Physical and mechanical properties of oriented strand lumber made from an Asian bamboo (Dendrocalamus asper Backer)

The study was conducted to determine the physical and mechanical properties as follows: modulus of rupture, modulus of elasticity, internal bond, thickness swelling and water absorption of oriented strand lumber (OSL) made from the Asian bamboo Dendrocalamus asper Backer. Thirty-six lab boards were produced from these bamboo strands with two manufacturing parameters varying, i.e., four resin types (MF, MUPF, PF, and pMDI) and three levels of resin content (7, 10, and 13%). The results indicate that OSL made from bamboo strands exhibits superior strength properties compared to the commercial products made from wood for the building sector. The resin type has a?significant effect on board properties. Moreover, all properties of the board improve generally with increasing resin content. With regard to the internal bond, bamboo-based OSL shows less strength than wood-based boards. The best results were obtained by using 13% pMDI content at 750?kg $ / $ m³ density.     

Time-temperature superposition principle on relaxational behavior of wood as a multi-phase material

The time-temperature superposition principle of wood is discussed by modeling the relaxation spectrum of wood and then the application is examined, considered a high order structure and a multi-phase system for wood. The relaxation spectrum of wood was theoretically derived on the several assumptions. After theoretical calculation on the assumptions, in the relaxation time region where wedge-type spectra overlap each other, which is probable for wood, the spectrum of wood is represented by $$lnH = - M_0 (ln\tau - lnA_T ) + M_1 $$ , whereM ₀ andM ₁ are constants related to volume fractions of wood components.A _T is represented by the following equation as a parameter which is the product of a slope (?b and ?c) of a wedge-type spectrum and a volume fraction (φ _B andφ _C) of a wood component related to the relaxation process: $$lnA_T = \phi _B b/ (\phi _B b + \phi _c c) \cdot lna_{Tb} + \phi _C c/ (\phi _B b + \phi _C c) \cdot lna_{Tc} $$ , wherea _Tb anda _Tc are shift factors of wedge-type spectra of wood components. This equation shows that the apparent shift factorA _T consists of shift factors of the relaxation processes of wood components. Consequently, the time-temperature superposition principle does not unconditionally apply for wood, since the temperature dependence of relaxation times is generally different from each other for relaxation processes of wood components. This can explain the experimental result for wood that relaxation curves at various temperatures do not superpose on a relaxation curve at a reference temperature, that is, the principle cannot be applied.     

Moisture movement in wood polypropylene composites

Moisture movement in an extruded wood polypropylene composite was evaluated by exposure to high humidity and immersion of the material in both fresh and seawater. The saturation moisture content was approximately 20 and 19% when exposed to distilled water and seawater, respectively. The moisture diffusion coefficient (D _m) of thin specimens exposed to high humidity was 3.4?×?10^?8?cm² $ / $ s. The D _m of small cubic specimens with extruded surfaces removed submerged in distilled water and seawater were estimated to be 3.1 and 2.3?×?10^?8?cm² $ / $ s, respectively. Use of these diffusion coefficients overestimates the rate of moisture movement in larger extrusion profiles indicating the role of transport phenomenon other than diffusion.     

Properties of oriented strandboard made of wood species from Brazilian planted forests: Part 1: 80 mm-long strands of Pinus taeda L.

This research is part of a general study on the properties of oriented strandboard (OSB) using wood strands of species from Brazilian planted forests. The OSB industry is the latest wood related activity established in Brazil. In this particular part of the study, 80 mm long strands of Pinus taeda L. were bonded using two resin types (urea-formaldehyde and phenol-formaldehyde) at two levels of resin content (5% and 8%) to produce three-layer cross-aligned OSB to a face to core layer ratio of 1:2 and target density of 0.75 g/cm³. Physical and mechanical properties of the boards were evaluated according to ASTM standard D 1037-96a (1997) and the results compared to standards available as requirements for commercial structural panels. The results indicate that all the mechanical properties evaluated were above the requirements set forth by the Canadian standard CSA O437.0 (1993) for structural panels. The results of Janka hardness were in average 4 folds higher than the minimal requirements for Grade R-1 waferboard. Screw withdrawal values were also above the minimum required by grade M-3 of ANSI A208.1 standard (1993). Nevertheless, values of thickness swelling and water absorption were very high. The low dimensional stability may be related to the high density of the boards (“springback” effect) and also to the fact that no wax was used.     

