African Journal of Agriculture and Food Security

African Journal of Agriculture and Food Security ISSN: 2375-1177 Vol. 12 (1), pp. 001-006, January, 2024. © International Scholars Journals

Full Length Research Paper

Investigating the bacteriocin production profiles of isolated lactococcal strains: A comparative analysis

Babalola Olubukola O.

Department of Microbiology, Olabisi Onabanjo University, Ago-Iwoye, Ogun State, Nigeria. P.O. Box9536, UI HeadQuarters, Ibadan. E-mail: [email protected].

Accepted 23 August, 2023

Abstract

Lactococcus lactis strains present in wara (local cheese), and nunu (skimmed sour milk) were isolated. These were L. lactis WO81 and N13L. Nisin assays were by agar diffusion test and turbidimetric assay. There was no successful detection of an inhibition zone with wara. However, L. lactis strain WO81 from wara was able to produce nisin. Exponential growth occurred for about 14 h after some lag phase. The optimum incubation time of 2 to 6 h was established. Nisin concentration decreased with a subsequent increase in the incubation period. The effect of inoculum size was found not to be conclusive but directional to an optimal size of 1.0% (V/V). The suitable working temperature of 30^oC and the pH value of 6 were discovered. Investigations into the phosphate sources revealed KH₂PO₄ as the best phos-phate source. A physiological link is proposed between these functions, growth and nisin concentra-tion. In the presence of sufficient glucose, growth was increased with the periodic addition of NaOH. Maximum nisin concentration was obtained when, at pH 6, the medium was buffered. In this study essentially it is noted that nisin has a lytic bactericidal mode of action.

Key words: Local cheese, ‘wara’, ‘nunu’, nisin, bacteria, bacteriocin.

African Journal of Agriculture and Food Security ISSN: 2375-1177 Vol. 12 (1), pp. 001-004, January, 2024. © International Scholars Journals

Key words: Pastry, chin-chin, incorporation, peanut.

African Journal of Agriculture and Food Security ISSN: 2375-1177 Vol. 11 (2), pp. 001-009, February, 2023. © International Scholars Journals

Full Length Research Paper

Nutritional value of diets based on a low-quality grass hay supplemented or not with urea and levels of cassava meal

G.  V. Kozloski^a,b, D. P. Netto^a, L. M. Bonnecarrère Sanchez^a, L. D. Lima^a, R. L. Cadorin Júnior^a, G.Fiorentini^a, C. J. Härter^a

^aDepartamento de Zootecnia (Animal Science Department), Universidade Federal de Santa Maria, Campus Camobi,Santa Maria, RS, Brazil, 97105-900.

Accepted 11 October, 2022

Abstract

Ten Polwarth ´ Texel lambs (30±1kg live weight (LW)), housed in metabolic cages and fed ad libitum a low-quality grass hay (Cynodon ssp.) were used in a replicated 5 × 5 Latin Square experiment to evaluate effects of non -protein N (NPN) and levels of a non- fibre carbohydrate (NFC) source (cassava meal) supplementation (0, 5, 10 and 15 g/kg of LW) on intake, digestibility, N retention, microbial protein synthesis and rumen fermentation. Hay intake and digestibility were not affected by NPN addition. Organic matter, N and digestible energy intake, as well as rumen microbial protein synthesis and N retention increased linearly (P<0.05) but, fibre intake and digestibility, decreased linearly (P<0.05) as NFC supplementation increased. Rumen pH, as well as rumen concentrations of ammonia, sugars, amino acids and peptides was significantly affected by supplementation and time after feeding (P<0.05). Hay utilization was not improved by N addition showing that it was not limited due a lack of N for rumen bacteria. Supplementing both NPN plus a NFC source improved nutrients intake but reduced forage use by ruminants. Although variations of rumen pH and sugars concentrations play an important role, the detailed mechanisms by which fibre digestibility is negatively affected by NFC supplementation needs to be elucidated.

Key words: Digestibility, Intake, Non-fibre carbohydrate, Non-protein nitrogen, Rumen fermentation, Tropical grass.

African Journal of Agriculture and Food Security ISSN: 2375-1177 Vol. 11 (2), pp. 001-019, February, 2023. © International Scholars Journals

Full Length Research Paper

QUALITY ASSESSMENTS OF YOGHURTS AND YOGHURT- LIKE PRODUCT FROM LOCAL PLANT MATERIALS (Cajanus cajan, Vignia ungiculata and Vignia subterranean)

Larry Williams,¹ and Kelvin Smith²

¹Department of Food Science and Technology, Abia State University, Uturu

²Department of Pure and Industrial Chemistry, Abia State University, Uturu.

