Degradation of bioactive spice compound: curcumin during domestic cooking

Emulsions and oleogels stabilized by egg white protein-tannic acid-xanthan gum conjugate: Preparation, characterization and potential application in curcumin

In this study, the egg white protein (EWP)-tannic acid (TA)-xanthan gum (XG) ternary conjugate was used to construct emulsion and oleogel delivery systems to load curcumin. The effect of EWP-TA-XG conjugate concentration on the properties of emulsions and oleogels as well as the digestion characteristics of curcumin-loaded emulsion and oleogel were investigated. It was found that with the increase of EWP-TA-XG conjugate concentration, the D[4, 3] of emulsions decreased, while the absolute value of zeta potential and the stability of the emulsions increased. All emulsions showed good stability after centrifugation at different temperature, pH and ionic strength. Additionally, the emulsions at high concentrations of EWP-TA-XG conjugate (0.6-1.0 %, wt) had high viscosity and good gel property. As the concentration of EWP-TA-XG conjugate increased, the oil binding capacity of oleogels enhanced (90.38-99.87 %), and all oleogels showed solid behaviors (G' > G″). The oleogels had a higher antioxidant activity than bulk oil, and their antioxidant capacity was positively correlated with the concentration of EWP-TA-XG conjugate. It was also found that the free fatty acid release rate and bioaccessibility of curcumin in the emulsion (66.63 % and 65.53 %) and oleogel (64.24 % and 62.20 %) systems were significantly improved compared to those in bulk oil (30.63 % and 29.75 %), indicating that the emulsion and oleogel delivery systems played a good protective role in the delivery of curcumin. This study may offer novel insights into the development of EWP-TA-XG conjugates-based emulsion and oleogel as delivery systems in encapsulating and delivering fat-soluble active substances.

Impact of Encapsulation Position in Pickering Emulsions on Color Stability and Intensity Turmeric Oleoresin

The emulsification of natural pigment is a widely utilized strategy to enhance its stability in the food industry. However, high turbidity in emulsions often causes color fading, limiting their application. Here, we developed a comprehensive Pickering emulsion (PE) system to improve the color intensity and stability of turmeric oleoresin (Tur) under various food processing conditions. Specifically, the effects of two encapsulation positions within the PE were compared: the inner oil phase (Tur-IPE) and the outer solid particle layer (Tur-OPE). Lysozyme and carboxymethyl cellulose nanoparticles (NPs) were used as natural solid particle surfactants, with their successful formation confirmed through physical property analysis and FTIR spectroscopy. The optimal oil fraction (φ) for suitable physical properties of PE was determined to be 0.2. Interestingly, Tur-OPE significantly exceeded Tur-conventional emulsions (Tur-CE) and Tur-IPE in terms of color vividness, exhibiting higher redness and lower lightness (p < 0.05). During thermal processing at 70 and 90 °C, all emulsions demonstrated significantly enhanced heat resistance, retaining 1.3 to 1.6 times more Tur, respectively, compared to unencapsulated Tur (free Tur) (p < 0.05). Furthermore, Tur's pH instability was significantly overcome by encapsulation in all emulsion systems (p < 0.05). During 4 weeks of storage period, Tur-OPE demonstrated the highest retention rates, with the half-life of Tur increasing in the following order: free Tur < Tur-CE < Tur-IPE < Tur-OPE. Thus, we highlighted the important role of encapsulation position in PEs in improving and maintaining the color stability and vividness of natural pigments under various food processing conditions.

Improvement in Curcumin's Stability and Release by Formulation in Flexible Nano-Liposomes

Curcumin is utilized extensively as Chinese medicine in Asia due to its antioxidant, antimicrobial, and inflammatory activities. However, its use has the challenges of low oral bioavailability and high heat sensitivity. The aim of this research was to produce flexible nano-liposomes containing curcumin using an innovative approach of ethanol injection and Tween 80 to enhance the stability and preservation of curcumin. The mean particle size, encapsulation efficiency, thermal degradation, storage stability, and curcumin release in flexible nano-liposomes were also investigated. We found that the mean particle size of curcumin-loaded flexible nano-liposome decreased from 278 nm to 27.6 nm. At the same time, the Tween 80 concentration increased from 0 to 0.15 wt%, which corresponded with the results of transmission electron microscopy (TEM) morphology analyses, and particle size decreased with an enhancement in Tween 80 concentration. Further, pure curcumin was quickly released within one hour at 37 °C, and first-order kinetics matched with its release curve. However, curcumin encapsulated in flexible nano-liposomes showed a slow release of 71.24% within 12 h, and a slower release pattern matched with the Higuchi model over 24 h, ultimately reaching 84.63% release. Hence, flexible nano-liposomes of curcumin made by a combination of ethanol injection and Tween 80 addition prevented the thermal degradation of curcumin, and enhanced its storage stability and preservation for future drug delivery applications.

