Evaluation of Fungi Species from Commercial Yoghurts in Birnin

Equity Journal of Science and Technology, 2019 6(1): 72 -77

ISSN; 2354 – 1814

EQUIJOST An Official Publication of Kebbi State University of Science and Technology, Aliero, Nigeria

Evaluation of Fungi Species from Commercial Yoghurts in Birnin Kebbi, Kebbi State Nigeria *1Keta, J.N., 2Suberu, H.A., 3Aliero, A.A., 4Mohammed, N.K., 1Anas, H., 1Mubarak, A. 1Department of Plant Sciences and Biotechnology, Kebbi State University of Science and Technology, Aliero, Nigeria 2Department of Biological Science, Federal University, Lokoja, Kogi State, Nigeria 3Department of Biological Science Federal University, Kalgo, Kebbi State, Nigeria 4Department of Microbiology, Kebbi State University of Science and Technology, Aliero *Corresponding author Email; [email protected];

Abstract

Yoghurt is frequently taken as a drink or prepared together with Fura in the northern part of Nigeria due to the quality of nutrients present. Five different commercial Yoghurts, namely Hamdala, Rufaida, Gamji, Alhilal and Batulah were purchased from distributors in Birnin Kebbi metropolis. Using culture growth medium (Potato dextrose Agar) and poured plate method, the fungi species present were analyzed. A total of five (5) fungal species were isolated and identified from the samples. These include Aspergillus niger, Aspergillus fumigatus, Penicillium, Fusarium species and Mucor species. The results obtained from the samples analyzed showed that the Yoghurts samples had fungal load in the range of 1.2 x 105 (as the lowest fungal count in Gamji and Hamdala Yoghurts) and 8.0 x 106 (as the highest fungal count in Batula, Alhalal and Rufaida yoghurts). The highest levels of fungal species identified from this study could be attributed to poor processing method, environment, equipment used and preservation method adopted by these industries. Thus, there is need for these Yoghurts industries to improve on the quality of their products by improving their processing method, proper hygienic environment, personnel as well as proper storing method.

Keywords: Fungi, Commercial Yoghurt, Birnin Kebbi

1. Introduction increased their nutritional qualities, which make it to have the same value as fresh milk [2]. Yogurt is a product of fermented milk that resulted from the need to prolong the shelf life Yoghurt is made from milk, which is known for to prevent milk spoilage [1]. However, not until ages. It is a custard-like food with a sour flavor in the 20th century when Yoghurt became a that is prepared from milk curdled by bacteria profitable commercially good product, Yoghurt such as Lactobacillus bulgaricus and manufacturers were not giving standards for its Streptococcus thermophilus that make it to have production. This however, have raised the value the same test and flavor as fruit [3]. The L. of Yoghurt products worldwide and also bulgaricus produces amino acids, which stimulate S. thermophilus to produce formic

Keta, J.N. et al.: Evaluation of Fungi Species from Commercial Yoghurts in Birnin Kebbi, Kebbi State Nigeria

