Amino acids effects on heterocyclic amines formation and physicochemical properties in pan-fried beef patties

The effects of surface application of amino acids on the formation of heterocyclic amines (HCAs) and meat quality properties were evaluated in pan-fried beef patties (230 °C/15 min). Tryptophan, lysine, leucine, and proline at three concentrations, 0.05%, 0.20%, and 0.50% (w/w), were tested. The meat crusts were analyzed for HCA content using liquid chromatography-tandem mass spectrometry. Results showed that surface application of all tested amino acids significantly reduced total HCA content (P < 0.05), and the interaction of amino acid type and concentration significantly affected (P < 0.05) both individual and total HCA formation. Tryptophan at 0.50% reduced total HCAs the most (0.92 ng/g, 93% inhibition), followed by 0.50% lysine (1.94 ng/g, 84% inhibition), while leucine (3.95 ng/g, 64% inhibition) and proline (4.71 ng/g, 56% inhibition) were less effective at 0.50%. In addition, applying amino acids to meat surface significantly influenced (P < 0.05) pH and surface color change of beef crusts; particularly, lysine at 0.20% and 0.50% increased pH and a^* (redness) but reduced b^* (yellowness), while tryptophan and leucine at 0.50% increased L^* (whiteness). No significant effect was observed on cooking loss. Adding amino acids at 0.50% affected (P < 0.05) formation of aldehydes and pyrazines (as the key flavor compounds of fried beef). Overall, the results of this study suggested that adding amino acids to ground beef patties could effectively mitigate mutagenic HCA formation during cooking.     

Determination of organic acids evolution during apple cider fermentation using an improved HPLC analysis method

An efficient method for analyzing ten organic acids in food, namely citric, pyruvic, malic, lactic, succinic, formic, acetic, adipic, propionic and butyric acids, using HPLC was developed. Boric acid was added into the mobile phase to separate lactic and succinic acids, and a post-column buffer solution [5 mmol/L p-toluensulfonic acid (p-TSA) + 20 mmol/L bis (2-hydroxyethyl) iminotris (hydroxymethyl) methane (bis–tris) + 100 μmol/L sodium ethylenediaminetetraacetic (EDTA-2Na)] was used to improve the sensitivity of detection. The average spiked recoveries for the ten organic acids ranged from 82.9 to 127.9% with relative standard deviations of 1.44–4.71%. The linear ranges of determination were from 15 to 1,000 mg/L with correlation coefficients of 0.9995–0.9999. The metabolism of organic acids in cider, and the effect of nutrients including diammonium phosphate (DAP), thiamine, biotin, niacinamide and pantothenic acid on their metabolism, were studied using this method of analysis. We found that before cider brewing, additions of 200 mg/L DAP and 0.3 mg/L thiamine to apple juice concentrate results in a high quality cider. F. Zhou and B. Ji contributed equally to this work.     

Antioxidant activities of the rice endosperm protein hydrolysate: identification of the active peptide

The defatted rice endosperm protein (REP) was digested using five different proteases (Alcalase, Chymotrypsin, Neutrase, Papain, and Flavorase) to produce the antioxidative peptide. The degree of hydrolysis of REP by Neutrase (20.00%) was slightly lower than that of Chymotrypsin, but higher than those of other enzymes. The Neutrase hydrolysate from rice endosperm protein (NHREP) took on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity similar to α-tocopherol. Also, the reaction condition of Neutrase hydrolysis was moderate (pH of 7.0 and temperature of 37 °C). Therefore, Neutrase was chosen to be the optimum enzyme for producing the antioxidative peptide from REP. In succession, the antioxidant activities of NHREP were further evaluated. The median effective concentration (EC₅₀) value of NHREP for hydroxyl radical scavenging activity was 2.0 mg/mL, while its superoxide radical scavenging activity did not surpassed 50% even at 6 mg/mL. The percentage inhibition of autooxidation in linoleic acid system by NHREP was 82.09%, similar to that of α-tocopherol (86.59%) on day 5 at the same concentration. NHREP displayed 89.15% chelating effect on ferrous ion at a concentration of 1000 μg/mL, and a high correlation was also observed between the reducing power and antioxidant activity of NHREP (r ² = 0.99678). Consequently, NHREP was purified and identified, and the sequence determination by MALDI-TOF/TOF MS/MS revealed that the active constituent contained eight amino acids in its sequence (Lys-His-Asn-Arg-Gly-Asp-Glu-Phe), with the molecular mass of 1002.5217 Da. After sequence interpretation and database searching, the MS/MS spectrum was matched to glutelin protein f (460–465).     