Feuchtebeständigkeit und Hydrolyseresistenz von Holz-zu-Holz-Bindungen in Spanplatten,hergestellt mit formaldehydarmen modifizierten Harnstoff-Formaldehydharzen unter Einsatz verschiedener Härtungsbeschleunigersysteme

In continuation of the work conducted in the first and second part of this series one-layer particleboards (pine wood) were made using three different low-emission UF-resins (UF1, UF2, UF4) and various amounts of different catalysts (ammonium sulfate, ammonium nitrate, a mixture of ammonium sulfate and formic acid). Melamine formaldehyde resin, resorcinol, quebracho-tannin and diphenylmethan diisocyanate (PMDI) were used as modifiers. The investigations led to the following results:

1. The use of ammonium nitrate as a catalyst led, compared with ammonium sulfate and the mixture from ammonium sulfate and formic acid, to higher mechanical properties and lower thickness swelling of the particleboards.
2. Particleboards bonded with resin UF1 modified with melamine formaldehyde resin showed, compared with the other investigated modifications, higher resistance in dry state, in the wet state and after water soaking and redrying of the particleboards. Also thickness swelling of these particleboards was lower.
3. Spraying PMDI prior to UF1 resin (preliminary spray method) improved the physico-mechanical properties of the particleboards (second place in the order of precedence after melamine resin).
4. Particleboards bonded with UF1 modified with resorcinol showed the lowest formaldehyde release, though this modification has a negative effect on the physico-mechanical properties of the boards.
5. Modification of UF1 with quebracho-tannin had an adverse effect on all properties of the particleboards.
6. Modification of the resins UF2 and UF4 during the condensation step of the resin led to similar effects on the properties of the particleboards as the modification by mixing modifier and resin prior to the application of the binder.

     

Zur Isolierung von Hemicellulosen desd-xylantyps aus Laubhölzern

The delignification of beech wood (Fagus sylvatica L.) with aqueous ClO₂-solutions as an alternative to sodium chlorite treatment was studied in relation to the yield ofd-xylan-type hemicelluloses. At a low active chlorine dosase and in a temperature range of 40...60°C a dependence was found between the degree of delignification and the yield of hemicelluloses; it reaches a maximum at 60...80% of lignin removal. A mild alkaline posttreatment of the ClO₂-delignified beech wood allows to obtain 4-O-methyl-d-glucorono-d-xylans with high purity at low yield losses.     

Enhancing the applicability of near infrared spectroscopy for estimating specific gravity of green timber from Eucalyptus tereticornis by developing composite calibration using both radial and tangential face of wood

Specific gravity is a very important factor in determining the economics of wood and wood products. This study is aimed to apply the near infrared spectroscopy technique with integrating sphere and fiber optic probe accessories for fast prediction of specific gravity of green timber (moisture content 27–30 %) of Eucalyptus tereticornis from 10 to 12 year old plantation. Specific gravity (basic density) was determined by conventional method (oven dry wt/green volume) and correlated with near infrared spectra using partial least square (PLS) regression. Calibrations using radial face, tangential face and composite face (both radial and tangential) were developed and compared. Coefficient of determination of cross validation ( $ {\text{r}}_{\text{cv}}^{ 2} $ ) for radial-longitudinal, tangential-longitudinal solid strips samples and composite face (both radial and tangential) was between 0.74–0.77 and 0.64–0.77 using integrating sphere and fiber optic probe, respectively. The coefficient of determination of prediction ( $ {\text{r}}_{\text{p}}^{ 2} $ ) was between 0.73–0.85 (with integrating sphere) and 0.69–0.83 (with fiber optic probe). The ratio of performance deviation (RPD) ranges from 2.06 to 2.46 for all models. Root mean square error of prediction (RMSEP) was higher than root mean square error of cross validation (RMSECV). For composite models with radial and tangential face $ {\text{r}}_{\text{cv}}^{ 2} $ / $ {\text{r}}_{\text{p}}^{ 2} $ was 0.74/0.76 using integrating sphere and 0.71/0.83 with fiber optic probe with Quant 2 automatic factors optimization process. The results indicate that the composite model is just as good as the radial and tangential face models and can adequately address the problem where it is difficult to obtain perfect radial or tangential surface, particularly in small girth plantation timber or where surface recognition is difficult.     

