BIOTRANSFORMATION DURING FERMENTATION OF UNDER-UTILISED SEEDS FROM Chrysophyllum albidum LINN, and Terminalia catappa LINN

Odutayo, Oluwatofunmi Esther and Covenant University, Theses (2021) BIOTRANSFORMATION DURING FERMENTATION OF UNDER-UTILISED SEEDS FROM Chrysophyllum albidum LINN, and Terminalia catappa LINN. ["eprint_fieldopt_thesis_type_phd" not defined] thesis, Covenant University Ota.

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Abstract

The majority of plant seeds are under-utilised because of their excessive antinutrient levels. As the quest for food security increases, approaches to reduce these antinutrients with food processing methods is now of importance. This study aims to investigate the biochemical changes in the natural fermentation of the C. albidum and T. catappa seeds, and characterise probiotic lactic acid bacteria associated with the fermentation process. The phytochemical and antioxidant assessments of extracts from the unfermented and fermented seeds were carried out and followed by the use of Gas Chromatography/Mass Spectrometry (GC/MS) for identification of phytochemical compounds. Their digestive enzymes (α-amylase, protease, and lipase) activities were also determined spectrophotometrically. Strains of lactic acid bacteria (LAB) were isolated from both fermented seeds and assessed for probiotic characteristics using biochemical and molecular methods. Significant (p<0.05) reductions in the levels of oxalate, phytate, tannin, and alkaloid in both seeds were observed after fermentation. The GC/MS analysis revealed a decrease from sixty-two compounds in the unfermented C. albidum seeds to thirty-nine in the fermented C. albidum seeds. There was also an increment from fifty-two compounds, in the unfermented T. cattapa seeds to fifty-three in the fermented T. catappa seeds. A significant decrease (p<0.05) was observed in the 2,2-diphenyl-1-picrylhydrazyl scavenging abilities of the fermented extracts from both seeds. C. albidum seeds had a significant (P<0.05) increase in only ferric reducing assay property (FRAP), but T. catappa seeds had significant reductions (P<0.05) in total antioxidant capacity (TAC) and FRAP after fermentation. There was a significant reduction (P<0.05) in the α-amylase activity in fermented C. albidum seeds, while fermentation significantly (P<0.05) increased the α-amylase activity in the fermented T. catappa seeds, and the activities of lipase in both fermented seeds. The protease activity was significantly increased in the fermented C. albidum seeds, while no significant difference was observed in the protease activities of the unfermented and fermented seeds of T. catappa. Three potential probiotic LAB strains isolated from the fermented C. albidum seeds, and seven from the fermented T. catappa seeds were identified using API 50 CHL and 16S rRNA sequencing. All strains were non haemolytic, which indicated their safety. Seven isolates grew in the acidic environment (pH 3.5) during the 48 hr incubation time, and all the ten strains grew in 1 % bile. All isolates from the fermented T. catappa seeds showed bactericidal activities against some selected pathogens, while all the strains showed good auto-aggregation properties. Fibronectin binding protein was detected in three of the isolates, while mucin binding protein was not detected in any, and bile salt hydrolase was detected in all the strains. A new isomer of di-hetero tricyclodecane, namely 2,5-methano-2H-furo[3,2-b]pyran,hexahydro- was identified in the fermented C. albidum seeds. The study established the prebiotic potentials of some phytochemicals present in the unfermented C. albidum and T. catappa seeds and thus reavealed that the isolated probiotics were unique to each seed, indicating that the growth of beneficial bacteria during the fermentation was partly dependent on their phytochemical components.

Item Type:	Thesis (["eprint_fieldopt_thesis_type_phd" not defined])
Uncontrolled Keywords:	Under-utilised seeds, Chrysophyllum albidum, Terminalia catappa, Fermentation, Probiotics
Subjects:	Q Science > Q Science (General) Q Science > QH Natural history
Divisions:	Faculty of Medicine, Health and Life Sciences > School of Biological Sciences
Depositing User:	Mrs Patricia Nwokealisi
Date Deposited:	18 Jul 2022 11:50
Last Modified:	18 Jul 2022 11:50
URI:	http://eprints.covenantuniversity.edu.ng/id/eprint/16099

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