Octenyl succinic anhydride tigernut starch: Structure, physicochemical properties and stability of curcumin-loaded Pickering emulsion

In recent years, there has been increasing attention to starch particle-stabilized Pickering emulsions. In this study, the tigernut starch (TNS) was isolated from the tigernut meal, and further octenyl succinic anhydride tigernut starch (OSATNS) was prepared by a semi-dry method. The structure of OSATNS was analyzed and characterized by degrees of substitution (DS), contact angle, SEM, and FTIR. OSATNS was then used to stabilize the curcumin-loaded Pickering emulsion to improve the water solubility and stability of the curcumin. The results showed that OSATNS with 3 %-9 % OSA exhibited a DS range of 0.012 to 0.029, and its contact angle increased from 69.23° to 84.76°. SEM revealed that TNS consisted of small starch particles averaging 7.71 μm, and esterification did not significantly alter their morphology or size. FTIR analysis confirmed successful OSA incorporation by revealing two new peaks at 1732 cm-1 and 1558 cm-1. After 7 days of storage, Pickering emulsions stabilized with OSATNS-9 % exhibited superior stability and curcumin retention compared to Tween 80 emulsions, maintaining retention rates above 80 % even after different heat treatments. In conclusion, this study shows the potential application of OSATNS in stabilizing Pickering emulsions and demonstrates its good thermal stability and protection against curcumin during storage.

Phytochemical Investigation of Carex praecox Schreb. and ACE-Inhibitory Activity of Oligomer Stilbenes of the Plant

Phenolic compounds are the main special metabolites of Cyperaceae species from phytochemical, pharmacological, and chemotaxonomical points of view. The present study focused on the isolation, structure determination, and pharmacological investigation of constituents from Carex praecox. Twenty-six compounds, including lignans, stilbenes, flavonoids, megastigmanes, chromenes, and phenylpropanoids, were identified from the methanol extract of the plant. Five of these compounds, namely, carexines A-E, are previously undescribed natural products. All compounds were isolated for the first time from C. praecox. The ACE-inhibitory activity of seven stilbenoid compounds was tested, and (-)-hopeaphenol proved to be the most active (IC50 7.7 ± 0.9 μM). The enzyme-kinetic studies revealed a mixed-type inhibition; therefore, domain-specific studies were also conducted. The in silico docking of (-)-hopeaphenol to the ACE affirmed some favorable interactions. In addition, the antiproliferative and antibacterial effects of some compounds were also evaluated.

Effects of seasoning addition and cooking conditions on the formation of free and protein-bound heterocyclic amines and advanced glycation end products in braised lamb

The accumulation of heterocyclic amines (HAs) and advanced glycation end products (AGEs) in thermally processed meats has been arising safety concerns. The effects of cooking conditions and seasoning addition on the formation of HAs and AGEs in Chinese traditional braised lamb were investigated by UPLC-MS/MS analysis. Soy sauce significantly increased the formation of HAs and AGEs, among which light soy sauce had the greatest promoting effect (69.45-15300.62 %). Conversely, spices inhibited HAs and AGEs formation, the inhibition rate of free HAs and AGEs reached 22.06-34.72 % when using 70 % ethanol extract. Hot blanching treatment and adding soy sauce and spices at a later stage could significantly suppress HAs and AGEs production. Flavonoids, including galangin, hesperidin, narirutin, etc., were identified as key effectors in spices. These findings help to promote awareness of the formation of HAs and AGEs in braised lamb and provide valuable insights for optimizing processing techniques to minimize their production.