A novel α-l-rhamnosidase with potential applications in citrus juice industry and in winemaking

The production of monoglycosylated flavonoids by α-l-rhamnosidases (EC 3.2.1.40) is an interesting development in biocatalysis. Applications of rhamnosidases in industry include removal of bitterness caused by naringin from citrus juices. In the present work, a psychrotolerant bacterial strain with α-l-rhamnosidase activity was isolated. The α-l-rhamnosidase was found to be able to degrade naringin and was purified and characterized. The α-l-rhamnosidase from Brevundimonas sp. Ci19 was able to release both rhamnose and prunin from naringin. The enzyme was partially purified with a performance of 2.7-fold purification. The α-l-rhamnosidase showed an optimum pH between 6.00 and 7.00 with substantial residual activity at pH 5.00 (85.3 %). The optimum temperature was between 20 and 37 °C. The enzyme showed activation in the presence of Ca²⁺ and Cd²⁺ ions and at a high ethanol concentration level (10 % v/v). Activity was found for β-d-glucosidase (EC 3.2.1.21) in the partially purified extract, but it was inactive in the acid pH region. This result indicates the potential for inactivation of β-d-glucosidase along with the high level of α-l-rhamnosidase activity necessary for the production of flavonoid glycosides. The α-l-rhamnosidase from Brevundimonas sp. Ci19 showed interesting properties for potential use not only in the citrus juice industry but also in winemaking.     

Feuchtebeständigkeit und Hydrolyseresistenz von Holz-zu-Holz-Bindungen in Spanplatten,hergestellt mit formaldehydarmen modifizierten Harnstoff-Formaldehydharzen unter Einsatz verschiedener Härtungsbeschleunigersysteme

Two different UF-resins (UF 1 and UF 2) with significant differences in their viscosity of their 50% solutions (UF 1: 70 mPa·s, UF 2: 46 mPa·s), but almost the same molar ratio F:U (UF 1: 1,11∶1, UF 2: 1,12∶1) and small differences in the content of free formaldehyde (UF 1: 0,07%, UF 2: 0,09%) and water tolerance (UF 1: 1∶0,90, UF 2: 1∶1,18) were modified with a melamine resin (F:M=1,6∶1), resorcinol, tannin and PMDI. The unmodified and modified resins were tested for some of their technological properties before and after curing using different catalyst systems (ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium sulfate/formic acid). The results show:

1. There are no remarkable differences between the gelation time of the unmodified resins, however, the resin with the higher content of free formaldehyde shows higher reactivity especially at high dilution.
2. The thermoanalytical data of the two resins (temperature curing maximum and reaction enthalpy) are more or less the same, when the same hardener is used.
3. The catalyst has a definite influence on the temperature of curing maximum and on the enthalpy of the curing reaction. A big difference in curing temperature was noticed between ammonium chloride, ammonium sulfate and ammonium nitrate on the one side and ammonium sulfate/formic acid on the other side.
4. The unmodified resins show big differences in the formaldehyde release after curing. UF 1 releases more formaldehyde after curing compared to UF 2, as measured by the WKI-flask-method and the Perforator method.
5. Modification of UF-resins with melamine resin, resorcinol, tannin and PMDI decreases the formaldehyde release of the cured resin significantly. The effect of melamine resin and resorcinol are extremly huge.
6. Melamine resin and resorcinol have no negative effect on the shelf life of UF-resins, however, tannin and PMDI do negatively affect the storage stability of the UF-resins.

     

Verklebung von Buchenholz für tragende Holzbauteile

The load bearing capacity of glulam could be enhanced by using lamella of European beech (Fagus sylvatica??L.). Essential requirements for the production of those beams are adhesives which allow for a durable und reliable bonding of lamella. The paper shows to what extent commercially available MUF and PU adhesives and adapted bonding parameters ensure gluing of European beech timber for load-bearing timber structures. Both beech wood containing heartwood and beech wood without heartwood were included in the study. With regard to technical approval, the chosen test methods were resistance to delamination according to EN??302-2 (2002) and shear test of glue line according to EN??392 (1995). From the two tested MUF systems it was evident, that delamination decreased by increasing the closed assembly time. The requirements of EN??301 (2006) were fulfilled for adhesive type??I and??II. Without any limitations beech wood containing heartwood could be glued using MUF-1. On the other hand, the results of the PU adhesive were insufficient. Light-optical micrograph examinations show that long assembly times secure the formation of a glue line. It was assumed that the curing process is retarded by beech wood. No relationship was found between the results of the shear strength test and the delamination test. For quality control of glulam the delamination test is recommended. Based on the positive results an application for technical approval of glulam consisting of beech was made. For this reason beech-glulam can be generally utilized in service class??1.     

