The application of hurdle technology in extending the shelf life and improving the quality of fermented freshwater fish (Pekasam): A Review

Abstract

Hurdle technology combines several preservation methods to secure the quality of foods by eliminating or controlling the growth of pathogens, making them last longer and, most importantly, safer for consumption. The hurdle approaches used for this Pekasam is microbially derived hurdle and physico-chemical hurdles. Inoculation of starter cultures with amine oxidase (AO) activity like lactic acid bacteria (LAB) in Pekasam is proven to reduce the accumulation of harmful biogenic amines, especially histamine, for up to 59.9%. This review also involves controlling the water activity and pH of Pekasam to a state where it inhibits the growth of microbes. This can be done by adding natural, cheap, and easy to find ingredients like lime juice (Citrus aurantifolia) to the basic Pekasam recipe. The presence of organic acids in the lime juice act as acidulants; it provides a low pH environment for microbes to retard their growth and therefore reduce the total plate count (TPC) whilst enhancing the flavour of Pekasam. However, in a long- ripened Pekasam, only the water activity hurdle is strengthened with time. Hence, a proper amount of salt is needed to sustain and maintain the water activity level below 0.94. The use of affordable herbs and spices with antimicrobial properties such as garlic, ginger and onion can prevent the proliferation of some pathogenic microbes, commonly found in Pekasam; thus, this helps in increasing the stability of the product. This review aims to outline the application of hurdle technology on fermented freshwater fish quality and shelf life. It focuses on recent accessible applications when combined, providing affordable food which helps those underprivileged people, especially during flash floods and other disruptive calamities such as the COVID-19 pandemic.