This study addresses the circular valorisation of Punica granatum peels through eco-friendly ultrasound-assisted extraction, yielding a phenol-rich extract (BM, 32.78% yield). Qualitative LC-MS/MS characterization allowed the identification of main constituents, notably punicalin, punicalagin, gallocatechin, and ellagic acid, whereas target phenolic compounds were individually quantified via LC-MS/MS using reference standards. We hypothesized that the lipase-assisted incorporation of pomegranate polyphenols into alginate improves structural stability while preserving antioxidant and anti-inflammatory properties. BM and the resulting phenolic-enriched polymer PBM exhibited high total phenolic content (319.02 and 129.53 mg GAE g–1, respectively) and strong DPPH/ABTS radical scavenging activity (IC50 = 0.0159–0.0678 mg mL–1). When incorporated into artisanal ice cream as a dual-action agent (GPBM at 0.3% w/w phenolic-enriched polymer vs free extract GBM at 2.4% w/w), rheological analysis showed that PBM reinforces the matrix, shifting the G’ and G’’ transition region to higher temperatures (+5 °C) and accelerating structural recovery at −7 °C to 350 s (compared to >1,200 s for control ice cream GC). Melting kinetics revealed superior stability for GPBM, delaying initial drip time to 480 s (vs 300 s in GC and 120 s in GBM) and the 50% drip-through end point to 1,620 s (vs 1,080 s in GC), while achieving a near-complete meltdown (4.32% residual weight vs 50.50% at 6,000 s in GBM, where the 50% drip-through end point was not reached). Furthermore, both ingredients dose-dependently reduced nitric oxide production in LPS-stimulated RAW 264.7 macrophages. Overall, PBM shows promise as a candidate ingredient with combined rheological and in vitro bioactive potential for frozen dessert formulations.
Abstract Enzymatic browning contributes to substantial postharvest losses in fresh produce, creating demand for effective clean-label inhibitors. However, the antibrowning potential of food-derived bioactive peptides and their underlying mechanisms remain poorly understood. This study produced four defatted wheat germ protein hydrolysates (DWGPHs) using Pronase, Protease N, Protease P, and trypsin and evaluated their antibrowning activity. Pronase-DWGPHs exhibited the strongest tyrosinase inhibition (21.3 ± 3.2% at 2.5 mg/mL) and browning suppression in apple juice (66.4 ± 2.2% at 20 mg/mL). Eight peptides were identified, and three were further evaluated (LGQMPPQCR, SDSQVFLFANSK, and FGDHLVYYEK). Peptide LGQMPPQCR showed the highest activity, achieving 95.2 ± 3.7% tyrosinase inhibition and 81.1 ± 0.8% browning reduction in apple juice at 5 mg/mL (P < 0.05). Molecular docking indicated that inhibition involves active-site binding, substrate competition, and redox interactions. These findings demonstrate that DWGPHs are promising natural antibrowning agents and provide mechanistic insight to guide their future development.
Abstract Açaí processing generates large quantities of seeds, creating an opportunity for valorization as food ingredients; however, poor flowability of spray-dried powders may limit handling and application. This study evaluated the effect of maltodextrin (20% w/w of total feed; 75.25% of theoretical dry feed solids) on the physicochemical, morphological, reconstitution, structural, and flow properties of spray-dried roasted açaí (Euterpe oleracea Mart.) seed extract. Drying at 180 °C produced powders with similar yields (63.94–66.55%) and low moisture contents (2.36–2.95%). Maltodextrin increased solubility, lightness, bulk and tapped densities, and hygroscopicity, while total phenolic compounds and tannins decreased. Both powders showed predominantly spherical particles and extremely poor flowability, although maltodextrin reduced the maximum wall friction angle against stainless steel. Fourier transform infrared spectra showed that the main characteristic functional-group bands were maintained after spray drying and maltodextrin addition. Overall, maltodextrin improved reconstitution and powder–wall interaction but did not overcome poor flowability, supporting further formulation and storage optimization for food applications.
Abstract The oxidation–reduction potential, or redox potential for short, has a long history in wine science and fermentation monitoring. Theoretical descriptions include the redox potential as a global measure of the ratio of redox couples, a mixed potential model based on all compounds electrochemically active at platinum electrodes, and as a potential determined only by the compounds involved in rate-limiting fermentation processes. Redox potentials for pH 3.3 model solutions with 0% ethanol, to represent juices prior to fermentation, and 12% ethanol for finished wines, have been examined, for both air-saturated and deaerated solutions, and with the addition of various redox-active species. Supporting cyclic voltammograms indicate which compounds are active at particular potentials. Ethanol and oxygen are shown to be directly active at platinum electrodes, while shifts in redox potential were observed with the addition of metal ions, caffeic acid, glutathione, hydrogen sulfide, or glucose, without fully accounting for the redox potential values of real wines. Theoretical curves based upon the Butler–Volmer equation are used to illustrate how mixed potentials are generated.
Abstract Multifunctional smart bilayer films were developed by solvent casting for active packaging of green grapes. The inner layer consisted of buckwheat starch/chitosan (BS/CH) incorporated with mulberry anthocyanin extract (MAE) as a pH-sensitive freshness indicator, while the upper zein/gelatin (ZN/GEL) layer contained β-cyclodextrin-encapsulated curry leaf essential oil (β-CD@CLEO; 2–12%, w/w) as an antimicrobial component. The idea of the study is to form a bilayer film in which the inner layer acts as an indicator layer and the upper layer possesses antioxidant, antimicrobial, and water-resistance capabilities. The effects of MAE and β-CD@CLEO on the physicochemical, mechanical, morphological, thermal, UV-barrier, antioxidant, and antibacterial properties of the films were investigated. The film containing 1% MAE and 8% β-CD@CLEO (F5 film) was chosen as the selected film formulation, as it exhibited the highest hydrophobicity and superior overall functional performance. F5 refers to the bilayer film containing 1% (w/w) mulberry anthocyanin extract (MAE) in the inner BS/CH layer and 8% (w/w) β-CD-encapsulated curry leaf essential oil (β-CD@CLEO) in the upper ZN/GEL layer. The F5 film exhibited a water contact angle of 82.50 ± 3.50° and a tensile strength of 40.2 ± 2.75 MPa, and the lowest water vapor permeability ((3.19 ± 0.48) × 10–11 g m–1 s–1 Pa–1). It was found that incorporation of MAE and β-CD@CLEO enhanced tensile properties, water resistance, and thermal stability. The films also exhibited excellent UV-barrier performance and sustained release behavior, where approximately 75.90% of CLEO was gradually released from F5 over 160 h. The bilayer films also showed robust antioxidant activity (75.73% DPPH and 35.01% ABTS) and antibacterial activity against E. coli and S. aureus, with inhibition zones of 15.92 ± 1.73 and 16.27 ± 0.78 mm, respectively. Packaging trials demonstrated that the selected F5 film significantly preserved grape quality, outperforming conventional polyethylene packaging.
