Depuration of cadmium from blue mussel (Mytilus edulis) by hydrolysis peptides and chelating metal elements

The present experiment was conducted to investigate the effects of prepared hairtail (Lepidopusc audatus) hydrolysis peptide–metal element (Fe^2 +, Zn^2 +, Ca^2 +, or Mg^2 +) complexes (PH–Fe^2 +, PH–Zn^2 +, PH–Ca^2 +, or PH–Mg^2 +) on the depuration of cadmium (Cd) from blue mussel (Mytilus edulis) tissues. Cd concentrations in anterior adductor muscle, posterior adductor muscle, gill, mantle, and visceral mass of mussels were 11.391, 15.323, 63.672, 19.509, and 109.621 μg/g, respectively, after 5 days of exposure to 0.32 mg/L Cd. Five groups of these exposed mussels were then exposed to seawater laced with four different concentrations of the peptide complexes listed above (5, 10, 15, and 20 mg/L) for 8 days. After 8 days of depuration, 5 mg/L of PH–Fe^2 +, PH–Zn^2 +, and PH–Ca^2 + showed no significant (P > 0.05) effects on Cd concentrations in mussel tissues. However, significant differences (P < 0.05) were observed in groups exposed to 20 mg/L of PH–Fe^2 +, PH–Zn^2 +, and PH–Ca^2 +. The Cd concentrations in anterior adductor muscle, posterior adductor muscle, gill, mantle, and visceral mass were significantly (P < 0.05) decreased by 29.56–35.83%, 27.51–33.62%, 31.59–40.34%, 25.83–31.28%, and 33.62–33.97%, respectively. Nevertheless, the variables of Cd concentrations in tissues treated with 5–20 mg/L PH–Mg^2 + showed no significant (P > 0.05) differences from controls at any point during the experimental period. For these reasons, PH–Fe^2 +, PH–Zn^2 +, and PH–Ca^2 + can be recommended as depuration agents in mussel feed to decrease the Cd concentrations in tissues.     

Purification and some properties of α-amylase from post-harvest Pachyrhizus erosus L. tuber

α-Amylase, a starch splitting enzyme, was purified to homogeneity from post-harvest Pachyrhizus erosus L. tuber by successive chromatography on DEAE- and CM-cellulose columns. Purification achieved was 110 fold from the crude extract with a yield of 22.8%. SDS-PAGE showed a molecular weight of 40 kDa for the enzyme. The enzyme is of α-type as it lost total activity in the presence of EDTA, a chelating agent. It is a glycoprotein that contains 2.6% sugar as estimated by the phenol-sulfuric acid method. The enzyme displayed optimum activity at pH 7.3 and 37 °C with an apparent K_m value of 0.29% for starch as substrate. The enzyme was strongly inhibited by Cu²⁺, Fe²⁺ and Zn²⁺, moderately by Li²⁺, Hg⁺ and Cd²⁺ and slightly by Ag⁺, Mg²⁺ and K⁺. Calcium ion almost doubled the activity whereas Fe³⁺, Mn²⁺ and Na⁺ enhanced it appreciably.     

Production of Citric Acid from Brewery Wastes by Surface Fermentation Using Aspergillus niger

The possible use of spent grain liquor and lager tank sediment as fermentation media for the production of citric acid by various Aspergillus niger strains has been investigated. A strain of A. niger ATCC 9142, on spent grain liquor, gave a citric acid concentration of 19 g/L, representing a yield of 78.5% (w/w) based on total reducing sugars consumed. On lager tank sediment 11.5 g/L citric acid were produced. The yield of citric acid, based on the total reducing sugars consumed, was 57.5% (w/w).     

Optimization of Aspergillus niger Fermentation for the Production of Glucose Oxidase

