Effects of alkaline pH and gallic acid enrichment on the physicochemical properties of sesame protein and common vetch starch-based composite films

In this study, sesame (Sesamum indicum L.) meal protein and common vetch (Vicia sativa L.) starch were extracted and used to obtain biodegradable composite films at different pH values (7, 9, and 11). Films were plasticized with glycerol (2.5 %) and enriched with gallic acid (0.25 %). Increasing pH promoted mechanical properties of the films with the developed barrier and thermal characteristics. Gallic acid addition at pH 7 resulted in lower tensile strength and higher elongation by reducing intermolecular forces, and a shift of diffraction peaks through lower angles due to crystal lattice expansion, as compared to neutral films without gallic acid. On the other hand, gallic acid-enriched films at neutral pH exhibited superior antioxidant properties. The mild alkalinity with gallic acid provided the lowest water vapor permeability, high thermal stability, improved mechanical properties and light barrier property due to deprotonation and subsequent interactions with biopolymers. The FTIR spectrum confirmed intense interactions, such as crosslinking and covalent bonding, promoted by mild alkalinity. Therefore, sesame protein and common vetch starch-based composite film with gallic acid incorporation at pH 9 can be recommended to be used in biodegradable active food packaging applications.

An Abies Extract Containing Nonvolatile Polyphenols Shows Virucidal Activity against SARS-CoV-2 That Is Enhanced in Increased pH Conditions

Researching the beneficial health properties of wood byproducts can prevent wastage by turning them into valuable resources. In this study, the virucidal activity of two extracts from Abies sachalinensis byproducts, ASE1, and ASE2, against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was investigated. ASE1 is rich in monoterpenoid volatile compounds, whereas ASE2 contains nonvolatile polyphenols. SARS-CoV-2 solutions were mixed with ASE1 or ASE2, and viral titer reduction was evaluated. At their original acidic pH, ASE2 showed stronger virucidal activity than ASE1. The virucidal activity of ASE2 was also significantly enhanced when pH was increased to neutral or basic, which was not the case for ASE1. At a neutral pH, ASE2 induced statistically significant viral titer reduction in 1 min. HCl and NaOH solutions, which had a pH close to that of acidic and basic ASE2 test mixtures, respectively, exhibited no virucidal activity against SARS-CoV-2. Among the SARS-CoV-2 variants, Omicron showed the highest vulnerability to ASE2. Western blotting, RT-PCR, and electron microscopic analysis revealed that neutral ASE2 interacts with SARS-CoV-2 spike proteins and moderately disrupts the SARS-CoV-2 genome and viral envelope. These findings reveal the virucidal potential of ASE2.

Development and Validation of a Green Stability-Indicating HPTLC Method for Estimation of Curcumin, Gallic Acid, and Ursolic Acid From Polyherbal Formulation Jatyadi Taila

BACKGROUND

Jatyadi taila (JT) is a well-known Ayurvedic wound-healing product, comprising 16 different medicinally important plants, including Curcuma longa, Terminalia chebula, and Jasminum officinale.

OBJECTIVE

The proposed work discusses the development and validation of the green and economical stability-indicating HPTLC method for quantification of the key marker phytoconstituents, curcumin (CUR), gallic acid (GA), and ursolic acid (UA), from JT.

METHOD

Quality standard parameters for JT were determined following standard procedures. The marker constituents CUR, GA, and UA were resolved from JT using toluene-ethyl acetate-formic acid (6:2:1, v/v/v) as the mobile phase and subsequently derivatized to estimate UA. The developed plates were subjected to HPTLC-MS analysis. All constituents were subjected to forced degradation to determine the proposed technique's stability-indicating property and the accelerated stability studies of marketed formulation and marker constituents. Greenness evaluation of the method was aided by the AGREE methodology.

RESULTS

The Rf values of CUR, GA, and UA were found to be 0.60 and 0.60; 0.27 and 0.28; and 0.74 and 0.77 from reference standard and oil samples respectively, when analyzed at 366 nm, 290 nm, and 366 nm, respectively. HPTLC-MS was carried out to verify the active constituents present in JT. The constituents followed first-order degradation kinetics. The quantity of CUR, GA, and UA in JT was reduced at the end of accelerated stability studies. The developed approach was validated in compliance with the International Conference on Harmonization (ICH) Q2 (R2) guideline.

CONCLUSIONS

Among the chosen key markers, GA was highly unstable during forced degradation. JT should be stored at a controlled temperature using more protective packaging material to ensure its quality and efficacy.

HIGHLIGHTS

The developed method can be used as a quality control tool for JT as it can be used to determine the stability of the key marker compounds the herbal formulation.

