Divair Christ

Physico-chemical properties of common beans under natural and accelerated storage conditions

S.R.M. Coelho, S.H. Prudencio, D. Christ, S.C. Sampaio, and V. Schoeninger. 2013. Physico-chemical characterization of common beans under natural and accelerated storage conditions. Cien. Inv. Agr. 40(3): 629-636. The common bean is an important food in the human diet. Certain storage conditions, high temperatures and high humidity, cause a texture defect that reduces the acceptability of common beans. The present study aimed at evaluating the effect of storage on the physico-chemical properties of common bean grains and the relationship between accelerated aging at 40 °C and 76% RH and storage under natural conditions. Two varieties of common beans (Iapar 81 – carioca variety and Iapar 44 – black variety) were stored at 40 oC and 76% RH for 15, 30, 45, 60 and 75 days to accelerate aging. The same varieties were stored under environmental conditions (natural aging) for 3, 6, 9 and 12 months. For both storage conditions of each variety, fresh beans stored at 5 oC were used as a control group. In all of the samples, hardness, pH, acidity and the soluble protein percentage were analyzed. Both storage processes, in the natural and accelerated conditions, caused an increase in acidity (4.0 to 5.9 and 3.2 to 6.4 g acetic acid kg -1 ) and a decrease in cellular pH (6.65 to 6.45 and 6.65 to 6.45) and protein solubility (77 to 54 and 76 to 38%). The greatest percentage changes in the parameters of acidity, pH and soluble proteins were observed in the beans in the accelerated aging condition. Beans’ hardness during storage has a negative correlation with pH, which shows that it is a good indicator of grain quality. Natural storage for one year is equivalent to accelerated aging for 45 days at 40 °C and 76% RH.

Acceptability of prebiotic fiber-treated whey drink fermented with Lactobacillus acidophilus

This work aimed to develop a fermented drink by diversifying the quantities of Lactobacillus acidophilus inoculum and prebiotic fiber in the form of inulin and using the total dry extract of whey and sucrose. After fermentation, the following measurements were made after 0, 7, 14, 21 and 28 days of storage at 6°C: titratable acidity (according to the Dornic method), pH, moisture content, fat content, ash content, protein content, lactose content and the probiotic cell count. After 28 days of storage, the viable L. acidophilus cell counts had decreased for all six treatments but were still above the minimum count of 7 log CFU/mL recommended by the Brazilian legislation. All samples presented satisfactory acceptability with the exception of treatment 6, in which the inulin was decanted, thereby altering the color and causing a decrease in acceptance. Keywords: Fermented milk, whey, probiotic microorganism, prebiotic, sensory evaluation. African Journal of Biotechnology Vol 13(25) 2565-2574