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Literature has consistently reported that coloured plants are rich in dietary bioactive compounds. Therefore, this study aims to compare the total phenolic content and antioxidant activities in selected coloured plants (blue butterfly pea flower, roselle calyx, yellow bell pepper and purple sweet potato).

Total Phenolic Content (TPC) was determined using Folin–Ciocalteu assay, while antioxidant activities were evaluated using 2,2-dophenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging, Ferric Reducing Antioxidant Power (FRAP) and Trolox Equivalent Antioxidant Capacity (TEAC) assays.

TPC was reported from 273.15 ± 19.57 µg GAE/g DW (blue butterfly pea flower extract) to 363.10 ± 7.94 µg GAE/g DW (roselle calyx extract). Antioxidant activities as determined by DPPH assay ranged from 17.26 ± 0.06% (purple sweet potato extract) to 83.38 ± 1.04% (yellow bell pepper extract); while for FRAP assay was 4.92 ± 0.18 mg Fe (II)/g DW (purple sweet potato extract) to 128.33 ± 11.59 mg Fe (II)/g DW (roselle calyx extract). On the other hand, TEAC values were in the range of 15.26 ± 2.83 µg Trolox/g DW (roselle calyx extract) to 364.27 ± 7.14 µg Trolox/g DW (blue butterfly pea flower extract). A significant moderate positive correlation was observed between TPC and DPPH (r = 0.562) as well as TPC and FRAP (r = 0.686).

This study was the first to compare the total phenolic content and antioxidant activities in coloured plants. Findings derived from this study can be extended to the formulation of natural food colourants and nutraceuticals.

This study aims to investigate the effect of spray drying temperature and maltodextrin addition on the contents of phenolics, flavonoids, anthocyanins and antioxidant activities (2,2-diphenyl-1-picrylhydrazyl [DPPH] radical scavenging activity, ferric reducing antioxidant power and reducing power) of karonda powder.

Over the past few decades, the demands for application of natural colorants in food production have been attracting the attention of academic research and food industry. Anthocyanins, a red pigment commonly found on plants, show high potentials in the preparation of spray-dried pigment powder. This study, therefore, was conducted using full factorial design with two factors, namely, inlet temperature (150°C and 160°C) and soluble solid concentration (10, 15 and 20°Brix) with maltodextrin as carrier to produce pigment powder from karonda, an anthocyanin-rich fruit which is native to southeast Asia.

Increasing soluble solid content from 10 to 15°Brix resulted in a 42%–57% reduction in phenolic, flavonoid and anthocyanin contents. However, when increasing the amount of maltodextrin from 15 to 20°Brix, a lower reduction (approximately 11%–19%) was observed. In samples with the same °Brix, there was no significant variation in antioxidant contents and activities, especially at high maltodextrin ratios. In addition, the reducing power of samples dried at higher temperature (160°C) was higher than that of samples dried at lower temperature. Karonda spray-dried powder showed a good positive correlation (p < 0.01) between antioxidant contents and DPPH• activity.

To the best of the authors’ knowledge, in this study, for the first time, the effect of spray drying conditions on the quality of karonda powder was investigated.

The aim of this paper is to study the effects of commercially available antioxidants on the oxidation stability of white mineral oils (paraffin oil).

Twelve commercially available antioxidants (Chimassorb 81, Tinuvin 326, Tinuvin 765, Tinuvin 571, Irganox L57, Irganox L109, Irganox L101, Irganox L115, Irganox L06, Irgafos 168, Naugard 445, BHT) were added to pharmaceutical and technical grade white mineral oils at 0.1%, 0.2%, 0.3%, 0.6% and 0.8% (w/w) concentrations. Light, heat and oxygen were applied to induce and accelerate oxidation. Total acid number, viscosity and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of the oils were measured to evaluate the performance of the antioxidant additives.

