PREVENTION AND DECREASING MANAGEMENT OF GEOSMIN FLAVOR IN PROCESSED FISHERY PRODUCTS

Abstract

A non - desirable geosmin flavor in processed fishery products has affected customers, acceptance in the industry. Such freshwater aquacultures facing that problem are as Stripped Catfish (Pangasianodon hypophthalmus), Tilapia (Orechromis niloticus), Giany Perch (Lates calcarifer), Scampi shrimp (Macrobrachium rosenbergii), or Panga (Pangasius sp.). Meanwhile, some low salting aquacultures with the some problem are for instance Tiger prawn (Penaeus monodon) and Whiteleg shrimp (Litopenaeus Vannamei). Actually, there exist many non - desirable musty - earthy odours but the case of geosmin has obvious characteristics and we have well known it is synthesized by a blue-green algae, i.e. Oscillatoria sp,. Mycrocystis sp., Anabaena sp., Lyngbya sp., Aphanizomenon sp., Symploca sp., and Phromidium sp. or bacteria such as Streptomyces sp. etc. Important factors causing the growth of bacteria and a blue-green algae are nitrogen, phosphorus, oxygen dissolved water, species, content, water salt, and light intensity. The rapid generation of geosmin flavor on aquaculture is by lipids in blood stream spreading through various sections of bodies. Three methods to prevent and reduce the musty-earthy odour are followed : 1) A geosmin prevention on the aquaculture processing can be coped with by controlling an optimum volume of feed and by controlling the content of oxygen. 2) A reduction of musty-earthy odour for fishes in a rest or pond can be dealt with by trapping those fishes until they have good flavor or moving fishes to a clean rest or pond as an alternative method. 3) we can also abate that problem with frozen or chilled processing. At the present, many researches present that some solutions, i.e. an ozone aqeous, acetic acid, calcium hydroxide, sodium chloride, and banana leaves, ash, can be utilized to manage the non - desirable flavor in the processing. Meanwhile, we should employ other methods such as a smoking, soaking in vegetable oil or marinade, or semi-streaming before canning, etc.