Search Results (61)

This study aimed to investigate the impact of ultrasonic pretreatment vacuum drying (UAVD) and temperature on drying kinetics and qualitative attributes of blood oranges in comparison to several drying methods: hot air drying (HAD), vacuum drying (VD), and freeze drying (FD). The drying kinetics and modeling, total phenolic content (TPC), antioxidant capability (assessed using DPPH and ABTS tests), individual phenolic profiles, vitamin C concentration, and color factors were meticulously examined. Drying times were recorded as 22.5 h, 12.5 h, and 9 h for HAD; 11.5 h, 9.5 h, and 8.5 h for VD; and 10 h, 8.5 h, and 7.5 h for UAVD at 50, 60, and 70 °C, respectively. The HAD, VD, and UAVD procedures were conducted at 50, 60, and 70 °C, resulting in reduced drying periods with increasing temperature. The integration of ultrasound markedly lowered drying durations. Eleven thin-layer drying models were utilized to recreate the drying process precisely. The D_eff values of the HAD, VD, and UAVD dried samples varied from 9.08 × 10⁻⁶ to 2.82 × 10⁻⁵ m²/s, from 2.60 × 10⁻⁵ to 2.96 × 10⁻⁵ m²/s, and from 2.20 × 10⁻⁵ to 2.99 × 10⁻⁵, respectively. Among the desiccated blood orange slices, the greatest total phenolic content (TPC) was observed in freeze-dried samples (131.27 mg GAE/100 g), followed by those dried using ultrasonic-assisted vacuum drying (UAVD) at 50 °C (128.77 mg GAE/g DM). Dried blood orange slices had a vitamin C content of 29.79 to 49.01 mg/100. The drying process substantially impacted the color parameters L*, a*, and b*. These findings highlight the efficacy of ultrasound-assisted drying in decreasing drying duration while improving the retention of bioactive components in blood orange slices. Full article

This study evaluated Maltodextrin (MD), Gum Arabic (GA), and Carboxymethylcellulose (CMC) in different ratios as coating materials to encapsulate citrus pomace phenolic compounds. Citrus encapsulates were obtained by ultrasound-assisted extraction followed by the freeze-drying process and were characterized regarding the microencapsulation efficiency, physical, and chemical properties. Carrier material choice reflected a significant effect on encapsulation efficiency, phenolic compounds retention, and reconstitution properties of encapsulated extract. The encapsulation efficiency of prepared encapsulates ranked from 50.909% to 84.000%, and it was strongly dependent upon CMC addition. A wide range of reconstitution parameters (water absorption index-WAI and water solubility index-WSI) suggested possible release mechanism modifications. HPLC analysis revealed the presence of three main phenolic compounds, namely Hesperidin, Naringin, and Rutin. A wall material mixture of MD, GA, and CMC in the same proportions was optimal for freeze-drying. This combination resulted in encapsulates with a low moisture content (1.936 ± 0.012%) and a low water activity (0.110 ± 0.001), indicating prolonged stability. Based on the obtained results, freeze-drying as an encapsulation technique should be considered as a promising solution to recover compounds from industry byproducts and protect them from environmental and gastrointestinal circumstances. Full article

Broccoli by-products, traditionally considered inedible, possess a comprehensive nutritional and functional profile. These by-products are abundant in glucosinolates, particularly glucoraphanin, and sulforaphane, an isothiocyanate renowned for its potent antioxidant and anticarcinogenic properties. Broccoli leaves are a significant source of phenolic compounds, including kaempferol and quercetin, as well as pigments, vitamins, and essential minerals. Additionally, they contain proteins, essential amino acids, lipids, and carbohydrates, with the leaves exhibiting the highest protein content among the by-products. Processing techniques such as ultrasound-assisted extraction and freeze-drying are crucial for maximizing the concentration and efficacy of these bioactive compounds. Advanced analytical methods, such as high-performance liquid chromatography–mass spectrometry (HPLC-MS), have enabled precise characterization of these bioactives. Broccoli by-products have diverse applications in the food industry, enhancing the nutritional quality of food products and serving as natural substitutes for synthetic additives. Their antioxidant, antimicrobial, and anti-inflammatory properties not only contribute to health promotion but also support sustainability by reducing agricultural waste and promoting a circular economy, thereby underscoring the value of these often underutilized components. Full article