Results showed that combined heat and oxygen treatment was the most effective of the three conditions tested to cause oxidation. Based on the data, the best antioxidant additives to be used in white oils are decided to be Irganox L06 and Irganox L101. It was also found that the grade of oils (technical or pharma) did not create a significant difference in the results obtained.

To the best of the authors’ knowledge, this is the first study that reports effects of antioxidant addition on the oxidative properties of white mineral oils. This study advances knowledge of the behavior of white mineral oils under real atmosphere and provides comprehensive data on how the antioxidants affect the light, thermal, oxidative degradation of white mineral oils. The data presented also provide an insight to extend life expectancy of white mineral oils.

Aloe vera gel has nutritional and therapeutic properties due to presence of bioactive components. The aim of this study is to investigate the effect of pasteurization and storage time at different temperatures on some bioactive components of Aloe vera gel juice.

Aloe vera gel juice (Aloe barbadensis Miller) was pasteurized at 90°C for 1 min and stored up to 30 days at 4 and 25°C. The effect of pasteurization and storage time on glucomannan, vitamin C, DPPH inhibition (percent) and color of the juice was evaluated.

The results showed that pasteurization reduced vitamin C content and antioxidant activity 16% and 57%, respectively. During storage at 4 and 25°C, vitamin C and glucomannan contents reduced from 84.47 to 54.96 and 46.82 mg vitamin C/100 g dm and from 2.11 to 1.77 and 1.71 g/L, respectively. DPPH inhibition (percent) and Browning index (BI) increased significantly at both storage temperatures, which was more intensive at 25 than 4°C.

This paper is believed to be the only one which investigates the effect of thermal pasteurization and storage time at different temperatures on some bioactive components of Aloe vera gel juice.

The purpose of this study is to evaluate the effect of the addition of dried lemongrass leaves (DLGL) powder, at different levels, on phenolics content, antioxidant activities, consumer acceptance and the inhibition of lipid peroxidation of roasted coffee (RC).

DLGL powder was incorporated at the levels of 0%, 2.5%, 5.0%, 7.5% and 10% of RC weight. The total flavonoids (TF), total phenolics (TP) and antioxidant activity measured using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and reducing power assay of RC, DLGL and binary mixture of them determined. The oxidative indices of coffee oil samples during storage were investigated. In addition, the sensory characteristics of RC fortified with different levels of DLGL powder were evaluated.

The TP content of DLGL powder was 1,100.32 mg/100 g DWb, nearly 1.2 times higher than found in RC beans. The TF content of RC enriched with 2.5%, 5.0%, 7.5% and 10% DLGL were found to be around 1.05, 1.10, 1.15 and 1.20 times higher than that in the control coffee samples. RC supplemented with various levels of DLGL powder showed higher DPPH radical scavenging and reducing power activities. At the end of the storage period (six months), the acid, peroxide, P-Anisidine and total oxidation value values of RC supplemented with 10% DLGL powder were about 1.94, 2.52, 2.60 and 2.59 times as low as in the control sample without any addition of DLGL powder, respectively. RC containing 2.5% and 5.0% DLGL powder had significantly (p < 0.05) the highest sensory scores. Consequently, the addition of DLGL in coffee at up to a 5% ratio may have potential health benefits.

RC containing 2.5% and 5.0% DLGL powder had significantly (p = 0.05) the highest sensory scores.

Consequently, the addition of DLGL in coffee at up to a 5% ratio may have potential health benefits.

This paper aims to study carotenoids as a natural food colorant from Canna flowers. There is a growing demand for eco-friendly and non-toxic colorants, specifically for health-sensitive applications such as colours of food and textiles. Red Canna variety can be grown in normal garden situations and gives ample of flowers yielding good amount of natural colorant for both the purposes.

In the present work, ultrasound extraction of natural colorant from Canna indica flowers has been studied. The use of ultrasound is found to have a significant improvement in the extraction efficiency of colorants obtained from dry and fresh Canna flowers in different mediums. Ultrasonic cavitational processing has twofold advantages, it is an eco-friendly and cost-effective process.

