2 research outputs found
Effect of Salt Addition and Fermentation Time on Phenolics, Microbial Dynamics, Volatile Organic Compounds, and Sensory Properties of the PDO Table Olives of Gaeta (Italy)
‘Oliva di Gaeta’ is almost certainly the most important and well-known PDO denomination
for table olives in Italy. Their production is based on a specific two-stage trade preparation called
the ‘Itrana’ method. In this work, we investigated how variations in the duration of the initial
water fermentation (i.e., 15 and 30 days) and the salt concentration (i.e., 6% and 8% NaCl) influence
the chemical features, microbial dynamics, polyphenols, volatile organic compounds, and sensory
features of ‘Oliva di Gaeta’. The time of the addition of salt did not affect the final concentration
in the brine, but a longer initial water fermentation (before salt addition) led to lower pH values.
The bacterial count constantly increased until the salt addition (i.e., either 15 or 30 days), while the
yeast population peaked on day 30. Generally, the two different salt concentrations did not affect the
count of microorganisms at the end of fermentation, with the only exception being a higher lactic
acid bacteria count for the treatment with 6% salt added at 30 days. At commercial maturity, the
crucial bitter tastant oleuropein was not completely removed from the drupes, and differences in salt
concentration and the length of the first-stage water fermentation did not influence its content at the
end of olive curing. Richer volatile profiles of olives were detected with higher-salt treatments, while
the combination of low salt and early saline treatment provided a more distinct profile. Longer initial
water fermentation caused a small increase in some phenolic compounds (e.g., iso-verbascoside,
verbascoside, and hydroxytyrosol-glucoside). A panel test indicated that salt application at 30 days
resulted in a more “Sour” and “Bitter” taste, irrespective of the salt concentration. The low salt
concentration coupled with the late saline treatment resulted in more “Fruity” notes, probably due
to the higher production of esters by lactobacilli. The slightly bitter perception of the olives was
consistent with the partial removal of oleuropein. Our work revealed the characteristics of the ‘Itrana’
method and that the variation in salt concentration and its time of application changes parameters
ranging from the microbial dynamics to the sensory profile. Specifically, our data indicate that
6% NaCl coupled with a longer initial water fermentation is the most different condition: it is less
effective in blocking microbial growth but, at the same time, is more potent in altering the nutritional
(e.g., polyphenols) and sensorial qualities (e.g., bitterness and fruitiness) of ‘Oliva di Gaeta’
Elexacaftor-Tezacaftor-Ivacaftor corrects monocyte microbicidal deficiency in cystic fibrosis
Question. Cystic Fibrosis (CF), which is caused by mutations in the cystic fibrosis
transmembrane conductance regulator (CFTR), is characterized by chronic bacterial lung
infection and inflammation. In CF, monocytes and monocyte-derived macrophages have been
shown to display defective phagocytosis and antimicrobial activity against relevant lung
pathogens, including Pseudomonas aeruginosa. Thus, we addressed the effect of the CFTR
triple modulator therapy, Elexacaftor/Tezacaftor/Ivacaftor (ETI), on the activity of CF
monocytes against P. aeruginosa.
Materials/patients and Methods Monocytes from people with CF (PWCF) before and after
1 and 6 months of ETI therapy were isolated from blood and infected with P. aeruginosa to
assess phagocytic activity and intracellular bacterial killing. The oxidative burst and IL-6
secretion were also determined. Monocytes from healthy controls were also included.
Results and answer to the question Longitudinal analysis of the clinical parameters
confirmed an improvement of lung function and lung microbiology by ETI. Both the
phagocytic and microbicidal deficiencies of the CF monocytes also improved significantly,
although not completely. Furthermore, we measured an exuberant oxidative burst in CF
monocytes before therapy, which was reduced considerably by ETI. This led to an
improvement of the ROS-dependent bactericidal activity. Inflammatory response to bacterial
stimuli was also lowered compared to pre-therapy. PWCF on ETI therapy, in a real-life
setting, in addition to clinical recovery, showed significant improvement in monocyte activity
against P. aeruginosa, which may have contributed to the overall effect of ETI on pulmonary
disease. This also suggests that CF monocyte dysfunctions may be specifically targeted to
ameliorate lung function in CF