Authentication propriety standard halal gelatine catfish skin from periodization quarantine (istihalah) in cultivation with feed containing pig contaminants

Abstract

The limitations of fish meal as a feed ingredient were addressed by utilizing food waste, specifically pig innards. Concurrently, the rising demand for halal gelatin in the market generated a substantial need for fish skin by-products. This study aimed to determine the authentication propriety of halal standards for gelatin derived from catfish skin that had been fed with fish meal containing pig components over three different quarantine periods (istihalah): 0, 3, and 6 days after harvesting. The verification of the halal standard was conducted through the specific DNA analysis of pig components. This testing was performed at each stage, including the feed containing pig, the fish skin, and the catfish gelatin. The gelatin in the catfish skin was predominantly composed of the amino acids glycine and proline. The fish enlargement stage resulted in a skin yield of 5.36 ± 0.75%. The yields of gelatin were 8.67%, 9.94%, and 9.19%, with gel strengths of 133.4 ± 1.2 bloom, 129.9 ± 1.4 bloom, and 121.9 ± 2.8 bloom for the 0, 3, and 6 days of istihalah, respectively. Gelatin characterization using FTIR indicated the presence of functional groups such as amide A, amide I, amide II, and amide III. Real-time PCR detected the presence of pig DNA in the feed; however, it was not detected in the skin and gelatin of the catfish. Ultimately, a quarantine period of 0 days for catfish fed with pig-containing feed was sufficient to cleanse the catfish skin of pig contaminants, with no indication of pig DNA being found.