Extraction, phytochemical characterization and anti-cancer mechanism of Haritaki churna: An ayurvedic formulation

Haritaki churna (HC), a single herb ayurvedic formulations is known to be prescribed for various gastro-intestinal disorders in Ayurveda. Haritaki churna aqueous extract (HCAE) has anti-cancer activity against different types of cancer cells with an IC50 in the range of 50-97 μg/ml. Bioavailability of Haritaki Churna is very high in digestive track and treatment of colorectal cancer cells HCT-116, DLD1, HT-29 with HCAE reduces its cellular viability with anti-cancer IC50 70μg/ml. HCAE consumption is safe for human as it didn't affect the cellular viability of primary human PBMCs or non-cancerogenic HEK-293 cells. Haritaki churna was found to be stable in biological gastric fluids and bioactive agents are not losing their anti-cancer activity under such harsh conditions. The HPLC Chromatogram of HCAE is giving 13 major peaks and 11 minor peaks. Exploiting LC-MS, IR and NMR spectroscopic techniques, a total of 13 compounds were identified from HCAE namely Shikimic acid, Chebulic acid, gallic acid, 5-hydroxymethylfurfural, Protocatechuic acid, 4-O-galloyl-shikimic Acid, 5-O-galloyl-shikimic Acid, Methylgallate, corilagin, 1, 2, 6, Tri-O-galloyl β-D-glucose, chebulagic acid, chebulinic acid, and Ellagic acid. Reconstitution and subtraction of phytochemicals from the mixture indicate that Ellagic acid significantly contribute into anti-cancer effect of HCAE. Cancer cells treated with ellagic acid from HCAE were incapable of completing their cell-cycle and halted the cell-cycle at DNA synthesis S-Phase, as demonstrated by decreased cyclin A2 expression levels with increasing ellagic acid concentration. Halting of cells at S-phase causes induction of apoptosis in cancer cells. Cancer cells exhibiting DNA fragmentation, changes in expression of several apoptotic proteins such as Bcl2, cytochrome-c and formation of cleaved products of caspase 3 and PARP-1 suggests ellagic acid induces cell death via mitochondrial pathway of apoptosis.

Oral bioavailability of bioactive compounds; modulating factors, in vitro analysis methods, and enhancing strategies

Foods are complex biosystems made up of a wide variety of compounds. Some of them, such as nutrients and bioactive compounds (bioactives), contribute to supporting body functions and bring important health benefits; others, such as food additives, are involved in processing techniques and contribute to improving sensory attributes and ensuring food safety. Also, there are antinutrients in foods that affect food bioefficiency and contaminants that increase the risk of toxicity. The bioefficiency of food is evaluated with bioavailability which represents the amount of nutrients or bioactives from the consumed food reaching the organs and tissues where they exert their biological activity. Oral bioavailability is the result of some physicochemical and biological processes in which food is involved such as liberation, absorption, distribution, metabolism, and elimination (LADME). In this paper, a general presentation of the factors influencing oral bioavailability of nutrients and bioactives as well as the in vitro techniques for evaluating bioaccessibility and is provided. In this context, a critical analysis of the effects of physiological factors related to the characteristics of the gastrointestinal tract (GIT) on oral bioavailability is discussed, such as pH, chemical composition, volumes of gastrointestinal (GI) fluids, transit time, enzymatic activity, mechanical processes, and so on, and the pharmacokinetics factors including BAC and solubility of bioactives, their transport across the cell membrane, their biodistribution and metabolism. The impact of matrix and food processing on the BAC of bioactives is also explained. The researchers' recent concerns for improving oral bioavailability of nutrients and food bioactives using both traditional techniques, for example, thermal treatments, mechanical processes, soaking, germination and fermentation, as well as food nanotechnologies, such as loading of bioactives in different colloidal delivery systems (CDSs), is also highlighted.

Developing colloidal structure of beer by grain organic compounds

The present article introduces the problem of determining the general structure of beer as a complex system of related biomolecules. The objective was to establish the correlation of various quantities of organic compounds in beer formulation. The research featured samples of filtered pasteurized beer obtained from a retail chain shop in Moscow (Russia). The experiment relied on standard research methods, including instrumental methods of analysis, e.g., high-performance liquid chromatography (HPLC). The obtained experimental data underwent a statistical analysis using the Statistica software (StatSoft, 2016). The research established the correlation between the type of grain (barley or wheat malt) and the content of organic compounds, e.g., β-glucan, polyphenols, soluble nitrogen, etc. The research also revealed some patterns in the distribution of proteins, which served as a framework for the system of organic compounds. The distribution of thiol proteins proved to depend on the dissolution degree of the grain and was different in barley light, barley dark, and wheat malt samples. The fraction distribution of β-glucan depended on the color of the malt. In light beer samples, it concentrated in high- and medium-molecular fractions of nitrogenous substances, in dark beer – in low-molecular fractions (≤ 63%). Initial wort density and alcohol content affected the amount of catechins and total polyphenols. Nitrogenous compounds depended on the color, initial extract, and alcohol content. The nitrogenous structure and other organic compounds of beer proved to depend on protein substances. The research also revealed a number of factors that affected the fraction distribution of biomolecules in different beer sorts.

