title: Studies on the influence of temperature, relative humidity and microenvironment on the natural fermentation of African oil bean seeds to 'Ugba'.
abstract: Studies on the enhancement of the traditional production of 'Ugba' (a protein-rich fermented food) from African oil bean seeds were undertaken by fermenting the bean seeds at different temperatures, relative humidities (RH) and microenvironments. Fermentation was monitored by pH, texture, amino-nitrogen content and the viable cell count of the substrate. The 40 degrees C, 98% RH or the 130 microm high density polyethylene (HDPE) treatment increased the fermentation microflora from ca. 10(6) CFU/g to ca. 10(8) CFU/g with high initial changes in pH (5.8-ca. 7.9) and texture (2.0 kg/cm2 to between 1.4 kg/cm2 and 0.9 kg/cm2) in 24 hours. Products with amino-nitrogen contents of between 12.00 mg N/100 g dry matter and 14.00 mg N/100 g dry matter were obtained in 3 days. The cell count of the 30 degrees C, 80% RH or 70 microm treatment increased from 10(6) CFU/g to ca. 10(7) CFU/g and the pH increased from 5.8 to about 6.7 with a coincident decrease in the texture value from 2.0 kg/cm2 to about 1.7 kg/cm2 in 24 hours. Products with amino-nitrogen contents between 15.00 mg N/100 g dry matter and 19.2 mg N/100 g dry matter were obtained after 3 days. Changes in the fermentation indicators were not significant at p < or = 0.05 (pH and texture) and at p < or = 0.01 (amino-nitrogen) after 3 days for the 25 degrees C, 59.9% RH or 50 microm low density polyethylene (LDPE) treatment. Products of fermentation at the combined optimal conditions (80% RH, 35 degrees C, and 70 microm HDPE) compared very well with the traditionally fermented products in terms of pH, texture and amino-nitrogen content.
authors.affiliation: School of Biological Sciences, Abia State University, Uturu, Nigeria.
authors.forename: N R
authors.initials: NR
authors.lastname: Isu
authors.forename: H O
authors.initials: HO
authors.lastname: Njoku
mesh_terms: D004777:Environment; D007887:Fabaceae; D005285:Fermentation; D005502:Food; D006801:Humans; D006813:Humidity; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen / Q000032:analysis; D010946:Plants, Medicinal; D012639:Seeds; D013696:Temperature
chemical_list: D009584:Nitrogen