A number of nutritional factors influencing glucose oxidase (EC 1.1.3.4) production by Aspergillus niger NCIM 545 were studied. The synthesis of glucose oxidase by A. niger was investigated in two steps using submerged fermentation at 30 ± 2 °C and 180 rpm for 96 h. Primarily, nutritional components were selected by one-factor-at-a-time method, and the significance of each component with respect to glucose oxidase production was identified by Plackett–Burman design (seven variables including six nutritional viz. sucrose, sodium nitrate, peptone, calcium carbonate, magnesium sulfate, and potassium dihydrogen phosphate, and one dummy or unassigned variable were studied with eight experiments). In the second step, concentration of most significant factors and their interaction were studied with response surface methodology (central composite design). Each variable in the design was studied at five different levels, with all variables taken at a central coded value of zero. Considerable amount of glucose oxidase was produced from A. niger species with sucrose as the carbon source, sodium nitrate as the inorganic nitrogen source, and peptone as the organic nitrogen source. Glucose oxidase activity increased remarkably by 28.93 fold (from 0.00993 to 0.29 U ml⁻¹) with CaCO₃-supplemented media. The outcome of Plackett–Burman design showed CaCO₃, peptone, and MgSO₄ as significant parameters. Further optimization using a three-factor central composite design with 20 experiments increased yield of glucose oxidase from 0.29 to 2.05 U ml⁻¹ (sevenfold) with a decrease in cultivation time from 96 to 72 h.     

Optimization and Modeling of Process Parameters for Lipase Production by Bacillus brevis

Statistical evaluation of fermentation conditions and nutritional factors by Plackett–Burman two-level factorial design followed by optimization of significant parameters using response surface methodology for lipase production by Bacillus brevis was performed in submerged batch fermentation. Temperature, glucose, and olive oil were found to be the significant factors affecting lipase production. Maximum lipase activity of 5.1 U ml⁻¹ and cell mass of 1.82 g l⁻¹ at 32 h were obtained at the optimized conditions of temperature, 33.7 °C; initial pH, 8; and speed of agitation, 100 rpm, with the medium components: olive oil, 13.73 ml l⁻¹; glucose, 13.98 g l⁻¹; peptone, 2 g l⁻¹; Tween 80, 5 ml l⁻¹; NaCl, 5 g l⁻¹; CH₃COONa, 5 g l⁻¹; KCl, 2 g l⁻¹; CaCl₂·2H₂O, 1 g l⁻¹; MnSO₄·H₂O, 0.5 g l⁻¹; FeSO₄·7H₂O, 0.1 g l⁻¹; and MgSO₄·7H₂O, 0.01 g l⁻¹. The lipase productivity and specific lipase activity were found to be 0.106 U (ml h)⁻¹ and 2.55 U mg⁻¹, respectively. Unstructured kinetic models and artificial neural network models were used to describe the lipase fermentation. The kinetic analysis of the lipase fermentation by B. brevis shows that lipase is a growth-associated product.     

Synthesis of Poly(Methacrylic Acid-)Starch Graft Copolymers Using Mn-IV-Acid System

When starch was treated with KMnO₄ solution, MnO₂ was deposited overall the starch. The amount of MnO₂ deposited relied on the KMnO₄ concentration. Subjecting the MnO₂-containing starch to a solution consisting of monomer (methacrylic acid, MAA) and acid (citric, tartaric, oxalic or sulphuric acid) resulted in formation of poly(MAA)-starch graft copolymer. The magnitude of grafting, expressed as meq. -COOH/100 g starch, was determined by amount of MnO₂ deposited, MAA concentration, temperature and duration of polymerization as well as kind and concentration of the acid. Incorporation of cations such as Fe⁺³, Cu⁺² and Li⁺¹ had a significant effect on grafting. The highest extent and rate of grafting were obtained with citric acid and the least with sulphuric acid; tartaric acid stood in-mid-way position. The magnitude of grafting increased as the acid concentration increased till a certain concentration beyond which grafting levelled off. Similar trend was observed when the magnitude of grafting was related to the amount of MnO₂ deposited. The extent and rate of grafting increased by raising the polymerization temperature from 30° to 50°C then decreased by raising the temperature further from 60° to 70°C. On the other hand, grafting enhanced significantly by addition of Fe⁺³, Cu⁺² or Li⁺¹ and followed the order Fe⁺³ > Cu⁺² > Li⁺¹. A tentative mechanism for grafting of starch with MAA using MnO₂-acid system was elucidated.     

Optimization of Citric Acid Production from a New Strain and Mutant of Aspergillus niger Using Solid State Fermentation

A new strain of Aspergillus niger isolated from soil and its mutant were used for citric acid production from carob under solid-state fermentation conditions. The parental strain produced 30 g/kg citric acid, while the mutant G4, selected after four rounds of gamma ray irradiation, produced 60 g/kg. Maximum citric acid production was obtained after 7 days of incubation, as the acid production was 34 and 64 g/kg for parental and mutant strains, respectively. The addition of 2% methanol increased citric acid production from the parental strain to 42 and the mutant G4 to 65 g/kg. Trace elements, namely Cu, Fe, and Zn, promoted the production of citric acid as the acid production from the parental strain increased to 46 g/kg and for mutant G4 increased to 73 g/kg after their addition. The optimum spore inoculum concentration for acid production was 10⁷ ml^?1, and the optimum pH was 5 for both parental and mutant strains.     

