Radical scavenging activity of various extracts and fractions of sweet orange peel (Citrus sinensis)

Functionalized ZnO-Based Nanocomposites for Diverse Biological Applications: Current Trends and Future Perspectives

The wide array of structures and characteristics found in ZnO-based nanostructures offers them a versatile range of uses. Over the past decade, significant attention has been drawn to the possible applications of these materials in the biomedical field, owing to their distinctive electronic, optical, catalytic, and antimicrobial attributes, alongside their exceptional biocompatibility and surface chemistry. With environmental degradation and an aging population contributing to escalating healthcare needs and costs, particularly in developing nations, there's a growing demand for more effective and affordable biomedical devices with innovative functionalities. This review delves into particular essential facets of different synthetic approaches (chemical and green) that contribute to the production of effective multifunctional nano-ZnO particles for biomedical applications. Outlining the conjugation of ZnO nanoparticles highlights the enhancement of biomedical capacity while lowering toxicity. Additionally, recent progress in the study of ZnO-based nano-biomaterials tailored for biomedical purposes is explored, including biosensing, bioimaging, tissue regeneration, drug delivery, as well as vaccines and immunotherapy. The final section focuses on nano-ZnO particles' toxicity mechanism with special emphasis to their neurotoxic potential, as well as the primary toxicity pathways, providing an overall review of the up-to-date development and future perspectives of nano-ZnO particles in the biomedicine field.

Artichoke Industrial Waste in Durum Wheat Bread: Effects of Two Different Preparation and Drying Methods of Flours and Evaluation of Quality Parameters during Short Storage

'Violetto di Ramacca' is a local variety of artichoke grown in Sicily (Southern Italy), known for its purple color with green streaks. In this study, the effects of two different preparation and drying methods (method A, fresh sample oven-dried at 40 °C for 48 h then mixed and ground into flour; and B, minced and frozen sample oven-dried at 40 °C for 24 h then blended and ground into flour) for flours from different parts of the artichoke (bracts, stems, and mix), used at different percentages of integration (5, 7.5, and 10%), in combination with re-milled semolina, have been evaluated. The polyphenol contents of the flours produced with the two methods were measured. The results showed significant differences between the methods and samples, with a range from 9.09 mg GAE/g d.m. (bracts 100%, method A) to 2.62 mg/g (mix 100%, method B). The values were then lowered in the flour products with supplements ranging from 0.96 mg GAE/g (bract flour 10%, method A) to 0.11 mg GAE/g (mixed flour 7.5%, method B). As the amounts of polyphenols increased, the antioxidant activity increased, with a range that varied in the pure flour from 8.59 mg trolox eq/g d.m. (bract flour, method A) to 3.83 mg trolox eq/g d.m. (mixed flour, method B). These flours were also analyzed for color, highlighting a clear difference between methods A (greener) and B (browner). The flours thus obtained were used to produce breads, which were evaluated for their physicochemical characteristics during 4 days of storage. The results showed a reduction in volumes and heights, an increase in the percentage of integration of the artichoke flours, a greater quantity of moisture in the integrated breads, and a lower reduction in the structural characteristics during storage compared to the control breads. The TPA was conducted on the breads from T0 to T4, highlighting that, although initially more compact, the integrated breads offered less alteration of the values during storage. The aw ranged from 0.63 (mix flour 5%, method B) to 0.90 (bract flour 5%, method B). The amounts of polyphenols (from 0.57 mg GAE/g in bread with bracts at 10% (method A) to 0.13 mg GAE/g in bread with mix 5% (method B)) and the antioxidant activity (from 0.55 mg trolox eq/g d.m. in bread with bract flour 10% (method A) to 0.14% mg trolox eq/g d.m. in bread with mix flour) were also evaluated, showing a trend similar to the values obtained in the flours. Colorimetric tests highlighted a color more similar to wholemeal bread in the loaves produced with method B. Statistical factor analysis and cluster analysis were conducted for all trials.

Spent coffee grounds as feedstock for the production of biosurfactants and the improved recovery of melanoidins

Spent coffee grounds (SCG) are wastes generated in high amounts worldwide. Their composition makes them a promising feedstock for biotechnological processes. Here we show that the production of the biosurfactant surfactin by submerged culture of a Bacillus subtilis strain growing on SCG is possible, reaching concentrations up to 8.8 mg/L when using SCG at 8.3 g/L in the medium. In addition, we report a synergy between the production of surfactin and the recovery of melanoidins, an added-value compound already present in SCG. More specifically, the concentration of melanoidins in the culture medium increased between 2.1 and 2.5 times thanks to the presence of the B. subtilis in the culture. Furthermore, we have observed a strong interaction between surfactin and melanoidin aggregates through dynamic light scattering measurements, and that both of them can be co-purified with an acid precipitation. We have also characterized the interfacial and antioxidant properties of the cell-free supernatant and surfactin extract, as well as the distribution of the congeners of the biosurfactant. Altogether, this work describes a promising approach to obtain biosurfactants and antioxidant molecules in a single operation, which can be used to design several new formulations of interest for bioremediation, amendment of soils, food and cosmetics.

Phytochemical Screening and In Vitro Evaluation of the Antioxidant Potential of Dichloromethane Extracts of Strychnos henningsii Gilg. and Ficus sycomorus L

Medicinal plants are a rich source of antioxidants such as flavonoids, phenols, tannins, and alkaloids among others and are currently used as alternative and complementary drugs in the management of stress-related disorders. Strychnos henningsii and Ficus sycomorus have been traditionally used by the people of Mbeere, Embu county, Kenya, as medicine for the treatment of various oxidative stress-related disorders such as diabetes and rheumatism; however, no empirical data are available to authenticate the said claim. The aim of this study was to evaluate preliminary phytochemical screening and in vitro antioxidant activity of dichloromethane (DCM) leaf extract of S. henningsii and stem bark extract of F. sycomorus using DPPH, hydrogen peroxide, and ferric reducing power assays; total flavonoids and phenolic compounds were also determined by colorimetric assay and Folin–Ciocalteu reaction, respectively. Phytochemical screening showed that both extracts possessed saponins, flavonoids, phenols, steroids, alkaloids, and cardiac glycosides; however, terpenoids were found to be absent in S. henningsii. The total phenolic and flavonoid content of the DCM stem bark extract of F. sycomorus was lower than that of the leaf extract of S. henningsii. These extracts significantly exhibited strong antioxidant activities at different concentrations tested. The IC50 values of S. henningsii and F. sycomorus were 0.325 mg/ml and 0.330 mg/ml for hydrogen peroxide and 0.068 mg/ml and 0.062 mg/ml for DPPH, respectively. Both DCM leaf and stem bark extracts of S. henningsii and F. sycomorus were found to have strong ferric reducing power. Therefore, both extracts showed significant nonenzyme-based antioxidant activities. The two plants possess phytochemicals that have significant antioxidant properties.

