based on analysis of refractive index, peroxide value (PV) and reactive 2-thiobarbituric acid (TBARS) as indicators of primary and secondary oxidation products ( [12]; [13]; [14]; [15]; [16]).

Reaction ordo determination
The speed of quality change of each product parameter is different. If the rate of damage is constant or linear, it follows the ordo 0 reaction. However, if the damage ratio is not constant, logarithmic or exponential, then an ordo 1 reaction is followed. Determination of the reaction ordo is a way to predict deterioration in quality in estimating shelf life. In kinetic reactions, food quality degradation follows ordo 0 and ordo 1. Ordo 0 can be detected by plotting between values of TBA as the Y axis and storage time as the X axis. Ordo 1 can be detected by plotting the value of ln TBA number as the Y axis and storage time as the X axis. The choice of ordo reaction can be seen by plotting the quality degradation data following the ordo 0 and ordo 1, then the linear regression equation is made. The reaction ordo with a larger R2 value is the reaction ordo used [17]. The value of determination (R2) for the increase in TBA number in the orde 0 reaction is higher than the ordo 1 reaction ( Table 1). The value of determination (R2) of ordo 0 in canned tongkol balado ranged from 0.9527 to 0.9763. Thus, it can be seen that the reaction kinetics of the increase in the TBA number during storage of Balado tongkol fish product in the package follow the pattern of ordo 0 reaction. The higher the value of determination, the more accurate the result of the data analysis. The positive slope value indicates an increase in the TBA number in canned balado tongkol ( Table 1). The value of the gradient or slope (k) states the relationship between the value of quality degradation and storage time. This is in accordance with [18] which showed an increase in the number of TBA (Thiobarbituric Acid) in andaliman sauce during storage. The increase in TBA number in this product is due to the heatinduced oxidation reaction. In the appearance of tomato paste, the brightness of the color also decreased to become more brownish due to lycopene oxidation [19].  Figure 1. Graphic of relationship of value of TBA degradation to time

Shelf life estimation
According to [20], The shelf life is the period until the quality of the product deteriorates, and it does not meet the standards specified on the packaging and should not be eaten. (the quality is not yet in the guaranteed quality level), due to the ongoing deterioration reaction. The deterioration reaction leads to poor quality and poor quality of the product, making it unsuitable for consumption. This deterioration reaction will cause changes to the canned balado tongkol fish product. Determination of the critical value of tongkol balado in can is obtained from the TBA number assessment parameter. Response order selection is made by plotting the degradation data after response ordo 0 and response ordo 1, and then writing a linear regression equation. The shelf life of tongkol balado fish product in can, assuming the temperature in room temperature of 25ºC for 24,6 weeks (24 months 18 days). [21] state that oxidation can lead to the formation of offflavor compounds and this condition is called rancid. It is the process of breaking down fat. Due to oxidation of unsaturated fatty acids, rancid processed foods lose nutritional value and cause discoloration, which affects quality. Oxidized compounds such as peroxides, ketones, and aldehydes are harmful to human health. While [22] stated that factors affecting the rate of oxidation include the chemical structure of lipids, the amount and type of oxygen, the presence of antioxidant and pro-oxidant compound, the nature of packaging materials, and storage temperature.

Conclusion
Estimating the shelf life of tongkol balado in can using the ASLT method by using the reaction approach of increasing the TBA values as a critical parameter. The kinetic reaction of increasing the TBA number in canned balado tongkol followed the ordo 0 reaction. Shelf life of tongkol balado in can using the