Marine microalgae are emerging as promising sources of polyphenols, renowned for their health-promoting benefits. Recovering polyphenols from microalgae requires suitable treatment and extraction techniques to ensure their release from the biomass and analytical methodologies to assess their efficiency. This review provides a comprehensive comparison of traditional and cutting-edge extraction and analytical procedures applied for polyphenolic characterization in marine microalgae over the past 26 years, with a unique perspective on optimizing their recovery and identification. It addresses (I) cell disruption techniques, including bead milling, high-speed homogenization, pulsed electric field, ultrasonication, microwave, freeze-thawing, and enzymatic/chemical hydrolysis; (II) extraction techniques, such as solid–liquid extraction, ultrasound and microwave-assisted extraction, pressurized-liquid extraction, and supercritical CO₂; (III) analytical methods, including total phenolic and flavonoid content assays and advanced chromatographic techniques like GC-MS, HPLC-DAD, and HPLC-MS. Key findings showed bead milling and chemical hydrolysis as effective cell disruption techniques, pressurized-liquid extraction and microwave-assisted extraction as promising efficient extraction methods, and HPLC-MS as the finest alternative for precise phenolic characterization. Unlike previous reviews, this study uniquely integrates both extractive and analytical approaches in one work, focusing exclusively on marine microalgae, a relatively underexplored area compared to freshwater species, offering actionable insights to guide future research and industrial applications. Full article

Capsicum chacoense (wild red pepper) and Acrocomia aculeata almond (Paraguayan coconut) are fruits native to Paraguay which are little-used and can be sources of important bioactive compounds. The aim of this work was to evaluate the use of Paraguayan coconut kernel oil as a green solvent for the extraction of carotenoids and capsaicinoids from wild red pepper. Ultrasound-assisted extraction was performed (solvent ratio; 0.7 g/mL, amplitude 80%, for 17 min). The freeze-dried red pepper fruit, coconut oil, and coconut+red pepper oil were characterized by total carotenoids, total capsaicinoids, total phenolic compounds (TPCs), total antioxidant capacity (TAC), fatty acid (FA) profile, and color. It was possible to extract 46.7% of the carotenoids and 42.5% of the capsaicinoids present in the red pepper. However, only about 7% of TCP and TAC were maintained in the coconut+red pepper oil obtained. In the FA profile of red pepper oil, oleic acid and palmitic acid were observed as the main FAs. Conversely, in coconut oil, lauric acid and oleic acid were observed as the main components. In coconut+red pepper oil, the same main FAs were found, but in a lower percentage of lauric acid and higher percentage of oleic acid. Based on the results, coconut oil is a green solvent for the extraction of lipophilic secondary metabolites such as carotenoids and capsaicinoids. These can provide sensory characteristics such as color and flavor to coconut oil from Capsicum chacoense. In the oil obtained (coconut+red pepper), a significant difference in the FA profile was also seen, where the majority FA was oleic acid. Full article

In this study, the effect of ultrasound-assisted freezing with frequencies of 21.5 and 40 kHz, and a power of 2.4 kW in the chopped mode of milk ice cream in comparison to a standard freezer on the freezing course and formed crystal structure was examined. The first part of the research included the preparation of an ice cream mixture on the basis of skimmed milk with the addition of an emulsifier, locust bean gum, xanthan gum, ι-carrageenan and a reference mixture without stabilizer addition. Ultrasound-assisted freezing shortened the processing time of both stabilized and non-stabilized ice cream. Stabilized samples of milk ice cream exposed to ultrasound (US) at a frequency of 21.5 kHz were characterized by the most homogeneous structure, consisting of crystals with the smallest diameters among all of the tested samples, the size of which, after 3 months of storage at −18 °C, was 7.8 µm (for the reference sample, it was 14.9 µm). The ice recrystallization inhibition (IRI effect) in the samples after US treatment with a frequency of 40 kHz was also observed, regardless of the addition of stabilizers, which may suggest that sonication with these parameters could replace or limit the addition of these substances. Full article

