Project topics and materials
Get Complete Project Material File(s) Now! »
STATEMENT OF PROBLEM
Nile perch (Lates niloticus) belongs to the genus Lates and the family Centropomidae. It was introduced in Lake Victoria in the 1950s but has grown to become the most dominant fish species in the lake and other lakes in the region (Acere, 1993). In Uganda, Nile perch catches represent approximately 46% (~ 100,000 tonnes per year) of all the fish landed (UIA, 2001). The fish has been widely consumed within the country since its introduction but industrial processing has only become wide spread in the last decade. Currently about ten firms, within Uganda alone, are involved in industrial processing of fish. These firms are involved in production of Nile perch fillets, mainly for the export market. Industrial processing of Nile perch in Uganda is estimated at 60,000 metric tonnes per annum. The balance of about 40,000 metric tonnes is either sold unprocessed or processed (mainly by smoking) by informal setups.
Approximately 50% of the raw material (fish) remains as processing waste after filleting (Shahidi, 1994). This is mainly in form of skeletons and skins. This creates approximately 30,000 metric tonnes of waste a year. Skins and bones are underutilised and pose a disposal problem for the processing firms.
Nile perch skins and bones could be used in the manufacture of gelatin. Gelatin is a denatured form of collagen that can be derived from any collagenous material. The traditional sources of gelatin are pigskins, bovine hides and bones. Recent outbreaks of Bovine spongiform encephalopathy (BSE) and increase in demand for kosher and halal foods have created a demand for alternative sources of gelatin for food applications. Gelatin from fish with scales such as Nile perch has potential for use in kosher and halal foods since it is generally acceptable for use as food by Muslims and Jews. It may also find market among the Hindu, who are not permitted to consume cattle products. Despite such potential, fish has generally not been widely used as a source of gelatin, probably because most species give gelatin of low quality compared to mammalian gelatin. Unlike mammalian gelatins, fish gelatins vary widely in composition, particularly with respect to their imino acids (proline and hydroxyproline) content and in their physico-chemical properties.
It is estimated that a total of about 700,000 people, out of Uganda’s total population currently estimated at 24 million are engaged in fish-related enterprises, including fishing, manufacture of fishing gear, artisan processing, fish trade and industrial scale processing (MAAIF, 2000). Processing of fish waste to value-added products like gelatin would enhance the contribution of the fisheries sector to the national economy and is likely to lead to an improvement of the income of those involved in the sector.
1 INTRODUCTION & LITERATURE REVIEW
l.1 STATEMENT OF PROBLEM
1.2 LITERATURE REVIEW
1.2.1 Gelatin sources and uses
1.2.2 Manufacture of gelatin and its effect on gelatin properties
1.2.3 Collagen
1.2.3.1 Amino acid composition
l.2.3.2 Collagen super secondary structure
1.2.3.3 Collagen variants
1.2.3.4 Age-related changes in collagen
1.2.3.5 Stability of collagen to chemicals, enzymes and heat..
1.2.4 Changes associated with conversion of collagen to gelatin
1.2.5 Properties of gelatin
1.2.6 Effect of cross linking on the functional properties of gelatin
l.2.7 Effect of age of source animals on the properties of gelatin
1.2.8 Use of Fourier transform infrared (FTIR) spectroscopy in the study of
collagen and gelatin
1.3 GAPS IN KNOWLEDGE
1.4 HYPOTHESES
2 RESEARCH
2.1 CHARACTERlSAnON OF ACID SOLUBLE COLLAGEN FROM SKINS OF YOUNG AND ADULT NILE PERCH (Lates niloticus)
2.2 EXTRACTION AND PHYSICO-CHEMICAL CHARACTERlSA nON OF NILE PERCH (Lates niloticus) SKIN AND BONE GELATIN
2.3 FOURIER TRANSFORM INFRARED (FTIR) SPECTROSCOPIC STUDY OF ACID SOLUBLE COLLAGEN AND GELATIN FROM SKINS AND BONES OF YOUNG AND ADULT NILE PERCH
3 DISCUSSION
3.1 DISCUSSION OF METHODS USED
3.2 DISCUSSION OF STUDY RESULTS
4. CONCLUSIONS AND RECOMMENDATIONS
5. REFERENCES
LIST OF PUBLICATIONS
