Development of probiotic vegetable juice using Lactobacillus Rhamnosus GR-1

Abstract

PurposeThe purpose of this paper is to assess the growth and viability of Lactobacillus rhamnosus GR-1 (L. rhamnosus GR-1) in carrot juice (CJ), carrot apple juice (CAJ), carrot orange juice (COJ) and carrot beet juice (CBJ) over 72 h of fermentation and 30 days of refrigerated storage at 4°C. The secondary objective is to evaluate sensory properties.Design/methodology/approachFour vegetable juice samples were inoculated with the probiotic strain L. rhamnosus GR-1 and fermented for 72 h. To observe the samples’ storage ability, the samples were refrigerated for 30 days. Microbial enumeration was conducted throughout the fermentation and storage periods to determine the viability of L. rhamnosus GR-1. Sensory evaluation with 106 participants was also conducted to assess the consumer acceptability of the vegetable juices.FindingsAll tested samples achieved mean microbial counts of at least 109 CFU/ml. During the 72-h fermentation period significant differences in microbial counts in juices CJ (p = 0.001), CAJ (p = 0.031), COJ (p = 0.047) and CBJ (p = 0.001) were observed. Over the 30-day storage period, significant differences in microbial counts were only found in juices CJ (p = 0.001) and COJ (p = 0.019). A significant decline in pH (p = 0.001) was also observed during 72 h of fermentation and 30-days of cold storage. Sensory evaluation of all juices showed significant differences in sensory attributes such as appearance (p = 0.001), flavour (p = 0.001), texture (p = 0.001) and overall acceptability (p = 0.001). Sensory results showed that the probiotic CBJ and CJ had the highest hedonic scores for flavour, texture and overall acceptability (p = 0.001) among participants. This study demonstrated that non-dairy vegetable juices could be an alternative to dairy-based probiotic products.Originality/valueCommercially available probiotic dairy-based foods make up a large sector of the consumer market. However, the growing consumer interest in healthful eating has led to an increased demand for plant-based products. The probiotic L. rhamnosus GR-1 provides numerous therapeutic benefits, such as reducing the recurrence of bacterial vaginosis, yeast and urinary tract infections. The results of this study may have a significant influence on the health of individuals, especially in less economically developed countries.