Effects of processing and storage on some chemical characteristics and lipid composition of a ghanaian fermented fish product

Abstract

Abstract:To evaluate the effectiveness of the traditional method of processing in preservation of the final product, the changes in composition of lipids, free amino acids and organic acids of 'momoni', a Ghanaian fermented fish product, were investigated using Japanese jack mackerel (Trachurusjaponicus) which is similar to African jack mackerel (Curanx hippos). The moisture content decreased drastically from 751 to 505 g kg-I after fermentation for 3 days, and then remained almost constant during subsequent storage. Changes in pH were minimal although a gradual decrease was observed from 6.2 in the raw material to 5.9 after 2 months storage. Salt accumulation due to the salting process increased up to 325 g kg-' but remained almost unchanged during subsequent storage. Volatile basic nitrogens (VBN) increased to 0.8 g kg-' on a salt-free dry matter basis, after 2 months storage. Most free amino acids, except histidine which was present in the highest concentration in the samples, increased during processing and subsequent storage. However, no detectable amount of histamine was formed after 2 months storage. Lactic acid, the most prominent organic acid (3.12 g kg-' salt-free dry matter) in the raw materials, decreased during processing and subsequent storage. Diphosphatidylglycerol, free fatty acids, and lysophosphatidylcholine increased appreciably. Processing resulted in depletion of sphingomyelin, phosphatidylserine and phosphatidylinositol with decreases in triglycerides, cholesterol, phosphatidylethanolamine and phosphatidylcholine. The proportion of the extracted total lipids present as polyunsaturated fatty acids decreased and this was accompanied by increases in the proportions of saturated fatty acids, indicating a high degree of oxidation. Peroxide value and thiobarbituric acid value increased on fermentation, confirming the observed oxidation, but decreased during storage. In conclusion, although oxidation was extensive, following hygienic and good manufacturing practices, this simple method could prevent spoilage taking place in fish if good-quality raw materials are used.

Effects of Hot Smoking and Sun Drying processes on Nutritional Composition of Giant Tiger Shrimp (Penaeus monodon, Fabricius, 1798)

“…Sundried shrimps would also find favour in the prevention of many human diseases including cancer, atherosclerosis, stroke, rheumatoid arthritis, neurodegeneration, and diabetes [Fang et al, 2002]. Yankah et al [1993] found raised histidine level in salted fish when sundried. Histidine is essential for children but its indispensability remains unresolved in healthy adult [FAO/WHO/UNU, 1985].…”

Microflora and Chemical Composition of Momoni, a Ghanaian Fermented Fish Condiment

“…The quantities of individual amino acids were determined on a Technicon Sequential Multiple (TSM) amino acid analyser. Salt content was determined according to the method of Yankah et al (1993). Minced momoni sample (0.5 g) was digested with 20 mL of concentrated HNO 3 for 2 h at 1001C.…”

“…The finished product is usually of low quality with a high salt content and deteriorates rapidly during retailing and storage (Yankah et al, 1993). There is no report in the literature of microbiological status of momoni.…”

Process Production, Physico Chemical and Sensory Attributes of Pelpeledgi; A Cameroonian Fermented Fish Product

“…The pH of the homogenized samples was measured with a pH-meter Model Hm 305 (TOA Electronic, Japan). Salt content was determined according to the method of (Yankah et al, 1993). About 0.5 g of Pelpeledgi was digested in a stomacher with 20 mL of concentrated HNO 3 for 2 h at 100°C on cooling, 100 mL water and 5 mL of ammonium iron sulphate indicator were added and the salt content was determined by titration with a solution of 0, 1 M AgNO 3 which was previously standardized using 0, 1 M standard KCl solution.…”