النشر العلمي

  • Quality Evaluation of Yoghurt Supplemented with Carrot Juice

In the present study, carrot juice was used in the preparation of
yoghurt using cow's milk. The effect of refrigerated storage (6C) in
the chemical and microbiological characteristics of yoghurt samples
was investigated during 1, 7 and 15 days of storage. The chemical
analyses showed that the moisture content was 88  0.4% in control
yoghurt in day 1 which was lower than those of carrot yoghurt
samples which ranged between 89  0.5% and 93  0.6%. The protein
content of control yoghurt (A), yoghurt supplemented with 5% carrot
juice (B1), yoghurt supplemented with 10% carrot juice (B2) and
yoghurt supplemented with 15% carrot juice (B3) was 4 ± 0.06%, 3.9
± 0.02%, 3.9 ± 0.01% and 3.8 ± 0.02%, respectively. The ash content
of carrot yoghurt samples ranged between 0.45  0.004% and 0.6 
0.07%. The total solids content was 12  0.7% in control yoghurt at
day 1 which was higher than those of carrot yoghurt samples (11 
0.3% and 7  0.6%). However, the total solids content of carrot
yoghurt decreased during storage. The acidity (expressed as lactic
acid %) increased progressively during storage of all yoghurt samples
while the pH decreased. The microbiological analyses revealed entire
absence of coliform bacteria during storage; however, few numbers of
yeasts were detected in the control yoghurt. On the other hand, the
total count of bacteria in control yoghurt was 3.3 x 104 c.f.u/ml at day
1 increased in carrot yoghurt samples to the range 3.5 x 104 - 4 x 104
c.f.u/ml. Also lactic acid bacteria increased in all yoghurt samples.
The sensory evaluation indicated acceptance of all yoghurt samples,
with preference to the yoghurt prepared using 5% carrot juice,
especially in its colour, texture and flavour.

published in Gezira Journal of Engineering and Applied Sciences Vol6 No1

  • Isolation, Identification and Characterization of Candida utilis from Some of the Sudanese traditionally Fermented Food Products

The aims of this study were to isolate, identify and characterize the yeast
Candida utilis (as a source of single cell protein SCP) from various local Sudanese
fermented foods (Kissra, Hulu Mur and Marisa). Hulu Mur samples were found to contain
the highest counts of yeast (6.89 cfu/g - 6.78 cfu/g) while the low counts were found in
Kissra samples (5.95 cfu/g - 5.84 cfu/g). Most of the C. utilis isolates had the same
biochemical profiles with some slight variations. The study showed that C. utilis can
utilize aerobically and anaerobically dextrose, sucrose, and raffinose and could assimilate
maltose under aerobic conditions only. The isolates could not utilize lactose, glactose,
cellubiose and arabinose under both aerobic and anaerobic conditions. It had an ability to
assimilate nitrate and grew at high concentration of ethanol. The study showed that the
biomass yield of C. utilis was 2.5 g\l using batch fermentation. On the other hand the
protein and moisture content of the product were 42% and 61%, respectively, therefore, it
can be used in the production of single cell protein (SCP).

published in Gezira j. of eng. & applied. 4 (2) :104 –114 (2009)

  • Chemical composition and in vitro protein digestibility of hulled and de-hulled Bambara groundnut ]Vigna subterranea (L.) Verdc.[ seeds

published in Gezira Journal of Agricultural Science ISSN 9556-1728 Vol 10 No 2

  • Quality and evaluation of syrup from local date (Phoenix dactylifera L.) cultivars

The objective of this work was to study the suitability of three local
cultivars of dates, namely; Barakawi, Mishriqi Wad Khateeb and Jawa for
the production of syrup. Date fruits were subjected to physical and chemical
analysis before the production of syrup. The processing operations are
extraction, filtration and concentration at atmospheric pressure. In addition,
the chemical, microbiological and sensory characteristics of date syrups
were evaluated immediately after processing. The results of the chemical
composition of date syrups indicated a relative high moisture content in
Mishriqi Wad Khateeb date syrup (32.4%) as compared with those of
Barakawi and Jawa date syrups which were 23.1% and 28.5%, respectively.
The ash content was 1.86%, 0.90% and 1.24% in Barakawi, Mishriqi Wad
Khateeb and Jawa date syrups, respectively. Also, the results indicated a
high percentage of total soluble solids in Barakawi date syrup (80.2%) as
compared with those of Jawa and Mishriqi Wad Khateeb date syrups which
were 74.2% and 69.5%, respectively. Total sugars were higher in Barakawi
date syrup (66.4%) when compared with those of Mishriqi Wad Khateeb
and Jawa date syrups which were 57.0% and 60.3%, respectively. The
highest contents of reducing sugars were found in Barakawi date syrup
(57.5%) followed by Jawa and Mishriqi Wad Khateeb date syrups which
were 55.2% and 50.2%, respectively. Titrable acidity was comparable in the
three date cultivars. The highest value of pH was found in Jawa date syrup
(4.48) as compared with Bara-kawi and Mishriqi Wad Khateeb date syrups
which were 4.03 and 4.16, respectively. The microbiological analysis of
date syrup samples revealed low levels of total microbial load. The sensory
evaluation indicated good acceptability for all samples of date syrups.
University Of Gezira
Journals Of University Of Gezira
Gezira Journal of Agricultural Science
ISSN 9556-1728 Vol7 No2
231

 

published in Gezira Journal of Agricultural Science ISSN 9556-1728 Vol7 No2

  • Extraction of pectin from some local fruits and its use in jam processing

In the present study, pectin was extracted from orange, grapefruit and guava fruits and used in jam processing. The percentages of pectin extracted from orange, grapefruit and guava powder were 28%, 26.4% and 2.8%, respectively. Jam made using pectin extracted from grapefruit (GrPJ), orange (OPJ) and guava (GuPJ) contained 66%, 67% and 67% total soluble solids, respectively. The reducing sugar contents of GrPJ, OPJ and GuPJ were 4.7%, 5%, and 4.1%, respectively, while the total sugar contents were 8.7%, 8.5% and 8.4%, respectively. The pH values of GrPJ, OPJ and GuPJ were 3.5, 3.4 and 3.6, respectively. Moisture contents of GrPJ, OPJ and GuPJ were 53.7%, 45.8% and 47.4%, respectively, and the ash contents were 0.23%, 0.18%, and 0.21%, respectively. The contents of sodium were 36, 34 and 35 mg/100g in OPJ, GrPJ and GuPJ, respectively, while the contents of potassium were 60, 68 and 69 mg/100 g, respectively. The contents of calcium were 80, 79 and 78 mg/100 g, respectively. The content of vitamin C of OPJ, GrPJ and GuPJ were 0.01, 0.02, and 0.02 mg/100g, respectively. Microbial analysis revealed that all jam samples were devoid of coliforms, staphylococci, yeasts and moulds. The sensory analysis indicated that all types of jams were accepted by panelists who preferred them in the order of jam made using commercial pectin followed by jam made using pectin extracted from orange, grapefruit and guava. Most panelists preferred the jam made using commercial pectin due to its appealing color and appearance.

published in Gezira Journal of Agricultural Science ISSN 9556-1728 Vol 9 No 2

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