In this paper, the qualitative and quantitative profile is evaluated of the bioactive compounds, antioxidant activity (AA), microbiostatic properties, as well as the color parameters of jostaberry extracts, obtained from frozen (FJ), freeze-dried (FDJ), and oven-dried berries (DJ). The optimal extraction conditions by ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) were selected after determination of the total polyphenol content (TPC), total flavonoid content (TFC), total antocyanin content (TA), AA by 2,2-diphenyl-1-picrylhydrazyl-hydrate (DPPH), and the free radical cation 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonates (ABTS). Non-conventional extraction methods are less destructive to anthocyanins, while drying the berries reduced TA, regardless of the extraction method. The oven-drying process reduced the concentration of TA in DJ extracts by 99.4% and of ascorbic acid by 92.42% compared to FJ. AA was influenced by the jostaberry pretreatment methods. The DPPH and ABTS tests recorded values (mg Trolox equivalent/g dry weight) between 17.60 and 35.26 and 35.64 and 109.17 for FJ extracts, between 7.50 and 7.96 and 45.73 and 82.22 for FDJ, as well as between 6.31 and 7.40 and 34.04 and 52.20 for DJ, respectively. The jostaberry pretreatment produced significant changes in all color parameters. Mutual information analysis, applied to determine the influence of ultrasound and microwave durations on TPC, TFC, TA, AA, pH, and color parameters in jostaberry extracts, showed the greatest influence on TA (0.367 bits) and TFC (0.329 bits). The DPPH and ABTS inhibition capacity of all FJ’ extracts had higher values and varied more strongly, depending on pH, heat treatment, and storage time, compared to the AA values of FDJ’ and DJ’ extracts. A significant antimicrobial effect was observed on all bacterial strains studied for FJP. FDJP was more active on Bacillus cereus, Staphylococcus aureus, and Escherichia coli. DJP was more active on Salmonella Abony and Pseudomonas aeruginosa. The antifungal effect of DJP was stronger compared to FDJP. Jostaberry extracts obtained under different conditions can be used in food production, offering a wide spectrum of red hues. Full article

This study investigated the effects of ultrasound–assisted immersion freezing (UIF) at different power rates (0, 200, 400, and 600 W) on the changes in beef quality and flavor after braising. The results demonstrated that UIF treatment at 400 W significantly reduced the juice loss (cooking loss decreased from 49.04% to 39.74%) and fat oxidation (TBARS value decreased from 0.32 mg/kg to 0.20 mg/kg) of braised beef. In addition, the tenderness (hardness value decreased from 5601.50 g to 2849.46 g) and color stability of braised beef were improved after UIF treatment. The flavor characteristics of braised beef were characterized using an electronic nose and an electronic tongue. The PCA analysis data showed that the cumulative contribution rates of the first and second principal components were 85% and 93.2%, respectively, with the first principal component accounting for a higher proportion. The UIF–400 W group had the highest concentration for the first principal component, and the differentiation was not significant compared to the control group. The total amino acid values of different power UIF treatment groups were improved compared to the AF treatment group, indicating that UIF can effectively reduce the losses caused by freezing. The results demonstrate that ultrasound–assisted freezing treatment is beneficial in enhancing the tenderness and flavor attributes of beef after braising, providing new insights into the processing of meat products with desirable quality characteristics. Full article

Valorisation of food by-products, like spent brewer’s yeast and fruit pomaces, represents an important strategy for contributing to sustainable food production. The aims of this study were to obtain Maillard conjugates based on spent yeast protein hydrolysate (SYH) with dextran (D) or maltodextrin (MD) by means of ultrasound treatment and to use them for developing encapsulation systems for the anthocyanins from aronia pomace. The ultrasound-assisted Maillard conjugation promoted the increase of antioxidant activity by about 50% compared to conventional heating and SYH, and was not dependent on the polysaccharide type. The ability of the conjugates to act as wall material for encapsulating various biologically active compounds was tested via a freeze-drying method. The retention efficiency ranged between 58.25 ± 0.38%–65.25 ± 2.21%, while encapsulation efficiency varied from 67.09 ± 2.26% to 88.72 ± 0.33%, indicating the strong effect of the carrier material used for encapsulation. The addition of the hydrolysed yeast cell wall played a positive effect on the encapsulation efficiency of anthocyanins when used in combination with the SYH:MD conjugates. On the other hand, the stability of anthocyanins during storage, as well as their bioavailability during gastrointestinal digestion, were higher when using the SYH:D conjugate. The study showed that hydrolysis combined with the ultrasound-assisted Maillard reaction has a great potential for the valorisation of spent brewer’s yeast as delivery material for the encapsulation of bioactive compounds. Full article

