Corn Protein Research Articles

Wanted and wanting: Antibody against methionine sulfoxide

Methionine residues in protein can be oxidized by reactive oxygen or nitrogen species to generate methionine sulfoxide. This covalent modification has been implicated in processes ranging from normal cell signaling to neurodegenerative diseases. A general method for detecting methionine sulfoxide in proteins would be of great value in studying these processes, but development of a chemical or immunochemical technique has been elusive. Recently, an antiserum raised against an oxidized corn protein, DZS18, was reported to be specific for methionine sulfoxide in proteins (Arch. Biochem. Biophys. 485:35–40; 2009). However, data included in that report indicate that the antiserum is not specific. Utilizing well-characterized native and methionine-oxidized glutamine synthetase and aprotinin, we confirm that the antiserum does not possess specificity for methionine sulfoxide.

Effect of Different Processing on Corn Starch and Protein

Scanning electron microscopy of samples showed that corn flour granules by fermented and wet-milling were angular, pentagonal or elliptical similar to native starches while samples with extruding and cooking were irregularly fibrous and large granules. Protein of samples with wet-milling exhibited an obvious DSC endotherm, To 85.81°C, Tp 92.95°C, Tc 101.73°C and ΔH 1.614J/g.While the fermented and extruded samples had no endotherm. Ultra-violet absorption spectrometry showed that absorbance of fermented and extruded samples increased and the λmax were slightly red shift. The λmax were 294nm, 297nm and 310nm for wet-milling , fermented and extruded flour, respectively. SDS-PAGE patterns of wet-milling flour contained four bands, fermented samples only three bands while extruded samples had same bands with dry-milling.

Reaction of Zein with Methylenediphenyl Diisocyanate in the Melt State: Thermal, Mechanical, and Physical Properties

Corn protein (zein) was melt-processed with methylenediphenyl 4,4′-diisocyanate (MDI) using triethylamine (TEA) as a catalyst to facilitate the reaction of the isocyanate groups with the nucleophilic moieties present on zein. The product of the reaction was examined using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to monitor changes in molecular weight. Techniques used to evaluate property changes after reaction included FTIR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and evaluation of mechanical properties. Our findings demonstrated that zein reacts with MDI in the melt state generating higher molecular weight compounds that after compression molding have improved physical properties and solvent resistance.

Production and functional characterisation of antioxidative hydrolysates from corn protein via enzymatic hydrolysis and ultrafiltration

Corn protein was hydrolysed by three microbial proteases and further separated by sequential ultra-filtration to 12 hydrolysate fractions which were investigated for free radical scavenging capacity and chelating activity. The oxygen radical absorbance capacity (ORAC) of the hydrolysates varied significantly between 65.6 and 191.4μmoles Trolox equivalents (TE)/g dried weight with a small peptide fraction (NP-F3) produced by neutral protease (NP) possessing the highest antioxidant activity. The 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activities of the hydrolysate fractions also varied significantly between 18.4 and 38.7μmoles TE/g. Two fractions (AP-F2 and AP-F3) produced by alkaline protease (AP) showed the strongest activity. However, no significant difference was detected on the chelating activity of the fractions. NP-F3, AP-F2, and AP-F3 were incorporated into ground beef to determine their effects on lipid oxidation during 15-day storage period. NP-F3 was the only fraction that inhibited lipid oxidation at both 250 and 500μg/g levels by as much as 52.9%.

A one‐step approach for esterification of zein with methanol

AbstractZein (corn protein) was reacted with methanol in the presence of para‐toluenesulphonic acid under mild conditions to give a material formed by esterification of predominantly the amide groups of the protein. The formation of methyl zeinate was confirmed by proton NMR. The new signal appeared at 3.67 ppm in zein methylation product, which is absent for pure zein can be assigned to the protons of the CH3 group of an ester. The strong CO stretching vibration due to the presence of ester group in the region of 1739 cm−1 in case of methylated zein was also noticed from FTIR studies. The increase in the C : N atom ratio in the zein methylation product obtained from elemental analysis results further indicates the conversion of a significant proportion of the CONH2 groups in zein to COOCH3 groups in the esterified product. The methylated product had glass transition temperature about 20°C lower than that of the unmodified zein. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