A green approach to phenolic compounds recovery from olive mill and winery wastes

The aim of this study was to evaluate the recovery of phenolic compounds from olive mill and winery wastes by conventional solid-liquid extraction (SLE) using water as the extraction solvent. The studied variables were extraction time (5-15 min), temperature (25-90 °C), solid-to-liquid ratio (1:10-1:100 (kg/L)), pH (3-10) and application of multiple extractions (1-3). The extraction efficiency was evaluated in terms of total phenolic content (TPC), determined by high performance liquid chromatography (HPLC-UV), but also from the recovery of some representative phenolic compounds. The optimized conditions were one extraction step, 10 min, 25 °C, 1:30 (kg/L), pH 5 for olive pomace, and one extraction step, 10 min, 70 °C, 1:100 (kg/L), pH 5 for winery residues. The extraction method is simple and suitable for scaling-up in industry, and the aqueous extracts are fully compatible with further purification schemes based on the use of membranes or resins. The optimized technique was applied to a set of different representative residues from olive mill and winery industries, to assess their suitability as sources for phenolic compounds recovery. The phenolic content in the extracts was evaluated by chromatographic analysis and by the Folin-Ciocalteu assay (FC). Furthermore, the antioxidant capacity was determined by 2,2-azinobis-3-etilbenzotiazolina-6-sulfonat (ABTS), 2,-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Because of their high contents in phenolic compounds and great antioxidant capacity, olive pomace and lees filters were identified as especially suited sources for phenolic compounds recovery.

Preparation and characterization of konjac glucomannan (KGM) and deacetylated KGM (Da-KGM) obtained by sonication

BACKGROUND

Konjac glucomannan (KGM) has been widely applied in the food industry as a thickening and gelation agent because of its unique colloidal properties of viscosity enhancement and gelling ability. The current study aimed to prepare and characterize KGM and deacetylated KGM (Da-KGM) samples obtained by sonication in neutral and alkali ethanol-water solutions.

RESULTS

The results showed that the deacetylation degree (DD) of Da-KGM increased exponentially with alkali concentration. Fourier transform infrared spectrometry further confirmed the deacetylation reaction through the dramatic decrease in the acetyl group band at 1740 cm^-1 . Besides, the high similarity among the tested groups in terms of X-ray diffraction (XRD) spectra implied a similar crystalline structure, while differential scanning calorimetry (DSC) curves revealed that the water binding capacity and decomposition temperature of KGM changed slightly with alkali and sonication treatment. The rheological profiles indicated that apparent viscosity (η₀ ) of sonicated KGM samples was unchanged except for the T60 group (60 min sonication treatment). Particularly, ultrasonic treatment under high alkaline conditions (0.10 mol L^-1 NaOH) was noted to promote the deacetylation reaction, and the obtained samples showed decreased apparent viscosity and weakened the gelation process in aqueous solution. Partial correction analysis indicated that alkali rather than ultrasonic treatment resulted in the change of DD and η₀ in Da-KGM. Moreover, sonication contributed to off-white color by reducing the browning caused by alkali in Da-KGM products.

CONCLUSION

Ultrasound-mediated heterogeneous deacetylation reaction is a feasible way to prepare Da-KGM samples with lightened browning and controllable DD. © 2022 Society of Chemical Industry.

Polyphenol Loaded W1/O/W2 Emulsions Stabilized with Lesser Mealworm (Alphitobius diaperinus) Protein Concentrate Produced by Membrane Emulsification: Stability under Simulated Storage, Process, and Digestion Conditions

