Improvement of phenolic compounds extraction from high-starch lotus (Nelumbo nucifera G.) seed kernels using glycerol: New insights to amylose/amylopectin – Phenolic relationships

Dynamic/static pressure-induced copolymerization and property changes of lotus seed starch with chlorogenic acid

Pressure promotes the formation of starch-polyphenol complexes, but their classification and properties are still unclear. This study aimed to elucidate the effects of dynamic high-pressure homogenization (10-50 MPa) and static hydrostatic pressure (100-500 MPa) on the copolymerization behavior and properties of lotus seed starch (LS)-endogenous polyphenol chlorogenic acid (CA) complexes. The results showed that both pressures induced LS-CA to form stable inclusion-type complexes and easily destructible noninclusion-type complexes. Increased pressure promoted the formation of inclusion-type complexes, with dynamic pressure having a particularly strong effect. However, noninclusion-type complexes began breaking down at 20 MPa under dynamic pressure and 300 MPa under static pressure. Inclusion-type complexes primarily improve starch ordering, and noninclusion-type complexes enhance water holding capacity, but excessive proportions of either type affect pasting performance. These findings offer insights into transforming specific starch structures through small molecular components and provide a theoretical basis for controlling functional starch product processing.

Comparative study on dynamic in vitro digestion characteristics of lotus seed starch-EGCG complex prepared by different processing methods

To study the effect of starch-polyphenol interaction induced by different processing methods on digestion characteristics, a dynamic in vitro human gastrointestinal system was employed to investigate the digestive characteristics of lotus seed starch-epigallocatechin gallate (EGCG) complex (LS-EGCG) prepared by different processing methods. Digestion altered crystal structure, particle size, morphology, pH, starch hydrolysis, and EGCG content. Processing broke physical barriers, reducing particle size by enzyme erosion. Enzymatic hydrolysis gradually exposed EGCG, indicated by green fluorescence. Heat and high pressure treatments enhanced starch dissolution, increasing sugar accumulation and hydrolysis. However, ultrasonic-microwave and high pressure microfluidization treatments formed dense structures, decreasing hydrolysis rates. Overall, the complex formed by high pressure microfluidization showed better enzyme resistance. The results provide a scientific basis for the development of food with quality and functional properties.

Insights into impact of chlorogenic acid on multi-scale structure and digestive properties of lotus seed starch under autoclaving treatment

The interaction between polyphenols and starch is an important factor affecting the structure and function of starch. Here, the impact of chlorogenic acid on the multi-scale structure and digestive properties of lotus seed starch under autoclaving treatment were evaluated in this study. The results showed that lotus seed starch granules were destroyed under autoclaving treatment, and chlorogenic acid promoted the formation of loose gel structure of lotus seed starch. In particular, the long- and short-range ordered structure of lotus seed starch-chlorogenic acid complexes were reduced compared with lotus seed starch under autoclaving treatment. The relative crystallinity of A-LS-CA complexes decreased from 23.4 % to 20.3 %, the value of R1047/1022 reduced from 0.87 to 0.80, and the proportion of amorphous region increased from 10.26 % to 13.85 %. In addition, thermal stability, storage modulus and loss modulus of lotus seed starch-chlorogenic acid complexes were reduced, indicating that the viscoelasticity of lotus seed starch gel was weakened with the addition of chlorogenic acid. It is remarkable that chlorogenic acid increased the proportion of resistant starch from 58.25 ± 1.43 % to 63.85 ± 0.96 % compared with lotus seed starch under autoclaving treatment. Here, the research results provided a theoretical guidance for the development of functional foods containing lotus seed starch.

Effects of Microwave Treatment on Physicochemical Attributes, Structural Analysis, and Digestive Characteristics of Pea Starch-Tea Polyphenol Complexes

Addressing the challenge of blood glucose fluctuations triggered by the ingestion of pea starch, we have adopted an eco-friendly strategy utilizing microwave irradiation to synthesize the novel pea starch-tea polyphenol complexes. These complexes exhibit high swelling capacity and low solubility, and their thermal profile with low gelatinization temperature and enthalpy indicates adaptability to various processing conditions. In vitro digestion studies showed that these complexes have a small amount of rapidly digestible starch and a large amount of resistant starch, leading to a slower digestion rate. These features are particularly advantageous for diabetics, mitigating glycemic excursions. Structurally, the pea starch-tea polyphenol complexes exhibited a B + V-shaped dense network with low crystallinity, high orderliness, and a prominent double helix content, enhancing its stability and functionality in food applications. In summary, these innovative complexes served as a robust platform for developing low glycemic index foods, catering to the nutritional needs of diabetics. It offers an environmentally sustainable approach to food processing, fostering human well-being and propelling innovation in the food industry.

