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Triple
simultaneous stabilizing action of rosemary spice (Rosemarinum
officinalis L.) in full-fat soya based flour rich in
protein and β-carotene
S. O. Oiye*, A. M. Mwangi,
J. K. Imungi and J. J. Sehmi
Department
of Food Technology and Nutrition, College of Agriculture and
Veterinary Sciences, University of Nairobi, P. O. Box 29053,
Nairobi, Kenya.
*Corresponding author. E-mail:
oiyeshad@gmail.com.
Accepted 23
April 2009 |
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This study aimed at demonstrating the stabilizing effect of
up to 0.4% (wt/wt flour) of rosemary spice (Rosemarinum
Officinalis L.) in a flour-based protein-rich product
intended for young children. The flour was made of full-fat
soya flour, meat (beef) powder, and carrot flour as
β-carotene source. Analysis was done for proximate
composition, β-carotene content, microbial load and sensory
evaluation for rancidity over time. Different levels of
rosemary spice salvaged a net of 3.42 - 3.83 mg/100 g of
β-carotene within a storage period of 7 weeks at 35°C
accounting for up to 18% of β-carotene sparing as compared
to the non-spicy sample. There was, however, no evidence of
increased protection of β-carotene with increase in rosemary
spice concentration. Rancid odors and flavour were detected
in samples with spice, latter than in samples with no spice.
Rosemary spice exhibited up to a net of 38% reduction in
microbial load in spicy samples as compared to the non-spicy
sample. In a protein, fat and β-carotene rich flour-based
product, rosemary spice exhibits triple stabilizing action.
The phenolic compounds (rosemarinic, carnosol and carnosic
acid) in rosemary spice limits β-carotene degradation and
decelerates the production of secondary products of lipid
oxidation while the terpene fractions are implicated for
halting the proliferation of micro-organisms.
Key
words:
Rosemary spice, high protein β-carotene-rich flour,
antioxidant effect, antimicrobial effect. |