Non-steroidal anti-inflammatory piroxicam (PRX) is a poorly water-soluble drug that provides relief in different arthritides. Reducing the particle size of PRX increases its bioavailability. For pediatric, geriatric, and dysphagic patients, oral dispersible systems ease administration. Moreover, fast disintegration followed by drug release and absorption through the oral mucosa can induce rapid systemic effects. We aimed to produce an orodispersible lyophilizate (OL) consisting of nanosized PRX. PRX was solved in ethyl acetate and then sonicated into a poloxamer-188 solution to perform spray-ultrasound-assisted solvent diffusion-based nanoprecipitation. The solid form was formulated via freeze drying in blister sockets. Mannitol and sodium alginate were applied as excipients. Dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) were used to determine the particle size. The morphology was characterized by scanning electron microscopy (SEM). To establish the crystallinity, X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) were used. A disintegration and in vitro dissolution test were performed. DLS and NTA presented a nanosized PRX diameter. The SEM pictures showed a porous structure. PRX became amorphous according to the XRPD and DSC curves. The disintegration time was less than 1 min and the dissolution profile improved. The final product was an innovative anti-inflammatory drug delivery system. Full article

The aim of the study was to compare the antioxidant activity and polyphenol content in extracts prepared from freeze-dried leaves of three apple cultivars: Ligol, Gala, and Gloster, using different solvents and extraction methods. The content of total polyphenols was determined using the Folin–Ciocâlteu reagent method, and a qualitative and quantitative analysis of polyphenols was performed using the HPLC method. The antioxidant capacity of the extracts was determined using the DPPH radical method. The colour parameters (in the CIEL*a*b system) of the obtained extracts were also determined. The antioxidant activity of apple leaf extracts increased with increasing polyphenol content. Water–alcoholic extracts from apple leaves were characterised by a significantly higher antioxidant capacity and polyphenol content in comparison with water extracts. The best solvent was a mixture of water and methanol (80%). Among the phenolic compounds identified in the extracts, the most common was phloridzin. The highest content of phloridzin (105.0 mg/1 g of dry weight) was found in water–methanol extracts from the leaves of the Ligol variety obtained with ultrasound-assisted extraction. The extracts with the highest antioxidant activity (131.2 μmol of Trolox/1 g of dry weight) and polyphenol content (81.9 mg GAE/1 g of dry weight) were water–methanol from the leaves of the Ligol cultivar, obtained by shaking them with a solvent. Full article

Lavender distillation produces huge quantities of solid waste yearly. This waste is usually discarded, resulting in serious environmental issues. However, it still contains residual essential oil and other bioactive compounds. This research reports on the development and comparison of optimized solid–liquid separation methods, i.e., microwave- (MAE) and ultrasound-assisted extraction (UAE) of phenolic compounds from lavender distillation waste. The optimal pretreatment conditions, such as waste moisture content and particle size, were also determined. The extracts were spray- or freeze-dried and the resulting powders were characterized for their physicochemical properties. The majority of the original phenolic compounds in lavender were found in the leachate fraction after distillation (61%), whereas 43% was found in the solid waste. Drying of the solid waste before extraction affected the process efficiency. UAE led to a higher phenolic content and greater antioxidant properties compared to MAE. Drying (spray or freeze) the extracts did not significantly affect their phenolic content, whereas the use of maltodextrin as a drying agent improved the drying process yield, especially when using the freeze-drying method. It is concluded that valorization of lavender distillation wastes can be achieved via an integrated process consisting of a green extraction method and a consequent drying process that results in a stable bioactive powder. Full article