Development and characterization of an active starch-based film as a chlorogenic acid delivery system

Given its health benefits for the human body, chlorogenic acid (CA) offers promising applications in the food industry. However, the instability and low bioavailability of CA remain to be solved. In this paper, a starch-based film prepared by the homogenization and solution-casting method was used as an effective carrier to alleviate these problems. Homogenization (10-50 MPa) reduced the starch paste viscosity and its particle sizes from 21.64 to 7.68 μm, which promoted the starch recrystallization and induced chemical cross-links between starch-CA, as confirmed by the FTIR result with an appearance of a new CO peak at about 1716 cm-1. Accordingly, the rapidly digestible starch content of the film was reduced to 27.83 % and the CA encapsulation efficiency was increased to 99.08 % (from 65.88 %). As a result, the film system extended CA's release time beyond 4 h and significantly increased the heat-treated CA's antioxidant activity. Besides, the tensile strength and elastic modulus of the film were also improved to 6.29 MPa (from 1.63 MPa) and 160.98 MPa (from 12.02 MPa), respectively, by homogenization. In conclusion, the developed active starch-based film could be used as an edible film for the production of functional food or active food packaging.

Mechanochemical-Assisted Extraction and Biological Activity Research of Phenolic Compounds from Lotus Seedpod (Receptaculum Nelumbinis)

To explore the feasibility of the mechanochemical-assisted extraction (MCAE) of phenolic compounds from lotus seedpod (Receptaculum Nelumbinis), a single-factor experiment combined with response-surface methodology (RSM) was used to optimize the extraction process. The results showed the optimal extraction conditions as follows: Li2CO3 as a solid reagent (25%), an extraction time of 80 min, liquid/solid ratio of 42.8 mL/g, and extraction temperature of 80.7 °C; and the maximum value of total phenolic content (TPC) was 106.15 ± 1.44 gallic acid equivalents (GAE)/g dry weight (DW). Additionally, the 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) were 279.75 ± 18.71, 618.60 ± 2.70, and 634.14 ± 7.17 µmol TE/g, respectively. Ultra-high pressure liquid chromatography combined with triple-time-of-flight mass spectrophotometry (UPLC-Triple-TOF/MS) analysis identified eight phenolic compounds mainly consisting of polyphenols and flavonoids. Moreover, the phenolic compounds showed potent inhibitory effects on both α-amylase and α-glucosidase, with inhibition rates of over 80%. Furthermore, the results showed different degrees of inhibition activity against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli, among which the inhibitory effect on the growth of B. subtilis was the best. This paper shows that the phenolic compounds have good biological activities, which provides a reference for the further exploitation of LSP.

Interaction of oat avenanthramides with starch and effects on in vitro avenanthramide bioaccessibility and starch digestibility

Oat avenanthramides possess multiple biologically beneficial properties. However, their interaction with starch has not been investigated. This study aims to study the interactions between avenanthramides and starches using high-performance liquid chromatography, rapid viscosity analysis, and simulated digestion. Phenolic acids were employed as a comparative group. The results demonstrated that avenanthramides exhibited higher binding rates with gelatinized starches than phenolic acids, ranging from 92.9% to 99.8%. Moreover, avenanthramides decreased the viscosity, breakdown, and setback of corn starch. Furthermore, starches slightly increased the bioaccessibility of avenanthramide 2c. Additionally, avenanthramides decreased the contents of rapidly digestible starch and slowly digesting starch in corn starch while increasing resistant starch contents. Interestingly, avenanthramides exhibited a more pronounced delaying effect on starch digestion than phenolic acids, which can be attributed to their higher binding affinity with starch. This study provides the first demonstration of the significant inhibitory effect of avenanthramides on starch digestion.