A query for effective mean particle size in dry and high-moisture corns

The objective of this study was to investigate whether prediction of fermentation potential (FP) of dry and high-moisture (HM) corns could be improved by using a concept of effective (e) mean particle size (MPS). A set of FP standards was created by processing a single lot of Reid Yellow Dent (RYD) corn to achieve MPS of 3,778, 2,786, 2,282, 1,808, 1,410, 806, 586, 378, 308, 226, and 105μm. In vitro gas production of RYD standards was measured, and peak absolute rate (PAR) of gas production (mL/0.2g of DM/h) was used to establish a standard relationship between PAR and MPS. To identify factors other than MPS affecting FP, the MPS and nutrient composition of 36 diverse samples of dry (n=18) and HM (n=18) corns were determined. Composition included dry matter (DM), crude protein, soluble crude protein, neutral detergent fiber, starch, NH3-N, prolamin protein, and fat. In vitro gas production of undried, unground dry and HM corns was measured, and PAR, time of peak absolute rate (h), maximum cumulative gas production (mL/0.2g of DM), gas production fractional rate (h−1), and lag (h) were determined. Nonlinear relationships between MPS, defined as the dependent variable, and PAR, as an independent variable, were used to identify FP deviations unexplained by MPS. When no variation in nutritional composition was present (RYD standards), the relationship between PAR and MPS was described by an exponential decay model [RYD_MPS=9,006 × e(−0.452×PAR); R2=0.96]. For diverse dry and HM corn populations, the variation in MPS explained by PAR was diminished (R2=0.50). To investigate factors that diminish the relationship between MPS and PAR in diverse corns, relative residual (rr) MPS was determined [rrMPS = (MPS – RYD_MPS)/MPS], where RYD_MPS was predicted from the PAR of diverse dry and HM corn. The rrMPS was most highly related to prolamin protein [rrMPSdry=0.58 − 0.15 × (prolamin protein, % of DM); R2=0.43] and NH3-N [rrMPSHM=0.21+0.08 × (NH3-N, % of total N); R2=0.46] for dry and HM corns, respectively. An eMPS was calculated as eMPS = MPS – MPS × rrMPS, where rrMPS was predicted from prolamin protein or NH3-N concentration in dry and HM corn, respectively. The natural logarithm of eMPS accounted for 84% of the variability in PAR and 53% of the variability in the fractional rate of gas production. Calculating eMPS by adjusting the MPS of dry corn for prolamin and HM corn for NH3-N concentration improved the assessment of industry corn FP.

Microstructure, degradation and in vitro MG63 cells interactions of a new poly(ε-caprolactone), zein, and hydroxyapatite composite for bone tissue engineering

Novel biodegradable biomaterials were investigated for potential application in bone tissue engineering. The biomaterials were prepared by blending poly(ε-caprolactone) and thermoplastic zein, a corn protein, with or without the incorporation of hydroxyapatite particles. The biomaterials were characterized in vitro to assess the degradation in phosphate buffer saline for 56 days by monitoring weight change, morphology, wettability, and tensile properties. The interaction between the biomaterials and MG63 was evaluated by proliferation, morphological characterization, and osteogenic differentiation assays up to 28 days in in vitro cultures. The incorporation of thermoplastic zein within poly(ε-caprolactone) enhanced the hydrophilicity and degradability, while minor effects were observed after the inclusion of the hydroxyapatite particles. Compared to the neat poly(ε-caprolactone), the multiphase poly(ε-caprolactone)/thermoplastic zein–hydroxyapatite composite improved the osteogenic differentiation of MG63 cells and is being considered a candidate material for bone tissue engineering applications.

Nanoscale Characterization of Zein Self-Assembly

Zein, a major protein of corn, is rich in α-helical structure. It has an amphiphilic character and is capable of self-assembly. Zein can self-assemble into various mesostructures that may find applications in food, agricultural, and biomedical engineering. Understanding the mechanism of zein self-assembly at the nanoscale is important for further development of zein structures. In this work, high-resolution transmission electron microscopy (TEM) images revealed nanosize zein stripes, rings, and discs containing a 0.35 nm periodicity, which is characteristic of β-sheet. TEM images were interpreted in terms of the transformation of original α-helices into β-sheet conformation after evaporation-induced self-assembly (EISA). The presence of β-sheet was also detected by circular dichroism (CD) spectroscopy. Zein β-sheets self-assembled into stripes, which curled into rings. Rings formed discs and eventually spheres. The formation of zein nanostructures was believed to be the result of β-sheet orientation, alignment, and packing.