Antimicrobial and antioxidant activity of spice essential oils

Essential oils of anise, bastard cardamom, cinnamon, dill, mace, zedoary, prikhom, and bitter ginger were determined for their antimicrobial and antioxidant activities. Of all, cinnamon oil had the highest antibacterial activity. The most sensitive bacteria was Bacillus cereus (0.5mg/mL minimum inhibitory concentration, MIC). Anise, cinnamon, dill, and prikhom exhibited strong antifungal activity against Rhodotorula glutinis, Aspergillus ochraceus, and Fusarium moniliforme. Two oil combinations: i) cinnamon and mace oils and ii) cinnamon and prikhom oils showed a synergistic effect against Staphylococcus aureus, Pseudomonas fluorescens, and Salmonella Rissen (0.32–0.38 mg/mL fractional inhibitory concentration index, FICI). Cinnamon, mace, and prikhom oils had strong antioxidant activity with 0.29–5.66 mg/mL IC₅₀, 61.46–68.52% antioxidant activity, 0.22–2.19 mM/mg reducing capacity, and 78.28–84.30% inhibition by 2,2-diphenyl-1-picrylhydrazyl (DPPH), β-carotene bleaching, ferric reducing (FRAP), and superoxide anion scavenging activity assays, respectively. These oils contained high amount of total phenolics (51.54–140.9 μg gallic acid equivalents/mg oil).     

Quantification of Amadori products in cheese

To obtain basic information about the extent of the early Maillard reaction in commercially available cheese varieties of varying degrees of maturity, Amadori products (APs) formed between reducing sugars and the ε-amino group of lysine (ε-APs) or the α-amino of selected amino acids (α-APs) were analyzed. APs were determined as the corresponding N-(2-furoylmethyl) amino acids (FMAAs) after acid hydrolysis using RP–HPLC with UV-detection as well as mass spectroscopy. Identification of the FMAAs resulting from the α-APs of lysine, valine, leucine, and isoleucine was achieved for the first time for cheese samples. The content of furosine, which is a hallmark for ε-APs, ranged from to 3–75 mg/100 g protein corresponding to 24–591 μmol ε-AP/100 g protein. ε-AP levels declined during ripening in all investigated cheeses, depending on the cheese type and stage of maturation. The mean content of four α-APs ranged from 138 to 681 μmol/100 g protein. Lowest concentrations were found in long-term ripened cheese samples, indicating a putative degradation of α-APs and ε-APs during advanced stages of maturation. The ratio of α-APs to ε-APs might be a useful indicator of cheese ripening.     

Antioxidant and antimicrobial activities of the methanol extracts from pummelo (Citrus grandis Osbeck) fruit albedo tissues

The present study was conducted to evaluate the antioxidant and antimicrobial properties of methanol (100 and 80% aqueous) extracts of pummelo fruits albedo (Citrus grandis Osbeck). The antioxidant and antibacterial activity for crude extracts and isolated compounds were evaluated using free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Paper disc diffusion method. A 100% Methanol (MeOH) extract was steeped in water at different pH levels and partitioned with ethyl acetate (EtOAc) to give basic, acidic, neutral, and phenolic fractions. The neutral extract was found to possess maximum antioxidant and antibacterial activity. Thereafter, neutral extract was carried out on a silica gel column and eluted with hexane:EtOAc:acetone and preparative TLC (PTLC) to give oil buntan compound, linoleic acid methyl ester, β-sitosterol, sigmasterol, limonin, nomilin and meranzin hydrate were isolated. While, 80% MeOH extract was fractionated also using a silica gel column and PTLC to give isomeranzin hydrate, p-coumaric acid and caffeic acid compound. The extract concentration providing 50% inhibition (IC₅₀) was as follows; oil buntan compound 95 μg/mL, caffeic acid 45 μg/mL, p-coumaric acid 105 μg/mL, limonin + nomilin (mixture) 135 μg/mL was lower than that of synthetic antioxidant butylated hydroxyanisole (BHA) 40 μg/mL. The inhibitory zone (mm) of bacteria tested was 2.9–4.1 mm caffeic acid and 11.6–15.1 mm p-coumaric acid.     

