Zulu Nontobeko Xolisiwe, Kunadu Angela Parry-Hanson, Kayitesi Eugenie, Dlamini Bhekisisa
Department of Biotechnology and Food Technology, University of Johannesburg, Johannesburg, Gauteng, South Africa.
Department of Nutrition and Food Science, University of Ghana, Accra, Ghana.
Int J Food Sci. 2025 Aug 10;2025:6198794. doi: 10.1155/ijfo/6198794. eCollection 2025.
The demand for dried starter cultures that are specific to indigenous fermented food products is increasing. In most cases, skim milk (SM) powder is used as a cryoprotectant for microbial cell protection during the preparation of starter cultures. However, the extent of cell protection during freeze-drying and the fermentation efficacy of dried cultures are dependent on the type of microbial strain and carrier media, hence the need to investigate the protective effects of alternative carrier media. This study evaluated the fermentation potential of lactic acid bacteria (LAB) preserved in coconut (CCN) powder and SM powder during (traditional fermented sorghum) production. was fermented with single and mixed strains of and . The pH, total titratable acidity (TTA), functional groups (Fourier transform infrared spectroscopy [FTIR]), microbial quality, and consumer acceptability were monitored during fermentation. prepared with LAB strains preserved in SM had a more rapid reduction ( > 0.05) in pH and lower final pH than prepared with LAB preserved in CCN. Mixed LAB strains showed a rapid reduction in pH of compared to single LAB strains and prepared with spontaneous fermentation. The highest TTA (3.57%) was observed with mixed LAB after 48 h on both SM and CCN . FTIR showed similar functional groups corresponding to O-H and phenolic compounds for both SM and CCN . The highest increase in LAB counts (up to 10 log CFU/mL) occurred in prepared with mixed strains of both CCN and SM, while the least increase occurred with spontaneously fermented . Enterobacteriaceae, yeasts, and molds were not detected in all the fermented samples. With consumer acceptability, CCN was the most preferred sample with the highest overall score (6.95), followed by the SM sample (5.67). In conclusion, this work indicates that the LAB strains preserved in CCN result in comparable fermentation performance to that of SM and produce that is preferred by consumers. Therefore, CCN should be considered as a carrier medium for the development of starter cultures.
对特定于本土发酵食品的干燥发酵剂的需求正在增加。在大多数情况下,脱脂奶粉(SM)被用作发酵剂制备过程中保护微生物细胞的冷冻保护剂。然而,冷冻干燥过程中的细胞保护程度以及干燥发酵剂的发酵效果取决于微生物菌株和载体介质的类型,因此需要研究替代载体介质的保护作用。本研究评估了保存在椰子粉(CCN)和SM粉中的乳酸菌(LAB)在(传统发酵高粱)生产过程中的发酵潜力。用单一和混合菌株的LAB对进行发酵。在发酵过程中监测pH值、总可滴定酸度(TTA)、官能团(傅里叶变换红外光谱[FTIR])、微生物质量和消费者可接受性。用保存在SM中的LAB菌株制备的在pH值下降更快(>0.05)且最终pH值低于用保存在CCN中的LAB制备的。与单一LAB菌株和自发发酵制备的相比,混合LAB菌株的pH值下降迅速。在SM和CCN上培养48小时后,混合LAB的TTA最高(3.57%)。FTIR显示SM和CCN对应于O-H和酚类化合物的官能团相似。用CCN和SM的混合菌株制备的中LAB计数增加最多(高达10 log CFU/mL),而自发发酵的增加最少。在所有发酵样品中均未检测到肠杆菌科、酵母和霉菌。在消费者可接受性方面,CCN是最受欢迎的样品,总体得分最高(6.95),其次是SM样品(5.67)。总之,这项工作表明保存在CCN中的LAB菌株具有与SM相当的发酵性能,并生产出消费者更喜欢的。因此,CCN应被视为开发发酵剂的载体介质。