A Scientometric Study to a Critical Review on Promising Anticancer and Neuroprotective Compounds: Citrus Flavonoids

Flavonoids derived from citrus plants are favored by phytomedicinal researchers due to their wide range of biological activities, and relevant studies have been sustained for 67 years (since the first paper published in 1955). In terms of a scientometric and critical review, the scientometrics of related papers, chemical structures, and pharmacological action of citrus flavonoids were comprehensively summarized. The modern pharmacological effects of citrus flavonoids are primarily focused on their anticancer activities (such as breast cancer, gastric cancer, lung cancer, and liver cancer), neuroprotective effects (such as anti-Alzheimer’s disease, Parkinson’s disease), and metabolic diseases. Furthermore, the therapeutic mechanism of cancers (including inducing apoptosis, inhibiting cell proliferation, and inhibiting cancer metastasis), neuroprotective effects (including antioxidant and anti-inflammatory), and metabolic diseases (such as non-alcoholic fatty liver disease, type 2 diabetes mellitus) were summarized and discussed. We anticipate that this review could provide an essential reference for anti-cancer and neuroprotective research of citrus flavonoids and provide researchers with a comprehensive understanding of citrus flavonoids.

The Chemical Variability, Nutraceutical Value, and Food-Industry and Cosmetic Applications of Citrus Plants: A Critical Review

Citrus fruits occupy an important position in the context of the fruit trade, considering that both fresh fruits and processed products are produced on a large scale. Citrus fruits are recognized as an essential component of the human diet, thanks to their high content of beneficial nutrients such as vitamins, minerals, terpenes, flavonoids, coumarins and dietary fibers. Among these, a wide range of positive biological activities are attributed to terpenes and flavonoids derivatives. In this review, a list of bibliographic reports (from 2015 onwards) on the phytochemical composition, beneficial effects and potential applications of citrus fruits and their by-products is systematically summarized. In detail, information regarding the nutraceutical and medicinal value closely linked to the presence of numerous bioactive metabolites and their growing use in the food industry and food packaging, also considering any technological strategies such as encapsulation to guarantee their stability over time, were evaluated. In addition, since citrus fruit, as well as its by-products, are interesting alternatives for the reformulation of natural cosmetic products, the sector of the cosmetic industry is also explored. More in-depth knowledge of the latest information in this field will contribute to future conscious use of citrus fruits.

Recyclable Cu-Ag bimetallic nanocatalyst for radical scavenging, dyes removal and antimicrobial applications

An ecofriendly and cost effective green method has been used for the synthesis of recyclable, high functional nanoparticles. Bimetallic nanoparticles (BmNPs), Cu-Ag, have been synthesized using beetroot extract as reducing and capping agent. Formation of BmNPs was initially confirmed by UV-visible analysis, having distinct peaks of Ag at 429 nm and Cu at 628 nm. FTIR analysis also confirmed the association of bioactive phytochemicals with Cu-Ag nanoparticles. Crystallinity and morphology of BmNPs was determined through X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS) and energy dispersion X-ray spectroscopy (EDAX). The size of spherical shape Cu-Ag BmNPs was found to be 75.58 nm and EDAX studies confirmed the percent elemental composition of Cu and Ag in synthesized nanocatalyst. Results of different analysis provided supported evidences regarding the formation of BmNPs. Catalytic potential of BmNPs was tested for the degradation of rhodamine B (Rh-B), methylene blue (MB) and methyl orange (MO) dyes. Cu-Ag BmNPs exhibited outstanding catalytic activity for the degradation of selected organic dyes and percent degradation was recorded more than 90% for each dye. In addition, antiradical property of BmNPs was tested employing DPPH^● and ABTS^●+ assays and it was found to be promising. Synthesized BmNPs also exhibited strong antimicrobial activity against Salmonella typhimurium and Bacillus subtilis. Recyclability of nanoparticles was also evaluated and recovery from dye degradation reaction mixture was successfully achieved. The recovered nanoparticles exhibited same catalytic potential for the degradation of Rh-B. The objective of the current study was to synthesize BmNPs Cu-Ag employing a cost effective green method having promising catalytic, antiradical and antimicrobial potential. Further, BmNPs were reused after recovery from catalytic reactions, proving that BmNPs can be recycled having the same efficiency as that of a freshly prepared Cu-Ag BmNPs.

Retardation of oxidative rancidity in ghee adding orange peel powder at different storage temperature

This study is aimed to determine and compare the antioxidant activity of Orange Peel Powder (OPP) in ghee at different temperatures (4 °C, 25 °C and 60 °C) for divergent storage periods (0, 7, 14 and 21 days). To compare the antioxidant potentiality, synthetic antioxidant BHA (Butylated Hydroxy Anisole) is used. Twelve ghee samples were prepared where one was control, another one was BHA treated and the rest ten were admixing OPP in ghee at different ratios. After sensory evaluation three highest scored ghee samples (0.5%. 1.0% and 1.5%) were selected. Samples were analyzed for peroxide (PV), thiobarbituric acid (TBA), free fatty acids (FFA) value and radical scavenging activity. Though storage temperature and storage period were increased OPP treated ghee samples peroxide, TBA and FFA values were lowered significantly compared to control samples. Moreover, 1.0% and 1.5% OPP treated ghee samples such values were lowered than BHA treated ghee samples and all these are on the favor of ghee quality. OPP treated ghee samples' DPPH quench potentiality is also stronger than BHA treated ghee samples. Therefore, OPP is a great source of antioxidants and this can be used in ghee as a natural source of antioxidants.

