The Effect of Yeast Kluyveromyces marxianus as a Probiotic on the Microbiological and Sensorial Properties of Set Yoghurt during Refrigerated Storage

Abstract

Background & objectives: Probiotic dairy products as a functional food have a positive effect on the health of consumers that have been confirmed by scientific evidence. Yoghurt is considered as one of the most popular dairy foods in Iran, which the incorporation of the probiotics into the yoghurt matrix can improve their microbiological and sensory properties and subsequently will play a vital role in promoting the health of the community. The aim of this study was to investigate the effect of yeast Kluyveromyces marxianus on the microbial and sensorial properties of probiotic yoghurt during refrigerated storage. Methods: In this in vitro study, the yeast Kluyveromyces marxianus PTCC=5189 was used to produce probiotic yoghurt and Aspergillus parasiticus PTCC=5018 (IR 63) and Penicillium chrysogenum PTCC=5074 were used as known pathogens and the main spoilage agents in yoghurt. Changes in the number of probiotic yeasts and spoilage species as well as the sensory acceptability of the samples during 28 days of storage at 4°C were evaluated and compared with the control samples. Results: The population of both species, involved in yoghurt spoilage, during refrigeration were significantly reduced by the presence of Kluyveromyces marxianus (p<0.01). After 28 days of storage, the number of Kluyveromyces marxianus was at the recommended level of the International Dairy Federation with a 7.35 log CFU/g. The sensory evaluation results demonstrated that the control yoghurt samples were more acceptable. Conclusion: Kluyveromyces marxianus has a significant effect on improving microbiological properties and can be used in the formulation and production of probiotic yoghurt with high storage capability and optimal sensory acceptability.

A systematic review to introduce the most effective postbiotics derived from probiotics for aflatoxin detoxification in vitro

“…This systematic review was based on the guidelines of the Preferred Reporting Items for Systematic Reviews Terms such as parapsychobiotics, paraprobiotics, nonviable probiotics, heat-killed probiotics, ghost probiotics, meta-biotics, cell-free supernatant, biogenic, tyndallized probiotics, bacterial lysates, and postbiotics are also used (Homayouni-Rad et al, 2021;Salminen et al, 2021), although term postbiotic is used more commonly.…”

“…It is important to note that postbiotics, unlike probiotics, do not add new species to intestinal microbiota, but like prebiotics, they develop the existing probiotics in the digestive system (Homayouni- Rad et al, 2020Rad et al, , 2021. Therefore, it is necessary to carry out a comprehensive investigation for safety, optimization of different extraction methods, identification of the chemical composition of postbiotics, and the physiological role of postbiotics in the biological system to facilitate and use postbiotic compounds in food formulations.…”

“…In mid-2021, the International Scientific Association for Probiotics and Prebiotics (ISAPP) provided a precise and wellconsidered definition of postbiotics, which is the "preparation of inanimate microorganisms and/or their components that confers a health benefit on the host" (Salminen et al, 2021). According to the above definition, the term postbiotic refers to a set of macro and micro molecules, such as inactive microorganisms (cells that are not alive), parts of a cell (surface layer proteins, endo-and exo-polysaccharides, teichoic acid, muropeptides and cell-free supernatants [CFS]), or metabolites of a cell (bacteriocins, short-chain fatty acids [SCFA], organic acids and enzymes that are produced naturally by living probiotic cells during fermentation) (Figure 2) (Homayouni-Rad et al, 2021).…”

“…Among the biological methods, detoxification using postbiotics has gradually Most effective postbiotics derived from probiotics for aflatoxin detoxification in vitro in vitro that the beneficial effects of probiotics and postbiotics include antibacterial, antiviral, antifungal, antioxidant, anti-proliferation, anti-mutation, anti-cancer, anti-obesity, anti-diabetic, anti-blood pressure, and immune system booster (Moradi et al, 2021). In addition, postbiotics have unique features, such as safe origin, no toxic effect, low cost of preparation and transportation, and long shelf life (Homayouni-Rad et al, 2021). Many results obtained from clinical studies indicated the suitability of digestion, absorption, metabolism and distribution of postbiotics (Asif et al, 2023;Gao et al, 2019;Shenderov 2013;Singh et al, 2018), and these characteristics are suitable for the food and pharmaceutical industries (Aghebati-Maleki et al, 2021).…”