Fish Spoilage Mechanisms and Preservation Techniques: Review

Ghaly

doi:10.3844/ajassp.2010.859.877

Abstract

Problem statement: Spoilage of food products is due to chemical, enzymatic or microbial activities One-fourth of the world’s 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. Methodology: 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. Conclusion: 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°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.

Highlights

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 spoilage of fish and fish products depends on a number of factors
These factors as well as the spoilage mechanism must be thoroughly understand before developing proper handling and pretreatment methods and preservation techniques for food products

Summary

INTRODUCTION

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. Low temperature storage and chemical techniques for controlling water activity, enzymatic, oxidative and microbial spoilage are the most common in the industry today (Akinola et al, 2006; Berkel et al, 2004). Berkel et al (2004) reported two possibilities for storing fresh fish at low temperatures: (a) cooling at -1° to +4°C, which inhibits the growth of microorganisms and (b) freezing at -18 to -30°C, which completely stops bacteria from growing Both enzymatic and non enzymatic changes continue but at a much slower rate. Controlling water activity: freezing is the best way to inhibit microbial growth (except psychrohpiles and spores) and slow chemical changes thereby preserving fish for a long time, it is an energy intensive operation and can only be used as a temporary method of preservation. Sugars and sodium chloride have been used to bind up the free water molecules and create an osmotic imbalance resulting in cell growth inhibition (Ray, 2004)

Freezing methods Description

Findings

CONCLUSION