Evaluating the Probiotic Potential of Lactic Acid Bacteria Implicated in Natural Fermentation of Table Olives, cv. Cobrançosa.

The probiotic features of Lactiplantibacillus (L.) pentosus and L. paraplantarum strains, endogenous in Cobrançosa table olives from northeast Portugal, were assessed in terms of functional properties and health benefits. Fourteen lactic acid bacteria strains were compared with Lacticaseibacillus casei from a commercial brand of probiotic yoghurt and L. pentosus B281 from Greek probiotic table olives, in attempts to select strains with higher probiotic performances than those references. For functional properties, the i53 and i106 strains, respectively, exhibited: 22.2 ± 2.2% and 23.0 ± 2.2% for Caco-2 cell adhesion capacity; 21.6 ± 7.8% and 21.5 ± 1.4% for hydrophobicity; 93.0 ± 3.0% and 88.5 ± 4.5% for autoaggregation ability by 24 h of incubation; and ability to co-aggregate with selected pathogens-from 29 to 40% to Gram+ (e.g., Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212); and from 16 to 44% for Gram- (e.g., Escherichia coli ATCC 25922 and Salmonella enteritidis ATCC 25928). The strains proved to be resistant (i.e., halo zone ≤14 mm) to some antibiotics (e.g., vancomycin, ofloxacin, and streptomycin), but susceptible (i.e., halo zone ≥ 20 mm) to others (e.g., ampicillin and cephalothin). The strains exhibited health-beneficial enzymatic activity (such as acid phosphatase and naphthol-AS-BI-phosphohydrolase), but not health-harmful enzymatic activity (such as ß-glucuronidase and N-acetyl-ß-glucosaminidase). Additionally, the antioxidant activity and cholesterol assimilation features, respectively, of the strains were 19.6 ± 2.8% and 77.5 ± 0.5% for i53, and 19.6 ± 1.8% and 72.2 ± 0.9% for i106. This study indicated that the addition of L. pentosus strains i53 and/or i106 to Cobrançosa table olives is likely to enhance the added value of the final product, in view of the associated potential benefits upon human health.

Potential of Microalgae Extracts for Food and Feed Supplementation-A Promising Source of Antioxidant and Anti-Inflammatory Compounds.

Microalgae are known producers of antioxidant and anti-inflammatory compounds, making them natural alternatives to be used as food and feed functional ingredients. This study aimed to valorise biomass and exploit new applications and commercial value for four commercially available microalgae: Isochrysis galbana, Nannochloropsis sp., Tetraselmis sp., and Phaeodactylum tricornutum. For that, five extracts were obtained: acetone (A), ethanol (E), water (W), ethanol:water (EW). The antioxidant capacity (ABTS•+/DPPH•/•NO/O2•-/ORAC-FL) and anti-inflammatory capacity (HBRC/COX-2) of the extracts were screened. The general biochemical composition (carbohydrates, soluble proteins, and lipids) and the main groups of bioactive compounds (carotenoids, phenolic compounds, and peptides) of extracts were quantified. The results of antioxidant assays revealed the potential of some microalgae extracts: in ABTS•+, Nannochloropsis sp. E and Tetraselmis sp. A, E, and P; in DPPH•, Tetraselmis sp. A and E; in •NO, P. tricornutum E and EW; in O2•-, Tetraselmis sp. W; and in ORAC-FL, I. galbana EW and P. tricornutum EW. Concerning anti-inflammatory capacity, P. tricornutum EW and Tetraselmis sp. W showed a promising HBRC protective effect and COX-2 inhibition. Hence, Tetraselmis sp. and P. tricornutum extracts seem to have potential to be incorporated as feed and food functional ingredients and preservatives.

Study of Lactic Acid Bacteria Biodiversity in Fermented Cobrançosa Table Olives to Determine Their Probiotic Potential.

Current market trends point at increasing demand for functional foods, namely those carrying probiotics. In the case of table olives, presence of probiotics would convey a competitive advantage to Mediterranean-based diets, already established for their cultural heritage and gastronomic character. This work assessed the safety and resistance to gastrointestinal digestion of 19 native LAB strains from Cobrançosa table olives. Strains were identified via molecular sequencing (4 fingerprints/10 strains for Lactiplantibacillus pentosus, and 2 fingerprints/9 strains for L. paraplantarum), and exposed to simulated gastrointestinal fluids, as per the INFOGEST in vitro protocol with modifications. None of those strains proved dangerous for human consumption. Survivability to the gastrointestinal resistance test ranged from 29% to 70%, with strain-dependent variability. L. paraplantarum i18, i27, and i102, and L. pentosus i10 and i11 exhibited statistically lower survival rates (29−35%) than probiotic the Greek table olive reference strain L. pentosus B281 (53%). Among the other strains, L. paraplantarum i101 and L. pentosus i53 and i106 showed the highest survival rates but were not significantly different from the strain of Lacticaseibacillus casei isolated from commercial probiotic yoghurt (65−70%). In vitro results proved that strains retrieved from fermenting cultivar Cobrançosa possess the potential to be claimed as probiotics­thus deserving further attention toward the development of a specific starter culture.

Viability of dietary substitution of live microalgae with dry Ulva rigida in broodstock conditioning of the Pacific oyster (Crassostrea gigas).

The current study evaluated the microalgae replacement by dry macroalgae (Ulva rigida) in the reproductive success and biochemical composition of the Pacific oyster (Crassostrea gigas) during broodstock conditioning. Five nutritional regimes were tested: 100% macroalgae (diet 1), 50% macroalgae+50% microalgae (diet 2), 25% macroalgae+75% microalgae (diet 3) and 100% microalgae (diet 4). An unfed group was used as a negative control. The microalgae blend was composed of 33% Isochrysis galbana and 67% diatoms (75% Skeletonema costatum+25% Chaetoceros calcitrans). Gonadal maturation was reflected in the physiological condition of the individuals. All treatments, except diet 1, showed an increase in condition index and were fully matured at the end of the trial, with the best physiological condition observed in oysters fed diet 3 and diet 4. Protein and total lipid content increased during the conditioning period, whereas glycogen content decreased. Oysters conditioned with diet 3 had higher protein and total lipid content and lower glycogen content than the other treatments. In addition, diet 3 showed the highest percentage of viable veliger larvae. The current study demonstrated that it is possible to replace 25% of microalgae with macroalgae in the broodstock conditioning, minimizing the operative cost in bivalve hatcheries.This article has an associated First Person interview with the first author of the paper.