Influence of storage on chemical, microbial and consumer acceptability of a milk-like product made from melon seeds.

The storage stability of melon milk at room (30 +/- 2 degrees C) and refrigeration (10 +/- 2 degrees C) temperatures was determined by analyzing changes in the chemical, microbial and sensory properties of the milk stored for 7 days. The results showed that at both storage temperatures, soluble solids and pH of the milk decreased while titratable acidity increased with storage. The standard plate counts increased appreciably while coliforms were absent in the milk with storage at both storage temperatures. The overall acceptability score of the melon milk dropped during storage, the drop being faster at 30 +/- 2 degrees C than at 10 +/- 2 degrees C. The milk samples stored at 30 +/- 2 degrees C and 10 +/- 2 degrees C were acceptable only within one and three days, respectively; thereafter, they were unacceptable.

Quality attributes of fermented yam flour supplemented with processed soy flour.

Pretreated soy flour was used to replace 10, 20, 30 and 40% of fermented yam flour as a protein supplement. The effect of the supplementation on the physicochemical and sensory properties of 'amala', a popular West African food made from rehydrated yam flour, was investigated. Blanching (10 min in boiling water) and subsequent fermentation (24 h) as pretreatment methods produced flour that was lighter in color than the unfermented samples. Protein content of the yam-soy mixture increased from 3.5% in the control to 19.7% for 40% soy fortification. Water binding capacity increased from 212.6 g/100 g for the yam flour control to 257.3 g/100 g for the blend with 40% soy flour. However, swelling capacity and solubility were adversely affected with increased soy flour addition as dough became sticky and soft. There was no significant difference in color, taste, flavor or overall acceptability when compared with the control up to 20% soy substitution. Dough with 20% soy flour is a possibility for increasing the protein content of yam flour in human feeding.

Microorganisms associated with natural fermentation of Prosopis africana seeds for the production of okpiye.

Okpiye is a food condiment prepared by the fermentation of Prosopis africana seeds. The traditional process for the production and microbiological characteristics of the condiment were investigated. During laboratory fermentation that lasted 96 h, the mesquite seeds underwent a natural fermentation that was characterised by the growth of microorganisms to 10(6)-10(8) cfu/g. Several species of bacteria especially B. subtilis, B. licheniformis, B. megaterium, Staphylococcus epidermidis and Micrococcus spp were found to be the most actively involved organisms. However, significant contributions to the microbial ecology were made by Enterobacter cloacae and Klebsiella pneumoniae. Lactobacillus spp were present in low numbers towards the end of the fermentation. The presence of Proteus and Pseudomonas spp in traditional fermented samples demonstrate the variability which may exist in the microflora of individual fermented samples. Variations in the important microbial groups show that Bacillus spp were the most prevalent species and occurred until the end of fermentation. Temperature, pH and titratable acidity varied with time and were influenced by the metabolic activities of the microorganisms.