α-Solanine and α-chaconine are the two most predominant glycoalkaloids (GAs) present in potato. Potato peel contains a high concentration of GAs, which are especially interesting for application in the pharmaceutical industry due to their different beneficial properties (such as anticarcinogenic, anti-inflammatory, antiallergic, antipyretic, antiviral, fungicide, and antibiotic activities, among others); so, potato peel waste can be valorized by extracting these biologically active compounds. For this, a green, quick, and efficient miniaturized analytical approach based on ultrasound-assisted extraction (UAE) combined with HPLC-DAD was developed to quantify α-solanine and α-chaconine in potato peel. Some parameters of the extraction were optimized, including the extraction method, the type of solvent, and the sample/solvent ratio, by a three-factor, three-level (3³) full factorial experimental design. The optimal extraction conditions were obtained with UAE using methanol as a solvent and a sample/solvent ratio of 1:10 (w/v, g/mL). The analytical greenness metric for sample preparation (AGREEprep) tool was used to assess the greenness of the methods used. The tool revealed an acceptable green analysis, with 0.61 points. The method was validated and applied to the evaluation of GAs in the peel of 15 commercial varieties of potato. The amount of glycoalkaloids found in the samples evaluated ranged from 143 to 1273 mg/kg and from 117 to 1742 mg/kg dry weight for α-solanine and α-chaconine, respectively. These results reveal the important variability that exists between potato varieties; so, their analysis is of great importance to select the most suitable ones for biovalorization (e.g., the Amandine and Rudolph varieties, with around 3000 mg/kg, in total, of both GAs). To provide higher stability to the peel during storage, freeze-drying or a medium-temperature drying process resulted preferable to avoid GA degradation. Overall, this study will contribute to the expansion of the future biovalorization of potato peel waste as well as provide a powerful analytical tool for GA analysis. Full article

Salting pretreatment is an effective method to improve the quality of frozen fish. This study investigated the quality changes and proteomic profile differences of frozen yellowfin tuna fillets pretreated with ultrasound-assisted salting (UAS) and static salting (SS). This study was centered on three aspects: physicochemical indicators’ determination, histological observation, and proteomic analysis. The results showed that UAS significantly increased yield, salt content, and water-holding capacity (WHC), decreased total volatile base nitrogen (TVBN) compared to SS (p < 0.05), and significantly increased water in the protein matrix within myofibrils. Histological observations showed that the tissue cells in the UAS group were less affected by frozen damage, with a more swollen structure and rougher surface of myofibrils observed. Furthermore, 4D label-free proteomics revealed 56 differentially abundant proteins (DAPs) in UAS vs. NT comparison, mainly structural proteins, metabolic enzymes, proteasomes, and their subunits, which are associated with metabolic pathways such as calcium signaling pathway, gap junction, actin cytoskeletal regulation, and necroptosis, which are intimately associated with quality changes in freeze-stored tuna fillets. In brief, UAS enhances the potential for the application of salting pretreatment to improve frozen meat quality, and 4D label-free proteomics provides knowledge to reveal the potential links between quality and molecular changes in processed frozen meat to optimize future UAS meat processing. Full article

The aim of this study was to investigate the effects of inulin incorporation and three different freezing treatments (static, air blast, and individual quick frozen; IQF) on some quality characteristics of sour cherry (Prunus cerasus L.). Frozen foodstuffs expose undesired changes during storage, such as enzyme activity, and after thawing, such as drip loss. To overcome such issues, inulin, which is known for its cryoprotectant attributes, was added to sour cherry samples by an ultrasound-assisted vacuum impregnation method prior to different freezing treatments. Inulin addition decreased the drip loss (13–18%) in all sample groups, while the pectin methylesterase activity was reduced in samples frozen by air blast and IQF methods. On the other hand, gradual reductions were observed in the total phenolic and monomeric anthocyanin contents, along with antioxidant capacities, by the DPPH and ABTS methods compared to the control groups, except for sour cherry samples subjected to air blast freezing. Among freezing techniques, IQF outshined others yielding conserved nutritional and quality characteristics. The results of this study indicate that inulin can be utilized to maintain or improve the quality characteristics of frozen foods. In conclusion, rapid freezing technologies such as IQF may enable the prevention of several problems widely encountered in frozen sour cherry fruits. Full article