Open Access Short Research Article

Microbiological Quality and Sensory Properties of Tarhanas Produced by Addition Saccharomyces cerevisiae and Sourdough as Starter Culture after Different Fermentation Periods

Fatma Coskun

Asian Food Science Journal, Page 1-8
DOI: 10.9734/AFSJ/2019/45492

Aims: The aim of this study was to investigate some effects of different starter cultures (Saccharomyces cerevisiae and sourdough) and different fermentation times (7, 14 and 21 days) on tarhana.

Place and Duration of Study: Food Engineering Department, Namık Kemal University, Tekirdag, Turkey,  October 2017.

Methodology: Wheat flour, full-fat commercial set-type yoghurt made from cow milk, starter culture (sourdough and dried baker’s yeast as Saccharomyces cerevisiae), fresh red pepper, onion, tomato, dill, parsley, dry mint, table salt and ground black pepper were used as materials. Tarhana doughs prepared using these materials were fermented for 7, 14 and 21 days. Physicochemical and microbiological analyses of tarhana samples were performed using standard methods. Tarhana soups were evaluated by panelists in terms of sensory properties at the end of the 21st day.

Results: pH values of baker's yeast added samples were lower than the others and their acidity were higher than the others during the fermentation period. Dry matter of samples increased with the prolongation of fermentation time. The dry matter of the sample produced using baker's yeast was slightly higher than that of the other sample at day 21. Total mesophilic aerobic bacteria and lactic acid bacteria (mesophilic rod) counts of tarhana samples with sourdough were always higher than the others during the fermentation. Yeast-mould counts of tarhana samples with baker’s yeast decreased slightly during the fermentation period, but were higher than the others. The coliform group bacteria was not detected on the 7th day of fermentation. Samples were left to fermentation for 7 and 14 days were less favoured than those were left to fermentation for 21 days. On the 21st day of fermentation, the sample added dry baker’s yeast was the most favoured sample.

Conclusion: As a result of the sensory analysis, considering the total score, although the difference between them is slight, baker's yeast added tarhana soups were more favoured than the others. Also, with the prolongation of the fermentation period, in terms of sensory properties, tarhanas were more favoured and microbiologically safer tarhanas were obtained.

Open Access Original Research Article

Molecular Characterisation of Bacteria Isolated from Various Part of Chicken (Gallus gallus domestica) Meat

S. A. Wemedo, S. I. Douglas, L. K. Nima

Asian Food Science Journal, Page 1-11
DOI: 10.9734/AFSJ/2019/45411

Aims: To investigate the types of bacteria found in the different parts of Chicken meat using biochemical and molecular techniques.

Study Design: Poultry birds were bought and processed in the respective markets by the butchers. Four parts of the poultry meat were minced and placed in sterile bottles which were taken to the lab for analysis. The control was bought and processed in the laboratory.

Place and Duration of Study: The Mile three and Mile one markets which are amongst the major markets in Port Harcourt metropolis, Rivers State, Nigeria were the area under study. The study duration was for three months.

Methodology: Ten gram of four parts (intestine, gizzard, muscle and skin) each was weighed and transferred into test tubes containing 90ml sterile normal saline. Subsequent 10-fold serial dilution was carried out and aliquots of preferred dilutions were inoculated unto Nutrient and MacConkey agar (TM media, India) plates. Incubation for 24 hours at 37°C followed. Resulting colonies were enumerated and distinct colonies were subcultured to get pure isolates followed by biochemical tests to identify the isolates. The boiling method of extraction was used in extracting the DNA of the various isolates. rRNA genes of the isolates were amplified using the 27F and 1492R universal primers on a ABI 9700 Applied Biosystems thermal cycler at a final volume of 25 µl for 35 cycles.

Results: The total heterotrophic load of the skin ranged from 0.2×108 to 5.5×108 Cfu/g. the bacterial load of the muscle, intestine and gizzard ranged from 0.0×108 to 1.0×108 Cfu/g; 1.2×108 to 2.9×108 Cfu/g and 1.7×108 to 2.0×108 Cfu/g. The coliform load of the skin ranged from 0.2×105 to 2.2×105 Cfu/g, while the total coliform of the muscle, intestine and gizzard ranged from 0.1×105 to 1.9×105 Cfu/g, 1.1×105 to 1.5×105 Cfu/g and 0.2×105 to 2.0×105 Cfu/g respectively. Nine bacteria genera which include Salmonella, Shigella, Vibrio, Enterococcus, Staphylococcus, Chryseobacterium, Aeromonas, Acinetobacter and Escherichia species were isolated and identified.

Conclusion: The bacteria identified in this study could be pathogenic if foods are not properly prepared. Thus, chicken meats should be properly processed to avoid cross contamination.