Aqueous citric acid as a promising cleaning agent of whey evaporators

Scale in evaporators for lactose production was identified as mainly calcium citrate tetrahydrate with phosphate contaminations. Dissolution of 3.00 g of scale in aqueous solutions of 0.100, 0.500, and 1.00 mol L⁻¹ citric acid with final volumes of 100, 50, and 25 mL was investigated. The highest concentration of citric acid was the most effective for all the investigated volumes. From the citric acid solutions, spontaneously supersaturated in calcium citrate tetrahydrate during scale dissolution in the smaller volumes for all citric acid concentrations, calcium citrate tetrahydrate slowly precipitated in acceptable purity for technical use. Dissolution efficiency of aqueous solutions of 0.200 mol L⁻¹ nitric acid combined with 0.100, 0.500, and 1.00 mol L⁻¹ citric acid with final volumes of 100, 50, and 25 mL showed synergistic effect especially for the higher concentrations and lower volumes of two acids.     

Bioactive lipids and fatty acids profile of Cistanche phelypaea

Oil extracted from the wild plant of Cistanche phelypaea was analyzed for its fatty acid, sterol, hydrocarbon and tocopherol contents. Total lipids (TL) content was 10 g/kg (on dry weight basis). The majority of fatty acids were of the unsaturated type (50.4 % of total fatty acids), while the saturated (mainly palmitic acid) were about 43.2 % of the total fatty acids. Oleic acid was the dominating fatty acid followed by palmitic and linoleic acids. High amounts of sterols were found in the oil with the main component β-sitosterol. Other phytosterols (e.g. stigmasterol, ∆⁷-avenasterol and ∆⁵-avenasterol) were present at approximately equal amounts (6–9 % of total sterols). The main identified hydrocarbon compounds were C₂₁, C₂₆ and C₃₂ constituting about 61.2 % of total hydrocarbons. Small amounts of C₁₂, C₁₈ and C₂₂, however, were also detected. Tocopherol levels were high in the oil (3.36 g/kg oil), wherein β-tocopherol was the main component followed by α-isomer. Both tocopherol components comprised more than 87 % of total vitamin E content in the oil. Furthermore, γ- and δ-tocopherols were detected in small amounts in the oil accounting for 14–16 % of the total vitamin E content. Information provided by the present work will be of importance for food applications and chemotaxonomy of Cistanche phelypaea.     

Potent effect of brown algae (<Emphasis Type="Italic">Ishige okamurae</Emphasis>) on suppression of allergic inflammation in human basophilic KU812F cells

The effect of solvent fractions from brown algae (Ishige okamurae) on allergic inflammatory reactions was investigated via measuring histamine release and cytokine generation in human basophilic KU812F cells induced by calcium ionophore A23187. Moreover, polyunsaturated fatty acids (PUFAs) profiles were identied and quantied in the most active fraction. It was found that n-hexane and ethyl acetate (EtOAc) fraction at 50 μg/mL significantly reduce histamine release with the release rates of 24 and 20%, respectively. Likewise, the suppressive effect of n-hexane and EtOAc fraction on production as well as expression of interleukin (IL)-4 and IL-13 was determined. Notably, EtOAc fraction exhibited more effective inhibition than n-hexane in all assays. Furthermore, GC analysis revealed that EtOAc fraction contains various anti-inflammatory PUFAs such as eicosapentaenoic acid, eicosatrienoic acid, linolenic acid, and γ-linolenic acid. Collectively, EtOAc fraction from brown algae could be a potential inhibitor of allergic inflammatory reactions in basophils that is suggested to be due to PUFAs.     

