by Juliana Maina, Julius Maina Mathara, Gideon M. Kikuvi and Eliud Wafula
Original Research
The use of drugs and antibiotics has increased the resistance of pathogenic bacteria in both animals and humans. This has been a significant problem and therefore triggers the investigation of novel antimicrobial agents produced by a bacterial strain of low virulence and having antimicrobial activity with a wide range of clinical significance. The use of bacteriocin has been extensively used in food industries, animals, and pharmaceutical industries. This is because it has been linked to antimicrobial activity, which has specific self-protection mechanisms. This study sought to evaluate antimicrobial activity and characteristics of bacteriocin producing Bacillus subtilis against Mastitis pathogens. For the screening of the isolates for bacteriocin properties against mastitis pathogens, antimicrobial activity was done using well diffusion methods on the nutrient agar. The results were obtained after 24hours and 48hours. Physiochemical characterization of the bacteriocin from Bacillus subtilis was determined at different temperatures of 60°C to 121°C for 15 minutes and monitor the effect of the temperature. The bacteriocin was also prepared at different pH (3-9) and incubated at room temperature; each sample's residual activity was determined against the indicator organisms. Metal ions (Cu2+, Zn2+, and Fe2+) on crude bacteriocin activity were determined to assess the residual antimicrobial activity by agar well diffusion assay. The results showed that bacteriocins from Bacillus subtilis were effective against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumonia. Physiochemical characterization showed that bacteriocin from different isolates had no inhibition from pH 3-5 and varied inhibition from pH 6-9 across the test organisms' isolates. On the temperature, crude bacteriocins at a temperature of 50°C to 60°C showed no activity loss based on initial activity. As temperature increases to 70°C to 80°C, there is reduced the bacteriocin activity of about 20%. 100°C had a 40% loss of the bacteriocin activity and 121°C with more than 50% loss of the activity. On metal ions, Cu2+, Fe2+, Zn2+ had a varied effect on bacteriocin activity against test organisms.
American Journal of Food Science and Technology. 2021, 9(1), 20-29. DOI: 10.12691/ajfst-9-1-4
Pub. Date: April 20, 2021
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by Durodola Olamide I, Ogunmuyiwa Oluwafemi T, Olasoju Abayomi S, Salami Adams A and Ogunsina Babatunde S
Original Research
The mass, axial dimensions, shape indices, and some frictional related properties of alligator pepper (Aframomum meleguta) were investigated at moisture contents of 4.26 and 3.31% for the pods and seeds, respectively, following standard procedures. The average length, major and minor diameter of the alligator pepper pods were 53.83, 22.68, and 19.32 mm, respectively, while the corresponding values for the seeds were 3.61, 3.12, and 2.55 mm, respectively. The average seeds/pod weight was 4.11/5.63 g. The arithmetic mean diameter, equivalent diameter, sphericity, aspect ratio, and surface area were 31.80, 28.65, 0.54, 43.20 mm, and 2591.93 mm2, for the pods; and 3.09, 3.06, 0.85, 0.01 mm, and 29.39mm2, for the seeds, respectively. The coefficient of friction of the seeds ranged from 0.50 to 0.67 with respect to the surfaces that were considered. The angle of repose of the seeds was 20.09o. This study provides baseline information on alligator pepper seeds, these can be useful for in the development or adaptation of technologies for processing it into value-added products thereby boosting obtainable income thereof.
American Journal of Food Science and Technology. 2021, 9(1), 16-19. DOI: 10.12691/ajfst-9-1-3
Pub. Date: March 14, 2021
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by YAO Konan Mathurin, KOFFI Koffi Marc, KAMBIRE Ollo, DORE Guea Carine Esther, Rose KOFFI-NEVRY and BOLI Zamblé Bi Irié Abel
Original Research
Corn is one of the most consumed cereals in Côte d'Ivoire. The objective of this study is to assess the impact of the soaking time of corn kernels with or without potash on the fungal and physicochemical quality of their flour. The method used consisted of determining the pH of the different samples using a pH meter. For the water content, the method used was oven drying. Concerning the fungal load, the mould count was done on the DRBC medium and the subculture on the MEA medium. All these analyses were carried out with flour samples of two corn varieties (yellow and white corn with or without potash) according to three durations (6, 9 and 12 h) of grains soaking. The results obtained show that yellow or white corn flours without potash are acidic with pH values between 4.2 and 6.1 while those with potash are basic, with pH ranging from 7.7 to 9.9. The moisture content of all the flours obtained just after grinding the grains varies between 31.7 and 37.6%. Significant differences were observed between the water contents of the flours obtained at the three different soaking times. Thus, the water contents of the flour obtained after 6 h of soaking the grains are lower than those obtained after 9 and 12 h of soaking. All cornmeal samples analyzed showed high fungal loads (105 to 109 CFU/g). However, a slowdown in fungal growth was observed with the flour samples with potash. The different moulds isolated from corn flour and identified belong to the genera Aspergillus, Penicillium, Mucor and Rhizopus. The genera Aspergillus and Penicillium are potential producers of mycotoxins and therefore capable of causing poisoning in consumers of these flours.
American Journal of Food Science and Technology. 2021, 9(1), 8-15. DOI: 10.12691/ajfst-9-1-2
Pub. Date: February 05, 2021
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by Ahmed M. E. Ali, Laila A. Shekib, Nahed M. Elshimy and Magda S. Sharara
Original Research
This study aimed to produce sucrose free dark chocolate and low in calories in order to be suitable for diabetes and those wishing to lose weight or using it for other industrial purpose. Therefore, a suggested recipes were used to prepare low calories dark chocolate using four different intense sugar namely: steviosid, acesulfam-k, sucralose and inulin instead of sucrose with the addition of wheat fiber isolate. The prepared chocolate samples were compared to a sucrose sample (control) in which sucrose was used in its manufacture. Physical properties, chemical composition and sensory properties were determined as well as the caloric value. The results indicates that the caloric value was reduced by 28.46, 28.69, 28.65 and 36.14 % in the prepared samples using stevioside, acesulfam-k, sucralose and inulin, respectively, compared with the sucrose sample. A slight difference between the prepared samples and the sucrose sample has occurred in the physical properties and the chemical composition while the percentage of fiber content significantly increased in prepared low calorie chocolate samples. Although the inulin sample recorded the lowest caloric value among the rest of the prepared samples and the control one, it was more solid than the other samples as well as it showed some unpalatable taste by arbitrators, so the sample which prepared using stevioside was chosen to be the best one for the rest samples, where it has a reduction in the calories by 28.46%, compared to the sucrose one, with high quality properties. Effect of storage at (10°C) on the stability of stevioside sample was studied by estimating its value of each free fatty acids and peroxide values every 15 days during the storage period (3 months). The results confirmed the high stability of the stevioside sample during the storage period.
American Journal of Food Science and Technology. 2021, 9(1), 1-7. DOI: 10.12691/ajfst-9-1-1
Pub. Date: February 05, 2021
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