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The purpose of this paper is to determine the antioxidant properties and phenol content of methanolic extracts of six white varieties and six purple/brown varieties of Indian rice and to find some relationship between the antioxidant properties, phenolic content in the varieties analyzed.

Methanolic extracts of different rice varieties were analyzed for their superoxide radical scavenging activity, 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity, total antioxidant capacity, reducing power and ferrous ion chelating properties. The extracts were analyzed for determination of total phenol content, anthocyanin content, oryzanol content. Phenolic acids were determined by HPLC.

All the rice varieties (white and purple/brown) showed activity in a dose‐dependent manner. Free phenolic acids, e.g. protocatechuic acid, caffeic acid, vanillic acid, p‐coumaric acid (PCA), ferulic acid and sinapic acid and the phenolic aldehyde vanillin could be detected in all the rice samples analyzed. No relationship could be established between activity and metabolite content. Principal component analysis and classification shows that superoxide radical scavenging activity, total phenolic acid, protocatechuic acid and ferulic acid are the components to differentiate the varieties from each other.

Little work has been done on the antioxidant activity of white rice. The authors report superoxide radical scavenging activity, DPPH radical scavenging activity, total antioxidant activity, reducing power and ferrous ion chelating properties and phenolic contents of six white varieties and six purple/brown varieties of Indian rice. Free phenolic acids like protocatechuic acid, caffeic acid, vanillic acid, PCA, ferulic acid and sinapic acid are reported from all the 12 varieties of rice.

Monascus pigment was widely applied in food processing industry as functional additive, so more attention was paid to the fermentation optimization of pigment production. Therefore, this paper aims to evaluate the best possible fermentative conditions for maximum production of biopigment using submerged fermentation (SFM) and solid state fermentation (SSF) by Monascus purpureus HBSD 08.

The biopigment was produced by using an SMF and an SSF with optimized substrate to achieve higher yield. The antioxidant activity was evaluated by DPPH radical scavenging ability, superoxide anion radical scavenging ability and hydroxyl radical scavenging ability. The pigment composition was analyzed by thin layer chromatography.

Maximum Monascus pigment production (79.6 U/ml and 1,102 U/g) were obtained under an SFM and an SFF. The antioxidant activity of the pigment in an SFM was significantly higher than that in an SFM. The composition of pigment was not different in an SFM and an SFF.

The study developed new conditions, and Monascus strain was a candidate for producing pigment in an SFM and an SFF. To the authors’ best knowledge, this is a first attempt toward comparative evaluation on antioxidant capacity and composition between pigment in an SSF and an SFM. This result will serve for Monascus pigment production.

The purpose of this paper is to investigate various extracts of Annona squamosa L (Annonanceae) and Carica papaya L (Caricaceae) seeds for their antioxidant activity, free radical scavenging ability, total phenolic and flavonoid contents.

Samples from both the seeds were prepared by subjecting them to microwave‐assisted extraction. After determining their antioxidant properties and polyphenolic contents, correlation between them was also investigated.

Highest antioxidant activity (3,179.66 g gallic acid equivalent/g of dry extract) and phenol content were registered by chloroform:methanol extract of C. papaya seeds. Maximum radical scavenging activity (3,201.63 ascorbic acid equivalent antioxidant capacity g/100 g of dry extract) was exerted by water extract of A. squamosa seeds, whereas acetone extract of C. papaya registered highest flavonoid content among all extracts. Polar extracts were found to be better free radical scavengers compared with those less polar. Hexane extracts showed least DPPH radical scavenging activity. Acetone proved efficient in extracting flavonoids, whereas phenols were best extracted in a mixture of chloroform and methanol. Phenolic metabolites seem to be contributing significantly towards antioxidant activity of the C. papaya extracts, but less so in the case of A. squamosa.

There have been few reports on antioxidant activity of non‐edible parts of commonly consumed fruits. The research indicates that seeds may be a promising source of antioxidants, which may have therapeutic implications.

The purpose of this paper is to focus on the antioxidant properties of two phenolic-rich varieties of Nigerian local rice and their anti-cholinesterase potential after in vitro-simulated gastrointestinal digestion, with the aim of establishing their actual antioxidant and nutraceutical potential after their passage through the gastrointestinal tract upon consumption.

Two local rice varieties, commonly referred to as “Gboko” and “Ofada” rice commonly grown in Benue State, a middle belt region of Nigeria and south western regions of Nigeria, respectively, were locally processed. Each of the processed grains were divided into two portions; one portion was left uncooked, while the second portion was boiled conventionally as eaten, dried and subsequently milled into powder. The milled samples of the raw and boiled rice were treated with acidified methanol to obtain the methanol extracts; another portion of each samples was subjected to in vitro enzyme digestion using standard methods to mimic human digestion; and the third portion was treated using the same scheme of in vitro digestion without the sets of enzyme which was used to serve as a control for enzyme treatment. The quali-quantitative phenolic profiles of the two local varieties were carried out with the aid of high-performance liquid chromatography with diode-array detection (HPLC-DAD) method. The antioxidant potential and anti-cholinesterase action of the methanolic extracts, the simulated in vitro digested model and the enzyme-treated controls of the rice samples were determined using standard methods and data obtained were subjected to ANOVA; the differences of means were separated using Duncan’s multiple range test (DMRT).