Evaluation of Antioxidant Properties of Dry Soup Mix Extracts Containing Dill <Emphasis Type="Italic">(Anethum sowa</Emphasis> L.) Leaf

Soups are consumed for nutritive benefits and also by patients whose intake of solids is considerably reduced due to several pathological reasons. Dehydrated soup mix is a convenient product due to its less volume and long storage life at ambient temperatures. Soup mix formulated with functional ingredients, modified potato flour (thickening agent), and dill leaf powder (DLP) was evaluated for its antioxidant properties. Aqueous and methanolic extracts of soup mix were prepared, and their total phenolic content, reducing power ability, and free radical-scavenging activity were determined. Significant improvement in total phenolics was observed as a result of addition of DLP that led to enhancement of its antioxidant properties. The phenolic acid profile of the soup mix base contained mainly tannic acid, while protocatechuic, gentisic, vanillic acid, and syringic acids were contributed by DLP. The reducing power ability of soup mix was increased by about 2.5 times in aqueous and about seven times in methanolic extracts, as a result of DLP addition. Concentration-dependent scavenging activity was observed, and IC₅₀ (scavenging of 50% 1,1-diphenyl-2-picrylhydrazyl radical) values were reduced from 16.5 to 3.8 μg/mL in aqueous and from 9.1 to 3.9 μg/mL in methanolic extracts as a result of addition of DLP. The moisture–humidity relationship studies of soup mix conducted to determine its sorption behavior showed that the product exhibited caking tendency above 8.9% moisture corresponding to a critical relative humidity of 56%.     

Influence of the degree of hydrolysis (DH) on antioxidant properties and radical-scavenging activities of peanut peptides prepared from fermented peanut meal

To study the influence of degree of hydrolysis (DH) on antioxidant properties of peanut peptides, the peanut meal was fermented by Bacillus subtilis. The fermentation time was 48, 72, and 96 h, respectively, to prepare peanut peptides at different degree of hydrolysis. The peanut peptides (11.18, 16.20, and 21.41% of DH, respectively) were extracted from fermentation liquid. The antioxidant properties of these peanut peptides were evaluated based on DPPH^· radical (1,1-Diphenyl-2-picrylhydrazyl radical) scavenging activity, superoxide anion-scavenging activity, reducing power, metal-chelating activity, and inhibition of linoleic acid autooxidation. Peanut peptides (21.41% of DH) at 1 mg/mL exhibited 80.86 and 29.35% of scavenging concentration percent on DPPH^· and superoxide anion radical, respectively. In addition, the reducing power of peanut peptides was 0.368 at 2 mg/mL, and they possessed 76.32% of Fe²⁺-chelation ability at 2 mg/mL and 63.75% of inhibition of linoleic acid autooxidation at 0.8 mg/mL. The antioxidant activities of the peanut peptides (21.41% of DH) were stronger compared with others (11.18 and 16.20% of DH), and this indicated the antioxidant activities of peanut peptides increased with increasing DH (p < 0.05). To know much about the peanut peptides, they were subjected to amino acid analysis and determination of molecular weight distribution. Some acidic amino acids and essential amino acids were found, and the average molecular weight distributions were concentrated in <1,400 Da (86.96%). Combined with the results of the amino acid profiles, the peanut peptides were believed to have high nutritive value besides antioxidant activities.     

