Enhanced Antioxidant Capacity of Puffed Turmeric (Curcuma longa L.) by High Hydrostatic Pressure Extraction (HHPE) of Bioactive Compounds

Chemical Composition of Turmeric (Curcuma longa L.) Ethanol Extract and Its Antimicrobial Activities and Free Radical Scavenging Capacities

Turmeric (Curcuma longa L.) is a perennial tuberous plant from the genus Curcuma (Zingiberaceae) and has been widely used in foods for thousands of years. The present study examined the ethanol extract of turmeric for its chemical composition, antimicrobial activity, and free radical scavenging properties. UHPLC-MS/MS analysis tentatively identified eight compounds in the turmeric extract. Potential antimicrobial effects of 0.1, 1.0, and 10 mg turmeric equivalents (TE)/mL were evaluated in vitro against a variety of Gram-negative bacteria (i.e., Escherichia coli, Klebsiella pneumoniae, and Pseudomonas sp.) and Gram-positive bacteria (i.e., Enterococcus faecalis, Listeria innocua, and Staphylococcus aureus). Concentrations of 0.1 and 1.0 mg TE/mL inhibited the growth of S. aureus and significantly suppressed that of Pseudomonas sp., E. faecalis, and L. innocua. The growth of all strains, including E. coli, was inhibited by 10 mg TE/mL. Moreover, free radical scavenging capacities were determined using HO●, ABTS●+, and DPPH● (HOSC, ABTS, and RDSC, respectively) radicals. The turmeric ethanol extract had a TPC value of 27.12 mg GAE/g, together with HOSC, RDSC, and ABTS values of 1524.59, 56.38, and 1.70 μmol TE/g, respectively. Our results suggest that turmeric extract has potential applications for use in functional foods to reduce microbial burdens and oxidative stress-related health problems.

The Extraction Process, Separation, and Identification of Curcuminoids from Turmeric Curcuma longa

Turmeric Curcuma longa is a well-known spice with various health benefits, attributed primarily to curcumin. Soxhlet extraction, cold maceration, ultrasound-assisted extraction (UAE), and supercritical fluid extraction were performed, and the content of total phenols, proanthocyanidins, and antioxidants was analysed by UV/VIS spectrophotometry. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed to identify and quantify the curcumin content. Supercritical extracts had the highest total phenolic content (538.95 mg GA/100 g material), while the Soxhlet extracts had the highest content of proanthocyanidins (4.77 mg PAC/100 g of material). Extracts obtained by UAE and supercritical extraction have the highest antioxidant potential. Antioxidant activity measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH•) was 64.27% and 1750.32 mg Trolox per g dry weight by 2,2-azinobis(3-ethylbenzothiazoline 6 sulphonic acid) (ABTS+•) for the extract obtained by supercritical extraction. The UAE resulted in the highest amount of curcumin (1.91 mg curcumin/g material). A kinetic study showed that extraction yield in supercritical extracts decreased with increasing temperature and that the content of isolated curcumin was inversely proportional to solvent-to-feed ratio (S/F). The present study has confirmed that turmeric is an excellent source of antioxidants, such as curcumin, that play an important role in reducing cellular stress by neutralising free radicals.

The Effects of Citric Acid Crosslinking on Fabrication and Characterization of Gelatin/Curcumin-Based Electrospun Antioxidant Nanofibers

Nanofibers, produced through the novel method of electrospinning, have a high ratio of surface area to volume, which allows them to have different optical, electrical, thermal, and mechanical properties than macroscale materials. In this study, it was aimed to produce nanofibers with gelatin and curcumin. The effects of gelatin concentration and crosslinking with citric acid on the characteristics of electrospun nanofibers were studied. Gelatin film containing neither citric acid nor curcumin was used as control. Solutions were evaluated by solution conductivity, color analysis, and rheological properties. Obtained nanofibers were characterized by morphological analysis (SEM), antioxidant activity (AA), thermal properties (TGA, XRD, DSC), water vapor permeability (WVP), and Fourier transform infrared (FTIR) analysis. It was found that the functional groups of gelatin were not changed significantly but some degree of crosslinking was seen, as indicated by the changes in AA, crystallinity, etc. Improvement in antioxidant activities was seen, which was the highest for gelatin and curcumin films (32%). The highest melting temperature (78 °C) and WVP (2.365 × 10^-10 gm^-1 s^-1 Pa^-1) was seen for gelatin and curcumin films crosslinked with 0.5% citric acid. Gelatin with curcumin films crosslinked with 1% citric acid showed the lowest crystallinity (1.56%). It was concluded that even though citric acid might not prove to be a stable crosslinking agent for the protein (gelatin), it contributed to the antioxidant nature of the films, along with curcumin. These films are promising candidates to be applied on cut fruits, to reduce water loss and oxidation and hence extend their shelf lives.

Impact of Cell Disintegration Techniques on Curcumin Recovery

In recent years, the improvement of curcumin recovery from turmeric by cell and tissue disintegration techniques has been gaining more attention; these emerging techniques were used for a reproducible and robust curcumin extraction process. Additionally, understanding the material characteristics is also needed to choose the optimized technique and appropriate processing parameters. In this review, an outlook about the distribution of different fractions in turmeric rhizomes is reviewed to explain matrix challenges on curcumin extraction. Moreover, the most important part, this review provides a comprehensive summary of the latest studies on ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), enzyme-assisted extraction (EAE), high-pressure-assisted extraction (HPAE), pulsed electric field-assisted extraction (PEFAE), and ohmic heating-assisted extraction (OHAE). Lastly, a detailed discussion about the advantages and disadvantages of emerging techniques will provide an all-inclusive understanding of the food industry’s potential of different available processes.

