Exploring the modulatory effect of trehalose-derived galactooligosaccharides on key gut microbiota groups.

Trehalose (α-d-glucopyranosyl-(1-1)-α-D-glucopyranoside) has found applications in diverse food products as a sweetener, stabilizer, and humectant. Recent attention has focused on trehalose due to its contradictory effects on the virulence of Clostridium difficile. In this study, we investigate the impact of novel trehalose-derived galactooligosaccharides (Treh-GOS) on the human gut microbiota using in vitro fecal fermentation models. Distinct Treh-GOS structures elicit varying taxonomic responses. For instance, ß-Gal-(1-4)-trehalose [DP3(1-4)] leads to an increase of Bifidobacterium, comparable to results observed with commercial GOS. Conversely, ß-Gal-(1-6)-trehalose [DP3(1-6)] prompts an increase in Lactobacillus. Notably, both of these trisaccharides yield the highest concentrations of butyric acid across all samples. On the other hand, Treh-GOS tetrasaccharide mixture (DP4), featuring a novel trehalose galactosylation in both glucose units, fosters the growth of Parabacteroides. Our findings underscore the capacity of novel Treh-GOS to modulate the human gut microbiota. Consequently, these innovative galactooligosaccharides emerge as promising candidates for novel prebiotic applications.

An eco-friendly extraction method to obtain pectin from passion fruit rinds (Passiflora edulis sp.) using subcritical water and pressurized natural deep eutectic solvents.

This work evaluated the efficiency of Subcritical Water Extraction (SWE) and Pressurized Natural Deep Eutectic Solvents (P-NaDESs) under different temperatures (100, 120, 140 and 160 °C) in obtaining pectin from Passion Fruit Rinds (PFR) and its residual biomass (PFR - UAPLE), and compare the results with those of Conventional Extraction (CE). The highest pectin yields, 19.1 and 27.6 %, were achieved using P-NaDES (Citric Acid:Glucose:Water) at 120 °C for PFR and its PFR-UAPLE, respectively. Regarding the Degree of Esterification (DE), pectin obtained with SWE and CE had DE below 50 %, while with P-NaDES (Citric Acid: Glucose:Water), DE was above 50 %. Higher Molecular Weights (MW) (98 and 81 kDa) were obtained with SWE and P-NaDES from PFR compared to PFR-UAPLE and CE. Galacturonic acid was the most abundant (74 to 78 %) monosaccharide obtained by SWE. In terms of morphology, water extraction provided pectin with more uniform textures, whereas extraction with acidified mixtures led to more heterogeneous surfaces. Overall, comparing SWE and P-NaDES, the obtained pectins differed in terms of monomeric composition, MW and DE. These results indicate that pectins obtained by both methods can have different applications depending on their structural characteristics.

Structural, chemical and technofunctional properties pectin modification by green and novel intermediate frequency ultrasound procedure.

The impact of intermediate frequency ultrasound (IFUS, 582, 864 and 1144 kHz), mode of operation (continue and pulsed) and ascorbic acid (Aa) addition on the structural, chemical and technofunctional properties of commercial citrus high methoxyl-grade pectin (HMP) was investigated. The chemical dosimetry of IFUS, monitored by the triiodide formation rate (I3-), demonstrated that the pulsed ratio (1900 ms on/100 ms off) at the three frequencies was similar to that of continue mode but IFUS1144 kHz produced more acoustic streaming demonstrated by the height liquid measured using image analysis. In presence of Aa, HMP presented higher fragmentation than in its absence. IFUS did not give rise any changes in the main functional groups of the HMP. In general, a reduction in molecular weight was observed, being the presence of Aa the most influencing factor. Regarding monosaccharides, IFUS modified the structure of homogalacturonan and rhamnogalacturonan-I and increased of GalA contents of the HMP in presence of Aa at the above three frequencies. A reducing of the consistency index (k) and increasing of the flow index (n) of HMP were showed by IFUS frequency and Aa addition. The emulsifying activity and stability index were increased for HMP treated by IFUS in continue mode at all frequencies and in presence of Aa. The results presented in this research shown the effectiveness of IFUS as tool to modify pectin into different structures with different functionalities.