Open Access Original Research Article

Determination of Optimum Processing Conditions for the Proximate Composition and Pasting Characteristics of Flour Made from Parboiled Cassava Chips: A Response Surface Analysis

M. Ogbonnaya, M. O. Iwe

Asian Food Science Journal, Page 1-13
DOI: 10.9734/AFSJ/2019/44825

The effects of processing conditions on the proximate composition and pasting properties were investigated using A Rotatable Central Composite Design (RCCD) for three variables. Processing conditions included parboiling time (10, 12, 13, 14 and 15 min), soaking time (24, 36, 48, 60 and 72h) and drying temperature (40, 45, 50, 55, and 60 ℃). Response data on the pasting properties were analysed in a regression model while the three-dimensional graphs were plotted. Crude protein, fat and fibre contents significantly decreased with increase in soaking time from 24 to 72h. There was also a significant decrease of peak viscosity (from 260.60 – 380.33 to 260.60 RVU) and peak time (from 4.82 to 3.54 min) with an increase in the time of soaking the parboiled cassava chips samples from 24 to 72 h. Increasing the soaking time beyond 48h resulted to increase in breakdown viscosity (175.30 – 221 RVU) of the parboiled cassava flour samples. The breakdown viscosity of the flour samples also decreased significantly with increase in drying temperature from 40℃ to 60℃. There was a decrease in the final viscosity (228.00 to 184.83 RVU) with an increase in the cooking time of cassava parenchyma from 10 to 15min. The optimum processing conditions were found to be parboiling time of 12 min (x1), a soaking time of 24 h (x2), and drying temperature of 60℃ (x3).

Open Access Original Research Article

Nutritional, Elemental and Amino Acid Profile Analyses of the Seeds of Aspilia africana: A Neglected and Underutilized Species (NUS)

Gambo Nanbol Ndam, Bakji Gomerep, Gosomji Andrew Dewan, Ibejekwe Sunday Igwebike, Apagu Thliza Ngamarju, Ayuba Stephen Dapel

Asian Food Science Journal, Page 1-8
DOI: 10.9734/AFSJ/2019/45776

This study was designed to investigate the nutritional, anti-nutritional, amino acid profile and elemental constituents of the seeds of Aspilia Africana; a neglected and underutilized species (NUS). The nutritional and anti-nutritional contents of A. africana was determined using standard methods. The nutritional analysis showed the presence of carbohydrate (39.40±0.17%), crude protein (21.78±0.24%), fat (20.80±0.25%), ash (6.95±0.44%), crude fiber (9.70±0.25%) and moisture (1.31±0.02%). Anti-nutrients present include; oxalate (0 33±0.02%), saponins (2.96±0.04%), alkaloids (3,99±0.02%), phytate (0.13±0.00%), tannins (155.09±0.78 mg/100 g) and cyanogenic glycosides (4.30±0.06 mg/100 g). Amino acid profile was determined using the model 120a PTH amino acid analyzer. All essential and non-essential amino acids were detected. The seeds were found to be rich in amino acids (12.26 g/100 g-2.19 g/100 g), except for tryptophan (1.02 g/100 g) and cysteine (1.15 g/100 g). Macro and micro minerals found include: Calcium (Ca), potassium (K), Sulphur (S), Phosphurus (P), Iron (Fe), Copper (Cu), Rubidium (Rb), Manganese (Mn), Rhenium (Re), Gold (Au), Chromium (Cr), Nickel (Ni), Zinc (Zn) and Strontium (Sr). This shows that A. africana seeds are rich in nutrients and capable of ameliorating the acute food shortage being experienced the world over.

Open Access Original Research Article

Physicochemical Properties and Mycological Quality of Wheat Flours Consumed in Calabar, Nigeria

Jeffrey A. Nosa-Obamwonyi, Sylvester P. Antai

Asian Food Science Journal, Page 1-9
DOI: 10.9734/AFSJ/2019/45641

This study was primarily aimed at investigating the physicochemical properties and mycological quality of white wheaten flour, wheat semolina and whole wheat meal produced and/or sold in Calabar. Ten (10) samples of each flour type were bought from ten different locations, and analysed using standard methods. Physicochemical parameters analysed were pH, moisture, crude ash, crude fat, gluten, crude protein and falling number. Mycologically, total fungal count (TFC) was also determined. The results showed that the physicochemical parameters of all but the ash contents of five white wheaten flour samples and the fat content of one white wheaten flour sample did not conform to Standards Organisation of Nigeria (SON) standards. One-way analysis of variance (ANOVA) showed that there were significant differences (< 0.01) between the three wheat flour types for ash, fat, gluten protein, falling number and TFC only Post-hoc analysis using Tukey’s honestly significant (HSD) test revealed ash, fat and TFC of the three wheat types were significantly different (< 0.05) from each other; the gluten and protein for both white wheaten flour and wheat semolina were significantly different (< 0.05) from whole wheat meal and; falling number for white wheaten flour was significantly different (< 0.05) from both wheat semolina and whole wheat meal. Although TFCs of the thirty samples conformed to SON standards, some fungi species with serious health implications were identified. This study highlights the need for a concerted effort towards ensuring that wheat flours produced conform to standards.