Phytochemical Profile, Antioxidant Potential, Proximate and Trace Elements Composition of Leaves, Stems and Ashes from 12 Combretum spp. Used as Food Additives

In this study, twelve Combretum spp. were investigated for their phytochemical content, antioxidant potential, and their proximate and trace elements/minerals composition. The qualitative phytochemical composition of the leaves, stems, and ashes of Combretum plants analysed revealed the presence of saponins, tannins, terpenoids, steroids, cardiac glycosides, and flavonoids. The following phytoconstituents were lost in the ashes; tannins apart from C. mkuzense and C. padoides; cardiac glycosides; and flavonoids. The quantitative phytochemical analyses revealed that both the leaves, stems, and some ashes such as C. apiculatum and C. vendae contained levels of phenolic compounds, tannins, and flavonoids. DPPH screening method indicated great scavenging activity with the 70% acetone leaf extracts of C. kraussii, C. zeyheriim, and C. mkuzense. There was a significant decrease in the antioxidant activity in the ashes compared to the leaves and the stems. AOAC and ICPE protocols performed the proximate and nutritional analysis of the 70% acetone extracts. The extracts had substantial amounts of ash, moisture, protein, and energy. The leaves and ashes of C. adenogonium and C. apiculatum could provide a good source of calcium in the diet. This study presents valuable information on the phytochemical composition, nutritional composition, and antioxidant properties of some Combretum species.

Preventive Effects of Mandarin Fruit Peel Hydroethanolic Extract, Hesperidin, and Quercetin on Acetaminophen-Induced Hepatonephrotoxicity in Wistar Rats

Acetaminophen, also known as N-acetyl-para-aminophenol (NAPAP), is a traditional antipyretic and analgesic that is used extensively around the world to treat colds and fevers. However, a NAPAP excess causes rapid, severe liver and kidney damage. The goal of the study was to examine the protective effects and determine the mechanisms of action of MPHE, hesperidin, and quercetin in NAPAP-induced hepatorenal damage in Wistar rats. Male Wistar rats received a 0.5 g/kg oral supplement of NAPAP every other day for a period of four weeks. During the same period of NAPAP supplementation, MPHE (50 mg/kg), quercetin (20 mg/kg), and hesperidin (20 mg/kg) were administered to rats receiving NAPAP. MPHE, quercetin, and hesperidin treatments significantly improved liver function in NAPAP-supplemented rats. The high serum levels of aminotransferases, alkaline phosphatase, lactate dehydrogenase, and γ-glutamyl transferase as well as total bilirubin were significantly reduced, while the levels of suppressed serum albumin were significantly increased, demonstrating this improvement. Treatments utilizing these natural substances significantly enhanced kidney function as seen by a considerable decline in the increased blood levels of urea, uric acid, and creatinine. Additionally, the injection of MPHE, hesperidin, and quercetin resulted in a decrease in the quantity of lipid peroxides while increasing the activities of superoxide dismutase, glutathione peroxidase, and glutathione-S-transferase in the liver and kidneys. The treatments markedly abated the NAPAP-induced liver and kidney histological perturbations and reduced the NAPAP-induced serum tumor necrosis factor-α level and liver and kidney proapoptotic protein 53 and caspase 3 expressions. Otherwise, serum interleukin-4 level significantly increased by treatments. The MPHE, hesperidin, and quercetin treatments resulted in marked decrease in liver and kidney histopathological scores including inflammation, necrosis, apoptosis, and congestion. In conclusion, the MPHE, quercetin, and hesperidin may induce hepatonephropreventive impacts in NAPAP-supplemented rats via enhancing the antioxidant defense system, anti-inflammatory activity, and antiapoptotic action.

Hesperetin (citrus peel flavonoid aglycone) encapsulation using pea protein-high methoxyl pectin electrostatic complexes: complex optimization and biological activity

BACKGROUND

Orange pomace polyphenols have potential for use as nutraceutical ingredients in functional foods and beverages. However, owing to their low water solubility and bioaccessibility, they are not being utilized to their full potential. The goal of this research is to assess the impact of encapsulation on hesperetin (HT - a model orange polyphenol) water solubility, antioxidant activity, and in vitro bioaccessibility.

RESULTS

In this study, a citrus flavonoid aglycone, HT, was encapsulated within water-dispersible colloidal complexes (d = 350 ± 8 nm) formed by electrostatic attraction of pea protein isolate and high-methoxyl pectin at a mixing ratio of 1:1 (v/v) and pH 4. The maximum amount of HT that could be dispersed in water was much higher for the encapsulated form (99 ± 7 μg mL^-1 ) than the non-encapsulated form (<10 μg mL^-1 ). The radical scavenging activity of the encapsulated HT (>90%, pH 4) was much higher than the non-encapsulated form (<15% at pH 4 or 7). The in vitro bioaccessibility of encapsulated HT (27 ± 7%) was also much higher than the non-encapsulated form (<7%).

CONCLUSION

These results suggest that a well-designed, biopolymer-based delivery system may improve the effective incorporation of HT, and potentially other orange pomace polyphenols, into food and beverage products. This could provide an additional high-value use for orange juicing by-products while introducing a new nutraceutical product to the food and beverage industry. © 2022 Society of Chemical Industry.

Hesperidin: A Review on Extraction Methods, Stability and Biological Activities

Hesperidin is a bioflavonoid occurring in high concentrations in citrus fruits. Its use has been associated with a great number of health benefits, including antioxidant, antibacterial, antimicrobial, anti-inflammatory and anticarcinogenic properties. The food industry uses large quantities of citrus fruit, especially for the production of juice. It results in the accumulation of huge amounts of by-products such as peels, seeds, cell and membrane residues, which are also a good source of hesperidin. Thus, its extraction from these by-products has attracted considerable scientific interest with aim to use as natural antioxidants. In this review, the extraction and determination methods for quantification of hesperidin in fruits and by-products are presented and discussed as well as its stability and biological activities.