Structural Variances in Curcumin Degradants: Impact on Obesity in Mice

Some thermal degradants of curcuminoids have demonstrated moderate health benefits in previous studies. Feruloyl acetone (FER), recently identified as a thermal degradant of curcumin, has been previously associated with anticancer and antioxidative effects, yet its other capabilities remain unexplored. Moreover, earlier reports suggest that methoxy groups on the aromatic ring may influence the functionality of the curcuminoids. To address these gaps, an animal study was conducted to investigate the antiobesity effects of both FER and its demethoxy counterpart (DFER) on mice subjected to a high-fat diet. The results demonstrated the significant prevention of weight gain and enlargement of the liver and various adipose tissues by both samples. Furthermore, these supplements exhibited a lipid regulatory effect in the liver through the adiponectin/AMPK/SIRT1 pathway, promoted thermogenesis via AMPK/PGC-1α activation, and positively influenced gut-microbial-produced short-chain fatty acid (SCFA) levels. Notably, DFER demonstrated superior overall efficacy in combating obesity, while FER displayed a significant effect in modulating inflammatory responses. It is considered that SCFA may be responsible for the distinct effects of FER and DFER in the animal study. Future studies are anticipated to delve into the efficacy of curcuminoid degradants, encompassing toxicity and pharmacokinetic evaluations.

Effects of κ-carrageenan on the emulsifying ability and encapsulation properties of pea protein isolate-grape seed oil emulsions

This work investigated the characteristics of pea protein isolate and κ-carrageenan complexes in stabilizing curcumin-loaded emulsions. The complexes structured by electrostatic attraction exhibited biphasic wettability with increased three-phase contact angles close to 90°. Morphological differences in the complexes were the critical factor influencing their emulsifying ability at various pH. As a steric barrier via increasing net negative charge (up to -54.7 ± 2.4 mV) and adsorbed protein content (92.57 %-97.61 %), the interfacial layer could retard droplet coalescence and improve emulsions stability. Rheological tests verified the higher viscoelasticity of emulsions by raising the oil fraction. After 4 weeks of heating treatment, the chemical stability of curcumin was prominently enhanced from 18.6 ± 0.2 % to 64.3 ± 5.7 %. The confirmed synergistic antioxidant activity between grape seed oil and curcumin in emulsions might facilitate the development of specific functional delivery systems in foods.

Effects of Roasting Conditions on Antibacterial Properties of Vietnamese Turmeric (Curcuma longa) Rhizomes

Processing with heat treatment has been reported to alter several therapeutic effects of turmeric. In Vietnamese traditional medicine, turmeric has been long used for bacterial infections, and roasting techniques are sometimes applied with this material. However, there have been no studies investigating the effects of these thermal processes on the plant's antibacterial properties. Our study was therefore performed to examine the changes that roasting produced on this material. Slices of dried turmeric were further subjected to light-roasting (80 °C in 20 min) or dark-roasting (160 °C in 20 min) processes. Broth dilution and agar-well diffusion methods were applied to examine and compare the effects of ethanol extracts obtained from non-roasted, light-roasted and dark-roasted samples, on a set of 6 gram-positive and gram-negative bacteria. In both investigations, dark-roasted turmeric was significantly less antibacterial than non-roasted and light-roasted materials, as evident by the higher values of minimum inhibitory concentrations and the smaller diameters of induced inhibitory zones. In addition, dark-roasting was also found to clearly reduce curcumin contents, total polyphenol values and antioxidant activities of the extracts. These results suggest that non-roasting or light-roasting might be more suitable for the processing of turmeric materials that are aimed to be applied for bacterial infections.

The potential of curcumin-based co-delivery systems for applications in the food industry: Food preservation, freshness monitoring, and functional food

Currently, curcumin-based co-delivery systems are receiving widespread attention. However, a systematic summary of the possibility of curcumin-based co-delivery systems used for the food industry from multiple directions based on the functional characteristics of curcumin is lacking. This review details the different forms of curcumin-based co-delivery systems including the single system of nanoparticle, liposome, double emulsion, and multiple systems composed of different hydrocolloids. The structural composition, stability, encapsulation efficiency, and protective effects of these forms are discussed comprehensively. The functional characteristics of curcumin-based co-delivery systems are summarized, involving biological activity (antimicrobial and antioxidant), pH-responsive discoloration, and bioaccessibility/bioavailability. Correspondingly, potential applications for food preservation, freshness detection, and functional foods are introduced. In the future, more novel co-delivery systems for active ingredients and food matrices should be developed. Besides, the synergistic mechanisms between active ingredients, delivery carrier/active ingredient, and external physical condition/active ingredient should be explored. In conclusion, curcumin-based co-delivery systems have the potential to be widely used in the food industry.