The total carotenoid content in dry and fresh flower extract was found to be between 136.56 and 978.89 mg/kg. The assessment of antioxidant activity (AOA) in dry and fresh flower extract was found to be 5.78-78.33 per cent assayed by scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and identified by electron paramagnetic resonance (EPR) studies.

The use of ultrasonication for the extraction of colorant has been the main feature and a step towards technological advancement in the area of finding newer method of efficient extraction of the colorant.

The ease of extraction due to ultrasound waves has been the highlight.

It is for the first time that the phytochemical data of red Canna flower and has been studied, the total carotenoid content and antioxidant activities of different extracts of Canna were measured. The extraction of natural dye from C. indica flowers using ultrasound has been found to have significant improvement in the extraction efficiency of the colorant obtained from flowers.

The purpose of this paper is to evaluate the antioxidant activity and toxicity of Clinacanthus nutans leaves from three conventional extraction methods, i.e. maceration, Soxhlet and magnetic stirring.

Total flavonoid content (TFC) and phenolic content (TPC) were determined using colorimetric method of aluminum chloride and Folin-Ciocalteu (FC) assay, respectively. Antioxidant property of C. nutans was evaluated using 2,2'-diphenyl-1-pierylhydrazyl (DPPH) free radical scavenging assay. Cytotoxic activity of C. nutans against brine shrimp was evaluated based on LC50 (lethality concentration) after 24 h exposure to the plant extract.

The highest TPC of C. nutans was observed with Soxhlet extraction method (98.87 ± 10.43 mg of gallic acid equivalents (GAE/g) followed by maceration (68.77 ± 2.45 mg of GAE/g) and magnetic stirring (46.75 ± 2.45 mg of GAE/g). Interestingly, remarkable highest TFC was observed with magnetic stirring (568.90 ± 4.85 mg of rutin equivalent (RE)/g) followed by maceration (249.60 ± 2.79 mg of RE/g) and Soxhlet (174.8 ± 1.74 mg of RE/g). On the other hands, the extract obtained using maceration method showed the highest antioxidant activity (IC50: 14.18 mg/mL compared to ascorbic acid 144.36 µg/mL). Cytotoxicity of C. nutans from all extraction methods showed similar LC50 values with maceration (3.81 mg/mL), Soxhlet (2.61 mg/mL) and magnetic stirring (4.56 mg/mL), respectively.

Both phenolic and flavonoids are responsible for the antioxidant activity, of C. nutans extracts. Based on Meyer's toxicity index, all extracts were nontoxic (LC50>1 mg/mL).

The purpose of this paper was to determine and compare nutritional composition of different parts of citrus fruits, namely, Citrus aurantium (peel: albedo, flavedo and pulp: juice, pomace) . This study was conducted through three stages of fruit maturity (green, yellow and orange). Total polyphenols, flavonoids, β-carotene, total chlorophyll, ascorbic acid, acidity, total soluble solid and the minerals (Ca, Mg, Zn, Na, K, Fe, Mn Cu) were evaluated. Moreover, the relationship between the total polyphenol, flavonoids and the antioxidant activity was determined.

Total polyphenols were determined by the Folin-Ciocalteu method. Flavonoids were assessed by the aluminum chloride colorimetric method. Ca, Mg, Zn, Fe, Mn and Cu were measured using an atomic absorption spectrophotometer. K and Na contents were determined by using a flame photometer. Other nutritional composition was determined by volumetric method.