Correlation between viscoelasticity, microstructure, and molecular properties of zein and pennisetin melts

AbstractCereals are a large source of biopolymers, where mainly the starch is used for food and feed. A rapidly growing cereal application is the production of biofuel, mainly produced from corn in the US. The starch is fermented to ethanol leaving spent grain rich in cereal proteins as a by‐product. The corn protein zein is currently extracted on a large scale and used in, for example, material applications. Similarly, pennisetin can be extracted from pearl millet, a crop critical for food security in sub‐Saharan Africa. The formation of viscoelastic melts is crucial for (bio)plastics production and the viscoelasticity, microstructure, and molecular properties of zein and pennisetin melts were determined here. The proteins were mixed with plasticizers (polyethyleneglycol or glycerol/citric acid) to form melts. The melts displayed a phase separated microstructure with protein‐rich and plasticizer‐rich regions with distinctly separate Tgs. The pennisetin melts formed cross‐links at temperatures above 60°C, which could be related to the high content of cysteine and methionine, as compared to zein. As a consequence, pennisetin melts showed a more thermocomplex behavior than zein melts. For zein melts, the mixture of glycerol and citric acid interacted with protein in addition to being a plasticizer causing a high‐molecular weight shoulder in the molecular weight distribution. The study showed that, although both zein and pennisetin form viscoelastic melts, the choice of plasticizer strongly affects both melt structure and physical properties. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Oil-in-water Pickering emulsions stabilized by colloidal particles from the water-insoluble protein zein

Few fully natural and biocompatible materials are available for the effective particle-stabilization of emulsions since strict requirements, such as insolubility in both fluid phases and intermediate wettability, need to be met. In this paper, we demonstrate the first use of water-insoluble proteins, employing the corn protein zein as a representative of this family, as effective particle-stabilizers of oil-in-water emulsions of natural oils and water. For this purpose, we synthesized zein colloidal particles through an anti-solvent precipitation procedure and demonstrated their use in the formation of stable oil-in-water Pickering emulsions as a function of particle concentration, pH and ionic strength. We confirmed that the wetting properties of zein, studied as a function of pH and ionic strength, strongly favor interfacial particle adsorption with oil-in-water three-phase contact angles θow close to 90°. We found that unmodified zein colloidal particles can produce stable, surfactant-free o/w emulsions with droplet sizes in the range 10–200 μm under experimental mixing conditions (2 min with Ultra Turrax homogenizer at 13500 rpm) at pH above and below the isoelectric point of zein, for low to moderate ionic strengths (1–10 mM). Under conditions where the particle volume fraction is low (<0.2 wt%) or at low pH, the resulting emulsions are not stable against coalescence. At a higher ionic strength, the zein particles have a tendency to aggregate and the resulting emulsions flocculate, forming an emulsion–gel phase.

ULTRAFILTRATION PREPARATION OF POTENT BIOACTIVE CORN PEPTIDE AS ALCOHOL METABOLISM STIMULATORIN VIVOAND STUDY ON ITS MECHANISM OF ACTION

ABSTRACT The aim of this study was to investigate the potential capability of an alcalase-hydrolyzed corn protein and fractions with different molecular mass (Mm) to facilitate alcohol metabolism by activating hepatic alcohol dehydrogenase (ADH). Results showed that corn peptide (CP) fraction with Mm fewer than 1,000 Da (CP < 1,000) exhibited the highest activity to activate ADH in vitro. The fraction administration (200 mg/kg body weight) with Mm fewer than 5,000 Da (CP < 5,000) demonstrated maximum ability to decrease blood alcohol concentration (BAC) in mice. There was a 45.1% reduction in BAC compared with that of the control group. Moreover, there was a strong linear relationship between BAC elimination rate and hepatic ADH activation rate (r = 0.9961). CP's potent capability to facilitate alcohol metabolism could be mainly correlated with the activation of hepatic ADH by hydrophobic CP with low Mm. CP's ·OH scavenging activity may also have synergistic contribution to the oxidative stress release. PRACTICAL APPLICATIONS There is an ever increasing need of an agent that could protect liver from alcoholic liver disease (ALD). Corn peptide (CP) is a potential candidate, which can facilitate alcohol metabolism and prevent ALD. CP was obtained from corn gluten meal (CGM), which was a by-product of corn industry. It will broaden the application and increase the value of CGM. CP, especially those with low molecular mass, has been reported with many bioactive functions, which was isolated with potent hepatic alcohol dehydrogenase (ADH) activating abilities and free radical-scavenging capacities. In general, CP could become a safe and potent alcohol metabolism stimulator and hepatoprotective agent. It could be manufactured in various forms, such as powder, tinctures, tablet, capsule and syrup. The future applications of CP would be mostly as a medicine, supplement or functional foods.