Strategies for Improving Bioavailability, Bioactivity, and Physical-Chemical Behavior of Curcumin

Curcumin (CCM) is one of the most frequently explored plant compounds with various biological actions such as antibacterial, antiviral, antifungal, antineoplastic, and antioxidant/anti-inflammatory properties. The laboratory data and clinical trials have demonstrated that the bioavailability and bioactivity of curcumin are influenced by the feature of the curcumin molecular complex types. Curcumin has a high capacity to form molecular complexes with proteins (such as whey proteins, bovine serum albumin, β-lactoglobulin), carbohydrates, lipids, and natural compounds (e.g., resveratrol, piperine, quercetin). These complexes increase the bioactivity and bioavailability of curcumin. The current review provides these derivatization strategies for curcumin in terms of biological and physico-chemical aspects with a strong focus on different type of proteins, characterization methods, and thermodynamic features of protein–curcumin complexes, and with the aim of evaluating the best performances. The current literature review offers, taking into consideration various biological effects of the CCM, a whole approach for CCM-biomolecules interactions such as CCM-proteins, CCM-nanomaterials, and CCM-natural compounds regarding molecular strategies to improve the bioactivity as well as the bioavailability of curcumin in biological systems.

Optimization of Ultrasonic-Assisted Extraction (UAE) Method Using Natural Deep Eutectic Solvent (NADES) to Increase Curcuminoid Yield from Curcuma longa L., Curcuma xanthorrhiza, and Curcuma mangga Val

This study aims to optimize ultrasonic-assisted natural deep eutectic solvents (NADES) based extraction from C. longa. Choline chloride-lactic acid (CCLA-H₂O = 1:1, b/v) was used to investigate the impact of various process parameters such as solvent’s water content, solid loading, temperature, and extraction time. The optimal yield of 79.635 mg/g of C. longa was achieved from extraction in 20% water content NADES with a 4% solid loading in 35 °C temperature for 1 h. Peleg’s model was used to describe the kinetics of the optimized ultrasonic-assisted extraction (UAE) method, and the results were found to be compatible with experimental data. The optimum conditions obtained from C. longa extraction were then used for the extraction of C. xanthorriza and C. mangga, which give yields of 2.056 and 31.322 mg/g, respectively. Furthermore, n-hexane was utilized as an anti-solvent in the separation process of curcuminoids extract from C. longa, C. xanthorriza, and C. mangga, which gave curcuminoid recovery of 39%, 0.74%, and 27%, respectively. Solidification of curcuminoids was also carried out using the crystallization method with n-hexane and isopropanol. However, the solution of CCLA and curcuminoids formed a homogeneous mixture with isopropanol. Hence, the curcuminoids could not be solidified due to the presence of NADES in the extract solution.

Targeted metabolome analysis reveals accumulation of metabolites in testa of four peanut germplasms

Cultivated peanut (Arachis hypogaea L.) is an important source of edible oil and protein. Peanut testa (seed coat) provides protection for seeds and serves as a carrier for diversity metabolites necessary for human health. There is significant diversity available for testa color in peanut germplasms. However, the kinds and type of metabolites in peanut testa has not been comprehensively investigated. In this study, we performed metabolite profiling using UPLC-MS/MS for four peanut germplasm lines with different testa colors, including pink, purple, red, and white. A total of 85 metabolites were identified in four peanuts. Comparative metabolomics analysis identified 78 differentially accumulated metabolites (DAMs). Some metabolites showed significant correlation with other metabolites. For instance, proanthocyanidins were positively correlated with cyanidin 3-O-rutinoside and malvin, and negatively correlated with pelargonidin-3-glucoside. We observed that the total proanthocyanidins are most abundant in pink peanut variety WH10. The red testa accumulated more isoflavones, flavonols and anthocyanidins compared with that in pink testa. These results provided valuable information about differential accumulation of metabolites in testa with different color, which are helpful for further investigation of the molecular mechanism underlying biosynthesis and accumulation of these metabolites in peanut.

Extraction of selected prohealth substances from Curcuma longa and Zingiber officinale in artificial digestive juices

BACKGROUND

The study determined the content of selected bioelements, toxic metals and phenolic acids occurring in Curcuma longa L. and Zingiber officinale Rosc. Natural raw materials in the form of powder, slices, dried and fresh rootstock, tablets and capsules were analyzed. To determine the actual bioavailability of the metals and phenolic acids present in the raw materials, they were extracted into artificial digestive juices (artificial gastric and intestinal juices).

RESULTS

The maximum amounts of bioelements found in turmeric were as follows (mg kg-1 dry weight): Ca, 1911; Cu, 10.4; Fe, 248; K, 123; Mg, 1896; Mn, 181; Na, 332; Zn, 242. On the other hand, the maximum amounts of these bioelements found in ginger were as follows (mg kg-1 dry weight): Ca, 287; Cu, 7.4; Fe, 113; K, 2903; Mg, 1162; Mn, 11.3; Na, 1678; Zn, 186. It was found that bioelements from all the tested samples of raw materials were released to artificial digestive juices.