Mining nutri-dense accessions from rice landraces of Assam, India

The Indian subcontinent is the primary center of origin of rice where huge diversity is found in the Indian rice gene pool, including landraces. North Eastern States of India are home to thousands of rice landraces which are highly diverse and good sources of nutritional traits, but most of them remain nutritionally uncharacterized. Hence, nutritional profiling of 395 Assam landraces was done for total starch, amylose content (AC), total dietary fiber (TDF), total protein content (TPC), oil, phenol, and total phytic acid (TPA) using official AOAC and standard methods, where the mean content for the estimated traits were found to be 75.2 g/100g, 22.2 g/100g, 4.67 g/100g, 9.8 g/100g, 5.26%, 0.40 GAE g/100g, and 0.34 g/100g for respectively. The glycaemic index (GI) was estimated in 24 selected accessions, out of which 17 accessions were found to have low GI (<55). Among different traits, significant correlations were found that can facilitate the direct and indirect selection such as estimated glycemic index (EGI) and amylose content (-0.803). Multivariate analyses, including principal component analysis (PCA) and hierarchical clustering analysis (HCA), revealed the similarities/differences in the nutritional attributes. Four principal components (PC) i.e., PC1, PC2, PC3, and PC4 were identified through principal component analysis (PCA) which, contributed 81.6% of the variance, where maximum loadings were from protein, oil, starch, and phytic acid. Sixteen clusters were identified through hierarchical clustering analysis (HCA) from which the trait-specific and biochemically most distant accessions could be identified for use in cultivar development in breeding programs.

Microwave-Induced Behavior and Digestive Properties of the Lotus Seed Starch-Chlorogenic Acid Complex

The effect of chlorogenic acid (CA) on the dielectric response of lotus seed starch (LS) after microwave treatment, the behavior and digestive characteristics of the resulting starch/chlorogenic acid complex (LS-CA) at different degrees of gelatinization and the inhibition of α-amylase by chlorogenic acid were investigated. The variation in dielectric loss factor, ε″, and dielectric loss tangent, tanδε, of the microwave thermal conversion indicated that LS-CA had a more efficient microwave-energy-to-thermal-energy conversion efficiency than LS. This gelatinized LS-CA to a greater extent at any given temperature between 65 and 85 °C than LS, and it accelerated the degradation of the starch crystalline structure. The greater disruption of the crystal structure decreased the bound water content and increased the thermal stability of LS-CA compared to LS. The simulated in vitro digestion found that the presence of the LS-CA complex improved the slow-digestion property of lotus seed starch by increasing its content of resistant and slowly digested starch. In addition, the release of chlorogenic acid during α-amylase hydrolysis further slowed starch digestion by inhibiting α-amylase activity. These findings provide a foundation for understanding the correlation between the complex behavior and digestive properties of naturally polyphenol-rich, starch-based foods, such as LS, under microwave treatment, which will facilitate the development of starch-based foods with tailored digestion rates, lower final degrees of hydrolysis and glycemic indices.

Optimization of Cyclodextrin-Assisted Extraction of Phenolics from Helichrysum italicum for Preparation of Extracts with Anti-Elastase and Anti-Collagenase Properties

Helichrysum italicum is a plant traditionally used for skin-related disorders that is becoming an increasingly popular ingredient in cosmetic products. In this work, a "green" ultrasound-assisted extraction method for H. italicum phenolics was developed using skin-friendly cyclodextrins (CDs). Extraction conditions needed for the greatest yield of target compounds (total phenolics, phenolic acids, and flavonoids) were calculated. The composition of the extracts was determined using LC-MS and spectrophotometric methods. Among the tested CDs, 2-hydroxylpropyl-beta-CD (HP-β-CD) was the best suited for extraction of target phenolics and used to prepare two optimized extracts, OPT 1 (the extract with the highest phenolic acid content) and OPT 2 (the extract with the highest total phenol and flavonoid content). The extracts were prepared at 80 °C, using 0.089 g of plant material/g solvent (0.6 mmol of HP-β-CD), with or without addition of 1.95% (w/w) lactic acid. The main metabolite in both extracts was 3,5-O-dicaffeoylquinic acid. It was found that the addition of lactic acid greatly contributes to the extraction of arzanol, a well-known anti-inflammatory agent. IC₅₀ values of the anti-elastase (22.360 ± 0.125 μL extract/mL and 20.067 ± 0.975 for OPT-1 and OPT-2, respectively) and anti-collagenase (12.035 ± 1.029 μL extract/mL and 14.392 ± 0.705 μL extract/mL for OPT-1 and OPT-2, respectively) activities of the extracts surpassed those of the applied positive controls, namely ursolic and gallic acids. This activity deems the prepared extracts promising ingredients for natural cosmetics, appropriate for direct use in cosmetic products, removing the need for the evaporation of conventional solvents.

