Bacteriological Evaluation of Locally Produced Soybean Milk

the bacteriological analysis conducted locally manufactured soymilk commonly found across different areas of Kogi indicates that the artisanal may be with varying bacteria. The study concludes that microorganisms present in the commonly available soybean milk in the study parameter could be attributed to ‘inadequate hygiene, unsanitary conditions of equipment, and raw materials. Pathogenic in soymilk can be either or Although most that soymilk or provides safe for and The present study to supporting study recommends that research

Soybean milk is a regular beverage commonly sold across the streets and markets in Nigeria and beyond. The demand for soybean milk is fast growing due to its affordability and similarity to dairy milk, including its health benefits. However, there is a growing concern about the public health-related issues associated with this artisanal product's production, storage, and distribution. The primary objective of the present investigation was to evaluate the bacteriological composition of the locally produced soybean milk commonly consumed in the Kogi state of Nigeria. The samples for the study were collected from vendors in different locations of the state. The analysis was conducted on the samples using established standard procedures. The result found certain microorganisms such as Micrococcus spp, Lactobacillus spp, Streptococcus spp, Enterobacter spp, Klebsiella spp, and other fungi, which comprises Aspergillus spp and Saccharomyces. The study concludes that the soybean milk consumed in the study parameter was mainly contaminated with varying bacteria.
Soymilk is consumed globally as a healthy protein drink and used as raw material to produce soy gel foods, such as tofu and soy yogurt (Peng et al., 2016). It is an excellent food item with numerous functional substances with antioxidant effects (Yamamoto et al., 2019). Soymilk has recently been applied in the dairy industry as a valuable ingredient to expand various products' texture, flavor, and nutritional value (Peng et al., 2016). According to Jimoh and Kolapo (2007), soymilk is a traditional oriental food-beverage growing in popularity in the United States and the world. Soymilk, a watery extract of the whole soybean, is rich in water-soluble protein, carbohydrates, and oil (Adebayo-Tayo et al., 2008).

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It is commonly characterized as having a beamy, grassy, or soy flavor, which reportedly can be improved by lactic acid fermentation as in yogurt-like products (Iwe, 2003). The increasing popularity of soymilk as a beverage worldwide is credited to health benefits, e.g., low cholesterol and lactose, its ability to reduce bone loss and menopausal symptoms, prevention of heart disease, and certain cancers ( The market for soybean milk in Nigeria is on the increase in recent years. Ugwu and Nwoke (2011) noted that many people had been trained for soybean milk processing and distribution through various means, including skills acquisitions and virtual training. However, there is a growing concern about the production and distribution hygiene of the product, including processing instruments, water content, storage (Chuku & Akani, 2015), and the surrounding environment ( The production and street vending of soybean milk in Kogi State is widespread. However, little is known about the microbial quality of the products consumed in the state, hence, justifying this study. Perhaps, a closer observation of the vendors and environment raises health-related safety issues. Indeed, soymilk consumption could threaten human health if harmful microorganisms are not adequately guided during production, storage, and distribution. Thus, contamination is possible following an unhygienic preparatory. Therefore, this study intends to evaluate the bacteriological composition of the locally made soybean milk in Kogi state.

Materials and Methods:-
The relevant materials and glassware were purchased from a reliable merchant and effectively sterilized. The reagents used in the study include crystal violet, Lugol's iodine, Safranin, Kovac's reagent, Lactophenol cotton blue, Hydrogen peroxide. Soybean milk was purchased from local vendors from different sites in Kogi state. They were immediately conveyed to the microbiology laboratory for analysis. The study followed the standard procedures outlined in Stanley et al.     . Lactobacillus spp, as observed above, has been associated with soymilk spoilage and an increase in acid production (Stanley et al., 2014). These organisms thrive in fermentable substrates as sugar, which can be reduced by acid. The presence of streptococcus spp indicates a high level of exposure and negligence occurring at any stage of the production process (Brooks et al., 2004). All the isolated organisms in the study have been linked with health-related concerns. Evidence has shown that bacteriological pathogens may find their way into food production, including soymilk processing, due to inadequate hygienic practices, insufficient decontamination, and mishandling of raw materials (Simangunsong & Susanna, 2019) Furthermore , table 3 shows Aspergillus spp and Saccharomyces spp as the fungi isolated based on their lactophenol cotton blue reactions. Aspergillus spp is a toxigenic mold capable of producing aflatoxin (Brooks et al., 2004). Thus, it is a public health concern. On the other hand, Saccharomyces spp has been shown to cause spoilage at the fermentation stage, probably due to high sugar levels. However, the role of Saccharomyces spp in the spoilage of soymilk is unclear.

Conclusion:-
The bacteriological evaluation of the locally manufactured soymilk commonly found across different areas of Kogi state indicates that the artisanal beverage may be contaminated with varying bacteria. The study concludes that microorganisms present in the commonly available soybean milk in the study parameter could be attributed to manufacturers 'inadequate hygiene, unsanitary conditions of processing equipment, and raw materials. Pathogenic bacteria in soymilk can be either infectious or toxin-producing. Although most pathogens that contaminate soymilk grow only slowly or not at all. Perhaps, soymilk provides a safe place for microorganisms to grow. Thus, it is recommended that a robust precautionary approach be adopted in the production, storage, and distribution of the product to effectively mitigate the contamination of microorganisms in soybean milk. The present study contributes to disease control literature by further supporting the contamination of locally produced soybean milk. Thus, the study recommends that research broaden the probable measures to lessen the prevalence of consuming contaminated soymilks in Nigeria. 17. Zhao, X.