The quali-quantitative assessment of phenolic compounds in the two studied local varieties revealed the presence of some phenolic acids and flavonoids, with a decreased level of most of the identified phenolic compounds after boiling. In vitro enzyme-digested rice for both raw and boiled rice samples showed significantly higher total phenolic content, total flavonoid content, ferric-reducing antioxidant power, 2, 2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS+) scavenging and NO− inhibitory activities than the aqueous-methanolic extracts and the enzyme-treated controls. The aqueous-methanolic extracts displayed a higher 1, 1 diphenyl-2-picrylhdrazyl radical scavenging activity and inhibited Fe2+-induced lipid oxidation in rat’s brain and liver homogenate than that displayed by the in vitro enzyme-digested samples. In vitro enzyme-digested and boiled “Gboko” and “Ofada” rice and raw “Ofada” rice have the potential of inhibiting acetylcholine esterase (AChE) activity. While methanolic extracts of raw and boiled “Ofada” and “Gboko” rice exhibited the potential to inhibit butrylcholinesterase activity. The result of this paper indicates that the selected rice varieties possess antioxidant capacities which are better released after the simulated in vitro enzyme digestion; the result also showed the anti-cholinesterase potential of the studied rice grains and, therefore, they can be considered as nutraceutical health supplements.

The paper has demonstrated the antioxidant potentials of the phenolic-containing two Nigerian local rice varieties and established their anti-cholinesterase potential after simulated in vitro enzyme digestion.

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.

The purpose of this paper is to carry out phytochemical investigations of different extracts of Eucalyptus globulus bark such as aqueous, methanolic and supercritical carbon dioxide fluid extract (SCFE) with ethyl acetate as entrainer. Three fractions (Eu 8, 9 and 10) containing steroidal δ‐lactone were isolated from SCF extract and the structure of Eu‐10 was earlier determined on the basis of NMR, HPLC‐MS, X‐Ray crystallography.

Column chromatography led to the isolation of flavonoids, tannins, steroids, etc. in different solvent systems. Isolated steroidal lactone (Eu‐8,9&10) of Withanolide series were tested for the presence of total phenolic content, total flavonoid content and the results were expressed as gGAE/100 g (TPC), and gQE/100 g (TFC), respectively. The antioxidant capacity was evaluated based on their ability to scavenge free radicals generated from ABTS, DPPH, FRAP and H₂O₂ by spectrophotometric method.

The result of the present study showed that different extracts of E. globulus bark and the isolated fractions, exhibited different antioxidant activity. This was due to the fact that they contained different amounts of flavonoid and phenolic compounds as per their ability to solubilize these compounds; the high scavenging property of E. globulus may be attributed to hydroxyl groups existing in the phenolic compounds. All the samples exhibited different extent of antioxidant activity (AOA) and showed higher potency when compared with BHT in scavenging action of DPPH free radical. Comparative data analysis showed SCF extract to be better than methanolic and aqueous extracts, both in terms of yield and AOA, while Eu‐10 was the best amongst purified fractions.

The present research has serious implications on identification of natural antioxidants from E. globulus. Natural antioxidants with better structure‐activity relationship are under investigation. Isolation of withanolide from Eucalyptus bark has opened newer horizon for its use.

Collection of Eucalyptus bark from the forest (a forest waste) by women folk can be a source of revenue generation and thus has social implication as well. It is an important agro product.

The steroidal lactone (Eu‐10) showed highest radical scavenging effect even at IC50, thus the isolated lactone proved to be the best potential scavenger of free radicals amongst all crude extracts and the isolated fractions.

The cowpea plant, being affordable and protein‐rich, is considered poor man's meat. The aim of this paper is to undertake a detailed investigation regarding in vitro total antioxidant capacity (TAC) and chemical constituents of the vegetable oils from seeds of this plant, taking its nutritional value into consideration.

Vegetable oils of different indigenous cowpea varieties were obtained using soxhelt extraction assembly and subjected to GC‐MS analyses and various antioxidant assays including 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulpohonic acid) (ABTS) radical cation scavenging, ferr, 2.2′‐diphenyl‐1‐picrylhydrazil (DPPH) radical scavenging, total phenolic contents (TPC), lipid peroxidation inhibition, and iron chelation activity.

Various chemical constituents including different hydrocarbons, tocopherols, ketones, fatty esters, estragole and cedrene were identified. TPCs were found to be 5.439, 5.7279, 7.6126, 6.7573 and 10.0591 mg/L gallic acid equivalent for S.A. Dandy, Elite, White Star, CP‐386 and FBD Rawan varieties, respectively. Employing ABTS radical decoloration assay a significant linear correlation (R²=0.997, 0.996, 0.997, 0.996 and 0.997 for S.A. Dandy, Elite, White Star, CP‐386 and FBD Rawan varieties, respectively) was found between the percent inhibition of ABTS radical cation and the amount of vegetable oils. The percent inhibition of the Fe(II)‐Ferrozine complex formation was found to be 29.45, 53.76, 82.91, 86.59 and 57.87 for the same varieties, respectively.