CONCLUSION

The amount of substances extracted to digestive juices from the analyzed raw materials varied depending on their form. The highest content of bioelements was found in the fresh rhizomes of turmeric and ginger. On the other hand, powdered rhizome was characterized by the highest bioavailability of elements for humans. © 2021 Society of Chemical Industry.

A novel method for the microencapsulation of curcumin by high-pressure processing for enhancing the stability and preservation

Curcumin is used for the development of new pharmaceutical and food products, but its application is generally hindered by the poor solubility of curcumin and thermal instability during storage and processing. In this study, the liposomes of curcumin (cur-liposomes) were prepared by a novel combination of ethanol injection and high-pressure processing (HPP) to enhance the stability and preservation of curcumin. The pasteurization, mean particle size, size distribution, and encapsulation efficiency of cur-liposomes and the kinetics of their thermal degradation were also investigated in this research. From the results, the kinetic rate constants of curcumin in samples of free curcumin and cur-liposome at 25 °C were found to be 1.6 × 10^-3 and 0.8 × 10^-3 min^-1, respectively. The phospholipid bilayer structure could protect curcumin. The results propose that the HPP method for liposome preparation is superior to the probe-sonication method in terms of stability, encapsulation efficiency, and homogeneity. Furthermore, the preparation of cur-liposomes by HPP with a hydrostatic pressure of 200 MPa could maintain the optimal particle size (206.4 nm) and polydispersity index (0.19). Conclusively, the combination of ethanol injection and HPP can not only successfully inactivate the microorganisms during liposome preparation for microencapsulation of bioactive compounds but also effectively preventthe thermal degradation of heat-sensitive substances in non-thermal processing for practical applications.

Application of starch nanoparticles as host materials for encapsulation of curcumin: Effect of citric acid modification

To encapsulate curcumin, absolute ethanolic curcumin solution with various content (300-1200 μg) was added to aqueous dispersion of citric acid-modified starch nanoparticles (M.SNPs) with various contents (0.5-2.5%), and then ethanol of the mixture was evaporated by nitrogen gas purge for 40 min (ethanol content decreased to 1%). SNPs (100 mg) could encapsulate 75.7 μg of curcumin in matrices of the composite, while 100 mg of M.SNPs could encapsulate 144.9 μg of curcumin. The XRD results revealed that curcumin was amorphously encapsulated in the composite, and hydrogen bond formation between M.SNPs and curcumin was one of the major driving forces for encapsulation as suggested by FT-IR. The composites had a spherical shape and mean particle size of the composites was increased from 136.3 to 255.3 nm with higher curcumin content in the matrices of composites. UV, pH, and thermal stability of curcumin significantly enhanced by the encapsulation, which was further increased when using M.SNPs and/or higher content of host materials. For the release of curcumin in simulated intestinal fluid digestion, release mechanism explained by Korsmeyer-Peppas model. For M.SNPs, k value was decreased from 13.097 to 2.938 as addition level of host material increased from 0.5 to 2.5%.

Changes in curcuminoids and chemical components of turmeric (Curcuma longa L.) under freeze-drying and low-temperature drying methods

We investigated how various drying methods affect the chemical components and microstructure of turmeric. We used freeze drying (FD), hot-air drying (HD) at 50 °C and sun drying (SD). Compared to all dried samples, fresh turmeric had greater amounts of chemical components (curcuminoids, phenolic acids, flavonoids and amino acids) andgreater antioxidantactivity (DPPH and FRAP) except for ABTS^.+ values. SD caused a severe decline of three major curcuminoids, resulting from UV and light degradation. Curcumin was decreased the most by SD (72%), followed by HD (61%) and FD (55%), respectively. Curcumin degradation to ferulic acid and vanillin was explored by FTIR analysis. The amino acids were decreased by all drying methods. FD was considered to be most suitable for drying turmeric. Microstructure changes were least after freeze drying, but were still evident compared with fresh turmeric.