Partial Purification and Characterization of Extracellular Fructofuranosidase with Transfructosylating Activity from <Emphasis Type="Italic">Candida</Emphasis> sp.

The present work was carried out with the aim to investigate some properties of an extracellular fructofuranosidase enzyme, with high transfructosylating activity, from Candida sp. LEB-I3 (Laboratory of Bioprocess Engineering, Unicamp, Brazil). The enzyme was produced through fermentation, and after cell separation from the fermented medium, the enzyme was concentrated by ethanol precipitation and than purified by anion exchange chromatography. The enzyme exhibited both fructofuranosidase (FA) and fructosyltransferase (FTA) activities on a low and high sucrose concentration. With sucrose as the substrate, the data fitted the Michaellis–Menten model for FA, showing rather a substrate inhibitory shape for fructosyltransferase activity. The K _m and v _max values were shown to be 13.4 g L⁻¹ and 21.0 μmol mL⁻¹ min⁻¹ and 25.5 g L⁻¹ and 52.5 μmol mL⁻¹ min⁻¹ for FA and FTA activities, respectively. FTA presented an inhibitory factor K _i of 729.8 g L⁻¹. The optimum conditions for FA activity were found to be pH 3.25–3.5 and temperatures around 69 °C, while for FTA, the optimum condition were 65 °C (±2 °C) and pH 4.00 (±0.25). Both activities were very stable at temperatures below 60 °C, while for FA, the best stability occurred at pH 5.0 and for FTA at pH  4.5–5.0. Despite the strong fructofuranosidase activity, causing hydrolysis of the fructooligosaccharides (FOS), the high transfructosilating activity allows a high FOS production from sucrose (44%).     

Inulinase Production by Agro-Industrial Residues: Optimization of Pretreatment of Substrates and Production Medium

In this work, production of inulinase was studied. Media formulation was optimized by experimental design and response surface techniques, as well as the pretreatment of the agro-industry residues used in the formulation of fermentation medium. Two agro-industry residues were investigated: sugarcane molasses (SCM) and corn steep liquor (CSL). Pretreatment with sulfuric acid was the most effective for clarification of SCM (pH 5.0, 24 h of resting time and final pH 4.0). Clarification of CSL was accomplished with phosphoric acid (pH 3.0, 24 h of resting time and final pH 5.5). A color reduction of approximately 70% was achieved for both substrates. The highest production of inulinase was obtained in a medium containing 100 g l⁻¹ of pretreated SCM, 100 g l⁻¹ of pretreated CSL and 6 g l⁻¹ of Prodex Lac (yeast hydrolysate), yielding 1,139 U ml⁻¹.     

Characterization of purified xylanase from finger millet (<Emphasis Type="Italic">Eleusine coracana-</Emphasis>Indaf 15) malt

Xylanase (E.C. 3.2.1.8) was purified to apparent homogeneity from 96 h finger millet (Eleusine coracana, Indaf-15) malt by a three step purification procedure via ammonium sulphate fractionation, DEAE-cellulose ion exchange and Sephadex G-75 gel permeation chromatographies with a recovery of 4.0% and fold purification of 60. Xylanase, having a molecular weight of 29 ± 2 kDa was found to be monomeric on SDS-PAGE. pH optimum of the enzyme was found to be in the range of 5.0–5.5. The activation energy was 25 kJmol⁻¹. Xylanase showed maximum stability at 35 °C in a pH range of 5.0–6.0. K _m and V _max of purified xylanase were found to be 0.2% and 4.5 μmol min⁻¹, respectively. Metal ions such as Ca²⁺, Mg²⁺, Mn²⁺, Cu²⁺, Fe²⁺, Ag²⁺ and Ni²⁺ enhanced xylanase activity at 5 mM concentration. p-chloromercuribenzoate, citric, oxalic and boric acids inhibited the enzyme in concentration dependent manner. The mode of action of xylanase was found to be “endo” as determined by the analysis of products liberated from larchwood xylan by ESI-MS and H¹NMR. In vitro studies using Bifidobacterium and Lactobacillus sp. confirmed the prebiotic activity of the xylo-oligosaccharides.     