Enhanced production of l-tryptophan with glucose feeding and surfactant addition and related metabolic flux redistribution in the recombinant Escherichia coli

The production of l-tryptophan was investigated in a recombinant strain Escherichia coli W3110-ZDrr. It was observed that phosphate and feeding strategies are key factors to ensure the good cell growth and high production of l-tryptophan. The simple exponential feeding strategy could only produce 10.6 g/L l-tryptophan due to the improper feeding rate; while the manual glucose-feedback feeding approach could effectively control the substrate and inhibit the formation of acetate, and thus improvemed the l-tryptophan production to 25.5 g/L. The modified exponential feeding approach avoided overfeeding or underfeeding and achieved high production of l-tryptophan. Moreover, the addition of Tween 60 or PL61 could enhance the cell growth and the production of l-tryptophan in the fed-batch mode. Subsequent metabolic flux analysis showed that more carbon flux was distributed into the biosynthesis of l-tryptophan when Tween 60 or PL61 was supplied. The present work presents one base for further large-scale production of this important amino acid.     

Isolation and structural determination of a novel flavonol triglycoside and 7 compounds from the leaves of oriental raisin tree (Hovenia dulcis) and their antioxidative activity

The hot water and ethanol extracts of oriental raisin tree (Hovenia dulcis Thunb) leaves showed DPPH radical scavenging activities. Antioxidants were purified and isolated from hot water and ethanol extracts by various column chromatographic procedures with the guided assay of DPPH radical scavenging. The structure of a novel flavonol triglycoside was determined to kaempferol 3-O-α-l-rhamnopyranoside-7-O-[α-d-glucopyranosyl(1→3)-α-l-rhamnopyranoside] (4). In addition, 7 known compounds were identified as caffeine (1), kaempferol 3,7-O-α-l-dirhamnopyranoside (2), kaempferol 3-O-α-l-rhamnopyranosyl( 1→6)-O-β-d-glucopyranosyl(1→2)-O-β-d-glucopyranoside (3), E-3-carboxy-2-petenedioate 5-methyl ester (5), quercetin 3-O-α-l-rhamnopyranoside (6), kaempferol 3-O-α-l-rhamnopyranoside (7), and quercetin 3-O-β-d-glucopyranoside (8). Compound 1–3 and 5–8 were newly identified in this plant. Quercetin glycosides (5, 7) showed higher DPPH radical scavenging activity than other compounds.     

Application of Mid- and Near-Infrared Spectroscopy for the Control and Chemical Evaluation of Brine Solutions and Traditional Sea Salts

Mid- and near-infrared spectroscopy methodologies were explored for the analysis of brine solutions and traditional sea salt samples. Brine solutions from different salt pans, corresponding to different stages of sodium chloride crystallisation, were collected. A total of 61 dried and non-dried traditional sea salts were also analysed. Partial least squares regression with leave-one-out cross-validation strategy was applied for the calibration of inorganic constituents Ca²⁺, Mg²⁺ and K⁺, alkalinity as HCO ₃ ^? , SO ₄ ^2? , NO ₂ ^? and NO ₃ ^? and phosphate in brine solutions. Promising results were obtained with the near-infrared (NIR) methodology for brine solutions with coefficients of determination R ²?>?0.90 for Mg⁺², K⁺, HCO ₃ ^? and SO ₄ ^2? . Using mid-infrared, the calibration for H₂PO ₄ ^? was R ²?=?0.85. In relation to the sea salt samples, the strategy adopted was the re-sampling based cross-validation using different spectral pre-processing treatments. In this case, the calibrations using the two IR methodologies fell bellow acceptable levels for the techniques; however, by comparing the R ² coefficient, the results were slightly better when using the NIR spectra of dried sea samples. In general, these results open a new possibility for the IR applications and also bring an opportunity for continuing with the NIR characterization for dried sea salt samples.     