Water-in-oil-in-water (W1/O/W2) emulsions are complex delivery systems for polyphenols amongst other bio-actives. To stabilize the oil-water interphase, dairy proteins are commonly employed, which are ideally replaced by other, more sustainable sources, such as insect proteins. In this study, lesser mealworm (Alphitobius diaperinus) protein concentrate (LMPC) is assessed and compared to whey protein (WPI) and pea protein (PPI), to stabilize W1/O/W2 emulsions and encapsulate a commercial polyphenol. The results show that LMPC is able to stabilize W1/O/W2 emulsions comparably to whey protein and pea protein when using a low-energy membrane emulsification system. The final droplet size (d4,3) is 7.4 μm and encapsulation efficiency is between 72 and 74%, regardless of the protein used. Under acidic conditions, the LMPC shows a similar performance to whey protein and outperforms pea protein. Under alkaline conditions, the three proteins perform similarly, while the LMPC-stabilized emulsions are less able to withstand osmotic pressure differences. The LMPC stabilized emulsions are also more prone to droplet coalescence after a freeze-thaw cycle than the WPI-stabilized ones, but they are the most stable when exposed to the highest temperatures tested (90 °C). The results show LMPC's ability to stabilize multiple emulsions and encapsulate a polyphenol, which opens the door for application in foods.

Gallic acid oxidation products alter the formation pathway of insulin amyloid fibrils

Amyloidogenic protein assembly into insoluble fibrillar aggregates is linked with several neurodegenerative disorders, such as Alzheimer’s or Parkinson’s disease, affecting millions of people worldwide. The search for a potential anti-amyloid drug has led to the discovery of hundreds of compounds, none of which have passed all clinical trials. Gallic acid has been shown to both modulate factors leading to the onset of neurodegenerative disorders, as well as directly inhibit amyloid formation. However, the conditions under which this effect is seen could lead to oxidation of this polyphenol, likely changing its properties. Here we examine the effect of gallic acid and its oxidised form on the aggregation of a model amyloidogenic protein–insulin at low pH conditions. We show a vastly higher inhibitory potential of the oxidised form, as well as an alteration in the aggregation pathway, leading to the formation of a specific fibril conformation.

Reducing Ochratoxin A Content in Grape Pomace by Different Methods

Grape pomace (GP) is the residue of grapes after wine making and is a valuable source of dietary polyphenol and fiber for health promotion. However, studies found the presence of ochratoxin A (OTA) in GP at very high concentrations, which raises a safety issue in the value-added utilization of GP. This study evaluated the effects of thermal pressure, baking, acid and enzymatic treatments on OTA content in GP. Thermal pressure treatment was conducted with wet GP at 121 °C for 10-30 min in an autoclave; acid treatments were conducted with hydrochloric acid, acetic acid, citric acid, and lactic acid, respectively, at 50 °C for 24 h. Baking was conducted using a cookie model. For enzymatic treatment, purified OTA solution was treated with carboxypeptidase A, alcalase, flavourzyme, pepsin, and lipase, respectively, and the effective enzymes were selected to treat GP. Results show that autoclaving for 10-30 min reduced 19-80% of OTA, varying with treatment time and GP variety. The effectiveness of acid treatment was similar to that of autoclaving and varied with acid type and GP variety. Baking increased the detectable OTA. Among all tested enzymes, carboxypeptidase A was the most effective in reducing OTA, followed by lipase and flavourzyme, but their effects were significantly lower in GP samples.

In vitro digestibility and release of a mango peel extract encapsulated within water-in-oil-in-water (W1/O/W2) emulsions containing sodium carboxymethyl cellulose

Mango peel is a rich source of phenolic compounds (PC), which can be used in food fortification. The use of water-in-oil-in-water (W₁/O/W₂) emulsions represents a potential strategy to encapsulate, protect and incorporate PC from mango peel into food products. Moreover, even though non-digestible biopolymers are usually incorporated into emulsions to enhance stability, little is known about the effect on the digestibility and release of PC. In this study, a mango peel extract (MPE) was encapsulated using W₁/O/W₂ emulsions containing sodium carboxymethyl cellulose (CMC; 0, 0.5, 1.0% w/w) in W₂, and their colloidal stability, lipid digestibility kinetics (free fatty acid release), and release (in terms of antioxidant activity) under in vitro digestion conditions were evaluated. The presence of CMC in emulsions caused flocculation of droplets, which remained unchanged during the gastric phase, suggesting that bridging flocculation occurred. Moreover, a slower lipid digestion rate was observed in emulsions containing CMC, with k-values ranging between 0.21 and 0.25 min^-1, compared to emulsions without CMC (around 0.14 min^-1). However, although CMC may slow down the lipolysis reaction during the first 40 min due to physical or steric hindrance, at the end of the intestinal phase, emulsions with or without CMC had a similar final FFA release. Moreover, MPE release was triggered under gastric conditions, probably by osmotic imbalance, showing a constant antioxidant activity value during the intestinal phase only in emulsions containing CMC. This study provides relevant insights to design double emulsions as delivery systems of water-soluble bioactive compounds with antioxidant activity, such as PC.