GC‐MS and standard in vitro antioxidative capacity analyses data clearly demonstrated the potency of the cowpea as antioxidant and radical scavenger plant which may be used as a good source of natural antioxidants. The plant seeds may prove a better and cost‐effective substitute of expensive food items.

The purpose of this paper is to evaluate the total polyphenolics, flavonoids and antioxidant properties of a ready to‐eat snack food prepared from Agaricus bisporous. A comparison of these properties with the raw, unprocessed mushroom was also carried out.

Extracts of raw and snack mushrooms (osmotically dehydrated, dried and spiced and following sensorial analysis) were analyzed for antioxidant activities using DPPH and ABTS radical scavenging methods. Flavonoids were determined by the method of Jia et al. Total polyphenolics (free and bound) were determined by the Folin‐Ciocalteu method; reducing power and hemolysis inhibition of the extracts were determined by the methods of Oyaizu and Zhang et al.

Scavenging activity of free extracts of raw and dry snack mushrooms on DPPH radical were 76 per cent and 72 per cent respectively. The ABTS radical scavenging activity of the free extracts of raw sample was 2.76 mg ascorbic acid equivalents/100 g and 2.67 mg ascorbic acid equivalents/100 g snack mushroom. Both free and bound polyphenolic contents in mushroom snacks were slightly higher than raw mushrooms, total flavonoids levels decreased marginally in snack mushrooms. Hemolysis inhibition was decreased (marginally) in free extract of snack mushroom as compared to raw mushroom whereas total reducing power of snack mushroom extract increased significantly. The antioxidant status was unaffected following storage of the snack at ambient temperature for up‐to 15 days.

Mushrooms snacks may serve as a good alternative for currently existing snack foods since they retain a significant amount of polyphenolics and antioxidants; mixed with other commonly used snack foods it may provide beneficial health effects to the consumers economically.

A simple, economical process for preparation of Agaricus bisporous snack using sequential application of osmotic dehydration and drying was optimized; the snack mushrooms possessed functional properties comparable to raw, unprocessed mushrooms.

This paper reports for the first time a simple, economical process for preparation of functional snack food from mushrooms.

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.

The purpose of this study was to assess the bacterial viability, antioxidative activity, antimutagenicity and sensory evaluation of fermented onion types by using probiotic starters after fermentation at 37 °C for 24 hours and storage in the refrigerator for 28 days.

For onion fermentation, Lactobacillus acidophilus (LA-5), Bifidobacterium bifidum (BB-12), and Streptococcus thermophilus (ST) were utilised. This research was conducted on three types of onion: white onion, red onion and scallion. With a 5% brine solution, the onions were sliced into 3-5 cm long and 1-2 cm wide slices. The process of fermentation was achieved by adding 2% (10⁸ CFU/ gm) of fresh probiotic starter and incubating it for 24 hours at 37 °C. The fermented onion samples were kept in the refrigerator for 28 days. After fermentation and storage, the pH and total acidity were estimated, the vitality of probiotic bacteria was evaluated in samples of the onion species. The Gas chromatography-mass spectrometry (GC-MS) technique was used to identify the bioactive components in fermented onion types. The antioxidant activity of fermented onions was measured using the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging activity assay and the hydroxyl radical scavenging activity test. The Ames test was used to detect the antimutagenicity of fermented onion samples.

After fermentation, the fermented scallion (p = 0.036) has the highest vitality of all the starter bacteria species. The fermentation of onion types produced a pH of between 4.1–4.7 and 0.19–0.23% total acidity, which is in the range of reduced 3.1–3.5 pH values and 0.42–0.63% total acidity after 28 days. The viability of Lactobacillus acidophilus and Bifidobacterium bifidum in fermented scallions was Log. 7.79 and 7.57 CFU/gm. The GC-MS technique found 14 bioactive compounds in fermented white onions and 13 compounds in fermented white onions, with 15 compounds in scallion fermentation. The majority of these bioactive compounds are strong antioxidants. The antioxidant properties of fermented scallion significantly increased after 28 days of storage time, showing an inhibitory effect on the DPPH assay (p = 0.02) and the scavenging activity of the hydroxyl radical assay (p = 0.01). Sensory evaluation tests revealed that the fermented scallion was a suitable product in terms of appearance, aroma and overall acceptability.

Commercially accessible probiotic foods account for a sizable portion of the consumer market. Furthermore, as consumer interest in healthy eating grows, so does demand for plant-based goods. All onion types fermented with probiotic bacteria have many chemical compounds that have both antioxidant and carcinogenic activity. The fermented scallion onion sample was significantly superior to the rest of the other types of onions.