EFEECTS OF FERMENTATIONON THE NUTRIENT AND ANTI-NUTRIENT PROPERTIES OF Persea americana (Mill) AND Dacryodes edulis (G.Don) SEEDS

Abstract

Avocado (Persea americana) seeds and African pear (Dacryodes edulis) seeds were fermented to check the effects of fermentation on their nutrient and anti-nutrient properties. The seeds were obtained from “Oja Oba”, Akure. Unfermented and fermented seeds were dried for analyses. The fermentation process lasted for 96 hours. Microbial population, isolation and identification of microorganisms were carried out using standard microbiological method. Temperature, pH, titratable acidity, proximate, anti-nutrient and mineral analyses were determined at 24 hours intervals. Microbial population of bacteria in avocado seeds ranged from 4.90 x 103± 0.10e(cfu/g) – 0.00 x 103± 0.00a(cfu/g) while that of African pear seeds ranged from 5.55 x 103± 0.05d(cfu/g) – 3.05 x 103± 0.05a(cfu/g). Fungi population on avocado seeds ranged from 1.45 x 103± 0.05a – 2.25 x 103± 0.05c(sfu/g) while that of African pear seeds ranged from 1.05 x 103± 0.05c – 3.50 x 102± 0.05a(sfu/g). Lactic acid bacteria in avocado ranged from 1.45 x 103± 0.05b – 2.20 x 103± 0.00c(cfu/g) while that of African pear ranged from 1.00 x 103± 0.00d – 3.50 x 102± 0.05b (cfu/g). Temperature changes were between 32.050C±0.05c and 28.150C±0.15a for avocado seeds and between 31.700C±0.10c and 27.750C±0.05a for African pear seeds. The pH of avocado seeds decreased from 5.22±0.015d to 4.52±0.015a while the pH of African pear seeds increased from 6.07±0.15a to 8.70±0.05c. Titratable acidity of avocado seeds increased from 20.60±0.10ag/L to 27.60±0.10eg/L while that of African pear seeds decreased from 17.99±.015eg/L to 14.57±0.01ag/L. Ten microorganisms were isolated in all, six bacteria; Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Micrococcus luteus, Proteus vulgaris, Lactobacillus plantarum, four fungi; Rhizopus stolonifer, Fusarium solani, Aspergillus niger, and Aspergillus flavus. Similar microorganisms were observed in both seeds except three organisms, Proteus vulgaris was found in avocado seeds but was not in African pear seeds while Micrococus luteus was found in African pear seeds but did not grow on avocado seeds. Rhizopus stolonifer also grew on avocado seeds but did not grow on African pear seeds. Proximate composition showed that protein, ash, fat and crude fibre content of avocado seeds were enhanced by fermentation but only the fat content of African pear seeds was enhanced while the anti-nutrient properties of both seeds were reduced. The study showed that both seeds are composed of appreciable quantity of nutrients.