Antioxidant capacity and antioxidative compounds in barley (<Emphasis Type="Italic">Hordeum</Emphasis><Emphasis Type="Italic">vulgare</Emphasis> L.) grain optimized using response surface methodology in hot air roasting

Response surface methodology was used to predict optimum conditions for hot air roasting of barley grains (temperature, time, and amount). Antioxidant capacity in the grains was highest under optimum conditions of 250 °C, 63.5 min and 42 g (one and a half layers). A correlation of R ² = 0.74 (p < 0.05) was found between 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and total phenolic contents. Ethanol and aqueous extracts were prepared from grains roasted under optimum conditions and assessed for antioxidant capacity. Antioxidative compounds in the extracts were then identified using GC–MS. The IC₅₀ value of ethanol extract was significantly lower (11.45 μg mL^–1) than that of aqueous extract (33.54 μg mL^–1) and α-tocopherol (12.6 μg mL^–1) but higher than BHT (9.59 μg mL^–1). The same trend was observed in linoleic acid assay. In reducing power, the ethanol extract and α-tocopherol were not significantly different. Phenolic acids p-hydroxybenzaldehyde, vallinic and gallic acids were identified as the major compounds in the extracts. The results obtained from this study show that it is possible to optimize antioxidant capacity in barley grains during roasting.     

Effects of eicosapentaenoic acid and docosahexaenoic acid on responses of LPS-stimulated intestinal B lymphocytes from broiler chickens studied in vitro

Effects of different ratios and concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on intestinal B lymphocyte proliferation, IgA secretion and expression of CD5 + CD79a were studied in vitro using cells isolated from broilers. Proliferation was determined by the 3-(4,5- dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay, and those groups with significant difference were selected to detect the IgA using ELISA kit. According to the significant difference of IgA secretion, the expression of CD5 and CD79a was analyzed by fluorescent antibody staining and flow cytometry. The results showed that EPA and DHA inhibited the in vitro proliferation of lipopolysaccharide (LPS)-stimulated B lymphocytes. EPA and DHA significantly suppressed the ability of LPS-stimulated B cells to secrete IgA with ratios of 1:1 at 20 μg/mL and 2:1 at 20 and 40 μg/mL (P < 0.05). In addition, CD5 and CD79a were maximally expressed on LPS-stimulated B cells when the EPA/DHA ratio was 2:1 at 20 μg/mL (P < 0.01), suggesting that the inflammatory reaction may be downregulated by the increasing expression of CD5 and CD79a and inhibitive secretion of IgA by B cell.     

Antioxidant activity of the differentially processed seeds of Jack bean (<Emphasis Type="Italic">Canavalia ensiformis</Emphasis> L. DC)

Antioxidant activity of 70% acetone extracts of raw and processed seeds of Jack bean (Canavalia ensiformis L. DC) was evaluated by various in vitro antioxidant assays, including total antioxidant, free radical scavenging, reducing power, metal ion chelating, β-carotene/linoleic acid bleaching, and antihemolytic activities. The total phenolics and tannin contents were higher in the extract of seeds processed by autoclaving with 1% ash solution (3.2 and 1.6 g/100 g extract, respectively). In general, all the extracts of processed seeds exhibited higher activity in various antioxidant systems, when compared to raw seeds but significant differences were noticed between processing methods. The extract of seeds autoclaved with 1% sugar solution showed higher DPPH radical scavenging activity (IC₅₀ 10.6 mg/mL). Interestingly, the extract of dry heated seeds registered higher inhibition of hemolysis (76.1%) compared to standards butylated hydroxyanisole (BHA) (66.2%) and α-tocopherol (59.3%) at the concentration of 500 μg/mL.     

Antibacterial activity of organic acids in aqueous extracts from pine needles (Pinus massoniana Lamb.)

Pine needle (Pinus massoniana Lamb.) of large quantity in China and health benefit makes its application on pharmaceutical and food industry in high demand. The chemical composition of pine needle aqueous extract (PNAE) analyzed by gas chromatograph-mass spectrometry revealed that among more than 10 compounds in PNAE, organic acids were over 76.92%, with acetic acid being 25.20%, hexadecanoic acid 18.19%, and 2-methoxy-4-vinylphenol 16.44%. Ultra-performance liquid chromatography-mass spectrometry disclosed other 5 short chain organic acids, including citric acid, succinic acid, malonic acid, malic acid, and oxalic acid. The antibacterial activity of PNAE on common spoilages and pathogenic bacteria showed that the growth of Bacillus subtilis, Staphylococcus aureus, Bacillus cereus, Micrococcus luteus, Escherichia coli, and Proteus vulgaris were inhibited significantly, with minimum inhibitory concentrations and minimum bactericidal concentrations being 3.8–15 and 7.5–30 mg/mL, respectively. Our findings suggested that pine needles with effective and safe antibacterial components possess the potential to be developed into efficacious natural antiseptic products for food disinfection and medical purpose.     

