Effectiveness of Aloe vera in Reducing Formaldehyde Levels on Indian Mackerel Fish (Rastrelliger kanagurta) During Cold Temperature Storage
Authors: Kartika Nurul Luthfia , Liviawaty Evi , Afrianto Eddy , Rostini Iis 
Published: September 2019

Aims: This research is aimed to know the impact of Aloe Vera to formaldehyde levels. Specifically, to know how Aloe Vera could reduce the formaldehyde levels on Indian mackerel fish during cold temperature storage.

Place and Duration of Study: Fisheries Product Processing Laboratory, Faculty of Fisheries and Marine Sciences, and Central Laboratory, Padjadjaran University between March until April 2019.

Methodology: This research used descriptively compared method with five different Aloe vera treatment concentrations (0%, 10%, 20%, 30% and 40%). Parameters of  observations such as formaldehyde levels, pH and organoleptic characteristics (fresh fish, formalin fish and after soaked with Aloe vera) descriptively compared with the literature.

Results: The results of the research show that Aloe vera could reduce the formaldehyde levels on Indian Mackerel, and the higher concentreation of Aloe vera used and the longer of storage period, the more reduced formaldehyde levels. The reduction caused by presence of saponins in Aloe vera. Saponins was effective in binding formaldehyde particles so that formaldehyde can dissolve with water. The highest percentage of fomaldehyde reduction was on the concentration of 40% Aloe vera solution, with a decrease percentage was 63.47% - 74.48% and the lowest percentage decrease in formalin levels found in the solution concentration Aloe vera 10%, with a decrease percentage was 50.14% - 68.22%. pH value of all treatment at the beggining was close to acidic (range 6.30 – 6.47), caused by Aloe vera gel and formalin which were both acidic. The pH value of all treatment after 10th observations days was still in the range of the pH value of fresh fish, which is 6.77 - 7.03. The increased pH value during cold temperature storage caused by fish undergoing a chemical process in the form of protein overhaul and the formation of alkaline compounds. The organoleptic parameters showed there is a difference between the characteristics of fresh fish, fish in formalin and after the fish soaked on Aloe vera solution. The fresh fish had average value of 7.00 – 8.33 based on the score sheet, which indicates Indian Mackerel was fresh before the treatment. After soaked in formalin, the appearance has changed to be not bright, formaldehyde can be smelled, texture changed slightly hard, and the eye became gloom and murky white. After soaked with Aloe vera, the appearance became a little bright and shiny, could be smelled aroma of Aloe vera, texture became dense, and loss of cloudy corneas.  

Conclusion: Based on the results, it can be concluded that by increasing Aloe vera solution until 40%, will also increased the reduction of formaldehyde levels on Indian mackerel fish during cold storage until 10th day. At a concentration of 40% Aloe vera solution, it can reduce the highest formaldehyde levels with a range of percentage decreases in formalin levels by 63.47% - 74.48%, so that aloe vera could effectively reduce formalin levels in Indian mackerel during cold temperature storage.