Comparative study on the effects of d-psicose and d-fructose in the Maillard reaction with β-lactoglobulin

d-Psicose, recognized as a noncaloric sweetener, has shown a great potential in food industry. In the present study, d-psicose and d-fructose were used to modify bovine β-lactoglobulin (β-Lg) through Maillard reaction. The Maillard reaction process and the physicochemical and structural properties of the modified proteins were also investigated. The result showed that compared to d-fructose, d-psicose played a more effective role in the Maillard reaction, especially after the initial stage of the reaction. Moreover, the modified β-Lg with d-psicose had more polymeric compounds, higher antioxidant activity, but lower thermal stability than that with d-fructose. These findings, especially the structural changes of the modified proteins, supplied detail information on the Maillard reaction of d-psicose, and could provide some guidance to the practical applications of this rare sugar on food industry.     

Influence of buffer and l-phenylalanine concentration in the Rhizomucor miehei lipase catalysed synthesis of l-phenylalanyl-d-glucose ester investigated through response surface methodology

Reaction conditions for Rhizomucor miehei lipase (RML) catalysed synthesis of l-phenylalanyl-d-glucose using unprotected l-phenylalanine and d-glucose were optimized using response surface methodology (RSM). A central composite rotatable design (CCRD) was employed involving 32 experiments of five variables (l-phenylalanine concentration in mmol, amount of RML in mg, pH, incubation period in h and buffer concentration in mM) at five levels. A second-order polynomial equation was developed in terms of linear, quadratic and cross product terms to study the effects of variables on esterification yields. A R ² value of 0.7 was obtained for this complex reaction. From the surface and contour plots it was found that higher yields were observed for a very narrow pH range of 4.5–6.5 at l-phenylalanine concentrations above 3 mmol. The extent of esterification decreased with increase in RML concentration for incubation periods below 60 h. However, longer incubation periods above 60 h, enhanced esterification at all RML concentrations. Lower conversions below 0.5 mmol required less than 3.5 mmol l-phenylalanine concentration and a broad range of buffer concentration from 0.1 mM (0.1 ml, 0.1 M buffer of pH 6.0) to 0.5 mM (0.5 ml, 0.1 M buffer of pH 6.0). However, higher conversions from 0.6 to 0.8 mmol required a buffer concentration above 0.25 mM (0.25 ml, 0.1 M buffer of pH 6.0) at l-phenylalanine concentrations above 3.5 mmol. An optimum predicted yield of 1.01 mmol for l-phenylalanyl-d-glucose at 3 mmol l-phenylalanine, 100 mg of RML, 24 h incubation period, 0.5 mM (0.5 ml of 0.1 M buffer), pH 4.8 acetate buffer was found to agree with 0.97 mmol obtained under these experimental conditions. Validation experiments carried out under random conditions also exhibited good correspondence between predicted and experimental yields.     

Microwave treatment of dietary gelatin does not generate cis-4-hydroxy-l-proline, an inhibitor of collagen biosynthesis

Aqueous solutions (5?g/100?ml) of commercial preparations of (a) an enzymatic partial hydrolysate of gelatin and (b) type A gelatin were subjected to threefold heating to boiling in a domestic microwave oven at 750?W and to conventional heating. Then samples were totally hydrolyzed (6?M hydrochloric acid, 110??°C, 24?h) and investigated for the presence of eight possible stereoisomers of 3- and 4-hydroxyproline (Hyp) using capillary gas chromatography. Amino acids were analyzed as N(O)-trifluoroacetyl 2-propyl esters on Chirasil-l-Val and detected by selected ion monitoring mass spectrometry. Blanks of (a) and (b) were analyzed in parallel. Relative amounts of 5.0±0.2% cis-4-d-Hyp were generated from native trans-4-l-Hyp as a result of total hydrolysis in all samples and independent of previous treatment. Notably, neither cis-3-l-Hyp nor cis-4-l-Hyp could be detected in either of the gelatin samples. Thus a report on the generation of antifibrotic and therefore potentially hazardous cis-3-l-Hyp and cis-4-l-Hyp from protein-bonded native trans-3-l-Hyp and trans-4-l-Hyp on microwave heating of infant formulae could not be confirmed.     

Electron Spin Resonance Analysis of Radiation-Induced Free Radicals in Shells and Membranes of Different Poultry Eggs

Radiation-induced free radicals were investigated in the shells and membranes of ostrich, duck, hen, and quail eggs using electron spin resonance (ESR) spectroscopy. The non-irradiated egg shells and membranes showed a single resonance signal centered at g?=?2.0048?±?0.0001 and 2.0072?±?0.0002, respectively. Upon irradiation (1–3 kGy), a dose-dependent asymmetric ESR signal centered at g?=?1.9998?±?0.0002 was also determined in all eggshell samples, whereas the membranes were found silent for radiation-specific ESR signals. An X-ray diffraction spectrometric study showed the abundance of calcite minerals in the all egg shells. Radiation-induced and trapped CO ₃ ^3? , CO ₃ ^? , and CO ₂ ^? paramagnetic entities in the calcite matrix of egg shells might be responsible for a typical ESR signal. The ESR-based identification of all irradiated eggshells was easily possible in practical dose range (1–3 kGy).     

