The effects of fortification of yogurt with various functional flours on survival and growth of probiotic bacteria and sensory properties of the yogurt
ISSN: 0034-6659
Article publication date: 29 February 2024
Issue publication date: 10 April 2024
Abstract
Purpose
The purpose of this study is to determine the viability of Lacticaseibacillus rhamnosus GR-1 (L. rhamnosus GR-1) in five yogurt samples with or without quinoa, chickpea, soybean and rice flour over various fermentation periods and refrigerated storage durations, with a focus on exploring the potential of functional foods, which provide health benefits beyond nutritional value. Additionally, the study aimed to evaluate consumer acceptance of yogurt fortified with functional flour. Using a nine-point hedonic scale, from 1 (dislike extremely) to 9 (like extremely), participants rated appearance, flavour, texture and overall acceptability.
Design/methodology/approach
The samples were inoculated with the probiotic strain L. rhamnosus GR-1 and fermented for 0, 2, 4 and 6 h at 38°C, followed by refrigerated storage at 4°C for 1, 15 and 30 days, respectively. Microbial enumeration was performed throughout fermentation and storage to assess the viability of L. rhamnosus GR-1. A sensory evaluation involving 86 participants was conducted to assess the consumer acceptability of the yogurt samples.
Findings
Notably, L. rhamnosus GR-1 achieved viable counts of 108 colony-forming units per mL in all treatments at all fermentation time points. Over the 30-day storage period, no statistically significant differences (p < 0.05) in average pH values were observed among the five treatments, and within each treatment, pH levels remained stable, with an overall mean of 4.2 ± 0.64. Treatment 4, which featured rice flour fortification, received higher hedonic scores from sensory panellists in terms of appearance, flavour, texture and overall acceptability. These findings indicate that incorporating functional flours in conjunction with cow’s milk effectively promotes and preserves the viability of L. rhamnosus GR-1 in yogurt.
Originality/value
Exploring the potential of probiotic yogurt enriched with diverse functional flours to enhance nutritional content and health benefits as well as attract new consumers, this study addressed a critical gap in understanding consumer perceptions and generated insights for creating innovative and health-promoting dairy products.
Keywords
Acknowledgements
The authors acknowledge Brescia University College, an affiliation of Western University, London, ON, Canada, for providing the necessary funds, laboratory facilities and equipment for this study.
Funding: This research received no external funding.
Author contributions: Alissa DeBruyne, Experiments, Data collection and Organization, Statistical analysis, Writing – Original draft. Sharareh Hekmat, Experiments – Design and supervision, Data analysis, Writing – Review. All authors have read and agreed to the published version of the manuscript.
Institutional review board statement: The study was approved by the Health Sciences Research Ethics Board at Western University.
Informed consent statement: Informed consent was obtained from all subjects involved in the study.
Conflicts of interest: The authors declare no conflict of interest.
Citation
DeBruyne, A.N. and Hekmat, S. (2024), "The effects of fortification of yogurt with various functional flours on survival and growth of probiotic bacteria and sensory properties of the yogurt", Nutrition & Food Science, Vol. 54 No. 3, pp. 597-612. https://doi.org/10.1108/NFS-11-2023-0257
Publisher
:Emerald Publishing Limited
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