Comprehensive review on naringenin and naringin polyphenols as a potent anticancer agent

Though the incidence of several cancers in Western societies is regulated wisely, some cancers such as breast, lung, and colorectal cancer are currently rising in many low- and middle-income countries due to increased risk factors triggered by societal and development problems. Surgery, chemotherapy, hormone, radiation, and targeted therapies are examples of traditional cancer treatment approaches. However, multiple short- and long-term adverse effects may also significantly affect patient prognosis depending on treatment-associated clinical factors. More and more research has been carried out to find new therapeutic agents in natural products, among which the bioactive compounds derived from plants have been increasingly studied. Naringin and naringenin are abundantly found in citrus fruits, such as oranges and grapefruits. A variety of cell signaling pathways mediates their anti-carcinogenic properties. Naringin and naringenin were also documented to overcome multidrug resistance, one of the major challenges to clinical practice due to multiple defense mechanisms in cancer. The effective parameters underlying the anticancer effects of naringenin and naringin include GSK3β inactivation, suppression of the gene and protein activation of NF-kB and COX-2, JAK2/STAT3 downregulation, downregulation of intracellular adhesion molecules-1, upregulation of Notch1 and tyrocite-specific genes, and activation of p38/MAPK and caspase-3. Thus, this review outlines the potential of naringin and naringenin in managing different types of cancers.

Comparison in Content of Total Polyphenol, Flavonoid, and Antioxidant Capacity from Different Organs and Extruded Condition of Moringa oleifera Lam

Recently, interest in exploring phytochemicals with health benefits has grown significantly. In this research, we aimed to develop the processing profile and functionality of Moringa oleifera Lam. Here, we implemented biopolymer-mediated extrudate formulations of M. oleifera (leaves, seed, and husk) in order to enhance the phenolic, flavonoid, and antioxidant capacity. The formulation-1 (F1) was prepared for leaves, seed, and husk using biopolymers (10% w/w), namely: whey protein isolate (10% w/w) and lecithin (5% w/w) with vitamin E (2% w/w). The formulation-2 (F2) was composed of lecithin (5% w/w) with ascorbyl palmitate (10% w/w) and vitamin E (2% w/w), processed by hot-melt extrusion (HME). It was observed that the total phenol and flavonoid contents were persistent in the lecithin-mediated F2 formulation of leaves, seed, and husk. Likewise, antioxidant capacity was significantly stayed in the F2 formulation of all organs, compared to the extrudate and control. The IC50 values revealed that the leaves of the F2 formulation showed strong free radical scavenging capacity compared to the F2 formulation of seed and husk. It was concluded that the F2 formulation could be used in the different parts of M. oleifera processing to boost functionality.

Nanoencapsulated Extract of a Red Seaweed (Rhodophyta) Species as a Promising Source of Natural Antioxidants

Marine seaweed species represent an important source of bioactive compounds possessing antioxidant activity. This study aimed at evaluating the antioxidant capacity of the Jania rubens algal extract by means of two antioxidant assays, i.e., 2,2-diphenyl-1-picrylhydrazyl and ferric-reducing antioxidant power. The seaweeds' total phenolic and flavonoid contents were also assayed as markers of antioxidant activity. To identify active agents responsible for the antioxidant activity, gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry were used for comprehensive metabolites characterization. To enhance the Jania rubens efficacy, the extract was nanoencapsulated using an ionic gelation method by means of high-pressure homogenization. The optimum nanoformulation had a particle size of 161 nm, a ζ potential of 31.2 mV, a polydispersity index of 0.211, and entrapment efficiency of 99.7%. The in vitro phytochemicals' release profiles of Jania rubens chitosan nanoparticles in comparison to the concentration of the raw algal extract were studied by the dialysis bag diffusion method revealing that the extract was released in a controlled pattern. The results indicated the potential advantages of the encapsulated Jania rubens extract, with its potent antioxidant activity, for use in different applications where sustained release is useful.

Comprehensive Characterization and Quantification of Antioxidant Compounds in Finger Lime (Citrus australasica L.) by HPLC-QTof-MS and UPLC-MS/MS

Australian finger limes (Citrus australasica L.), an unusual citrus due to its unique pulp with a caviar-like appearance, has reached the global market as a promising source of bioactive compounds that promote health. This research was, therefore, performed to shed light on the bioactivity and composition of different parts of Citrus australasica L. (peel and pulp). Initial ultrasound-assisted extraction using MeOH:H2O (80:20, v/v) was carried out. After that, four fractions (hexane, ethyl acetate, butanol and water) were generated through liquid–liquid partitioning, and the total phenolic content (TPC) and antioxidant activity were evaluated using the Folin–Ciocalteu and the ferric reducing antioxidant power (FRAP) assays, respectively. The ethyl acetate fraction in the peel, which presented the highest values of TPC and antioxidant activity, was characterized using high-performance liquid chromatography coupled to quadrupole time-of-flight (HPLC-QTof) mass spectrometry. Fifteen compounds were identified, of which seven were characterized for the first time in this matrix. Moreover, ten phenolic compounds were quantified using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The major compounds in the sample were citric acid, pyrogallol, caffeic acid, coumarin, rutin, naringin, 2-coumaric acid, didymin, naringenin and isorhamnetin, which were found in a range from 2.7 to 8106.7 µg/g sample dry weight. Finally, the results presented in this novel work confirmed that the peel by-product of C. australasica L. is a potential source of bioactive compounds and could result in a positive outcome for the food, cosmetics and pharmaceutical industries.

Advances in sustainable approaches utilizing orange peel waste to produce highly value-added bioproducts

Orange peel waste (OPW), a discarded part of orange fruit, is a rich source of essential constituents that can be transformed into highly value-added bioproducts. OPW is being generated in million tonnes globally and returns to the environment without complete benefit. Thus, a high volume of annually produced OPW in the industry requires effective valorization. In this regard, limited data is available that summarizes the broader spectrum for the sustainable fate of OPW to produce value-added bioproducts. The main objective of this treatise is to explore the sustainable production of bioproducts from OPW. Therefore, this review covers all the aspects of OPW, from its production to complete valorization. The review encompasses the extraction technologies employed for extracting different valuable bioactive compounds, such as: essential oil (EO), pectin, and carotenoids, from OPW. Furthermore, the suitability of bioconversion technologies (digestion/fermentation) in transforming OPW to other useful bioproducts, such as: biochemicals (lactic acid and succinic acid), biopolysaccharides (xanthan and curdlan gum), and bioenergy (biomethane and bioethanol) is discussed. Also, it includes the concept of OPW-based biorefineries and their development that shall play a definite role in future to cover demands for: food, chemicals, materials, fuels, power, and heat. Lastly, this review focuses on OPW-supplemented functional food products such as: beverages, yogurts, and extruded products. In conclusion, insights provided in this review maximize the potential of OPW for commercial purposes, leading to a safe, and waste-free environment.