Hypocholesterolemic Activity and Characterization of Protein Hydrolysates from Defatted Corn Protein

Hypocholesterolemic Activity and Characterization of Protein Hydrolysates from Defatted Corn Protein

톤백을 이용한 옥수수 사일리지 조제에 관한 연구

본 시험은 수확시기가 옥수수 톤백 사일리지의 품질에 미치는 영향을 구명하기 위하여 2009년부터 2010년까지 국립축산과학원에서 수행되었다. 옥수수 사일리지 전용 품종인 광평옥을 이용하여 숙기별 3회(유숙기, 황숙기 및 완숙기)에 걸쳐 수확을 하여 사일리지로 조제하였다. 숙기가 진행됨에 따라 옥수수 원형 곤포 사일리지의 조단백질 함량은 감소하는 경향을 보였으나 ADF와 NDF 함량 그리고 TDN 및 in vitro 건물소화율은 비슷하였다. 숙기별 수분함량, pH 및 사료가치는 사일리지 제조 방법 및 젖산균에 의해 영향을 받지 않았다. 유숙기에서 옥수수 톤백 사일리지의 젖산 함량은 원형 곤포 사일리지보다 증가하였으나(P<0.05), 황숙기 및 완숙기에서는 옥수수 톤백 사일리지의 젖산 함량이 원형 곤포 사일리지보다 감소하였다(P<0.05). 유숙기에서 옥수수 톤백 사일리지의 Flieg's score는 원형 곤포 사일리지보다 높았다. 그리고 옥수수 톤백 사일리지와 원형 곤포 사일리지의 Flieg's score는 젖산균에 의해서 영향을 받지 않았다. 따라서 본 연구에서는 옥수수 톤백 사일리지는 새로운 사일리지 제조방법이 될 수 있고 또한 양질의 사일리지 발효에 적합한 것으로 나타났다. This study was conducted to investigate the effect of harvest stage of corn on the quality of gunny bag silage manufactured with corn grown in paddy land of Department of Animal Resources Development, National Institute of Animal Science, RDA from 2009 to 2010. Corn "Kwangpyungok" was harvested at three different growth stages (milk, yellow ripen and ripen stage) and ensiled at each harvest stages. The content of crude protein (CP) of corn in gunny bag silage decreased with delayed harvest maturity, but the contents of ADF (acid detergent fiber), NDF (neutral detergent fiber), TDN (total digestible nutrient) and in vitro dry matter digestibility (IVDMD) were not changed with delayed harvest maturity. The contents of moisture, pH, and the nutritive values at three different harvest stages were not influenced by the method of silage manufacture and inoculant. The content of lactate in corn bag silage at milk stage was significantly increased (P<0.05), as compared with that of round baled corn silage. However, The contents of lactate in corn bag silage at yellow ripen stage and ripen stage were significantly decreased (P<0.05). Flieg's score in corn bag silage manufactured at milk stage increased as compared with that of round baled corn silage, and Flieg's score was hardly influenced by inoculant. Therefore, we suggest that manufacture method of bag silage can be new silage technique to improve the fermentation of corn silage and that smallscale stock farmer could be substituted bag silage for roll bale silage on small farm land.

Defatted Corn Protein Extraction: Optimization by Response Surface Methodology and Functional Properties

Defatted Corn Protein Extraction: Optimization by Response Surface Methodology and Functional Properties

Characterization of the proteins fractions extracted from leaves of Amaranthus dubius (Amaranthus spp.)

Amaranth is an ancient plant belonging to the Amaranthaceae family, which is believed to have originated in Central and South America. The high nutritional quality of the amaranth seed protein is one of the main factors that has attracted the attention of the researchers. However, till date, the protein profile of the leaves of the most researched varieties has not been well studied. Moreover, the nutritional profile of Amaranthus dubius remains unknown. Therefore, it would be interesting to study it. Protein from A. dubius leaves has a high nutritional value due to its balanced amino acid composition. The concentrations of albumins, globulins, prolamins and glutelins are 73.42, 6.60, 6.47 and 6.11%, respectively. It was found that the best agent for extraction of globulins was Na2HPO4 and for glutelins, it was NaOH. The highest amino acid content was found in the albumins fraction and the lowest one in the glutelins fraction. The chemical score of the essential amino acids from proteins of the leaves of A. dubius flour was 92.83%; the flour has only one limiting essential amino acid: Leucine (Leu). The leaves of A. dubius can be used as complement dietary for rice, wheat and corn proteins. Key words: Amaranth, amino acids, protein content, protein fractions.

