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Thermal (T) and ultrasound (US) pasteurization processes were applied to apple juice and the phenolic compounds (TPC) were quantified before and after in vitro digestion by HPLC-DAD-ESI-MS n , with their bioaccessibility ascertained. Digested samples were analysed for their inhibitory capacity against α-glucosidase. Since some of the compounds exhibit fluorescence, both steady state and time-resolved fluorescence methods were used to investigate the binding to a blood transport protein, human serum albumin (HSA). It was found that processing induced an increase in the TPC content, which was more pronounced when US was applied. In contrast, digestion reduced the TPC content, evening out the overall effect. Still T and US pasteurized juices exhibited a higher quantity of TPC upon digestion as compared to the raw sample. No correlation was found between the TPC content and α-glucosidase inhibition, as the T and US pasteurized juices showed the highest and lowest inhibitory capacities against the enzyme, respectively. This is indicative that other compounds, such as those formed upon thermal treatment, may be involved in the antidiabetic effect of apple juice. The fluorescence study showed that binding occurred to HSA, at slightly different rates for different species present in the US treated extract. Considering energy consumption, US pasteurization is the most power consuming treatment despite its shorter duration. Overall, no univocal indication on the best pasteurization process can be gathered. Thus, it is necessary to define the desired target in order to drive technological interventions by a customized approach.

Summary: The present study aimed at understanding the response of dietary fibres and phenolic compounds to apple matrix disintegration and thermal treatment. Apple was processed by mimicking industrial operations of blanching, destructuring by high‐speed homogenisation (HSH) or high‐pressure homogenisation (HPH), and pasteurisation. A viscous puree (0.73 Pa × s), made of juice embedding intact cells and large cell clusters, was obtained by HSH. Conversely, HPH completely disrupted apple tissue leading to a fluid homogenate (0.27 Pa × s) in which the fibrous matrix was suspended. Despite these differences, apple puree and homogenate presented similar content of total and soluble dietary fibre, with no significant differences in the chemical structure of apple pectin, as demonstrated by FT‐IR and NMR analyses. Apple puree and homogenate retained more than 80% of the phenolic content originally present in apple pulp (about 2125 mg/gdw) without detriment to radical scavenging activity. This minor phenolic depletion, regardless of the different extent of mechanical disintegration, was mainly due to the decrease of thermolabile flavanols upon application of analogous heat treatments. [ABSTRACT FROM AUTHOR]

Abstract The in vitro α-glucosidase inhibitory activity of raw, mildly (F 71.7 5 = 0.4 min, 5 Log reductions of Cryptosporidium parvum) and intensively ( F 90 12 =14.8 min, 2 Log reductions of Alicyclobacillus acidoterrestris) pasteurized apple juice was studied. Raw apple juice (23 mg dw /mL) caused 90% α-glucosidase inhibition. Analogous results were obtained for the mildly treated sample. The most intense treatment reduced by 35% the α-glucosidase inhibition. However, such a decrease was associated with an increase in the phenolic content, suggesting that α-glucosidase inhibition might not rely on these compounds, but depend on more complex mechanisms. Apple juice was combined with acarbose to investigate their interaction towards α-glucosidase inhibition. A synergistic behavior was observed for concentrations <2 mg/mL. Increasing the concentration of the combined system (up to 9 mg/mL) produced an antagonistic effect, while a further increase (<9 mg/mL) allowed approaching an addictive behavior. Highlights • Apple juice inhibited α -glucosidase in a concentration-dependent way. • Conventional pasteurization did not affect the α -glucosidase inhibitory capacity of apple juice. • Severe pasteurization reduced by 35% the apple juice inhibitory capacity. • Apple juice-acarbose system played a synergistic effect up to 40% α -glucosidase inhibition. [ABSTRACT FROM AUTHOR]

Prunus spinosa fruits (PSF) contain different phenolic compounds showing antioxidant and anti-inflammatory activities. Innovative drug delivery systems such as biomimetic nanoparticles could improve the activity of PSF extract by promoting (i) the protection of payload into the lipidic bilayer, (ii) increased accumulation to the diseased tissue due to specific targeting properties, (iii) improved biocompatibility, (iv) low toxicity and increased bioavailability. Using membrane proteins extracted from human monocyte cell line THP-1 cells and a mixture of phospholipids, we formulated two types of PSF-extract-loaded biomimetic vesicles differing from each other for the presence of either 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or 1,2-dioleoyl-sn-glycero-3-phospho-(1′-rac-glycerol) (DOPG). The biological activity of free extract (PSF), compared to both types of extract-loaded vesicles (PSF-DOPCs and PSF-DOPGs) and empty vesicles (DOPCs and DOPGs), was evaluated in vitro on HUVEC cells. PSF-DOPCs showed preferential incorporation of the extract. When enriched into the nanovesicles, the extract showed a significantly increased anti-inflammatory activity, and a pronounced wound-healing effect (with PSF-DOPCs more efficient than PSF-DOPGs) compared to free PSF. This innovative drug delivery system, combining nutraceutical active ingredients into a biomimetic formulation, represents a possible adjuvant therapy for the treatment of wound healing. This nanoplatform could be useful for the encapsulation/enrichment of other nutraceutical products with short stability and low bioavailability. [ABSTRACT FROM AUTHOR]