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Oiye,
S. O., Muroki, N. M.
Applied
Nutrition Programme, Department of Food Technology and Nutrition,
Abstract
In
this era of increased concern on safety of chemical food additives,
natural methods of preservation and natural preservatives are
receiving increased attention. Despite their demonstrated potential
use in food as preservatives, spices still remain primarily as food
condiments. A lot of research has been done in the effort to
demonstrate the antimicrobial potency of spices in cultured media.
Though spices are less effective in foods than in cultured media, it
is the use in foods that is of practical importance. This has not been
exploited vis-a-vis the chemical additives. The antioxidant components
of spices have been investigated but with minimal commercial
utilization. Spices mostly used as antimicrobials and antioxidants do
not exhibit toxicity at levels consumed. These are
therefore evidently a group of plants, which have not fully
been utilized in food technology. This review discusses and evaluates
the antimicrobial and antioxidant potency of spices and advocates for
more research and commercial utilization in foods.
Key
words: Spices,
chemical additives, anti-microbials, antioxidants
2.
Simple and Low-Cost Exposed -Layer Grain Drying Apparatus
1Tilahun
Seyoum Workenh* and 2Patrick.
M. Grace
1Alemaya
University, College of Agriculture, Department of Agricultural
Engineering, P.O.Box 138, Dire Dawa, Ethiopia
2University
College Dublin, Faculty of Engineering and Architecture, Department of
Agricultural and Food Engineering, Earlsfort Terrace, Dublin 2,
Ireland.
*Corresponding
author
Abstract
Thin-layer
drying apparatus was developed from standard “off-the- shelf”
equipment: a fan convection laboratory oven and a weighing scale.
Using this apparatus the thin-layer drying data for wheat under
constant conditions were obtained for a range of drying air
temperature from 30°C to 150°C and the initial moisture content from
0.20 to 0.42 (d.b.). The smooth drying characteristic curves were
obtained and used to develop coefficients for three thin layer models
namely: Grace (modified Henderson) model, Chen and Johnson, and the
numerical diffusion models. The
Grace and the Chen and Johnson models were the best at describing the
drying curves giving a standard error of the moisture ratio less than
0.027. The drying apparatus enables monitoring of the sample weight
during drying without opening the oven. The drying air properties
(relative humidity and temperature) inside the oven were kept constant
throughout drying. The next special feature of it was that the sample
kept on drying even at the time of recording its weight. No
temperature change was observed after the oven was switched on after
30 seconds. This apparatus is relatively simple and can be used for
drying of biological materials. However, several thin-layer grain
drying researchers have obtained moisture loss by using fast sampling
devices through out the drying period. During the study a fast
sampling device was not used because it was necessary to turn off the
oven before taking measurements.
Key
words: Drying
apparatus, thin-layer grain drying, drying model
3.
Sensory Properties of traditionally-fermented buttermilk
Bille,
P.G., Ozuuko, A.T.R. and Ngwira, T.
Department
of Food Science and Technology, Faculty of Agriculture and Natural
Resources, University of Namibia,
Abstract
An
investigation was carried out to test the hypothesis that the main
problems of traditionally-fermented milk products processed in the
rural setup are based on variable sensory quality, hygiene and
unattractive presentation to consumers. Sensory evaluation scores of 9
samples of traditional fermented buttermilk and control buttermilk
from ten panelists for appearance, smell, taste and consistency on a
5-point hedonic scale were subjected to analysis of variance (ANOVA)
to judge whether or not differences existed for various
characteristics (p<0.05
and p<0.01). Those which showed differences between the means were
subjected to Duncan’s Multiple Range Test. The results showed that
the means of control samples differed significantly from other means
and scored the highest points in all characteristics. The control
samples were then considered superior.
4.
Development of Models for Predicting the Yield and Quality of Soymilk
T.
Y. Tunde Akintunde and B. O. Akintunde
Department
of Mechanical Engineering, the Polytechnic, Ibadan
Federal
College of Agriculture, PMB 5029 Moor Plantation, Ibadan, Nigeria
Abstract
Models
were developed to predict the yield and quality of soymilk, one of
soybean products. The quality characteristics investigated were total
solids, protein content and fat content. The processing parameters
considered were Amount of water added during grinding per Kg of dry
seed, AW; Blanching time, BT
and Heating time, HT.
