Assessment of Impact of Different Preservation Methods on the Nutritional Composition of Catfish Heteropneustes fossilis

Introduction

Fish is considered as nutritionally valuable part of the human diet as it is a rich source of animal protein and omega 3 fatty acids [1]. They are 90% digestible and constitute important part of food in poverty prone countries. It is also good source of Selenium, Vitamin D, Phosphorus and Calcium [2, 3]. Many researchers have Assessment of Impact of Different Preservation Methods on the Nutritional Composition of Catfish Heteropneustes fossilis shown positive health effects of consuming fishes such as decreased risk of coronary heart and cardiovascular diseases, decreased inflammatory disease as arthritis and prevention of cancer as shown by many researchers [4, 5].

Due to high therapeutic and nutritional benefits, consumption of fish has gradually increased in the last decades. Growing human population in many countries Int J Zoo Animal Biol

has also caused increased demand for fish food. To meet the ever-increasing demand for fish, aquaculture has expanded very rapidly and is now the fastest growing food producing industry in the world.

One of the major problems faced by the fisheries industries is spoilage of fish. In the tropical countries such as India, hot climate favours the rapid growth of bacteria which leads to spoilage of fishes and deterioration of its quality which in turn also decrease the capital gain [6].

According to Adesehinwa AOK, et al. [7] capture fish provides over 60% of total domestic production per- anum. But it faces about 30-50% post-harvest losses due to spoilage of fishes. Hence fishes should be well preserved to maintain its quality and to avoid its spoilage.

Preservation techniques are required to prevent fish spoilage and increase shelf life [8]. They should be designed to inhibit the activity of spoilage bacteria and metabolic changes that result in the loss of fish quality. Spoilage bacteria produce unpleasant odor and flavor associated with spoiled fish.

Preservation should be done in such a manner that the fishes remain fresh for a long time, with minimum loss of flavor, test, odor, nutritive value and digestibility of their flesh.

There are many methods of fish preservation such as freezing, Oven drying, Sun drying etc [9]. Every preservation method has its own limitations and has different impact on nutritive value of fishes.

In present study we tried to evaluate the effect of different preservation methods such as Freezing, Oven drying, Sun drying on nutritive value of Heteropneustes fossilis preserved for 7 days and also tried to know which preservation method retains maximum nutritive value in fish. H. fossilis fish is very excellent in taste and have high market and medicinal value [10]. Due to its high nutritive value this fish is recommended in the diet of the sick and convalescent [11].

Results

The effect of different preservative methods on nutritional contents such as protein, lipid, moisture, ash, glucose and triglycerides of H. fossilis has shown in figure 1-6.

The protein content was found to be significantly highest (P<0.05) in fresh fish (22±0.44%), followed by frozen fish (19.4±4.97%), sun dried fish (14.18±4.59%) and oven dried fish (12.2±7.61%) respectively (Figure 1).

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(4.734±0.61%), and frozen fish (4.26±0.371%) and least was found fresh fish (2. 6±0.23%) (Figure 2).

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Vaseem H, et al. Assessment of Impact of Different Preservation Methods on the Nutritional Composition of Catfish Heteropneustes fossilis. Int J Zoo Animal Biol 2019, 2(6): 000190.

Copyright© Vaseem H, et al.

sun dried fish (3.99±0.23%). The moisture content in frozen fish and oven dried fish were 58.42±3.21% and 8.77±0.17% respectively (Figure 3).

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1.2±0.03% and 1.1±0.029% of ash content respectively (Figure 4).

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The significantly highest (P<0.05) amount of glucose was found in fresh fish (16.08±0.32 mg/gm), followed by sun dried fish (15.20±0.40 mg/gm), followed by oven Vaseem H, et al. Assessment of Impact of Different Preservation Methods on the Nutritional Composition of Catfish Heteropneustes fossilis. Int J Zoo Animal Biol 2019, 2(6): 000190.

dried fish (14.56±0.29) and least was observed in frozen fish (12.2±0.68) (Figure 5).

Copyright© Vaseem H, et al.

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Discussion

Effect of different preservative methods on the nutritional content of H. fossilis in this study is in agreement with the report of Bassey FI, et al. [14] who reported that different preservative methods cause alteration in percentage of protein, lipid, moisture and ash content.

In present study protein was found to be lower in all samples after preservation (Figure 1). It might be as a Vaseem H, et al. Assessment of Impact of Different Preservation Methods on the Nutritional Composition of Catfish Heteropneustes fossilis. Int J Zoo Animal Biol 2019, 2(6): 000190.

result of denaturation of protein molecule after preservation. Oluwaniyi OO, et al. [15] has also observed the decrease protein content in fishes after preservation.

Lipid showed opposite trend to the changes in protein percentage as after preservation of fishes, lipid percentage gets increased after all preservation method than fresh fish (Figure 2). This is in contradiction with the studies of Roopma G, et al. [16] and Saliu JK, et al. [17] who observed decreased lipid content in fishes after preservation.

Copyright© Vaseem H, et al.

Moisture content was found to be decreased in all preserved fishes in comparison to fresh fishes (Figure 3). Ali Aberoumand A, et al. [18] has also noticed decreased moisture content in frozen fishes. Sun dried and oven dried method also caused decreased moisture content in fishes due to dehydration process.

Ash content was found to be higher in all preserved fish compare to fresh fish (Figure 4). Decrease in moisture content after preservation might be the reason for increased ash content [19].

Variation in glucose content was also observed in fishes after preservation. Decreased level of glucose was obtained in all preserved fishes when compared to fresh fishes (Figure 5).

Increased triglyceride content in all preserved fishes might be reason for increased triglyceride level in all fishes after preservation (Figure 6).

Conclusion

This study showed the effect of different preservative methods such as freezing, sun drying, and oven drying on the nutritional contents of H. fossilis in comparison to fresh fish. The protein, moisture and glucose contents were found to be higher in fresh fish than all the preserved fish. The least amount of lipid, triglycerides and ash was observed in fresh fish. The protein is the most important nutrient as it contains all the essential amino acids that builds the body and maintain body functions. Therefore, fresh fish should be more preferable for consumption compared to preserved fish.