This study was conducted to optimize the production of spray-dried white dragon fruit (Hylocereus undatus) powder using resistant maltodextrin as wall material. The inlet air temperature (140 °C, 150 °C and 160 °C), outlet temperature (75 °C, 80 °C and 85 °C) and resistant maltodextrin concentrations (20%, 25% and 30%) were tested as independent variables. Process yield, moisture content, water activity, solubility, hygroscopicity and bulk density of the powders were analysed as responses. Process yield significantly (p
The effect of mixed strain culture of lactic acid bacteria (LAB) and Yeast, and yeast or L.
brevis, L. plantarum, or L. sanfranciscencis on the physicochemical properties (pH, TTA,
organic acid, ethanol, and sugar content) of rice bran sourdough was investigated. Starter
culture with optimum physicochemical properties was used to ferment rice and wheat bran
for sourdough production. Rice and wheat bran sourdough and non-fermented rice and
wheat bran were mixed with wheat flour at 10% substitution level for bread production.
Results showed that rice bran fermented with L. plantarum had the best physicochemical
properties compared to rice bran sourdough produced by other LAB or mixed culture. The
specific volume of bread sample made with rice bran sourdough (4.65 cm3
/g) was higher
than that of the bread samples made from wheat bran sourdough (4.32 cm3
/g) and nonfermented
bran (3.74 – 4.24 cm3
/g), but not significantly different from the control (100%
wheat) bread (4.85 cm3
/g). The crumb colour of the rice bran and rice bran sourdough
substituted bread was lighter than that of the other bread samples. Crust colour of all the
bread samples was not significantly different (p > 0.05). At the end of 6 days storage
period, bread samples from control and wheat bran sourdough were firmer than that from
rice bran sourdough, however, crumb firmness values were highest in non-fermented bran
substituted bread. Sensory analysis result revealed that rice bran sourdough bread was
more acceptable than wheat bran sourdough bread, and non-fermented rice and wheat bran
substituted bread.
The nutritive value of spontaneously fermented brown rice flour medida, a Sudanese cereal thin porridge, is low. This study was carried out to improve the nutritional quality of medida. The flour was soaked and malted at 30◦C to optimise the protein content. Flour malted for two days had the highest protein content. Skim milk was added to the malted brown rice flour medida and fermented using Bifidobacterium longum BB 536. Maximum count of B. longum BB 536 up to 9 log CFU/ ml was attained at 4.6 final fermentation pH. The resultant viscosity was similar to that of the spontaneously fermented brown rice flour medida. There was significant (P< 0.01) increase in both the energy density and the protein content, having increased 12 folds and 24 folds, respectively. The essential amino acids including lysine and methionine were highly augmented. The resultant medida have stable flowing characteristics and meet the whole protein and energy requirements for infants and children aged 1 - 10 years old.