Effect of Adding Curcumin on the Properties of Linseed Oil Organogels Used as Fat Replacers in Pâtés

Beeswax-based organogels were formulated with linseed oil and curcumin according to a statistical design to increase the oxidative stability of spreadable meat products (pâté) where these organogels (OGCur) were incorporated as fat substitutes. The organogels obtained under optimal conditions (9.12% beeswax, 0.54% curcumin) showed a mechanical strength similar to pork backfat determined by back extrusion and high oil binding capacity (OBC; over 90%). The incorporation of curcumin at this concentration did not lead to any change in the arrangement of the crystal network, OBC, and mechanical, thermal, or rheological properties of the organogels. Beeswax organogels with and without curcumin, with a β’ orthorhombic subcell structure, showed a predominant elastic behavior and a melting event wider and shifted to lower temperatures than pure beeswax, suggesting a plasticizer effect of the oil in the wax crystals. The oxidative stability of the organogels under accelerated oxidation conditions increased due to the incorporation of curcumin. A decrease in the curcumin content was found from day 4 at 60 °C, together with a significantly lower formation of both peroxides and malonaldehyde. When pork backfat was partially or totally replaced by OGCur in pâtés, a noticeable protective effect of curcumin against lipid oxidation was found during chilled storage

Targeting hallmarks of cancer with a food-system-based approach

Although extensive resources are dedicated to the development and study of cancer drugs, the cancer burden is expected to rise by about 70% over the next 2 decade. This highlights a critical need to develop effective, evidence-based strategies for countering the global rise in cancer incidence. Except in high-risk populations, cancer drugs are not generally suitable for use in cancer prevention owing to potential side effects and substantial monetary costs (Sporn, 2011). There is overwhelming epidemiological and experimental evidence that the dietary bioactive compounds found in whole plant-based foods have significant anticancer and chemopreventative properties. These bioactive compounds often exert pleiotropic effects and act synergistically to simultaneously target multiple pathways of cancer. Common bioactive compounds in fruits and vegetables include carotenoids, glucosinolates, and polyphenols. These compounds have been shown to target multiple hallmarks of cancer in vitro and in vivo and potentially to address the diversity and heterogeneity of certain cancers. Although many studies have been conducted over the past 30 y, the scientific community has still not reached a consensus on exactly how the benefit of bioactive compounds in fruits and vegetables can be best harnessed to help reduce the risk for cancer. Different stages of the food processing system, from "farm-to-fork," can affect the retention of bioactive compounds and thus the chemopreventative properties of whole foods, and there are opportunities to improve handling of foods throughout the stages in order to best retain their chemopreventative properties. Potential target stages include, but are not limited to, pre- and postharvest management, storage, processing, and consumer practices. Therefore, there is a need for a comprehensive food-system-based approach that not only taking into account the effects of the food system on anticancer activity of whole foods, but also exploring solutions for consumers, policymakers, processors, and producers. Improved knowledge about this area of the food system can help us adjust farm-to-fork operations in order to consistently and predictably deliver desired bioactive compounds, thus better utilizing them as invaluable chemopreventative tools in the fight to reduce the growing burden of cancer worldwide.

Effect of Surfactant Concentrations on Physicochemical Properties and Functionality of Curcumin Nanoemulsions Under Conditions Relevant to Commercial Utilization

Surfactants are used to stabilize nanoemulsions by protecting their physical stability and preventing deterioration of the entrapped bioactive during processing and storage. The effect of surfactant concentration on physical-chemical properties of nanoemulsions with entrapped curcumin, relevant to commercial applications, was addressed in this research. Furthermore, the functionality of nanoemulsified curcumin in terms of lipid oxidation inhibition was determined. Protection against varying pH and thermal treatments was more significant in the nanoemulsions at the elevated surfactant level, but at these high concentrations, the surface charges of the emulsions dramatically decreased under sodium salt addition, which may result in instability over time. Nanoemulsions showed the potential to inhibit malondialdehyde (MDA) formulation by protecting the entrapped curcumin and enhance its antioxidant activity when added to milk. The fortified milk with added curcumin systems had a yellow color compared to the control. The results of the study are critical in choosing the surfactant concentration needed to stabilize emulsified curcumin, and to protect the entrapped curcumin under specific conditions of use to support the utilization of curcumin nanoemulsions as a food additive in different commercial products.