Chemical aspects of polyphenol-protein interactions and their antibacterial activity

The hunt for novel antibiotics has become a global public health imperative due to the rise in multidrug-resistant microorganisms, untreatable infection cases, overuse, and inefficacy of modern antibiotics. Polyphenols are getting much attention in research due to their multiple biological effects; their use as antimicrobial agents is attributed to their activity and that microbes have a hard time developing resistance to these natural compounds. Polyphenols are secondary metabolites produced in higher plants. They are known to possess various functional properties in the human body. Polyphenols also exhibit antibacterial activities against foodborne pathogens. Their antibacterial mechanism is based on inhibiting bacterial biofilm formation or inactivating enzymes. This review focused on polyphenol-protein interactions and the creation of this complex as a possible antibacterial agent. Also, different phenolic interactions on bacterial proteins, efflux pump, cell membrane, bacterial adhesion, toxins, and other bacterial proteins will be explored; these interactions can work in a synergic combination with antibiotics or act alone to assure bacterial inhibition. Additionally, our review will focus on polyphenol-protein interaction as a possible strategy to eradicate bacteria because polyphenols have shown a robust enzyme-inhibitory characteristic and a high tendency to complex with proteins, a response that neutralizes any bactericidal potential.

Study on the Effect of Crushed Rice-Lotus Seed Starch Reconstituted Rice on Lipid Metabolism Histology in Rats

The study investigated the changes of lipid metabolism histology in rats under the three groups of dietary modifications after dietary intervention in (Sprague-Dawley, SD) SD rats using lotus seed reconstituted rice, ordinary rice, and high-fat feed made from lotus seed starch-rice flour after extrusion and puffing. It was found that the high-fat feed could lead to the disorder of lipid metabolism in rats, and the accumulation of lipid metabolism substances caused by the high-fat feed was significantly increased; the intervention of ordinary rice and high-dose reconstituted rice revealed that the high-dose reconstituted rice could improve the disorder of lipid metabolism and the accumulation of lipid substances caused by the high-fat feed to a greater extent. The main lipid substances were PC, TAG, Cer, CE, SM, PE, LPC, Acar, DAG, FAHFA, OxPI, PI, SQDG, Cer/NS, GlcADG, HBMP, Cer/NDS, HexCer/NS, etc., and the study confirmed that the reconstituted rice made from lotus seeds in this experiment was better than ordinary rice, and the high-dose reconstituted rice obtained from the study has a better modulating effect on lipid metabolism disorders and organism damage caused by high-fat feed.

Effect of chlorogenic acid on the structural properties and digestibility of lotus seed starch during microwave gelatinization

The structural evolution of lotus starch (LS)-chlorogenic acid (CA) complexes was investigated after microwave-heating treatment, to reveal the relationship between the interactions of lotus starch and chlorogenic acid molecules, and the digestive properties of the starch, after microwave gelatinization. During the early stage of microwave gelatinization (65, 70 °C), CA was mainly participating in the rearrangement of starch molecules in a weakly-bound form, and at that stage, the LS-CA complex acted as an inhibitor of digestion, under small intestine conditions, mainly through the release of CA, which inhibited amylase. However, during the late stage of microwave gelatinization (85 °C), many chlorogenic acid molecules entered the hydrophobic helical cavity of the starch, promoting formation of the V-type starch helical structure in the LS-CA complex, which made a major contribution to inhibiting digestion under oral digestion conditions.

Structural and physicochemical properties of lotus seed starch-chlorogenic acid complexes prepared by microwave irradiation

Lotus seed (LS) has a high starch content and possesses many useful functional properties, which are mainly attributed to its phenolic compound content. The objective of this study was to investigate the effect of microwave irradiation (MW) treatment on the structural and physicochemical properties of a lotus seed starch-chlorogenic acid (CA) blend. MW treatment appeared to promote the formation of LS-CA complexes and the modified starch displayed more rougher structures than native starch. The particle size distribution of starch remained approximately constant when the microwave power was 200 W, but increased sharply with further increases in microwave power; a similar trend was observed in the swelling and solubility of starch. XRD and FT-IR spectra show that MW treatment degraded the ordered crystalline structure of starch, facilitating exposure of the starch chains originally buried in the crystalline and amorphous regions within the grains. During this treatment, CA interacted with starch molecules by hydrogen bonding and form a LS-CA complex, which inhibited the self-assembly process of starch chains. These findings demonstrated the potential use of MW treatment in controlling the storage and processing quality of lotus seed, or other starchy foods rich in polyphenols.