Production of composites by using gliadin as a bonding material

In previous papers, a new technology that produces biopolymer composites by particle-bonding was introduced. During the manufacturing process, micrometer-scale raw material was coated with a corn ( Zea mays L.) protein, zein, which was then processed to form a rigid material. The coating of raw-material particles with zein makes use of the unique property of this protein in aqueous ethanol solution. In this paper, it is shown that the behavior of a wheat ( Triticum aestivum L.) protein, gliadin, is very similar to zein in aqueous ethanol. Size variation of aggregates in 45–65% aqueous ethanol was investigated with a turbidimeter in conjunction with Size Exclusion Chromatography. Confirming the resemblance of gliadin to zein in terms of aggregation behavior in aqueous alcohol, composites were fabricated by particle-bonding and their mechanical property was measured with a Universal Testing Machine. Test results showed that gliadin is a good substitute for zein in the production of composites.

Food-Based Lure Performance in Three Locations in Puerto Rico: Attractiveness toAnastrepha suspensaandA. Obliqua(Diptera: Tephritidae)

ABSTRACT Lures based on odors released by hydrolyzed protein were assessed for their attractiveness to Anastrepha obliqua and A. suspensa at 3 locations in Puerto Rico in Aug through Oct 2009. Lures compared included ammonium acetate combined with putrescine, hydrolyzed corn protein (Nulure) with borax, freeze-dried Nulure, freeze-dried Nulure in combination with ammonium acetate, freeze-dried Nulure in combination with ammonium acetate and putrescine, and the Unipak lure, a single lure containing ammonium acetate and putrescine. Where the distribution of trapped flies departed significantly from what would be expected given an equal attraction of the baits, Nulure and freeze-dried Nulure always attracted fewer flies than the other baits tested, regardless of species, sex, or location. Although all of the baits or bait combinations containing ammonium acetate attracted more flies than the Nulure or freeze-dried Nulure baits, there was a distinct trend of ammonium acetate and putrescine and the Unipak lure...

Effect of zein on biodegradable inserts for the delivery of tetracycline within periodontal pockets

Treatment with antibiotics within the periodontal pocket against bacterial infections represents a useful and adjunctive tool to conventional therapy for healing and teeth preservation. With this function in view, an implantable, tetracycline delivery device for the treatment of periodontal disease was developed. The aim of this study was to develop biodegradable, tetracycline-loaded microparticles made of two polymers: PLGA and zein which were compressed into monolithic devices. In this polymer delivery system, the encapsulation efficiency, release characteristics, drug-polymer interaction, and antibacterial activity of loaded drug were investigated. The interaction of tetracycline with the corn protein zein was studied by nuclear magnetic resonance (NMR), Fourier transform infrared, and X-ray diffraction. The hydrophobic interaction of tetracycline with zein in the formulations was deduced from the NMR studies, whereas X-ray diffraction studies showed a new crystalline state of the drug in the presence of the protein. Zein was not denatured by preparation of inserts. Sustained release of tetracycline was obtained, and the proportion of zein in the inserts had a great impact on the drug release. Finally, an effective tetracycline release from inserts against Staphylococcus aureus was achieved over 30 days. In conclusion, the PLGA:zein delivery system described in this study was found to be effective in controlled delivery of tetracycline, and hence may be suitable for intra-pocket delivery of antimicrobial agents in the treatment of periodontitis.