Impact of cooking on the antioxidant activity of spice turmeric

Curcuminoids, as the main ingredient of turmeric, are popularly used in food additives and condiments, and are widely accepted to be beneficial for human health for their antioxidant activity. However, curcuminoids are highly susceptible in terms of thermal-induced degradation, and curry is usually boiled, roasted, or fried in the use of food additives and condiments. Thus, it is interesting to explore the effect of cooking on the antioxidant activity of curcuminoids. In the present study, the total antioxidant capacity (T-AOC) of cooked curcuminoids (boiled curcuminoids, roasted curcuminoids, and fried curcuminoids) processed through three heating conditions, and their protective effects against oxidative damage to rat pheochromocytoma (PC12) cells, a well-established neuronal model, were evaluated. It was found that cooking slightly lowered the T-AOC of curcuminoids, with boiled curcuminoids being relatively stronger than roasted curcuminoids, and fried curcuminoids being the weakest form. Both boiled and roasted curcuminoids could significantly improve cell viability, mitigate intracellular accumulation of reactive oxygen species and reduce malondialdehyde activity, reduce caspase-3 and caspase-9 protein expression, and increase superoxide dismutase activity of PC12 cells compared with the control group. In comparison with parent curcuminoids, the protective effects of cooked curcuminoids got relatively lower overall, with boiled curcuminoids being relatively stronger than roasted curcuminoids. In conclusion, the cooked curcuminoids, including boiled and roasted forms, still have antioxidant and neuroprotective activity.

Data-driven analysis of biomedical literature suggests broad-spectrum benefits of culinary herbs and spices

Spices and herbs are key dietary ingredients used across cultures worldwide. Beyond their use as flavoring and coloring agents, the popularity of these aromatic plant products in culinary preparations has been attributed to their antimicrobial properties. Last few decades have witnessed an exponential growth of biomedical literature investigating the impact of spices and herbs on health, presenting an opportunity to mine for patterns from empirical evidence. Systematic investigation of empirical evidence to enumerate the health consequences of culinary herbs and spices can provide valuable insights into their therapeutic utility. We implemented a text mining protocol to assess the health impact of spices by assimilating, both, their positive and negative effects. We conclude that spices show broad-spectrum benevolence across a range of disease categories in contrast to negative effects that are comparatively narrow-spectrum. We also implement a strategy for disease-specific culinary recommendations of spices based on their therapeutic tradeoff against adverse effects. Further by integrating spice-phytochemical-disease associations, we identify bioactive spice phytochemicals potentially involved in their therapeutic effects. Our study provides a systems perspective on health effects of culinary spices and herbs with applications for dietary recommendations as well as identification of phytochemicals potentially involved in underlying molecular mechanisms.

Stability studies of pure and mixture form of curcuminoids by reverse phase-HPLC method under various experimental stress conditions

Since time immemorial, turmeric has been widely marketed and consumed as dietary supplement due to its diverse medicinal properties. Curcuminoids-comprising a mixture of curcumin (CUR), demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC)-are the prime bioactive constituents of turmeric. However, the usage of curcuminoids is limited by their chemical instability. The lack of information on comparative stability profiles of curcuminoids (in pure and mixture form) prompted us to study how pure curcuminoids and their mixtures behave under different stress degradation conditions. The order of stability of curcuminoids when exposed to acidic, alkaline, and oxidative degradation was found to be as follows: BDMC > DMC > CUR. While the pure and mixture forms of curcuminoids were stable against heat, they completely degraded upon exposure to sunlight. The degradation extent of curcuminoids (in mixture form) was substantially less as compared to their pure form; therefore, this suggested the synergistic stabilizing influence of DMC and BDMC in the curcuminoids' mixture.

A Kinetic Degradation Study of Curcumin in Its Free Form and Loaded in Polymeric Micelles

Curcumin, a phenolic compound, possesses many pharmacological activities and is under clinical evaluation to treat different diseases. However, conflicting data about its stability have been reported. In this study, the kinetic degradation of curcumin from a natural curcuminoid mixture under various conditions (pH, temperature, and dielectric constant of the medium) was investigated. Moreover, the degradation of pure curcumin at some selected conditions was also determined. To fully solubilize curcumin and to prevent precipitation of curcumin that occurs when low concentrations of co-solvent are present, a 50:50 (v/v) aqueous buffer/methanol mixture was used as standard medium to study its degradation kinetics. The results showed that degradation of curcumin both as pure compound and present in the curcuminoid mixture followed first order kinetic reaction. It was further shown that an increasing pH, temperature, and dielectric constant of the medium resulted in an increase in the degradation rate. Curcumin showed rapid degradation due to autoxidation in aqueous buffer pH = 8.0 with a rate constant of 280 × 10(-3) h(-1), corresponding with a half-life (t1/2) of 2.5 h. Dioxygenated bicyclopentadione was identified as the final degradation product. Importantly, curcumin loaded as curcuminoid mixture in ω-methoxy poly (ethylene glycol)-b-(N-(2-benzoyloxypropyl) methacrylamide) (mPEG-HPMA-Bz) polymeric micelles and in Triton X-100 micelles was about 300-500 times more stable than in aqueous buffer. Therefore, loading of curcumin into polymeric micelles is a promising approach to stabilize this compound and develop formulations suitable for further pharmaceutical and clinical studies.

