Different probiotic strains are incorporated into cultured-milk drinks by respective manufacturers with the common aim of providing health benefits to the consumers. Four common cultured-milk products (brands N, S, V and Y) were evaluated for their quality of probiotic strains used, based on the susceptibility of the probiotics to various pH levels simulated to mimic the gastrointestinal system. Results showed that brands Y and V have higher initial probiotic inoculum compared to brands N and S although probiotics from brands N and S were more tolerant to pH 3. Generally, all probiotic strains preferred higher pH with highest viability of Lactobacillus spp., Bifidobacterium spp., and Streptococcus thermophilus observed at pH 8.1. Our study also discovered that among the four brands tested, brand V contained probiotic strains which are most likely to remain viable after passage through the gastrointestinal system.
In this study, three potential probiotic strains were selected to ferment blueberry and blackberry juices. The viable cell counts of selected strains were increased by 0.4-0.7 log CFU/mL in berry juices environments after 48-h fermentation. Meanwhile, the contents of cyanindin-3-glucoside and peonidin-3-glucoside decreased over 30%. Heatmap presented an upgrade trend of syringic acid, ferulic acid, gallic acid and lactic acid during fermentation. However, the contents of p-coumaric acid, protocatechuic acid, chlorogenic acid, critic acid and malic acid showed downgrade trend. The metabolism of phenolics probably contributed to the enhancement of the ABTS radical scavenging activity (40%-60%) in fermented berry juices. Moreover, the three strains presented different capacities on changing the quality of berry juices according to the PCA and LDA analysis. The contents of individual organic acids had positive correlations with sensory quality, especially for sourness. Overall, probiotic fermentation could improve the sensory quality of berry juices.
Nowadays, functional food market is dominated by dairy-based probiotic products, mainly
yogurt. The nutritional values of yogurt can be further enhanced by the inclusion of miracle
fruit (Synsepalum dulcificum) and potential probiotic Lactococcus lactis Gh1. The present
work investigated the anti-oxidative capacity and survivability of probiotic strains of six
yogurts fortified with S. dulcificum pulp extract and encapsulated L. lactis Gh1 (in
alginate-starch coating agent via extrusion technique). The flavonoid contents (TFC) were not
significantly different between yogurts, whereas the phenolic contents (TPC) showed an
increasing trend throughout the storage. Among the yogurts, the one supplemented with both
S. dulcificum and encapsulated L. lactis Gh1 showed the highest TFC (1.18 µg QE/mL) and
TPC (15.382 μg GAE/mL). The antioxidant assay (DPPH) showed a gradual increase on the
first 7 d, but decreased afterward. In comparison, yogurts fortified with S. dulcificum demonstrated higher antioxidant activity (± 80% DPPH inhibition) than the plain yogurts (± 50%
DPPH inhibition). The viability of starter cultures (Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) drastically increased during the first week (log 8 ~ 10
CFU/mL) especially for yogurts containing free cell L. lactis, but subsequently decreased ( log
6 ~ 8 CFU/mL). The viability of L. lactis Gh1 in yogurts maintained at high count (log 9.43
and 9.04 CFU/mL) throughout 21 d when it was being encapsulated. In general, the fortification of S. dulcificum extract with microencapsulated L. lactis Gh1 had greatly enhanced the
quality and potential benefits of the functional yogurts.
The dairy products remain as the largest reservoir for isolation of probiotic microorganisms. While probiotics have been immensely reported to exert various health benefits, it is also a common notion that these health potentials are strain and host dependent, leading to the need of more human evidence based on specific strains, health targets, and populations. This randomized, single-blind, and placebo-controlled human study aimed to evaluate the potential benefits of putative probiotic strains isolated from kefir on gastrointestinal parameters in fifty-six healthy adults. The consumption of AB-kefir (Bifidobacterium longum, Lactobacillus acidophilus, L. fermentum, L. helveticus, L. paracasei, L. rhamnosus, and Streptococcus thermophiles; total 10 log CFU/sachet) daily for 3 week reduced symptoms of abdominal pain, bloating (P = 0.014), and appetite (P = 0.041) in male subjects as compared to the control. Gut microbiota distribution profiles were shifted upon consumption of AB-kefir compared to baseline, where the abundance of bifidobacteria was increased in male subjects and maintained upon cessation of AB-kefir consumption. The consumption of AB-kefir also increased gastrointestinal abundance of total anaerobes (P = 0.038) and total bacterial (P = 0.049) in female subjects compared to the control after 3 weeks. Our results indicated that AB-kefir could potentially be developed as a natural strategy to improve gastrointestinal functions in adults.