Abstract:
This study was carried out to evaluate the level of chemical migration from three different packaging materials into “moinmoin”, a traditional steamed cowpea paste. The packaging materials were Thaumatococcus daniellii leaf (“ewe eran”), rigid plastic container and flexible plastic film. These packaging materials and the cowpea “oloyin” used in the study were obtained from the King’s market, Akure, Nigeria. “Moinmoin” was prepared via the traditional method using the different packaging materials, respectively. The samples (Thaumatococcus daniellii leaf, cowpea paste, rigid plastic container, flexible plastic film and the subsequent “moinmoin” samples prepared using the packaging materials) were subjected to various analyses, using standard procedures, and these included the evaluation of phytochemicals (tannins, phenols, flavonoids, steroids, glycosides, phytates, oxalates, saponins, alkaloids and terpenoids); qualitative screening and quantitative assessment of phthalates using Gas Chromatography-Mass Spectrometry, while data analysis was carried out using Statistical Package for Social Science. Results obtained from qualitative evaluation of T. daniellii leaves and cowpea paste revealed the presence of phytochemicals such as tannins, phenols, flavonoids, phytates, oxalates, and saponins. The quantitative evaluation of the phytochemicals present showed lower values in “moinmoin” samples through thermal degradation and interaction between the packaging materials and the food product. The gas chromatography–mass spectrometry analysis carried out on the rigid plastic container and flexible plastic film showed a total of 82 and 22 chemical constituents present in them respectively. The compounds identified were majorly hydrocarbons. Phthalates were particularly identified to have migrated into “moinmoin” from both rigid plastic container and flexible plastic film materials, respectively. The concentration of phthalate in “moinmoin” present in rigid plastic container was 1.745×10-4 mg/100 g while “moinmoin” sample prepared with low
density polythene contained 4.818×10-5 mg/100 g. Both rigid plastic container and flexible plastic film materials samples were below tolerable daily intake of 0.15 mg/100 g according to the Commission Regulation (European Union) No. 10/2011. It can be concluded that there was migration of chemicals (phytochemicals and phthalates) from the packaging materials into “moinmoin” samples during processing.