Purification and enzymatic characteristics of a novel polyphenol oxidase from lotus seed (Nelumbo nucifera Gaertn.)

A polyphenol oxidase (PPO) from lotus seed was purified by the procedures including ammonium sulphate precipitation and affinity chromatography. The apparent molecular mass was 38.6 kDa by SDS‐PAGE. Kinetic studies showed that the K_m and V_max values for catechol were 6.04 mm and 416.67 U, respectively. The PPO performed optimal activity in 20 °C and pH 7.0. The enzymatic activity could be mainly maintained up to 50 °C and pH 4.0–7.0. The activity could be inhibited by various inhibitors including thiourea, urea, sodium hydrogen sulphite, EDTA·2Na, SDS, citric acid, guanidine hydrochloride, ascorbic acid, sodium sulphite and sodium thiosulphate. The metal ions Ba²⁺, Mg²⁺, Ca²⁺, Mn²⁺, Co²⁺ and Zn²⁺ could inhibit the activity of PPO, while Cu²⁺ performed obvious enhancement. The enzymatic properties of PPO could probably provide practical application in inhibiting the PPO activity and preventing enzymatic browning in the process of picking, transportation, processing and storage of fresh lotus seeds.     

ITS-RFLP characterization of black <Emphasis Type="Italic">Aspergillus</Emphasis> isolates responsible for ochratoxin A contamination in cocoa beans

In the present study, ochratoxigenic mycobiota in cocoa beans was identified at species level by digestion of the ITS products using the endonucleases HhaI, NlaIII and RsaI. Of the 132 isolates of Aspergillus section Nigri collected from cocoa beans, 89 were identified as A. tubingensis, 27 as A. niger, 10 as A. tubingensis-like and 6 as A. carbonarius. No variation was observed between RFLP patterns (C, N, T1 and T2) described previously for grape isolates and those of the cocoa isolates analysed. With respect to OTA-producing fungi, a high percentage of black aspergilli (50.7%) was able to produce OTA. Additionally, most of the OTA-producing isolates were of moderate toxigenicity, producing amounts of OTA from 10 μg g⁻¹ to 100 μg g⁻¹. Percentages of OTA-producing isolates in the A. niger aggregate were higher than in other substrates, ranging from 30% to 51.7%. Furthermore, the detected levels of OTA production in the A. niger aggregate, particularly in A. tubingensis species was higher than in A. carbonarius, ranging from 0.7 μg g⁻¹ to 120 μg g⁻¹ (mean 24.55 μg g⁻¹). Due to the high occurrence, percentage of ocratoxigenic isolates and their ability to produce OTA, isolates belonging to the A. niger aggregate could be considered as the main cause of OTA contamination in cocoa beans used for manufacturing cocoa products.     

The potential role of isothermal calorimetry in studies of the stability of fresh-cut fruits

Attention is drawn to the feasibility of using high sensitivity isothermal heat conduction calorimetry to study metabolic responses of differently processed and stored fresh-cut fruit. The heat production of endogenous (tissue metabolism during 12 h of analysis at 10 °C for kiwifruit and strawberry) and exogenous (microbial growth during 18 d of analysis at 10 °C for cantaloupe) biological processes was investigated.Osmotic dehydration of fresh kiwifruit in sucrose solution (61.5 g/L) at different treatment times (30, 60 and 180 min), resulted in metabolic heat production decrease, confirming the progressive cell death induced by osmotic dehydration.Analysis on strawberry slices under two atmospheric conditions (air and innovative modified atmosphere) seemed to confirm the inhibitory effect of N₂O on metabolic activity.Cantaloupe samples immersed in three different syrups (SS: sucrose syrup (20 °Brix); SS₁: SS + 0.5 g/L ascorbic acid + 0.5 g/L citric acid; SS₂: SS₁ + 0.1 g/L potassium sorbate) showed a stability increase when additives with antimicrobial properties were included.Our findings confirm that isothermal calorimetry provides a versatile and high sensitive tool for conducting fundamental metabolic studies on the effect of different processing operations on the quality and shelf life of fresh-cut fruit and vegetables.     