acid. The presences of S. thermophilus revolve Yogurt could be contaminated with different the milk sour and produce a distinctive, typical microbial organisms among which the pleasant smell. Yoghurt can be produce using dominant ones are the molds or fungi. Some of animal milk depending on the resources these could be pathogenic in nature and some available and geographical location of the could cause spoilage of the product due to their industries as well as the consumer preferences metabolic activities on the specific products. [4]. Other substances apart from milk that are However, the unhygienic nature of preparation added during manufacturing of Yoghurt and production method, post production contribute in determining the state of the processes, environmental conditions Yoghurt condition [5]. surrounding the production and storage conditions are all necessary for the spoilage of Yoghurt is said to be low in saturated fatty acids Yoghurt products [11, 12]. Molds and yeast are and cholesterol level, but is nutritionally rich in the primary contaminants in Yoghurts produced protein and vitamins such as, calcium, iron, in Nigeria and other countries [13]. These potassium, and phosphorus, which maintain the microorganisms as they grow in Yoghurt, Red blood cells, improve the good function of utilize some of the acid present and cause a the nervous system in human body [6]. Yoghurt corresponding decrease in the acidity of the is said to prevent high blood pressure in Yoghurt, which may favor the growth of hypertensive people. The percentage of putrefactive organisms in the product. potassium in Yoghurt is higher having 600 mg Therefore, this research study aimed at per bottle container of Yoghurt, and these assessing and identifying the different fungal would help to flush the excess sodium and iron species responsible for the spoilage of Yoghurt out of the human metabolic system when taken products in the study area. and could also help in maintaining the normal activities or metabolic activities in the human 2. Materials and Methods body system [11]. The proteins, carbohydrate 2.1 Sample Collection and Serial Dilution and vitamins contents present in Yoghurt are found to be greater compared to those in fresh Yoghurt samples were collected from five (5) milk [7, 8]. However, there is little difference different Yoghurt companies in Birnin Kebbi between fresh milk and Yoghurt product in metropolis. From each company, five (5) terms of energy and sugar contents. This is to Yoghurt samples, packaged in plastic bottles, say that the sweeter Yoghurt provides more were collected to make a total of twenty-five energy when compared to fresh milk [9]. (25) samples. The five (5) Yoghurt product companies selected within Birnin Kebbi for the According to our research source, there are two sample collection were Gamji, Alhalil, Rufaida, types of commercially prepared Yoghurts Batulah and Hamdala. The samples collected produced in Birnin Kebbi metropolis. These were brought to the Department of Plant are: the powdered Yoghurt and the soft or liquid Science and Biotechnology, Kebbi State yoghurt. But the most commonly produced type University of Science and Technology, Aliero in Birnin Kebbi metropolis is the soft Yoghurt and the samples were kept refrigerated for one [10]. However, in Northern Nigeria Yoghurt is day before serial dilution. Two grams (2 g) of a very important product of “Fura” delicacy each sample was measured and added to a which gives Yoghurt its paramount importance conical flask containing 9 ml of distilled water as many people now prefer Yoghurt with Fura from which serial dilution was carried out up to than as it was originally known to be taken with seven places as describe previously [13]. fresh cow milk. 2.2 Culture media preparation

Keta, J.N. et al.: Evaluation of Fungi Species from Commercial Yoghurts in Birnin Kebbi, Kebbi State Nigeria

Potato Dextrose Agar (PDA) was used to result showed higher fungal load in Yoghurt culture the organisms. The medium was samples obtained from Alhalil, Rufaida and prepared according to the manufacturer’s Batulah Yoghurt companies (8.0 x 105 – 8.0 x instructions. The prepared media were allowed 106 colony). While Hamdala and Gamji to cool down over night before being poured Yoghurts had lowest fungal load (1.6 x 10 and into petri dish plates, which were then 1.2 x 105). incubated at 28 oC for 3-5 days. After five days, fungal growth was observed on the petri dish Table 3.1: Total Fungi count of five samples and the same method was used to sub cultured in replicates the fungal myclia on fresh medium in other to Colony Form No. of obtained pure culture the isolated [14]. Sample Name Per Unit Colony (CFU/g) 2.3 Fungi Identification Gamji Yoghurt 4 4.0×106 The fungi were identified using morphological Gamji Yoghurt 12 1.2×105 and cultural characteristics, type of fruiting 4 structure and spores produced and also, by Gamji Yoghurt 4 4.0×10 making comparison with mycological atlas. Hamdalah 16 1.6×106 The technique of [15,16] was adopted for Yoghurt identification of the unknown isolated fungi Hamdalah 4 4.0×105 using cotton blue in lacto phenol stain. The Yoghurt slides were mounted and observed with x10 and Hamdalah 4 4.0×104 x40 objective lenses respectively [16]. Yoghurt Statistical analysis was done based on the Batullah Yoghurt 8 8.0×106 colony formation unit per gram (Cfu/g). Batullah Yoghurt 8 8.0×105 3. Results and Discussion Batullah Yoghurt 20 2.0×104 6 3.1 Results Alhalal Yoghurt 8 8.0×10 Alhalal Yoghurt 8 8.0×105 The results of the fungal load obtained and 4 analyzed from the five (5) Yoghurt companies, Alhalal Yoghurt 16 1.6×10 namely Gamji, Alhalil, Rufaida, Batulah and Rufaida Yoghurt 8 8.0×106 Hamdala are shown in Table 3.1. The Rufaida Yoghurt 8 8.0×105 morphological and microscopic features of the Rufaida Yoghurt 16 1.6×104 fungal isolates are shown in Table 3.2. The