In vitro evaluation of the antioxidant activities in the differentially processed seeds from underutilized legume, Bauhinia vahlii Wight & Arn

Antioxidant potential and total phenolics content of 70% acetone extracts of the raw and processed seeds of Bauhinia vahlii were evaluated. The extract of raw seeds contained higher levels of total phenolics (30.8 g/100 g) and tannins (19.6 g/100 g) compared to dry heated and soaking followed by autoclaving seed extracts. Extracts were screened for antioxidant and free radical scavenging activities using various chemical and in vitro model systems. In all the models, except DPPH radical scavenging activity, the extract from raw seeds manifested the strongest antioxidant activity than that from processed seeds. In β-carotene/linoleic acid emulsion system and superoxide scavenging activity, the raw seed extract registered more activity when compared to the standards (butylated hydroxyanisole and α-tocopherol). Whereas, the extract from dry heated seed exhibited higher DPPH^· scavenging activity (IC₅₀ 70.77 μg/mL) than the raw seeds (IC₅₀ 74.4 μg/mL). This study has to some extent validated the antioxidant potential of the seeds of B. vahlii.     

Rapid characterization and identification of fatty acids in margarines using horizontal attenuate total reflectance Fourier transform infrared spectroscopy (HATR-FTIR)

Fourier transform infrared spectroscopy (FTIR) with horizontal attenuated total reflectance (HATR) coupled to multivariate analysis was used to predict chemical composition, fatty acid profile, nutritional relationships between fatty acids, and to identify trans fatty acids (TFA) of margarines. For model building and validation, a set of 42 margarines samples were analyzed in terms of fatty acid profile, total fat, moisture, and salt content. The quantitative models were based on incorporating the above chemical parameters of the different margarines and HATR-FTIR spectral information into the calibration model using chemometric analysis. Chemical parameters for total fat, moisture, and salt content ranged 39–84.5%, 14.5–59%, and 0.3–2.6%, respectively. Regarding fatty acids, the concentration of TFA, saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), and polyunsaturated fatty acid (PUFA) ranged 0–34.06%, 17.17–54.20%, 15.26–34.49%, and 4.02–53.89% (g/100 g margarine), respectively. Principal components regression (PCR) and partial least square analysis (PLS) were used to inspect the variation within the sample set. The best model to predict the chemical composition was obtained using the algorithm partial least squares (PLS) with a R ² greater than 0.933 and SEC and SEP less than 1.294 and 1.406, respectively. The optimized SIMCA model used to identify high or low TFA content showed 100% correct classification rate of both margarines with less than 2.0 g TFA/100 g fat as more than 2.0 g TFA/100 g fat. Compared with traditional chemical analysis, the FTIR-HATR models analyzed margarines in minutes and directly in their neat form.     

Liquid Chromatographic Determination of Resveratrol and Piceid Isomers in Honey

In this work, a liquid chromatography method with diode array and fluorescence detection and electrospray ionization mass spectrometry (LC-DAD-FLD and LC-ESI-MS) has been developed for the determination of residues of resveratrol in all its forms (free isomers and glycosylates) in honey. This procedure involves a solid-phase extraction on polymeric cartridges for the isolation of trans/cis-isomers of resveratrol and piceid from diluted honey samples. Chromatographic separation of the analytes was performed in isocratic mode on a C₁₈ column (150 mm × 4.6 mm i.d., 5 μm) operated at 30 °C. The mobile phase consisted of a mixture of water with 1% formic acid and acetonitrile (75/25, v/v), and the flow rate was set at 1.0 mL/min. Average analyte recoveries were from 71% to 113% in replica sets of fortified honey samples. The detection limits when using LC-DAD-FLD were between 40 and 120 μg/kg, meanwhile for LC-ESI-MS were between 1.4 and 14.6 μg/kg. The proposed method was applied to the analysis of honey samples collected from treated beehives in experimental apiaries after a preliminary field trial, and they were not found any residues over the detection limits of the studied compounds.     