The
models developed had coefficient of determination ranging from 0.78 to
0.99. Predicted values of the dependent variables compared quite well
with the observed values when plotted against the independent
variables. The predicted coefficients were also statistically
significant (P< 0.05). Results showed that the yield and quality
characteristics were affected by all the processing parameters. Hence,
the production process must be effectively monitored to process
soymilk of high yield and quality.
5.
Indigenous processing methods and raw materials of borde,
Kebede
Abegaz1 2 *, Fekadu Beyene2,
Thor Langsrud1 and Judith A. Narvhus1
1
Department of Food Science, Agricultural University of Norway, P.O.Box
5036, N-1432 Ås, Norway.
2
Awassa College of Agriculture, Debub University, P.O.Box 5, Awassa,
Ethiopia.
*Corresponding
author
Abstract
A
study of village-level processing techniques and raw materials used
for the production of borde was carried out using open-ended
questionnaires and on the spot interviews with producers at six
localities in southern Ethiopia. The major focus of the study was on
indigenous processing methods, types and proportions of ingredients,
sources of energy, shelf life, sensory properties and the importance
of borde for household food security. From results of the
study, borde was characterized as an opaque, effervescent,
whitish-grey to brown coloured beverage with a thick consistency and
sweet-sour taste. It may be prepared from grits/flour of unmalted
maize, barley, wheat, sorghum and/or finger millet and their malts
using locally available earthenware and metal equipment. The type of
unmalted cereal ingredients and amount of malt used for borde
preparation varied within and between localities and were selected
according to availability, price and preferences. A flow chart of borde
production was constructed showing four major processing stages. The
short shelf life of borde and the seasonal variations in
production volume were identified as major problems for the vendors in
the study areas.
Keywords:
indigenous
methods; cereal fermentation; borde; beverage; Ethiopia
6.
Microbial and Sensory Quality of Freshly Processed and Reconstituted
“Kununzaki”-
A Nigerian Millet Based
Beverage
*J.M.
Babajide, O. O. Atanda, M. A. Idowu, and O. O. Lasekan
Department
of Food Science and Technology, University of Agriculture, PMB 2240,
Abeokuta, Nigeria.
*Corresponding
Author
Abstract
The
microbial and sensory qualities of freshly processed and reconstituted
Kununzaki beverages prepared from steeped millet grains were carried out. The samples were analysed for Aerobic plate, Fungi, Coliform,
Staphylococcal, Salmonella and Shigella counts. The samples were also evaluated for difference and
preference. The study
showed that the reconstituted beverage had better microbiological
quality with detectable difference between the two samples
with the fresh sample being preferred.
Key
words: Millet
grains, Kununzaki, microbial quality, sensory quality.
7.
Evaluation of Capsicum as a Source of Natural Antioxidant in
Elizabeth
Maforimbo
Department
of Research and Specialist Services,
Abstract
Solvent
extraction to obtain oleoresins of flavonoid and carotenoid extracts
was done from 200 grams of commercial paprika powder. Petroleum ether
was used to defat the sample. Methanol and n-butanol were used in turn
to extract the polar flavonoids, while chilled acetone and petroleum
ether were used in turn for the extraction of nonpolar carotenoids.
The
flavonoid yield was 5.92grams while that for the carotenoids was 39.15
grams per 100g of the powder. These residues were tested on sunflower
oil to evaluate their antioxidant effects. The accelerated methods
used for oxidation were the Automated Rancimat, Oven heating and UV
light at 254 nm. The oxidation of sunflower oil was measured using
changes in peroxide values and the UV absorbances (Conjugated diene)
at 232 nm, E1% 1cm.
The
extracts tested possess antioxidant effect and this phenomenon was
enhanced by increasing their concentration, since they were impure.
The major components of paprika (b-carotene and capsanthin) were also
tested on the oil as pure standards while Butylenehydroxytoluene (BHT)
was used as a standard antioxidant.
Results
showed that carotenoids seemed to be effective in retarding oil
peroxidation under photoxidation, while showing pro-oxidant activity
under oven heating autoxidation, and showing slight antioxidant
activity under Rancimat autoxidotion tests. The flavonoids were
effective in retarding oil oxidation under both photoxidation and
thermal autoxidation tests, with the column separated fractions 3 and
4 conferring better antioxidant activity under the Rancimat test.
These column separated fractions, were identified by the UV Spectra as
3-hydroxyflavanones or dihydroflavonols.
Key words: Paprika,
Carotenoids, Flavonoids, natural antioxidants.