Keta, J.N. et al.: Evaluation of Fungi Species from Commercial Yoghurts in Birnin Kebbi, Kebbi State Nigeria

Table 3.2: Morphological and microscopic features of the isolated fungi species Colony Appearance Microscopic Examination Mold Species Colonies were green and Septate hypha formed with smooth walled Penicillium velvety. The reverse side conidiosphore bearing long chains of species was pale yellow in color conidia.

Colonies were green Sporangia are back and zygospores and Mucor species sporangio sphores were long branched hyphae were of septate

White, later becoming black Septate hyphae with simple thick walls. Aspergillus niger and some pale yellow Conidiosphores bearing conidial head containing conidian was seen

Colonies were commonly Conidiosphores are short, smooth walled Aspergillus blue green with narrow bearing conical shaped terminal vesicles fumigates white borders

Colonies are usually fast- Multi celled sicked from macro conidia Fusarium species growing pale or bright in seen colour

3.2 Discussion Aspergillus niger and Fusarium species from Yoghurt samples were also reported. In The results obtained in this study showed that, addition, Alli and co-workers [12] isolated the five-selected Yoghurt Companies exhibited Penicillium species from a Yoghurt product. variation with respect to the isolated fungi. According to previous studies [18, 13], Mucor These variations ranged from different species species and Aspergillus fumigatus were found of fungi obtained from each sample product, growing in Yoghurt product. which includes fungal species of Penicillium species Mucor species Aspergillus niger, The growth of these fungal species in various Aspergillus fumigates and Fusarium species. Yoghurt samples analyzed in this research These fungal isolates obtained in this research could be attributed to the acid content of the were also isolated, identified and reported by Yoghurt. This deduction is supported by a [17]. In a similar research [11], isolates of previous report [7], which states that, when

Keta, J.N. et al.: Evaluation of Fungi Species from Commercial Yoghurts in Birnin Kebbi, Kebbi State Nigeria