The result showed that the concentrations of antioxidants, total polyphenols, flavonoids, vitamin C, total chlorophyll, total acidity and antioxidant activity (DPPH%) decreased during the maturity of fruit while the value of pH and β-carotene increases. In addition, the concentrations of the most minerals decreased through the maturation of fruit except Na. Anova statistical analysis of all the studied chemical variables was shown significant differences between all the samples. The pH, total soluble solids, β-caroteniod: orange juice had the highest average while green juice had the lowest. Ascorbic acid, total acidity, total chlorophyll: green juice had the highest average while orange juice has the lowest. Total phenol, K, Mg, Fe, Cu, Mn: green flavedo had the highest average while orange juice had the lowest. Flavonoid, antioxidant activity (DPPH%), Ca, Zn: green albedo had the highest average while orange juice had the lowest. Na: orange flavedo had the highest average while green juice had the lowest. The correlations between total polyphenol, flavonoid and antioxidant capacity were significantly higher (R = 0.935 and 0.960, respectively).

The stage of maturity affects nutritional composition in Citrus aurantium fruits (C. aurantium) peel and pulp, where some minerals of composition increased and others decreased, according to the results. This is the first study on comparing the nutritional composition of pulp: juice, pomace and peel: albedo, flavedo of Citrus aurantium L. during maturity in Syria, and it was also not found in previous works.

Equisetum arvense L. (Equisetum) is a weed that is very difficult to remove because of its deep roots. The purpose of this paper is to examine the dyeability and antioxidant activity of Equisetum extracted from hot water.

Dry Equisetum was extracted at 100°C for 2 h, and its dyeability according to time, temperature and repetition cycle, and the mordant effect by skim milk powder were confirmed. The color change according to the K/S, fastness to rubbing, light, sweat and washing, UV protection rate and antioxidant activity were evaluated.

UV‒Vis spectroscopy showed that the Equisetum extract contained a flavonoid compound. The addition of Equisetum to artificial silk produced the greatest color difference when dyed at 60°C for 1 h, and the K/S value increased slightly after the pre-mordant treatment. In the fastness test, light and washing had no significant effect, but the fastness to rubbing was very good at Grades 4 and 5, and there was also a considerable improvement in the UV protection rate. The antioxidant activity of the extract was confirmed by an analysis of the radical scavenging ability through the DPPH (1,1-diphenyl 2-picryl-hydrazyl) and ABTS ([2,2’- azino-bis (3-ethylbenzothialzoline-6-sulfonic acid) diammonium salt]) tests.

These results revealed a new natural antioxidant-containing dyestuff, weed grass, which is easy to obtain, easy to use as a dyeing material and has excellent antioxidant activity in an extracted dye solution and dyeing fabric.

This paper aims to study the effect of cooking and food additives, such as lemon juice and vinegar, on phenols and flavonoids contents and antioxidant activity of purslane.

The Folin–Ciocalteu method was used to determine total phenols content (TP), while total flavonoid content (TF) was determined by the aluminum chloride method. Two methods were used for determination of antioxidant activity: DPPH (1, 1-diphenyl-2-picrylhydrazyl) assay to determine radical scavenging activity, and ferric-reducing antioxidant power (FRAP) to measure the reducing power.

According to the results, leafs had higher values of TP, TF and antioxidant activity than aerial parts. Both lemon juice and vinegar retracted antioxidant properties of leafs. TP and TF of leaves showed deterioration after treatment with lemon by 58% and 21.8%, respectively, and FRAP and radical scavenging activity decreased by 75.8% and 74.5%, respectively (p < 0.001). Also, TP, TF, FRAP and DPPH radical scavenging activity decreased in leaves by 82.2%, 30.5%, 87.8% and 90.9%, respectively, after treatment of leaves with vinegar. TF increased after cooking in studied parts, where no significant statistical difference was observed in TP and antioxidant activity (DPPH assay and FRAP) of cooked aerial parts. Adding lemon juice after cooking increased antioxidant properties of purslane (p < 0.001).

Purslane has antioxidant activity because it is rich in polyphenols and flavonoids. Effects of food additives and cooking were studied using different measurements. According to the authors’ knowledge, this is the first work that studied the effect of food additives on antioxidant properties of purslane.