Supplementation with the Symbiotic Formulation Prodefen® Increases Neuronal Nitric Oxide Synthase and Decreases Oxidative Stress in Superior Mesenteric Artery from Spontaneously Hypertensive Rats.

In recent years, gut dysbiosis has been related to some peripheral vascular alterations linked to hypertension. In this work, we explore whether gut dysbiosis is related to vascular innervation dysfunction and altered nitric oxide (NO) production in the superior mesenteric artery, one of the main vascular beds involved in peripheral vascular resistance. For this purpose, we used spontaneously hypertensive rats, either treated or not with the commercial synbiotic formulation Prodefen® (108 colony forming units/day, 4 weeks). Prodefen® diminished systolic blood pressure and serum endotoxin, as well as the vasoconstriction elicited by electrical field stimulation (EFS), and enhanced acetic and butyric acid in fecal samples, and the vasodilation induced by the exogenous NO donor DEA-NO. Unspecific nitric oxide synthase (NOS) inhibitor L-NAME increased EFS-induced vasoconstriction more markedly in rats supplemented with Prodefen®. Both neuronal NO release and neuronal NOS activity were enhanced by Prodefen®, through a hyperactivation of protein kinase (PK)A, PKC and phosphatidylinositol 3 kinase-AKT signaling pathways. The superoxide anion scavenger tempol increased both NO release and DEA-NO vasodilation only in control animals. Prodefen® caused an increase in both nuclear erythroid related factor 2 and superoxide dismutase activities, consequently reducing both superoxide anion and peroxynitrite releases. In summary, Prodefen® could be an interesting non-pharmacological approach to ameliorate hypertension.

Extraction optimization and structural characterization of pectin from persimmon fruit (Diospyros kaki Thunb. var. Rojo brillante).

In this work we have efficiently extracted and characterized pectin from different tissues of astringent (AS) and non-astringent (NAS) persimmon fruits (peel, pulp, whole fruit) for the first time. The highest pectin extraction (≥7.2%) was carried out at 80 °C, 120 min with 1.5% sodium citrate in peel of both AS and NAS persimmon samples. All persimmon pectins showed a molecular weight and galacturonic acid content upper than 328 kDa and 78%, respectively, indicating their suitability as food ingredient. Pectin extracted from AS pulp and peel tissues exhibited an enriched structure in rhamnose and arabinose, whereas the opposite behavior was observed in NAS persimmon whole fruit samples. Remarkably, both pulp tissues (AS and NAS) presented the highest levels of glucose and mannose, non-pectic carbohydrates. In addition, techno-functional assessment (zeta potential, particle size, apparent viscosity, gelation) showed the suitability of the persimmon pectins for a broad range of industrial applications.

Berry fruits as source of pectin: Conventional and non-conventional extraction techniques.

Three non-conventional extraction techniques (enzyme-assisted with cellulase, citric acid ultrasound-assisted and enzyme-ultrasound-assisted treatment) and conventional citric acid extraction were applied to obtain pectin from raspberry, blueberry, strawberry and redcurrant, and were compared in terms of extraction yields and physicochemical properties of the extracted pectins. Except for pectin from raspberry, conventional citric acid extraction led to the highest extraction yield (~8%) and, for the same berries, the lowest pectin recovery was found for the extraction with cellulase (~4%). Regarding the structural characteristics of pectins, enzymatically extracted pectins from redcurrant and strawberry exhibited the highest levels of galacturonic acid (≥73%) whereas, in general, this monosaccharide was found from 51 to 69% in the rest of samples. Although, ultrasound-assisted extraction did not improve pectin yield, it minimized the levels of "non-pectic" components leading to the obtainment of purer pectin. The different monomeric composition and the wide range of molecular weight of the obtained pectins pointed out their usefulness in different potential food applications (e.g., thickening, gelling ingredients) and biological activities. This has been evidenced by the differences found in their physicochemical and techno-functional characteristics. Finally, it can be considered that the berries here studied are efficient sources of pectin.