Exogenous Application of Ascorbic Acid Enhances the Antimicrobial and Antioxidant Potential of Ocimum sanctum L. Grown under Salt Stress

Ocimum sanctum L. (Tulsi) is the most important medicinal plant that has antimicrobial, antioxidants, and anticarcinogenic effects on human health. Plants, when under stress, gather several antioxidants and osmoprotectants. The present work focuses on the abiotic stress response of Tulsi and its mitigation by the application of ascorbic acid. In addition to this, an enhancement of antioxidant and antimicrobial activity was also analyzed using ascorbic acid. During the present work, when plants were grown under NaCl stress and ascorbic acid (AA) was provided with foliar applications, it ascertained encouraging effects on growth; likewise, its effect remains stable under salinity stress. The enzymatic antioxidants activity showed a significant change in response to AA alone or in combination. The highest catalase activity was recorded in plants subjected to 0.5 mM AA in combination with 100 mM NaCl (0.65 units/mL of enzyme). Likewise, a similar trend was recorded for the superoxide dismutase activity of Tulsi plants. The highest activity of SOD was recorded in plants subjected to 0.5 mM AA in combination with 100 mM NaCl (66.1 units/mg of protein). Flavonoid content showed its highest amount (27.41 mg/g) when plants were treated with 0.5 mM AA + 100 mM NaCl while the highest phenolic content (1.88 mg/g) was analyzed in salt treated plants sprayed with 0.5 mM AA. In the case of antimicrobial activity, 0.5 mM AA treated plants gave the highest value for the Staphylococcus aureus as 2.15 cm and in Clostridium species was 2.1 cm in the plants treated with 1 mM AA alone. Hence, the findings of the present study may lead to the conclusion that AA has a significant role in defense mechanisms of plants in response to salt stress. Further, it enhances the antimicrobial and antioxidant potential of Tulsi plants grown under salt stress.

Pera orange (Citrus sinensis) and Moro orange (Citrus sinensis (L.) Osbeck) juices attenuate left ventricular dysfunction and oxidative stress and improve myocardial energy metabolism in acute doxorubicin-induced cardiotoxicity in rats

OBJECTIVES

Doxorubicin is a highly effective chemotherapeutic agent for treating several types of cancer; however, it can induce cardiotoxicity. We evaluated the influence of Pera and Moro orange juices on cardiac remodeling induced by acute administration of doxorubicin in rats.

METHODS

We allocated 120 male Wistar rats into six groups: control (C), Pera orange juice (PO), Moro orange juice (MO), doxorubicin (D), doxorubicin + Pera orange juice (DPO), and doxorubicin + Moro orange juice (DMO). Groups PO and DPO received Pera orange juice, MO and DMO received Moro orange juice, and C and D received water with maltodextrin (100 g/L) for 4 wk. Subsequently, groups D, DPO, and DMO received 20 mg/kg doxorubicin and C, PO, and MO received saline. Echocardiogram and euthanasia were performed 48 h after doxorubicin injection. Juice and animal-serum flavonoid identification and quantification were evaluated by liquid chromatography/electrospray ionization multistage mass spectrometry. Oxidative stress and myocardial metabolism were evaluated by spectrophotometry.

RESULTS

Systolic and diastolic left ventricular dysfunction increased oxidative stress and pathologic changes in myocardial energy metabolism of rats treated with doxorubicin. Intake of both orange juices improved left ventricular function, decreased oxidative stress, and attenuated the myocardial energy metabolism changes. Moro orange juice had a more pronounced effect than Pera orange juice in glutathione peroxidase activity, citrate synthase, and β-hydroxyacyl-CoA dehydrogenase activity.

CONCLUSIONS

Pera and Moro orange juices attenuated cardiac remodeling induced by doxorubicin, improved myocardial energy metabolism, and attenuated oxidative stress. However, Moro orange juice was more effective than Pera orange juice in modifying energy metabolism.

Optimization of Natural Antioxidants Extraction from Pineapple Peel and Their Stabilization by Spray Drying

Pineapple peel still contains an important amount of phenolic compounds and vitamins with valuable antioxidant activity. In this way, the aim of this study was the recovery of the bioactive compounds from pineapple peel using environmentally friendly and low-cost techniques, envisaging their application in food products. From the solid-liquid extraction conditions tested, the one delivering an extract with higher total phenolic content and antioxidant capacity was a single extraction step with a solvent-pineapple peel ratio of 1:1 (w/w) for 25 min at ambient temperature, using ethanol-water (80-20%) as a solvent. The resulting extract revealed a total phenolic content value of 11.10 ± 0.01 mg gallic acid equivalent (GAE)/g dry extract, antioxidant activity of 91.79 ± 1.98 µmol Trolox/g dry extract by the DPPH method, and 174.50 ± 9.98 µmol Trolox/g dry extract by the FRAP method. The antioxidant rich extract was subjected to stabilization by the spray drying process at 150 °C of inlet air temperature using maltodextrin (5% w/w) as an encapsulating agent. The results showed that the antioxidant capacity of the encapsulated compounds was maintained after encapsulation. The loaded microparticles obtained, which consist of a bioactive powder, present a great potential to be incorporated in food products or to produce bioactive packaging systems.

Optimization of Ultrasound-Assisted Extraction via Sonotrode of Phenolic Compounds from Orange By-Products

Orange peel is the main by-product from orange juice industry. It is a known source of bioactive compounds, mostly phenolic compounds, and it has been widely studied for its healthy activities. Thus, this research focuses on the establishment of ultrasound-assisted extraction of phenolic compounds in orange peel using a sonotrode. For this purpose, a Box–Behnken design of 27 experiments was carried out with four independent factors—ratio ethanol/water (v/v), time (min), amplitude (%), and pulse (%). Quantitative analyses of phenolic compounds were performed and the antioxidant activity was measured by ABTS and DPPH methods. The validity of the experimental design was confirmed by ANOVA and the optimal sonotrode extraction conditions were obtained by response surface methodology (RSM). The extracts obtained in the established conditions were analyzed by High Performance Liquid Chromatography (HPLC) coupled to mass spectrometer detector and 74 polar compounds were identified. The highest phenolic content and antioxidant activity were obtained using 45/55 ethanol/water (v/v), 35 min, amplitude 90% (110 W), and pulse 100%. The established method allows an increment of phenolics recovery up to 60% higher than a conventional extraction. Moreover, the effect of drying on phenolic content was also evaluated.

