Probiotic strains are incorporated into food substrates to contribute to fermentation process. The technological suitability of such strains to improve the flavor and nutritional value of fermented food is strain-specific. Potentially probiotic yeasts isolated from Nigerian traditional fermented foods were assessed for production of volatile compounds by gas chromatography-mass spectrophotometry. Phytases were characterized for activity and stability at different pH (3–8) and temperatures (25-50 °C). A total of 45 volatiles compounds were identified from intracellular cell-free extracts of Pichia kluyveri LKC17, Issatchenkia orientalis OSL11, P. kudriavzevii OG32, P. kudriavzevii ROM11, and Candida tropicalis BOM21. They include alcohols (14), carbonyls (13), esters (10), and organic acids (8). Phenylethyl alcohol was the highest higher-alcohol in Issatchenkia orientalis OSL11 (27.51 %). The largest proportion of esters was detected in P. kudriavzevii OG32 (17.38 %). Pichia kudriavzevii OG32 and C. tropicalis BOM21 showed vigorous gowth in minimal medium supplemented with sodium phytate (2 g L−1). Extracellular phytases from P. kudriavzevii OG32 and Candida tropicalis BOM2 showed optimal activiy at pH 4.6 (104.28 U) and pH 3.6 (81.43 U) respectively. Results obtained revealed species- and strain-specific potentials of the yeast strains to improve flavor and mineral bioavailability of fermented food products. Therefore, the application of these yeasts as starter cultures during food fermentation process is a very promising method to enhance the flavor profile and enhance mineral bioavailability in indigenous cereal-based fermented food products.

中文翻译：

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从尼日利亚传统发酵谷物食品中分离出的潜在益生菌酵母的挥发性化合物和植酸酶的生产和表征

将益生菌菌株掺入食品底物中以促进发酵过程。这种菌株在提高发酵食品的风味和营养价值方面的技术适用性是菌株特异性的。通过气相色谱-质谱法评估了从尼日利亚传统发酵食品中分离出的潜在益生菌酵母中挥发性化合物的产生。表征了植酸酶在不同pH（3-8）和温度（25-50°C）下的活性和稳定性。从克鲁维氏毕赤酵母LKC17，东方伊萨奇氏菌OSL11，库氏疟原虫OG32，库氏疟原虫ROM11和热带念珠菌BOM21的细胞内无细胞提取物中鉴定出总共45种挥发性化合物。它们包括醇（14），羰基（13），酯（10）和有机酸（8）。苯乙醇是东方伊索氏菌OSL11中最高的高级醇（27.51％）。在库氏假单胞菌OG32中检测到最大比例的酯（17.38％）。在补充了肌醇六磷酸钠（2 g L-1）的基本培养基中，库氏毕赤酵母OG32和热带念珠菌BOM21表现出旺盛的生长。来自库氏假单胞菌OG32和热带假丝酵母BOM2的细胞外植酸酶分别在pH 4.6（104.28 U）和pH 3.6（81.43 U）下显示最佳活性。获得的结果表明，酵母菌株具有物种和菌株特异性的潜力，可以改善发酵食品的风味和矿物质的生物利用度。因此，