Production and Application of Xylanase from Penicillium sp. Utilizing Coffee By-products

The lignocellulosic coffee by-products such as coffee pulp, coffee cherry husk, silver skin, and spent coffee were evaluated for their efficacy as a sole carbon sources for the production of xylanase in solid-state fermentation using Penicillium sp. CFR 303. Among the residues, coffee cherry husk was observed to produce maximum xylanase activity of 9,475 U/g. The process parameters such as moisture (50%), pH (5.0), temperature (30 °C), particle size (1.5 mm), inoculum size (20%), fermentation time (5 days), carbon source (xylose), and nitrogen source (peptone) were optimized and the enzyme activity was in the range of 19,560–20,388 U/g. The enzyme production was further improved to 23,494 U/g with steam as a pre-treatment. The extracellular xylanase from the fungal source was purified to homogeneity from culture supernatant by ammonium sulfate fractionation, DE32-cellulose with a recovery yield of 25.5%. It appeared as a single band on SDS-PAGE gel with a molecular mass of approximately 27 kDa. It had optimum parameters of 50 °C temperature, pH 5.0, K _m 5.6 mg/mL, and V _max 925 μmol mg⁻¹ min⁻¹ with brichwood xylan as a substrate. The crude enzyme hydrolysed lignocellulosic substrate as well as industrial pulp. Production of xylanase utilizing coffee by-products constitutes a renewable resource and is reported for the first time.     

Production of Citric Acid from Beet Molasses by Immobilized Cells of Aspergillus niger

Citric acid was produced from beet molasses by immobilized cells in shake flasks and glass bioreactor. Maximum concentration of citric acid (35 g/L) was observed from immobilized A. niger cells in shake flasks after 28 days fermentation. In repeated batch fermentations, the A. niger cells entrapped in Ca-alginate gel beads retained ability to produce citric acid for up to 84 days.     

Purification and Characterization of a Halotolerant Alkaline Serine Protease from Penicillium citrinum YL-1 Isolated from Traditional Chinese Fish Sauce

A halotolerant alkaline serine protease from Penicillium citrinum YL-1 which was isolated from traditional Chinese fish sauce was purified by ammonium sulfate precipitation, dialysis, and DEAE 52-Cellulose column, thereby resulting in a 4.66-fold increase in specific activity (110.68 U/mg). The molecular weight (MW) was estimated to be 32.27 kDa using SDS-PAGE analysis. The protease exhibited optimal activity toward the substrate casein at pH 8.0 at 40°C and was stable at pH 6.0–8.0 and 4–30°C. Activity was inhibited by NaCl and retained at 28.3, 21.4 and 18.1% of the initial activity after incubation for 6 h at 20, 25 and 30% NaCl concentrations, respectively. The enzyme was stimulated by Mn²⁺ and inhibited by K⁺, Ca²⁺, Zn²⁺, Mg²⁺, Fe²⁺, and Fe³⁺. K_m and V_max of the protease for casein were 1.93 mg/ml and 56.81 μg/(min·ml), respectively. Protease activity was strongly inhibited by phenylmethyl sulfonylfluoride (PMSF), which confirmed the serine protease nature of the enzyme. The protease can hydrolyze tilapia protein in the absence or presence of NaCl (5–30%), thus suggesting that this protease is more halotolerant than the protease from other bacteria with high salinity resistance based on the current literature. These properties make the halotolerant alkaline serine protease a suitable candidate enzyme for fish protein hydrolysis during fish sauce fermentation.     

Isolation and characterization of melanin from Osmanthus fragrans’ seeds

Melanin derived from Osmanthus fragrans’ seeds was isolated from O. fragrans’ seeds by alkaline extraction, acid hydrolysis, and repeated precipitation with a yield of 0.34 g/100 g (wet weight basis). Physical and chemical properties of the melanin revealed that the melanin derived directly from O. fragrans’ seeds were similar to typical melanin. The melanin was stable under ultraviolet light or room-light, stable in the range of 25-100 °C, relatively stable in alkaline solution, reducer and salt, but was bleached by strong oxidants (KMnO₄, K₂Cr₂O₇ and NaOCl). The metal-ion of Ca²⁺, Cu²⁺, Fe³⁺ and Zn²⁺ had the function of color increase or color preservation to the melanin. Although Mg²⁺, Al³⁺ and Na⁺ reduce pigment color, it was not obvious. Amino acid and organic acid did not affect the melanin, while sugar, starch, and glucose affected it slightly.     