Emerging Non-Thermal Food Processing Technologies: Editorial Overview

According to the statistics, there is a strong consumer trend towards high-quality and healthy foods with “fresh-like” characteristics [...]

Therapeutic Applications of Curcumin in Diabetes: A Review and Perspective

Diabetes is a metabolic disease with multifactorial causes which requires lifelong drug therapy as well as lifestyle changes. There is now growing scientific evidence to support the effectiveness of the use of herbal supplements in the prevention and control of diabetes. Curcumin is one of the most studied bioactive components of traditional medicine, but its physicochemical characteristics are represented by low solubility, poor absorption, and low efficacy. Nanotechnology-based pharmaceutical formulations can help overcome the problems of reduced bioavailability of curcumin and increase its antidiabetic effects. The objectives of this review were to review the effects of nanocurcumin on DM and to search for databases such as PubMed/MEDLINE and ScienceDirect. The results showed that the antidiabetic activity of nanocurcumin is due to complex pharmacological mechanisms by reducing the characteristic hyperglycemia of DM. In light of these results, nanocurcumin may be considered as potential agent in the pharmacotherapeutic management of patients with diabetes.

Effect of Co-Administration of Curcumin with Amlodipine in Hypertension

Curcumin, a curcuminoid known as the main bioactive compound of turmeric, is used in foods, cosmetics, and pharmaceutical products. Amlodipine is a general antihypertensive drug used in combination with various other antihypertensive agents. To date, no studies have examined the effects of the co-administration of amlodipine with curcumin. In this study, the vasodilatory effects of curcumin, amlodipine, and the co-administration of curcumin with amlodipine on isolated rat aortic rings pre-contracted with phenylephrine were evaluated, and the hypotensive effects were evaluated using the tail cuff method. To measure blood pressure, male spontaneously hypertensive rats were divided into four groups, each containing six rats, as follows: amlodipine 1 mg/kg alone treated, amlodipine 1 mg/kg with curcumin 30 mg/kg treated, amlodipine 1 mg/kg with curcumin 100 mg/kg treated, and amlodipine 1 mg/kg with curcumin 300 mg/kg treated groups. Amlodipine and curcumin were intraperitoneally injected, and systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured at 1, 2, 4, and 8 h after administration. The combined administration of curcumin and amlodipine induced a stronger vasorelaxant effect than amlodipine alone. However, co-administration did not significantly lower SBP and DBP compared to the single administration of amlodipine. The results of this study suggest that hypertensive patients taking amlodipine can consume curcumin or turmeric for food or other medical purposes without inhibiting the blood pressure-lowering effect of amlodipine.

Dermatological effects of Curcuma species: a systematic review

Curcuma and its derivatives are associated with anti-inflammatory and antioxidant activities in the skin. They exhibit beneficial effects in wound healing and prevention of chronic ultraviolet B damage and may prevent facial redness such as rosacea and flushing. This review aims to provide an up-to-date and rigorous synthesis of studies that demonstrated the clinical efficacy of curcuminoids in the skin. We evaluated studies published in the MEDLINE-PubMed/PMC (National Library of Medicine) databases, and followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for this review. This search included papers published in the past 10 years in controlled clinical trials, double-blind and randomized controlled studies, and case studies. The search resulted in 12 studies published in the past 10 years. Curcuma species (Curcuma longa and Curcuma aeruginosa) and curcumin were found to produce various dermatological effects, including influencing antioxidant and anti-inflammatory processes in the production of hyaluronan, increasing skin moisture, and reducing axillary hair growth. Curcuma was also found to reduce thickness, erythema, pruritus, burning and pain in psoriasis lesions and to improve radiodermatitis lesions. Our review results show that Curcuma species may play a role in skin health management and may exhibit various dermatological effects, thus it could be a new therapeutic arsenal for dermatology professionals. Nevertheless, more clinical trials should be conducted with humans to establish the optimum delivery method and dosages for different dermatological conditions.

Nutritional Supplements for the Treatment of Neuropathic Pain

Neuropathic pain affects 7-10% of the population and is often ineffectively and incompletely treated. Although the gold standard for treatment of neuropathic pain includes tricyclic antidepressants (TCAs), serotonin-noradrenaline reuptake inhibitors, and anticonvulsants, patients suffering from neuropathic pain are increasingly turning to nonpharmacologic treatments, including nutritional supplements for analgesia. So-called "nutraceuticals" have garnered significant interest among patients seeking to self-treat their neuropathic pain with readily available supplements. The supplements most often used by patients include vitamins such as vitamin B and vitamin D, trace minerals zinc and magnesium, and herbal remedies such as curcumin and St. John's Wort. However, evidence surrounding the efficacy and mechanisms of these supplements in neuropathic pain is limited, and the scientific literature consists primarily of preclinical animal models, case studies, and small randomized controlled trials (RCTs). Further exploration into large randomized controlled trials is needed to fully inform patients and physicians on the utility of these supplements in neuropathic pain. In this review, we explore the basis behind using several nutritional supplements commonly used by patients with neuropathic pain seen in rheumatology clinics.