Valorization of Bio-Residues from the Processing of Main Portuguese Fruit Crops: From Discarded Waste to Health Promoting Compounds

Food processing generates a large amount of bio-residues, which have become the focus of different studies aimed at valorizing this low-cost source of bioactive compounds. High fruit consumption is associated with beneficial health effects and, therefore, bio-waste and its constituents arouse therapeutic interest. The present work focuses on the main Portuguese fruit crops and revises (i) the chemical constituents of apple, orange, and pear pomace as potential sources of functional/bioactive compounds; (ii) the bioactive evidence and potential therapeutic use of bio-waste generated in the processing of the main Portuguese fruit crops; and (iii) potential applications in the food, nutraceutical, pharmaceutical, and cosmetics industries. The current evidence of the effect of these bio-residues as antioxidant, anti-inflammatory, and antimicrobial agents is also summarized. Conclusions of the revised data are that these bio-wastes hold great potential to be employed in specific nutritional and pharmaceutical applications.

Characterization, Antimicrobial and Antioxidant Evaluation of Biofabricated Silver Nanoparticles from Endophytic Pantoea anthophila

Endophyte mediated nanoparticles fabrication were emerging as a new frontier in nanomedicines that produce high biocompatible and functionalized silver nanoparticles. In this study, silver nanoparticles were successfully biosynthesized from the extracellular extract of endophytic bacterium Pantoea anthophila isolated from the stem of Waltheria indica for the first time. The synthesized nanoparticles showed a strong absorption band at 410 nm in the UV-Visible range. The dynamic light scattering and zeta potential analysis indicated that the average particle size was 16 nm at 5.30 mV. FTIR spectrum displayed the presence of various functional groups at 3423.65, 1633.71, 1022.27, 607.58 cm-1 that stabilised the nanoparticle. X-ray diffraction peaks were conferred to 100, 200, 220 and 311 planes of a face centred cubic structure. TEM and SEM micrograph revealed the spherical-shaped, polycrystalline nature with the presence of elemental silver analysed by EDAX. Selected area electron diffraction also confirms the orientation of silver nanoparticles with X-ray diffraction analysis. Antimicrobial activity against 10 different human pathogenic bacteria and fungi showed a broad spectrum inhibition against both Gram-positive and Gram-negative bacteria. Among the bacterial pathogens, B. Subtilis exhibited low activity compared to other pathogens. C. albicans was greatly controlled than other fungal species. A strong free radical scavenging activity of silver nanoparticles with IC50 values 31.29 ± 0.73, 19.83 ± 1.57, 35.64 ± 0.94, 42.07 ± 1.30, 29.70 ± 2.26, 29.10 ± 0.82, 36.80 ± 0.63 μg/ml was obtained in different antioxidant assays that were comparable to the reference. The study suggests that the silver nanoparticles can be biosynthesized from endophytic P. anthophila metabolites with significant therapeutic potential. With proper validation, the biosynthesized silver nanoparticles can be developed as a promising antiviral and anticancer drug candidate.

Inajá oil processing by-product: A novel source of bioactive catechins and procyanidins from a Brazilian native fruit

Agro-industrial activities generate large amounts of solid residues, which are generally discarded or used as animal feed. Interestingly, some of these by-products could serve as natural sources of bioactive compounds with great potential for industrial exploitation. This study aimed to optimize the extraction of phenolic antioxidants from the pulp residue (oil processing by-product) of inajá (Maximiliana maripa, a native species found in the Brazilian Amazon). The antioxidant properties of the optimized extract and its phenolic profile by high-resolution mass spectrometry (LC-ESI-QTOF-MS) were further determined. Central composite rotatable design and statistical analysis demonstrated that the temperature of 70 °C and 50% (v/v) ethanol concentration improved the extraction of phenolic compounds with antioxidant properties. The optimized extract also showed scavenging activity against the ABTS radical cation and reactive oxygen species (ROS; peroxyl and superoxide radical, and hypochlorous acid). Moreover, the optimized extract was able to reduce NF-κB activation and TNF-α release, which are modulated by ROS. Flavan-3-ols were the major phenolics present in the optimized extract. Collectively, our findings support the use of inajá cake as a new source of bioactive catechins and procyanidins. This innovative approach adds value to this agro-industrial by-product in the functional food, nutraceutical, pharmaceutical, and/or cosmetic industries and complies with the circular economy agenda.

Antioxidant, antimicrobial, and cytotoxic activities of extracts from the seed and pulp of Jujube (Ziziphus jujuba) grown in Iran

The aim of the present study was to investigate the biological activities of the ultrasound-assisted extracts obtained from pulp and seed of jujube (Ziziphus jujuba) fruits. To reach this purpose, total phenolic content (TPC), total flavonoid content (TFC), total pro-anthocyanin, DPPH radical scavenging activity, rancimat test, as well as antimicrobial activity and cytotoxicity test of both jujube pulp and seed extracts were evaluated. Total phenolic content (TPC), total flavonoid content (TFC), and total pro-anthocyanin in pulp extract were higher than those obtained from seed extract. In addition, DPPH radical scavenging activity of pulp extract (IC50 = 53.97 µg/ml) was higher than that of seed extract (IC50 = 88.68 µg/ml). Furthermore, the highest antimicrobial activity was observed against Escherichia coli and Staphylococcus aureus (MIC = 20 mg/ml) for both seed and pulp extracts. In vitro cytotoxicity evaluation on seven cell lines revealed that pulp and seed extracts of jujube had no cytotoxic activity. The present results suggested the promising antioxidant properties of jujube, which can be used in the fabrication of functional bioactive ingredients for different purposes.

Industrial Fruits By-Products and Their Antioxidant Profile: Can They Be Exploited for Industrial Food Applications?