Green and Efficient Extraction Approach for Polyphenol Recovery from Lotus Seedpods (Receptaculum Nelumbinis): Gas-Assisted Combined with Glycerol

In this paper, the gas-assisted combined with glycerol extraction (GAGE) for polyphenol recovery from lotus seedpods (LSPs) was modeled and optimized. Box-Behnken design was applied to optimize the total polyphenol content (TPC) of LSP along with enhancing antioxidant activities using response surface methodology based on the TPC extraction yield (%), which was affected by glycerol concentration, time, temperature, and glycerol-to-solid ratio. The optimal conditions for the LSP extract were glycerol-to-solid ratio, 42 mL/g; time, 50 min; concentration of glycerol, 45%; and temperature, 70 °C. Ultra-high-pressure liquid chromatography integrated with triple-time-of-flight mass spectrophotometry (UPLC-Triple-TOF/MS) analysis revealed nine biologically active polyphenols. Furthermore, Fourier-transform infrared spectroscopy and scanning electron microscopy results demonstrated the effect and influence during extraction. The findings suggested that GAGE is a potential, green, and high-efficiency alternative that could be used to recover polyphenols from plant source byproducts.

Flavonoids from Whole-Grain Oat Alleviated High-Fat Diet-Induced Hyperlipidemia via Regulating Bile Acid Metabolism and Gut Microbiota in Mice

A high-fat diet (HFD) causes hyperlipidemia, which worsens disturbances in bile acid (BA) metabolism and gut microbiota. This study aimed to investigate the regulation of flavonoids from whole-grain oat (FO) on BA metabolism and gut microbiota in HFD-induced hyperlipidemic mice. The experiment results showed that FO improved serum lipid profiles and decreased body weight and lipid deposition in HFD-fed mice. Through real-time qualitative polymerase chain reaction (RT-qPCR) and Western blot assays, by up-regulating the expression of PPARα, CPT-1, CYP7A1, FXR, TGR5, NTCP, and BSTP, and down-regulating those of SREBP-1c, FAS, and ASBT, FO suppressed lipogenesis, promoted lipolysis and BA synthesis, and efflux to faeces via the FXR pathway. 16s rRNA sequencing revealed that FO significantly increased Akkermansia and significantly decreased Lachnoclostridium, Blautia, Colidextribacter, and Desulfovibrio. Spearman's correlation analysis showed that these bacteria were strongly correlated with hyperlipidemia-related parameters. Therefore, our results indicated that FO possessed an antihyperlipidemic effect via regulating the gut-liver axis, i.e., BA metabolism and gut microbiota.

Insights into the multi-scale structural properties and digestibility of lotus seed starch-chlorogenic acid complexes prepared by microwave irradiation

By inspecting starch hierarchical structural evolution, this work explored how microwave irradiation tailored the digestion characteristics of lotus seed starch-chlorogenic acid mixtures. The results showed that after microwave treatment, the granular structure, short-range ordered structure, helical conformation, and lamellar structure of starch exhibited different degrees of disorganization. In this procedure, chlorogenic acid interacted with starch molecules to form lotus seed starch-chlorogenic acid complexes and participated in the reorganization of the matrixes of the starch substrate in three forms: V-type inclusion complex, non-inclusion complex, and simply physically entrapped. These structural changes, coupled with the inhibition of chlorogenic acid on carbohydrate hydrolyzing enzymes, contributed to the slowly digestible features of lotus seed starch-chlorogenic acid complexes. This study provided a basis for understanding the multi-scale structure-digestibility relationship of starchy foods rich in phenolic acids under microwave treatment.