Evaluation of daily intake of PCDD/Fs and indicator PCBs in formula-fed Spanish children

Human exposure to polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) occurs predominantly via food intake. In this study, the exposure assessment of these contaminants has been estimated for infant formula-fed children up to 1 year of age. PCDD/F concentrations in the infant formulae was low, ranging between 0.09 and 0.17 pg WHO-TEQ g^?1 fat and between 0.30 and 0.46 pg WHO-TEQ g^?1 fat when results were calculated with the lower and medium bound values, respectively. Indicator PCB contamination levels were below 1 ng g^?1 fat in all cases. Thus, the estimated daily intake of PCDD/Fs and indicator PCBs for infants has been assessed taking into account the above-mentioned contamination levels as well as different scenarios of body weight and food consumption data for babies aged 0–12 months. The results vary in the different scenarios considered but, on the whole, the daily estimated dioxin and indicator PCBs intake of the average infant population due to the consumption of infant formulae does not exceed the tolerable daily intake (TDI) of 2 pg WHO-TEQ kg^?1 bw day^?1 recommended by the Scientific Committee on Food (available at http://ec.europa.eu/food/fs/sc/scf/out90_en.pdf) nor the threshold value of 10 ng kg^?1 bw day^?1 proposed by the Dutch National Institute of Health and Environment (RIVM) (Baars et al. 2001 Baars, AJ, Theelen, RMC, Janssen, PJCM, Hesse, JM, Van Apeldoorn, ME, Meijerink, MCM, Verdam, L and Zeilmaker, MJ. 2001. Re-evaluation of human toxicological maximum permissible risk levels. Report no. 711701025, Bilthoven, , The Netherlands: National Institute of Public Health and the Environment (RIVM).  [Google Scholar]. Report no. 711701025, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands).     

Effect of l-lysine on the physicochemical properties of pork sausage

Effects of l-lysine on physicochemical properties of pork sausage were investigated. WHC values significantly increased using 0.8% l-lysine, but significantly decreased at 0.4% l-lysine (p<0.05), compared with controls. l-Lysine increased pH values and a* values, but significantly decreased CL, cohesiveness, L* values, and b* values (p<0.05), compared with controls. Addition of 0.4% l-lysine significantly (p<0.05) increased hardness, springiness, and chewiness values, compared with controls. SEM analysis showed that addition of 0.8% l-lysine induced formation of a smoother, more compact, and more uniform gel matrix, compared with controls. DSC analysis indicated that addition of 0.8% l-lysine significantly (p<0.05) increased thermal transition temperatures and enthalphy values, compared with controls, showing that interactions between l-lysine and myofibrillar proteins affected the properties of pork sausages.     

Purification and identification of novel antioxidative peptide released from Black-bone silky fowl (Gallus gallus domesticus Brisson)

Papain-treated Black-bone silky fowl (BSF) muscle hydrolysate was subjected to 6 kDa cutoff membrane ultrafiltration, and the resulting BSF peptides (<6 kDa) were purified by two-step reverse-phase high-performance liquid chromatography. The molecular weight (MW) distribution and amino acid composition were investigated for characterization of the BSF peptides. The results showed that the major amino acids of BSF peptides were Glu, Tyr, Lys, Asp, Leu, Ala, Thr and Pro, and the MW was from 281 to 7,982 Da. BSF peptides exhibited a strong antioxidant capacity. At 10 mg/mL, they displayed more powerful $ {\text{O}}_{2}^{ \cdot - } $ , DPPH^· and ABTS^·+ scavenging activity and reducing power than carnosine. The peptide fraction 8 with more hydrophilicity revealed stronger $ {\text{O}}_{2}^{ \cdot - } $ and ABTS^·+ scavenging activity and reducing power than BSF peptides and carnosine. Besides, a peptide, separated from fraction 8 and showed the strongest antioxidant capacity, was purified and identified by LC-ESI-MS/MS to be Glu-Pro-Asp-Arg-Tyr (678 Da).