Development of a mixed jussara and mango juice with added Lactobacillus rhamnosus GG submitted to sub-lethal acid and baric stresses.

This study evaluated the interference of sub-lethal acid (SLA) stress and high isostatic pressure (HIP) stress on the survival of Lactobacillus rhamnosus GG (LGG) in mixed jussara and mango juice with the pH adjusted to 3.0 and 3.5, during 90 days of storage at 6 °C. The SLA stress at pH 4.0 previously applied to the LGG cells had no effect on the survival of this bacterium in mixed jussara and mango juices. On the other hand, the application of 200 MPa/5 min/25 °C treatment to LGG cells was shown to be efficient in the cross protection of this bacterium in an acid medium. Pressures above 400 MPa/5 min/25 °C caused a reduction in the viability in an acid medium and lower pressures (< 100 MPa) showed similar results compared to control treatment in the LGG survival. No changes in pH, acidity and soluble solids were observed in mixed juices. In addition, these products showed elevated levels of anthocyanins, phenolic compounds and antioxidant capacity. This highlights the capacity of the HIP process to promote the cross protection of LGG in an acid medium.

In vitro and in vivo resistance of Lactobacillus rhamnosus GG carried by a mixed pineapple (Ananas comosus L. Merril) and jussara (Euterpe edulis Martius) juice to the gastrointestinal tract.

This study evaluated the viability of Lactobacillus rhamnosus GG (LGG) and its in vitro and in vivo resistance to the gastrointestinal tract (GIT) when carried by a mixed fermented pineapple and jussara juice. The effects of product ingestion on the biochemical characteristics of the blood and on the development of aberrant crypt foci (ACF) in Wistar rats were also determined. The LGG viability in probiotic juice was higher than 7.2 log CFU/mL throughout 28 days at 8 °C. The mean count of the probiotic microorganism in the fecal samples of the rats was 5.6 log CFU/g, identical to the count at the end of the in vitro trial (enteric phase II), indicating that the mixed pineapple and jussara juice was an excellent vehicle for LGG. No difference (p > .05) was verified to ACF among the groups. However, the results for the probiotic culture viability and its in vitro and in vivo resistance to the gastrointestinal tract suggest that this juice is an excellent carrier matrix for LGG and contributed to a reduction in the levels of the LDL (low density lipoprotein) fraction of the blood cholesterol, thus being an aid in the control of coronary diseases.

Effect of probiotic bacteria in composition of children's saliva.

Probiotics are widely used in the food industry and may affect the oral microbiota. This study aimed to evaluate the effect of petit-suisse plus probiotic on the microbiota of children's saliva. Strawberry flavor petit-suisse cheese plus green banana flour without Lactobacillus casei (control) and with addition of Lactobacillus casei (probiotic) were prepared and used in the experiments. The feasibility of adding probiotic to petit-suisse was assessed over 28 days. Saliva samples from volunteers who consumed the petit-suisses produced were collected before the period of consumption of the products (T0), on the last day of consumption of petit-suisse (T1) and two weeks after the consumption stopped (T2 - post treatment). The samples were immediately fixed with paraformaldehyde in a final concentration of 2%, after which the bacteria of interest were identified by Fluorescent In Situ Hybridization (FISH) and counted with the aid of an epifluorescence microscope. Lactic bacteria were viable between 108 and 109 CFU·g-1 for 28 days of storage at 4 °C. Both products (control and with L. casei added) were able to significantly reduce (p < 0.05) the total number of microorganisms and Streptococcus mutans in the volunteers' saliva. However, only the product plus L. casei decreased density of Agreggatibacter actinomycetemcomitans, as well as being able to maintain the low density of Porphyromonas gingivalis post treatment. Therefore, the petit-suisse cheese developed showed the ability to carry probiotic microorganism, being a potential alternative for reducing potentially pathogenic microbiota in the oral cavity.