Fruit by-products have a low economic value and have proven biological activities, such as antioxidant capacity due to the presence of active compounds. The main objective of this study was to obtain and determine the antioxidant capacity, through DPPH radical assay and β-carotene bleaching assay, of three food grade extracts from apple, lemon, and orange industrial by-products. Furthermore, the extracts were characterized by ultra-high performance liquid chromatography coupled to mass spectrometry (UHPLC-MS/MS). LC with diode array detector (LC-DAD) was used for the quantification of the main polyphenols. Lemon extract presented the highest inhibition percentage of DPPH radical (51.7%) and the highest total phenolics content (43.4 mg GAE/g) from the by-products studied. Orange by-product was that with the higher number of polyphenols while lemon extract was that with the highest content of individual phenolics. The by-product obtained from the lemon was that with higher amounts of hydroxycinnamic acids (407 µg/g of by-product), mainly chlorogenic acid (386.7 µg/g), followed by the apple by-product (128.0 µg/g of by-product), which showed higher amounts of rosmarinic and chlorogenic acids. These industrial by-products have great potential as a source of natural antioxidants to be used directly as food additives or to be incorporated in packaging to produce active food packaging.

Biotransformation of Citrus Waste-I: Production of Biofuel and Valuable Compounds by Fermentation

Citrus is the largest grown fruit crop on the globe with an annual production of ~110–124 million tons. Approximately, 45–55% of the whole fruit post-processing is generally discarded as waste by the food processing industries. The waste is a huge problem to the environment in terms of land and water pollution along with displeasure from aesthetic viewpoint and spread of diseases owing to its huge content of fermentable sugars. The waste can be utilized as a raw material feedstock for producing a number of valuable chemicals and products, such as bioethanol, biogas, bio-oil, organic acids, enzymes, and so on. The production of these chemicals from waste biomass gives an inexpensive alternative to the harsh chemicals used during industrial synthesis processes as well as the possibility of controlling pollution from the waste discarded to the environment. The derived chemicals can be further utilized in the production of industrially important chemicals, as solvents and building blocks of newer chemicals. Furthermore, organic acids, pectin, enzymes, prebiotics, etc., derived from citrus wastes have an edge over their synthetic counterparts in practical applications in the food processing and pharmaceutical industries.

Green thin film for stable electrical switching in a low-cost washable memory device: proof of concept

Low-cost and washable resistive switching (RS) memory devices with stable retention and low operational voltage are important for higher speed and denser non-volatile memories. In the case of green electronics, pectin has emerged as a suitable alternative to toxic metal oxides for resistive switching applications. Herein, a pectin-based thin film was fabricated on a fluorine-doped tin oxide glass substrate for RS mechanism. The presence of sp3-C groups with low binding energy corresponds to tunable charged defects and the oxygen vacancies confirmed by the O 1s spectra that plays a decisive role in the resistive switching mechanism, as revealed by X-ray photoemission spectroscopy (XPS). The surface morphology of the pectin film shows homogeneous growth and negligible surface roughness (38.98 ± 9.09). The pectin film can dissolve in DI water (10 minutes) owing to its ionization of carboxylic groups, that meet the trends of transient electronics. The developed Ag/pectin/FTO-based memory cell exhibits stable and reproducible bipolar resistive switching behavior along with an excellent ON/OFF ratio (104) and negligible electrical degradation was observed over 30 repeated cycles. Hence, it appears to be a valuable application for green electronics. Indeed, biocompatible storage devices derived from natural pectin are promising for high-density safe applications for information storage systems, flexible electronics, and green electronics.

Optimized Conditions for Flavonoid Extraction from Pomelo Peel Byproducts under Enzyme- and Ultrasound-Assisted Extraction Using Response Surface Methodology

Pomelo (Citrus maxima (Burm.) Merrill) peel, which has been considered as a byproduct, is a potential source of flavonoids. In this study, the extraction conditions of total flavonoids from peels of Da Xanh pomelo were optimized using the response surface methodology with the Box–Behnken design. The combination of two novel extraction methods, including enzyme-assisted and ultrasound-assisted extractions, was used for the optimization. The results indicated that the optimal extraction condition was a liquid-to-solid ratio of 142.99 mL/g, enzyme concentration of 3.45%, and the time of 65.23 min for incubation and of 69.26 min for sonication treatment. Total phenolic and total flavonoid contents of the pomelo peel extracts, under optimal condition of the combined method (16.79 mg GAE/g and 10.69 mg RE/g, respectively), were significantly higher than those of the conventional method (6.58 mg GAE/g and 2.42 mg RE/g, respectively). The naringin and hesperidin contents of extracts under optimal condition increased by 5.70% and 1.20%, respectively, compared to the extracts under the conventional method.

Optimization of Vacuum-Microwave-Assisted Extraction of Natural Polyphenols and Flavonoids from Raw Solid Waste of the Orange Juice Producing Industry at Industrial Scale

Orange pomace (OP) is a solid waste produced in bulk as a byproduct of the orange juice industry and accounts for approximately 50% of the quantity of the fruits processed into juice. In numerous literature references there is information about diverse uses of orange pomace for the production of high-added-value products including production of natural antioxidant and antimicrobial extracts rich in polyphenols and flavonoids which can substitute the hazardous chemical antioxidants/antimicrobials used in agro-food and cosmetics sectors. In this work and for the first time, according to our knowledge, the eco-friendly aqueous vacuum microwave assisted extraction of orange pomace was investigated and optimized at real industrial scale in order to produce aqueous antioxidant/antimicrobial extracts. A Response Surface Optimization methodology with a multipoint historical data experimental design was employed to obtain the optimal values of the process parameters in order to achieve the maximum rates of extraction of OP total polyphenols and/or total flavonoids for economically optimum production at industrial scale. The three factors used for the optimization were: (a) microwave power (b) water to raw pomace ratio and (c) extraction time. Moreover, the effectiveness and statistical soundness of the derived cubic polynomial predictive models were verified by ANOVA.