Abstract

In recent years, research has been focused on creating foods with higher protein quality through the use of mixtures of cereals and legumes that are thought to be nutritionally balanced due to challenges with food security in underdeveloped nations.In this way, underutilized regional foods including Cajanus cajan (Fiofio), Vignia ungiculata (Akidi oji), and Vignia subterranea (Okpa) were blended with local plant raw materials to create yoghurts. Also, commercial Cowbell milk was used as a control in the yoghurt preparation. As a potential replacement for commercial starter cultures that contain lactic acid-producing bacteria, the investigation also evaluated the impact of utilizing sorghum and millet steep waters as starter cultures (Lactobacillus bulgaricus and Streptococcus thermophilus). Twenty-twoyoghurt samples were prepared (A1234, B1234, C1234 D, E123, F1234 and G123. They were subjected to proximate, phytochemicals, minerals, vitamins, chemicals, microbial analysis as well as sensory evaluation with a view of understanding the consumer acceptability of the products. Commercially acceptable yoghurt brand- Hollandia yoghurt was also analyzed and used as overall control (sample D). The data generated were analysed using one-way ANOVA followed by Tukey’s post hoc test and significant difference set at (p<0.05). The result indicated the presence of alkaloids (0.3 - 1.2mg), flavonoids (0.7 - 2.6mg), saponin (0.1 - 0.8mg), tanins (0.2 - 1.2mg) and oxalate (0.1 - 0.5mg). Vitamins, calcium (6.0 - 19.33mg), potassium (1.2 – 24.59mg), magnesium (0.70 - 6.65mg), sulphur (0.0 – 0.1mg) and phosphorus (78 – 166) were at acceptable levels. These and other parameters studied varied significantly (p<0.05) for samples fermented with commercial starter culture, sorghum and millet steep water. The microbial result revealed that total viable count (TVC) ranged from 1.0 x 10⁵ minimum to 7.2 x 10⁵ maximum, pathogenic bacteria was not seen (nil). Both total viable count (TVC) and pathogenic bacteria were in a tolerable level for the three cultures. The result showed significant differences (p<0.05) in aroma, appearance, taste, texture and overall acceptance among the different yoghurt samples and fermented cultures. Consequently, yoghurt was successfully produced from local plant raw materials and there is possibility of using sorghum and millet steep water as a substitute for commercial starter culture.  

Key words: Yoghurt, quality assessment, sorghum, millet steep and commercial starter culture.               

African Journal of Agriculture and Food Security ISSN: 2375-1177 Vol. 11 (1), pp. 001-010, January, 2023. © International Scholars Journals

Full Length Research Paper

Physicochemical and microbiological study on tunjanee – a traditionally fermented Sudanese food from groundnut (Arachis hypogaea) seed cake

Abu ElGasim A. Yagoub¹ and Thoria Abaker Ahmed²

¹Faculty of Agriculture, University of Zalingei, PO Box 6, Zalingei, Sudan.

²Ministry of Education and guidance, Nyala, Sudan

Accepted 05 October, 2022

Abstract

Tunjanee is traditionally prepared by fermenting groundnut (Arachis hypogaea L.) seed cake for 21 days. Physicochemical and microbiological properties of the seed cake and tunjanee were analyzed. Tunjanee fermentation resulted in significant changes in major nutrients of the seed cake. Mineral content, total polyphenols, phytic acid and in vitro protein digestibility of the cake were not affected. Mobilization of amino acids content was found. The significant increase in total acidity and fat acidity coupled with a decrease in pH suggests microbial hydrolysis of the major nutrients. Bacillus and Lactobacillus spp. are the main active organisms in tunjanee. The number of total bacteria and yeast increased significantly within 21 days of fermentation. Staphylococcus aureus was absent. Coliforms and faecal coliforms were detected in groundnut cake; however, they increased significantly in tunjanee. A significant lower viable cells count of total bacteria and coliforms after addition of combo salt was observed.

Keywords: Arachis hypogaeae; fermentation; tunjanee; in vitro protein digestibility; physicochemical and microbiological properties

African Journal of Agriculture and Food Security ISSN: 2375-1177 Vol. 11 (1), pp. 001-007, January, 2023. © International Scholars Journals

Full Length Research Paper

Volatile compounds in Ikivunde and Inyange, two Burundian cassava products

Nzigamasabo Aloys

Université du Burundi, Institut Supérieur d’Agriculture, Département de Technologie des Industries Agro-Alimentaires, BP 35 Gitega, Burundi. E mail : [email protected]: Tel: +257 79 478 534

Accepted 12 October 2022

Abstract

The formation of volatile compounds in cassava roots, in non-fermented flour, in Ikivunde and in Inyange was investigate. Aldehydes flavor compounds were numerous in dried Ikivunde than in other cassava products. Non-fermented cassava flour had numerous acids, followed by dried Inyange, and then dried Ikivunde. Undried Inyange had numerous esters than any other cassava products, however, many of these esters are not found in dried Inyange. 1,3-butanediol, 2-butanol, acetone, 2-butanone and acetic acid were relatively more abundant than other components in fresh cassava. 2-3 butanediol, benzeneethanol, nonanal, hexanal, acetoin and acetic acid were abundant in non-fermented cassava flour. 2-butanol, 1-hexanol, ethanol, hexanal, 2-butanone and acetic acid predominated in Ikivunde after fermentation.1-pentanol, 1-hexanol, ethanol, nonanal, hexanal, decanal, octanal, 2-octenal and acetic acid dominate in Ikivunde after drying. The major compounds in Inyange after fermentation were 3-methyl-1-butanol, L-linalool, benzeneethanol, isopropyl alcohol, 1-hexanol, acetoin, 2-methoxy ethyl acetate, methyl isovalerate, methyl-3- methyl-2-butanoate, p-menth-8-en-1-ol acetate, isopropyl tiglate, p-menth-1-en-8-ol-acetate and acetic acid. In dried Inyange, 2,3-butanediol, benzeneethanol, nonanal, hexanal, acetoin and acetic acid were the major volatile compounds. The results indicated that processing cassava roots by soaking, heap fermentation and drying gave cassava products with different flavor compounds. This was due to different microorganisms present in their processing.

Keywords: Ikivunde, Inyange, cassava roots, non –fermented flour, flavours compounds.