Green Extraction of Phenolic Compounds from Lotus Seedpod (Receptaculum Nelumbinis) Assisted by Ultrasound Coupled with Glycerol

Lotus Receptaculum Nelumbinis has been sparking wide research interests due to its rich phenolic compounds. In the present work, ultrasonic-assisted extraction coupled with glycerol was employed to extract phenolic compounds from Receptaculum Nelumbinis and the process was optimized using a response surface methodology with Box-Behnken design (BBD). The optimal conditions for the total phenolic content (TPC) extract were obtained: glycerol concentration of 40%, an extraction temperature of 66 °C, ultrasonic time of 44 min, and the solvent-to-solid ratio of 55 mL/g. Under these optimum extraction conditions, the extraction yield of TPC was 92.84 ± 2.13 mg gallic acid equivalents (GAE) /g. Besides, the antioxidant activities demonstrated the ability of free radical scavenging by four different methods that included 2,2-Diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and reducing activity (RA) were 459.73 ± 7.07, 529.97 ± 7.30, 907.61 ± 20.28, and 983.66 ± 11.80 μmol TE/g, respectively. Six phenolic compounds were identified by ultra-high pressure liquid chromatography combined with triple-time-of-flight mass spectrophotometry (UPLC-Triple-TOF/MS) from the extracts. Meanwhile, Fourier transform infrared (FTIR) was conducted to identify the characteristic functional groups of the extracts and thus reflected the presence of polyphenols and flavonoids. Scanning electron microscopy (SEM) illustrated the microstructure difference of four treatments, which might explain the relationships between antioxidant activities and the structures of phenolic compounds.

Black rice (Oryza sativa L.) processing: Evaluation of physicochemical properties, in vitro starch digestibility, and phenolic functions linked to type 2 diabetes

Black rice is recognized for managing diabetes in Chinese folk medicine. Therefore, the present study investigates the effect of thermal treatments and the succeeding cooking on black rice physicochemical properties, phenolic composition, total antioxidant activity (TAA), enzymes and glycation inhibition in addition to starch digestibility. Thermal decomposition of anthocyanin and cyanidin-3-glucoside was evident across all processing methods and reflected in increasing levels of protocatechuic acid, while proanthocyanidins (TPAC) were susceptible to cooking. Roasting of grains sustained total phenolics (TPC), flavonoids (TFC), TPAC, and antilipase activity. Additionally, the combined effect of frying and cooking diminished TFC, TPAC, and α-glucosidase inhibition. The thermally treated grains showed pronounced activity against α-amylase, α-glucosidase, and glycation, whereas their cooked counterparts reduced the estimated glycemic index (eGI), and enhanced resistant starch (RS). Processed grains chrominance, TAA, and apparent amylose content (AAC) showed a significant correlation with phenolics. These findings are demonstrating that black rice processing is favorable for the dietary management of metabolic disorders such as diabetes and hyperlipidemia.

Glycerolic Licorice Extracts as Active Cosmeceutical Ingredients: Extraction Optimization, Chemical Characterization, and Biological Activity

A green ultrasound-assisted extraction (UAE) method using glycerol/water mixtures for extraction of licorice (Glycyrrhiza glabra) bioactive constituents was developed in this study. The response surface method, according to the Box-Behnken design, was employed to optimize the extraction parameters: glycerol concentration (X₁), temperature (X₂), and the amount of herbal drug used in the production (X₃). The responses were content of total phenols (TP), TP extraction efficiency (TPy) and the content of licorice characteristic constituents, glabridin (Gla) and isoliquiritigenin (Iso). Response surface analysis predicted the optimal extraction conditions for maximized amounts of TP, Tpy, Gla, and Iso. The extracts were prepared using the calculated conditions. The analysis of the selected constituents confirmed the validity of the model. Furthermore, biological activity of the extracts was tested. The results demonstrate that UAE using glycerol is a fast and efficient method for preparation of extracts with excellent radical scavenging, Fe²⁺ chelating and antioxidant activity. Furthermore, the observed notable tyrosinase and elastase inhibitory activity of the extracts, as well as their anti-inflammatory activity, indicate the anti-aging properties of the investigated extracts. The fact that the extracts were prepared using the safe, cosmetically active solvent, glycerol, makes them suitable for direct use in specialized cosmeceutical formulations.