Kenaf (Hibiscus cannabinus L.) Leaves and Seed as a Potential Source of the Bioactive Compounds: Effects of Various Extraction Solvents on Biological Properties

Hibiscus cannabinus (Kenaf) is a potential source of bioactive constituents and natural antioxidant. The current study determined the impact of various solvents on extraction yield, recovery of polyphenol and flavonoid, antioxidant, anticancer, and antibacterial properties of Kenaf leaves and seed. The powder of leaves and seed was separately extracted with n-hexane, ethyl acetate, ethanol, and water solvent. Among them, the ethanol extract of leaves and seed showed the highest extraction yield, and their GC-MS analysis revealed a total of 55 and 14 bioactive compounds, respectively. The total polyphenols (TP) and flavonoids (TF) content were quantified by a spectrophotometric technique where water extracts displayed a noteworthy amount of TP and TF content compared to other extracts. A similar demonstration was noticed in antioxidant activity, evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) and hydrogen peroxide scavenging capacity. In addition, cytotoxicity and anti-lung cancer activity were identified against mouse embryonic fibroblast (NIH3T3) and human lung cancer (A549) cells. All extracts of leaves and seed were observed as non-toxic to the NIH3T3 cells, but slight toxicity was expressed by n-hexane extracts at the optimum dose (1000 µg/mL) of treatment. In parallel, n-hexane and ethanol extracts (leaves and seed) exposed promising anti-lung cancer activity at the same concentration. Furthermore, antibacterial activity was assessed using disc diffusion assay, and seed extracts exhibited a significant inhibition zone against Gram-positive and Gram-negative microorganisms. Overall, Kenaf seed extracted with polar solvents was found very potent in terms of important bioactive compounds and pharmacological aspects, which can be an excellent biological matrix of natural antioxidants.

Pretreatment methods affecting the color, flavor, bioactive compounds, and antioxidant activity of jujube wine

In the case of wine production, the selection of optimal pretreatment methods and starter cultures are the 2 key points before fermentation. In this research, the fresh jujube was separately underwent alcoholic fermentation at 20°C with 3 different pretreatment methods (with peel, without peel, and juice) and 5 different starter cultures, respectively. Color analysis, electronic sense analysis, bioactive compound analysis, and antioxidant activity analysis combined with multivariate statistical analysis were applied to evaluated the effects of pretreatment methods and starter cultures on the overall quality of jujube wine. It was found that both pretreatment methods and starter cultures have effects on the quality of jujube wines, in which pretreatment methods have much more significant effects. The jujube wines fermented with different pretreatment methods were classified clearly by their overall quality, and that of the jujube wines fermented with peel was the best among all, since it can not only enhance the color and flavor quality of the wine, but also maximize the preservation of bioactive compounds and antioxidant activity of jujube for better consumer acceptance. This will provide a theoretical reference and application basis for the quality improvement of jujube wine.

Recovery of Aromatics from Orange Juice Evaporator Condensate Streams by Reverse Osmosis

The aim of this work was to analyze the potential of reverse osmosis (RO) membranes in the recovery and concentration of aroma compounds from orange juice evaporator condensate (EC) streams. Concentration experiments were performed by using three RO spiral-wound aromatic polyamide membranes (SG1812C-34D, SC1812C-34D and SE1812) with different NaCl rejections. The effect of transmembrane pressure, axial feed flowrate and volume concentration ratio (VCR) on permeate flux was studied. Rejections of the investigated membranes towards specific aroma compounds (octanol, α-terpineol, terpinen-4-ol, cis-carveol, karvon, linalool) in selected operating conditions were also evaluated. The concentrations of the aroma compounds were determined by gas chromatography coupled with mass spectrometry (GC-MS) using headspace solid-phase microextraction (HS-SPME) as a sample preparation approach. For all selected membranes, the permeate flux increased linearly by increasing the operating pressure from 5 to 25 bar; on the other hand, the feed flowrate did not have any significant effect on the permeate flux. High retention values towards aroma compounds (>80%) were measured for all selected membranes. However, the SC membrane showed the highest rejection values (>96%) and the best correlation between concentration factor of aroma compounds and VCR.

A synergistic combination of shrimp shell derived chitosan polysaccharide with Citrus sinensis peel extract for the development of colourful and bioactive cellulosic textile

Green finishing formulations have established an important place in textile dyeing and finishing industry. The use of plant extracts along with chemical metallic mordants is reported to increase colour values and improve fastness properties. However, metal salts as mordants constantly pose environmental and human health risks. The purpose of this work is to examine and extend the knowledge of natural dyeing technology considering the use of biological macromolecule chitosan (CS) to increase dye uptake, fastness and impart functional properties. The cotton was pre-coated with chitosan using pad-dry method and optimal chitosan concentrations were selected by evaluating the colour spectrometry data in term of CIEL*a*b* values. The chemical nature of the extract was characterized by UV-Vis, Fourier-transform infrared spectroscopy (FT-IR) and Thermogravimetric analysis (TGA) whereas dyed samples were analysed by Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX) with mapping analysis, FT-IR, and TGA. Results showed that the aqueous extract of Citrus sinensis peel yielded interestingly shades all lying in yellow- red quadrant of CIELa*b* colour space with acceptable grades of wash and dry-wet fastness properties. This study reveals important information to understand synergism between two natural products in imparting semi durable antioxidant and antibacterial activity against E. coli and S. aureus, and thus offers full potential to be used in natural dyeing technology.

Chemical composition, antioxidant, antibacterial, and tyrosinase inhibition activity of extracts from Newhall navel orange (Citrus sinensis Osbeck cv. Newhall) peel

BACKGROUND

Newhall navel orange (Citrus sinensis Osbeck cv. Newhall) is the major navel orange cultivar planted in China. Almost all Newhall navel orange peels produced in that country are currently discarded, which is not only harmful to the environment but also a waste of resources. It is therefore necessary to carry out research to explore the utilization potential of this resource.

RESULTS

A 95% ethanol extract (EE) of Newhall orange peel was prepared and fractionated into three subextracts: petroleum ether extract (PEE), ethyl acetate extract (EtOAcE), and water extract (WE) by simple liquid / liquid extractions. These four extracts were then subjected to antioxidant, antibacterial, and tyrosinase inhibition assays. Interestingly, EtOAcE was significantly superior to all other three extracts, exhibiting the best biological effects. The total polyphenol content (TPC), total flavonoid content (TFC), and primary individual flavonoids of these four extracts were analyzed and compared. This was followed by principal component analysis (PCA) and the Pearson's correlation test. The result indicates that the primary bioactive compounds responsible for the biological effects of the EtOAcE are sinensetin, 4',5,6,7-tetramethoxyflavone, nobiletin, 3,3',4',5,6,7-hexamethoxyflavone, and narirutin. In view of its easy preparation and potent biological effects, EtOAcE might demonstrate excellent application potential in various industrial areas.

CONCLUSIONS

This study successfully identified EtOAcE as a potent naturally occurring antioxidant, antibacterial, and tyrosinase inhibitory agent, which might add value to the utilization of Newhall navel orange peel in the food, cosmetic, and pharmaceutical industries. © 2020 Society of Chemical Industry.