Quality characteristics of Lanhouin: A traditional processed fermented fish product in the Republic of Benin

Abstract

Lanhouin, a fermented fish product is processed by spontaneous and largely uncontrolled fermentation. Disadvantages of this type of fermentation are that very little control can be exercised over the fermentation process and the product is often of variable quality with inherent risks of quality defects. Samples of lanhouin processed from cassava croaker /cassava fish (Speudotolithus sp.) or Spanish mackerel / king fish (Scomberomorus tritor), widely used as condiment in Benin, Togo, and Ghana, were purchased from processors and retailers in the processing sites and markets respectively, for product characterization. The samples were obtained from 20 retailers and 20 processors randomly selected in urban and rural processing sites and markets. The samples were transported under aseptic conditions to laboratory for analyses. The chemical composition of samples was determined using Pearson's and AOAC methods. The microbiological status was investigated according to the Nordic Committee on Food Analysis standard methods. The results showed that the pH values of the majority (78.5 %) of samples were above 7 and the water activity values ranged from 0.65 to 0.87. High level of free fatty acids (FFA) and thiobarbituric acid number (TBA) were also recorded for all the samples. Moisture, protein, salt, total volatile nitrogen and histamine contents ranged between 50.1-56.6 %, 24.6 - 26 5 %, 5.2 - 7.3 %, 294.5 - 374.5 mg N / 100 g and 21.4 -33.1 mg / 100 g respectively. Significant differences (p < 0.05) were observed on these parameters within and between species. The histamine contents in most of the samples (75%) exceeded the recommended level of 20 mg / 100 g. The total viable counts of the majority (83.5 %) of the samples were high. Micrococci and bacilli were the predominant organisms enumerated in the products. Their numbers ranged between 3.2 X 10⁴- 6.4 X 10⁵ and 1.6 X 10³- 2.6 X 10⁴ respectively. Few numbers of coliform bacteria and Clostridium spp. were enumerated in some of the samples (6 %).No Salmonella and no yeasts were found in any sample.

Keywords: fish, fermentation,lanhouin, quality