Antioxidant and antibacterial activities of polyphenolic compounds from bitter cumin (Cuminum nigrum L.)

Cumin is one of the commonly used spices in food preparations. It is also used in traditional ayurvedic medicine as a stimulant, carminative and astringent. Earlier we have reported that bitter cumin (Cuminum nigrum L.) possess the most potent antioxidant activity among cumin varieties—cumin, black cumin and bitter cumin. In this study, we have further characterized the polyphenolic compounds of bitter cumin and also their antioxidant and antibacterial activity using different model systems. The major polyphenolic compounds of cumin seeds were extracted with 70% methanol, 70% acetone, water, separated by HPLC and their structures were elucidated by LC-MS. The profile of phenolic acids/flavonols in bitter cumin were found to be gallic acid, protocatechuic acid, caffeic acid, ellagic acid, ferulic acid, quercetin and kaempferol. The antioxidant activity of the cumin extract was tested on 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging, soybean lipoxygenase-dependent lipid peroxidation, rat liver microsomal lipid peroxidation and superoxide anion (O²⁻) scavenging. The bitter cumin extract exhibited high antioxidant activity with IC₅₀ values of 14.0±0.5 μg, 28.0±3.0 μg, 110±14.0 μg and 125.4±8.7 μg of the extract, respectively for DPPH free radical scavenging, soybean lipoxygenase-dependent lipid peroxidation, rat liver microsomal lipid peroxidation and superoxide anion scavenging. Further, the extract offered a significant protection against DNA damage induced by hydroxyl radicals. Among a spectrum of food-borne pathogenic and spoilage bacteria tested, the cumin extract significantly inhibited the growth of Bacillus subtilis, Bacillus cereus and Staphylococcus aureus. Thus, bitter cumin with an array of polyphenolic compounds possesses potent antioxidant and antibacterial activities.An erratum to this article can be found at     

Antihyperglycemic activity of polyphenolic components of black/bitter cumin <Emphasis Type="Italic">Centratherum anthelminticum</Emphasis> (L.) Kuntze seeds

The effect of black/bitter cumin seeds Centratherum anthelminticum (L.) Kuntze extract (CA) containing mixture of polyphenolic compounds was tested on rat intestinal α-glucosidases, human salivary α-amylase activity and postprandial hyperglycemia in rats. Polyphenolic components of C. anthelminticum seeds (CA) dose dependently inhibited rat intestinal disaccharidases. IC₅₀ values were found to be 34.1 ± 3.8, 62.2 ± 4.5 and 500.5 ± 11.9 μg of CA for rat intestinal sucrase, maltase and p-nitrophenyl α-d-glucopyranoside (PNP-glycoside), respectively. CA also inhibited human salivary α-amylase activity with IC₅₀ value of 185.5 ± 4.9 μg. The inhibitory effect of CA was found to be 8–32 fold more potent than dl-catechin but less effective than acarbose on rat intestinal disaccharidases and salivary α-amylase. The enzyme kinetic studies showed a non-competitive type of inhibition with a low K _i value of 30.24 μg, 76.67 μg and 341.60 μg of CA for maltase, sucrase and PNP-glycoside hydrolysis activities, respectively. The in vitro inhibition of glucosidases was further confirmed by in vivo maltose tolerance test in rats. Feeding of CA at 50–200 mg/kg body weight (b.wt) to maltose (2.0 g/kg b.wt), loaded rats significantly reduced the postprandial plasma glucose levels compared with acarbose. The inhibitory components of CA were identified as a mixture of polyphenolic compounds viz., gallic acid, protocatechuic acid, caffeic acid, ellagic acid, ferulic acid, quercetin and kaempferol. This study demonstrated that CA exerts antihyperglycemic effect by decreasing postprandial glucose in rats by modulating α- amylase and glucosidases (sucrase and maltase) activity and thus may be useful for the management of diabetes mellitus.