Development and performance evaluation of Roller type fish descaling machine and extraction Of chitosan from fish scales for its utilization in Food preservation

Abstract

A roller type fish descaling machine (FDM) was developed to address the needs of small fish newlinefarmers and vendors of inland fisheries sector. FDM consists of scalp roller assembly with newlinedifferent kinds of rollers for conveying the fish and descaling it, shaper bracket assembly to newlinehold the fish tightly against the rollers, electric motors, chain and sprocket assembly for newlinepower transmission and a supporting frame. The size and number of rollers were designed newlinebased on average length and width of fish weighing around 800 to 1000 g. Performance newlineevaluation of the FDM was carried out with Rohu fish (Labeo rohita) for selected speed newlinelevels of conveyor and descaling rollers. The maximum descaling efficiency of 83.70% was newlineachieved for an optimum conveyor roller speed (7.54 m min-1) and descaling roller speed newline(56.52 m min-1). The capacity of FDM for the maximum estimated descaling efficiency was newlinefound to be 66.40 kgh-1.The production cost of the machine was estimated about and#8377; 2,05,000 newlinewith operational costs of and#8377; 5.60 kg-1 and and#8377; 280 h-1. Chitosan was extracted from the rohu fish newlinescales by demineralization, deproteinization and deacetylation processes. The chitosan newlinesolution with different concentrations was coated on fresh fig fruits (Ficus carica var. Brown newlineTurkey) to study its effectiveness in preservation of the fruit. It was found that fig fruits newlinecoated with chitosan reduced the physiological weight loss, colour change, pH, TSS, newlinemicrobial load and decay loss with the increasing chitosan concentration, indicating less newlinespoilage of fig fruits due to water vapour barrier and anti-microbial property of the coated newlinechitosan. newline