Fish Spoilage Mechanisms and Preservation Techniques: Review

Abstract

<b>Problem statement:</b> Spoilage of food products is due to chemical, enzymatic or microbial activities One-fourth of the worlds food supply and 30% of landed fish are lost through microbial activity alone. With the ever growing world population and the need to store and transport the food from one place to another where it is needed, food preservation becomes necessary in order to increase its shelf life and maintain its nutritional value, texture and flavor. The freshness and quality of fish have always gained the attention by Food Regulatory Agencies and Food Processing Industry. Proper handling, pretreatment and preservation techniques can improve the quality fish and fish products and increase their shelf life. <b>Methodology:</b> Historically salting, drying, smoking, fermentation and canning were the methods to prevent fish spoilage and extend its shelf life. In response to consumer demand for texture, appearance and taste, new methods were developed including: Cooling, freezing and chemical preservation. A comprehensive review of the literature on the subject of fish spoilage and modern preservation techniques was carried out. <b>Conclusion:</b> Fish spoilage results from three basic mechanisms: Enzymatic autolysis, oxidation, microbial growth. Low temperature storage and chemical techniques for controlling water activity, enzymatic, oxidative and microbial spoilage are the most common in the industry today. A process involving the addition of an EDTA (1 mM)-TBHQ (0.02%) combination and ascorbic acid and storage at refrigerated temperatures (5&deg;C) in darkness can be the most positive for controlling the spoilage of fish and fish product. The suggested process would address antimicrobial activity as well as destructive oxidation of the desired lipids and fats. However, more efforts are required to understand the role of proximate composition of fish, post harvest history, environmental conditions, initial microbial load, type and nature of bacteria and their interaction in order to optimize the shelf-life of fish

Post-harvesting and Major Related Problems of Fish Production

“…Spoilage therefore is the indicative of Post-harvest change. This change may be graded as the change from absolute freshness to limits of acceptability to unacceptability [23]. Spoilage is usually accompanied by change in physical characteristics.…”

“…In addition, the following factors contribute to spoilage of fish. This includes; High moisture content, high fat content, high protein content, weak muscle tissue, ambient temperature, unhygienic handling and time [23].…”

Shelflife of whole fresh lake Malawi tilapia (Oreochromis species - Chambo) stored in ice

“…However, spoilage in fresh fish progresses even when stored in ice resulting into gradual loss of freshness and quality [1]. Activity of microbes and enzymes has been pin-pointed for causing spoilage of fresh fish in ice [7]. The fact that the chambo is transported to distant places from the lake underscores the need for estimating the duration it would remain in safe and acceptable condition.…”

Assessment of Smoked Fish Quality Using Two Smoking Kilns and Hybrid Solar Dryer on Some Commercial Fish Species in Yola, Nigeria

“…Freshness is usually judged in the trade entirely by its appearance, odor and texture of the raw fish. Assessment depends upon senses known as sensory or organoleptic evaluation [20]. Smoking is a traditional method of processing fish around the globe, thereby extending its shelf life.…”