소형 사각 곤포기를 이용한 옥수수 사각 압축곤포 사일리지 조제에 관한 연구

본 시험은 수확시기가 옥수수 사각 압축곤포사일리지의 품질에 미치는 영향을 구명하기 위하여 2009년부터 2010년까지 국립축산과학원에서 수행되었다. 옥수수 사일리지 전용 품종인 광평옥을 이용하여 숙기별 3회(유숙기, 황숙기 및 완숙기)에 걸쳐 수확을 하여 사일리지로 조제하였다. 숙기가 진행됨에 따라 옥수수 원형곤포 사일리지의 조단백질 함량은 감소하는 경향을 보였으나(P<0.05) ADF 및 NDF 함량은 차이가 나타나지 않았다. 그리고 TDN 및 in vitro 건물소화율도 비슷하였다. 숙기별 수분함량, pH 및 사료가치는 사일리지 제조 방법 및 젖산균에 의해 영향을 받지 않았다. 유숙기에서 옥수수 사각 압축곤포 사일리지의 젖산 함량은 원형곤포 사일리지보다 현저하게 증가하였으나(P<0.05) 황숙기에서는 현저하게 감소하였다(P<0.05). 숙기별 사각 압축곤포 사일리지의 초산 함량은 원형곤포 사일리지보다 현저하게 감소하였다(P<0.05). 유숙기에서 옥수수 사각 압축곤포 사일리지의 Flieg's score는 원형곤포 사일리지보다 약간 증가하였으나 황숙기와 완숙기에는 비슷한 경향을 나타냈다. 그리고 옥수수 사각 압축곤포 사일리지와 원형곤포 사일리지의 Flieg's score는 젖산균에 의해서 영향을 받지 않았다. 따라서 본 연구에서는 옥수수사각 압축곤포 사일리지는 새로운 사일리지 제조방법이 될 수 있고 또한 양질의 옥수수 사일리지 발효에 적합한 것으로 나타났다. This study was conducted to investigate the effect of harvest stage of corn on the quality of square baled corn silage manufactured with corn grown in paddy land of Department of Animal Resources Development, National Institute of Animal Science, RDA from 2009 to 2010. Corn "Kwangpyungok" was harvested at three different growth stages (milk, yellow ripen and ripen stage) and ensiled at each harvest time. Square baled corn silage was manufactured by use of square silage wrapping compressor. Each treatment was replicated three times. The content of crude protein (CP) of corn in square baled corn silage decreased with delayed maturity, but the content of ADF (acid detergent fiber), NDF (neutral detergent fiber), TDN (total digestible nutrient) and in vitro dry matter digestibility (IVDMD) were not changed. The content of moisture, pH and the nutritive values at three different harvest stages were not influenced by the method of silage manufacture and inoculant. The content of lactate of square baled corn silage harvested in milk stage of corn was significantly increased, as compared with that of round baled corn silage (P<0.05), but in stage of yellow ripen was significantly decreased (P<0.05). The content of acetate in square baled corn silage significantly decreased with delayed harvest maturity, as compared with that of round baled corn silage (P<0.05). Flieg's score of square baled corn silage harvested in milk stage of corn was slightly higher than that of round baled corn silage, but Flieg's scores in yellow ripen stage and ripen stage were not influenced by the method of silage manufacture. Flieg's score with delayed maturity was not influenced by the method of silage manufacture and inoculant. The manufacture of square baled corn silage was proved to be suitable for the fermentation of corn silage. Therefore, this study suggest that square baled corn silage can be a way of new silage manufacture technique.

Wettability, surface microstructure and mechanical properties of films based on phosphorus oxychloride‐treated zein

Zein, the predominant protein in corn, has been extensively studied as an alternative packaging material in edible and biodegradable films. However, films made from 100% zein are brittle under normal conditions. The aim of this investigation was to improve the film-forming properties of zein by chemical phosphorylation. The surface hydrophobicity, surface microstructure and mechanical properties of films based on untreated and phosphorus oxychloride (POCl(3))-treated zein were evaluated and compared. The effect of POCl(3) treatment on the rheological properties of zein solutions was also studied. POCl(3) treatment, especially at pH 7 and 9, led to an increase in the apparent viscosity of zein solutions. Atomic force microscopy (AFM) analysis showed that the film based on POCl(3) -treated zein at pH 7 had a stone-like surface microstructure with a higher roughness (R(q)) than the untreated zein film. The AFM data may partially account for the phenomenon that this film exhibited high surface hydrophobicity (H(0) ). POCl(3) treatment diminished the tensile strength (TS) of zein films from 4.83-6.67 to 1.3-2.29 MPa. However, the elongation at break (EAB) of the films at pH 7 and 9 increased from 3.0-4.5% (control film) to 150.1-122.7% (POCl(3) -treated film), indicating the potential application of zein films in wrapping foods or in non-food industries such as sugar, fruit or troche that need good extension packing materials. The data presented suggest that the properties of zein films could be modulated by chemical phosphorylation treatment with POCl(3) at an appropriate pH value.