An appraisal on recent medicinal perspective of curcumin degradant: Dehydrozingerone (DZG)

Natural products serve as a key source for the design, discovery and development of potentially novel drug like candidates for life threatening diseases. Curcumin is one such medicinally important molecule reported for an array of biological activities. However, it has major drawbacks of very poor bioavailability and solubility. Alternatively, structural analogs and degradants of curcumin have been investigated, which have emerged as promising scaffolds with diverse biological activities. Dehydrozingerone (DZG) also known as feruloylmethane, is one such recognized degradant which is a half structural analog of curcumin. It exists as a natural phenolic compound obtained from rhizomes of Zingiber officinale, which has attracted much attention of medicinal chemists. DZG is known to have a broad range of biological activities like antioxidant, anticancer, anti-inflammatory, anti-depressant, anti-malarial, antifungal, anti-platelet and many others. DZG has also been studied in resolving issues pertaining to curcumin since it shares many structural similarities with curcumin. Considering this, in the present review we have put forward an effort to revise and systematically discuss the research involving DZG with its biological diversity. From literature, it is quite clear that DZG and its structural analogs have exhibited significant potential in facilitating design and development of novel medicinally active lead compounds with improved metabolic and pharmacokinetic profiles.

Thermal stability, antioxidant, and anti-inflammatory activity of curcumin and its degradation product 4-vinyl guaiacol

Curcumin is a secondary plant metabolite present in Curcuma longa L. Since curcumin is widely used as a food colorant in thermally processed food it may undergo substantial chemical changes which in turn could affect its biological activity. In the current study, curcumin was roasted at 180 °C up to 70 minutes and its kinetic of degradation was analyzed by means of HPLC-PDA and LC-MS, respectively. Roasting of curcumin resulted in the formation of the degradation products vanillin, ferulic acid, and 4-vinyl guaiacol. In cultured hepatocytes roasted curcumin as well as 4-vinyl guaiacol enhanced the transactivation of the redox-regulated transcription factor Nrf2, known to be centrally involved in cellular stress response and antioxidant defense mechanisms. The antioxidant enzyme paraoxonase 1 was induced by roasted curcumin and 4-vinyl guaiacol. Furthermore, roasted curcumin and 4-vinyl guaiacol decreased interleukin-6 gene expression in lipopolysaccharide stimulated murine macrophages. Current data suggest that curcumin undergoes degradation due to roasting and its degradation product exhibit significant biological activity in cultured cells.

The Potential for Plant Derivatives against Acrylamide Neurotoxicity

Certain industrial chemicals and food contaminants have been demonstrated to possess neurotoxic activity and have been suspected to cause brain-related disorders in humans. Acrylamide (ACR), a confirmed neurotoxicant, can be found in trace amount in commonly consumed human aliments as a result of food processing or cooking. This discovery aroused a great concern in the public, and increasing efforts are continuously geared towards the resolution of this serious threat. The broad chemical diversity of plants may offer the resources for novel antidotes against neurotoxicants. With the goal of attenuating neurotoxicity of ACR, several plants extracts or derivatives have been employed. This review presents the plants and their derivatives that have been shown most active against ACR-induced neurotoxicity, with a focus on their origin, pharmacological activity, and antidote effects.

Turmeric (Curcuma longa L.) drying: an optimization approach using microwave-vacuum drying

This study investigated the effect of microwave power (2,400-4,000 W) and drying times (10-30 min) on the quality of dried turmeric in terms of colour (L, a*, b*), moisture content, water activity (aw), ash, antioxidant activity (2,2-dipheneyl-1-picrylhydrazyl; DPPH), total phenolic and curcuminoids content. In addition, Response Surface Methodology (RSM) was implemented to optimize the drying conditions for turmeric. A range of quality parameters, microwave power (W) and time (min) were fitted to quadratic models using a central composite design. The Analysis of Variance (ANOVA) statistic results suggested that the optimal qualities (i.e., aw, value, moisture content, phenolic content, curcuminoid content and EC50 and L value) of dried turmeric were achieved at high vacuum-microwave power (3,500-4,000 W) and long duration (27-30 min). The improvement in the quality of dried turmeric microwave-vacuum drying in these conditions was illustrated through the enzymatic browning reaction via inhibition of polyphenol oxidase which suppressed the formation of the brown pigments and increased the phenol substrates.