Ultrasound-Assisted Extraction Optimization of Phenolic Compounds from Citrus latifolia Waste for Chitosan Bioactive Nanoparticles Development

Bioactive Phenols-loaded chitosan nanoparticles (PL-CNps) were developed by ionic gelation from Persian lemon (Citrus latifolia) waste (PLW) and chitosan nanoparticles. Response Surface Methodology (RSM) was used to determine the optimal Ultrasound-Assisted Extraction (UAE) conditions for the total phenolic compounds (TPC) recovery from PLW (58.13 mg GAE/g dw), evaluating the ethanol concentration, extraction time, amplitude, and solid/liquid ratio. Eight compounds expressed as mg/g dry weight (dw) were identified by ultra-performance liquid chromatography coupled photo diode array (UPLC-PDA) analysis: eriocitrin (20.71 ± 0.09), diosmin (18.59 ± 0.13), hesperidin (7.30 ± 0.04), sinapic acid (3.67 ± 0.04), catechin (2.92 ± 0.05), coumaric acid (2.86 ± 0.01), neohesperidin (1.63 ± 0.00), and naringenin (0.44 ± 0.00). The PL-CNps presented size of 232.7 nm, polydispersity index of 0.182, Z potential of -3.8 mV, and encapsulation efficiency of 81.16%. The results indicated that a synergic effect between phenolic compounds from PLW and chitosan nanoparticles was observed in antioxidant and antibacterial activity, according to Limpel's equation. Such results indicate that PLW in such bioprocesses shows excellent potential as substrates for the production of value-added compounds with a special application for the food industry.

Recovery of lotus (Nelumbo nucifera Gaertn.) seedpod flavonoids using polar macroporous resins: The updated understanding on adsorption/desorption mechanisms and the involved intermolecular attractions and bonding

Macroporous resins have been employed in the effective recovery of flavonoids from plants. In this study, S8 polar resins were used to recover flavonoids and procyanidins from lotus seedpods. Adsorption kinetics, isotherms, and thermodynamics studies revealed that the adsorption process involved physico-chemical interactions, including flavonoid-resin and flavonoid-flavonoid electrostatic interactions, π-π aromatic stacking, moderate and strong hydrogen bonding, and repulsive forces. These forces worked complementarily in adsorption, except for the repulsive force, which opposed the adsorption. Further, adsorption temperature determined the adsorption behavior, with multilayer adsorption enhancing adsorption capacity. In dynamic desorption tests, an acetone/water/acetic acid mixture (58.77: 39.34: 1.89) designed by the D-optimal design method was able to desorb 95.57% and 89.85% of total flavonoids and procyanidins, respectively, using less than two bed volumes of solvent. Ultra-performance liquid chromatography triple-time of flight/mass spectrometry (UPLC-TOF/MS) analysis showed that 26 flavonoids, including 5 procyanidins, were detected after the recovery.

Alternative Ultrasound-Assisted Method for the Extraction of the Bioactive Compounds Present in Myrtle (Myrtus communis L.)

The bioactive compounds in myrtle berries, such as phenolic compounds and anthocyanins, have shown a potentially positive effect on human health. Efficient extraction methods are to be used to obtain maximum amounts of such beneficial compounds from myrtle. For that reason, this study evaluates the effectiveness of a rapid ultrasound-assisted method (UAE) to extract anthocyanins and phenolic compounds from myrtle berries. The influence of solvent composition, as well as pH, temperature, ultrasound amplitude, cycle and solvent-sample ratio on the total phenolic compounds and anthocyanins content in the extracts obtained were evaluated. The response variables were optimized by means of a Box-Behnken design. It was found that the double interaction of the methanol composition and the cycle, the interaction between methanol composition and temperature, and the interaction between the cycle and solvent-sample ratio were the most influential variables on the extraction of total phenolic compounds (92.8% methanol in water, 0.2 s of cycle, 60 °C and 10:0.5 mL:g). The methanol composition and the interaction between methanol composition and pH were the most influential variables on the extraction of anthocyanins (74.1% methanol in water at pH 7). The methods that have been developed presented high repeatability and intermediate precision (RSD < 5%) and the bioactive compounds show a high recovery with short extraction times. Both methods were used to analyze the composition of the bioactive compounds in myrtle berries collected from different locations in the province of Cadiz (Spain). The results obtained by UAE were compared to those achieved in a previous study where microwave-assisted extraction (MAE) methods were employed. Similar extraction yields were obtained for phenolic compounds and anthocyanins by MAE and UAE under optimal conditions. However, UAE presents the advantage of using milder conditions for the extraction of anthocyanins from myrtle, which makes of this a more suitable method for the extraction of these degradable compounds.