Optimization of the Production of Total Carotenoids by Sporidiobolus salmonicolor (CBS 2636) Using Response Surface Technique

This work aimed at evaluating the conditions of growth and the recovery of total carotenoids produced by Sporidiobolus salmonicolor (CBS 2636). Optimization of carotenoid production was achieved by experimental design technique. A Plackett–Burman design was used, followed by a complete second-order design, to optimize the concentration of total carotenoids in a conventional medium. Maximum concentration of 1,019 μg l⁻¹ of total carotenoids was obtained in a medium containing 40 g l⁻¹ glucose, 10 g l⁻¹ malt extract, and 14 g l⁻¹ peptone, at 180 rpm, 25 °C, and initial pH of 4.0. So far, no previous systematic study using microorganisms of the genus Sporobolomyces (formerly Sporidiobolus) for production of carotenoids has been reported. In this study, very good yields of carotenoids (1 mg l⁻¹) could be obtained after optimization of fermentation medium and operation conditions.     

Short communication: Nutrient consumption patterns of Lactobacillus acidophilus KLDS 1.0738 in controlled pH batch fermentations

This work focused on elucidating the nutrient consumption patterns of Lactobacillus acidophilus to guide the design of media for high-cell-density culture. We investigated the nutrient consumption patterns of L. acidophilus KLDS 1.0738 in chemically defined media in controlled pH batch fermentations. The most abundantly consumed amino acids, vitamins, ions, and purines and pyrimidines were Glu and Gly, pyridoxine and nicotinamide, K⁺ and PO₄^3?, and guanine and uracil, respectively. The highest consumption rates for amino acids, vitamins, ions, and purines and pyrimidines were Asp and Arg, folic acid and pyridoxine, Fe²⁺ and Mn²⁺, and uracil and thymine, respectively. Furthermore, most of the amino acids, as well as guanine, thymine, pyridoxine, folic acid, nicotinamide, Mg²⁺, PO₄^3?, and K⁺ had the highest bioavailability from the end of the lag growth phase to the mid-exponential growth phase. The overall consumption of glucose, adenine nucleotides, 2'-deoxyguanosine monohydrate, calcium pantothenate, Fe²⁺ and Mn²⁺ decreased with increasing average growth rate, indicating more effective use of these nutritional components at a higher average growth rate, as biomass yield based on nutritional component consumption increased. Our findings help to formulate complex media for high-cell-density cultivation and provide a theoretical basis for L. acidophilus feeding strategies.     

Antioxidant activity of lignans from fringe tree (Chionanthus virginicus L.)

Fringe tree (Chionanthus virginicus L.), a shrub of the eastern part of America, used as a raw material by pharmaceutical industries for cholagoque, diuretic, tonic and the preparation of homeopathic tinctures. The identification of lignans as major antioxidant components and determination of their antioxidant activities are of considerable interest, because of the role they play in pharmacological actions. The potential antioxidant activity of the lignans such as phillyrin, pinoresinol-β-d-glucoside (PDG) and pinoresinol di-β-d-glucoside (PDDG) from root bark of fringe tree (C. virginicus L.) were examined by different antioxidant tests including; 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH^•) scavenging, superoxide anion radical (O₂ ^•-) scavenging, total antioxidant activity by ferric thiocyanate method, reducing activity by Fe³⁺–Fe²⁺ transformation, hydrogen peroxide (H₂O₂) scavenging and ferrous metal (Fe⁺²) chelating activities. Phillyrin, PDG and PDDG, as antioxidants, neutralized the activities of radicals and inhibited the peroxidation reactions of linoleic acid emulsion. The total antioxidant activity was determined according to the ferric thiocyanate method. Butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and trolox, which is a water-soluble analogue of tocopherol, were used as the reference antioxidant compounds. Phillyrin, PDG and PDDG showed 67.6, 77.3 and 64.2% inhibition on lipid peroxidation of linoleic acid emulsion, respectively, at the concentration of 20 μg/mL. On the other hand, BHA, BHT, α-tocopherol and trolox exhibited 74.4, 71.2, 54.7 and 20.6% inhibition on peroxidation of linoleic acid emulsion, respectively, at the above mentioned concentration. In addition, phillyrin, PDG and PDDG were effective on DPPH^•, ABTS^•+ and O₂ ^•- scavenging, H₂O₂ scavenging, total reducing power and metal chelating effect on ferrous ions activities. Also, BHA, BHT, α-tocopherol and trolox were used as references antioxidants for these various antioxidant activities.