yeast grows in Yoghurt it decreases the acidity [1] Tamine, A.Y. and Robisons, R.K., 2007: of the Yoghurt thereby creating a good medium Historical background in Tamine and Robins for other microorganisms to grow. The fungal Yoghurt Scince and Technology 3rd ed. species isolated and identified in the present Woodhesd publishing. LTD. Cambridge. UK. study are not surprising when considering the Pp. 1-10. low level of hygienic conditions involved in the production, distribution and handling of these [2] Ruud, S. and Bert, D., 2004: Yoghurt Yoghurts. The morphological and microscopic production issues of diary production. Http: features reported here coincide with those of www.Gironet/home/berding/dtp. Vol. 72. fungal species reported in the study conducted by Mbajiuka, S. C. et al. [19]. Fungi are known [3] American Heritage., 2000: Dictionary of to produce aflatoxin that can be harmful to life English Language 4th Edition, Muffin even if present in a very small quantity [20]. Houghton. Strains of some fungal genera such as Aspergillus, Fusarium and Penicillium species [4] Alderton, R., 2000: Milk Products Produced reported in this present study do not produce by Lactic Acid Fermentation. Journal of toxic metabolites that could be said to be Yoghurt History and carcinogenic agents, but can still be a threat to ManufacturingTechniques, 6: 1 -5. human metabolic process as they can cause [5] Ahmed, I., Gulzar, M., Shahzad, F., Yaqub, serious health problems when consumed in high M. and Zhoor, T., 2013: Quality assessment of amounts [21]. Yoghurt produced at large industrial and small 4. Conclusion scale. Journal of animal and plant science. 6(2) 3-6 The prevalence of fungal species found in this study demand appropriate control measures and [6] Kolars, J.C. and Aouji, M., 2002: Yoghurt – good hygienic conditions for Yoghurt an auto digesting source of lactose. New manufactures and proper storage facilities England Journal of Medicine, 310 (1): 1 - 3 during and after production. Furthermore, there is need to improve on the personal hygiene in [7] Porter, C. and Dryden M.E., 2005: Lactic order to prevent microbial growth and growth fermentation of Diary Foods and their of harmful and pathogenic species of fungi in Biological Significance. Journal of Diary the products as the consumption of these Science. 61: 7 - 12. Yoghurt products in high quantity could results in various health risks to the consumers and, [8] Parnel, E.M., Kakuda Y. and Deman J.M., therefore, a public treat to human health. 2006: Physical Properties of Yoghurt. Journal of Diary Science. 69 (10): 2593. Acknowledgment [9] Dryden, M. E., 1999: Lactic fermentation of We highly appreciate the following Yoghurts diary food and their biological significance. companies that we used their products: Journal of Diary Science. 6: 9 - 12. Hamdallah Yoghurts Company, Rufaida Yoghurt Company Birnin Kebbi, Alhalal [10] Hardman, M. and Milliken, K., 1998: Yoghurt Company Birnin Kebbi, Batulah Probiotics in yoghurt Production. A Journal of Yoghurt Company Birnin Kebbi and Gamji Science Technology, 10: 1 - 9. Yoghurt Company Birnin Kebbi. [11] Oyeleke, S.B., 2009: Microbial assessment References of some commercially prepared yogurt retailed

Keta, J.N. et al.: Evaluation of Fungi Species from Commercial Yoghurts in Birnin Kebbi, Kebbi State Nigeria

in minna, Niger State. Department of Fruits. International journal of current Microbiology to best publisher, Minna Nigeria. microbiology and applied. 3;501-512. PP. 36-35 [20] Zain, M.E., 2011: Impact of mycotoxins on humans and animals. Journal of Saudi chemical society. 15:129-144. [12] Alli, J.A., Oluwadun, A., Okonko, I.O., Fagade, O.E., Kolade, A.F. and Ogunleye, [21] Uraih, N. and Ogbadu, G., 2008: Incidence V.O., 2010: Microbial Assessment and of aflatoxin in Nigerian sorghum. Microbios, Microbiological Quality of Some commercially 14: 29 – 31. Prepared Yogurt Retailed in Ibadan, Oyo State, Southwestern Nigeria. British Journal of Dairy Sciences, 1(2): 34-38

[13] Oyeleke, S.B. and Manga, S.B., 2008: Essential of laboratory practical in microbiology to best publisher, Minna, Nigeria. Pp. 36-75.

[14] Chessbrough, M., 2000: District Laboratory practice in Tropical Countries. Part 2 press Syndicate of the University of Cambrigdehire UK. Pp. 63-70.

[15] Chessbrough, M., 2003: Medical laboratory manual Tropical health technology, low priced edition. Doddington, Cambrigdehire. England. Pp. 20-35.

[16] Barnett, J. and Hunter. B., 1998: Illustrated Genera of Imperfect Fungi. Aps Press. 1: 32- 80.

[17] Porter, C. and Dryden, M.E., 2005: Lactic fermentation of Dairy Foods and their Biological Significance. Journal of Diary Science, 61: 7 - 12.

[18] Atanda, O.O. and Ikenebomeh, M.J., 1991: Microbiology of ‘Nono’. World Journal of Microbiology and Biotechnology, 7:89-91

[19] Mbajiuka, S.C. and Enya, E., 2004: Isolation of microorganisms associated with deteriotion of Tomato (Lycopersicum esculentum) and PawPaw (Carica papaya)