Unmodified Corn Starch Research Articles

Effect of rosin based quaternary ammonium salt on mechanical, hydrophily, antibacterial of cornstarch/polydopamine film for food packaging

Food packaging made of biobased materials is environmentally friendly, among which starch film is a type of biobased packaging with great development value. Some existing studies have attempted to add polydopamine (PDA) to enhance cross-linking, but there are still problems such as weakness and hydrophilicity, which greatly limit its application. Therefore, this study synthesized rosin based quaternary ammonium salt-modified cornstarch (ST-B), which was used to replace part of unmodified cornstarch (ST). In the prepared ST/PDA0.5/ST-B5 film, the introduction of a rigid rosin structure increased the stress and water contact angle of the ST/PDA0.5 film by 62 % and 26 %, respectively, while reducing its wettability and WVP; thus, further enhancing its antioxidant activity. Due to the antibacterial ability of rosin quaternary ammonium cations, the packaging film containing 7 wt% ST-B can kill >94.6 % of S. aureus and 99.9 % of E. coli, and can also extend the shelf life of strawberries. In addition, it is proven that the packaging film has good biocompatibility and high safety within cytotoxicity tests and 30-day gavage tests in mice. Therefore, the prepared ST/PDA/ST-B film has more potential for application in food preservation.

Improving the thermal stability and branching efficiency of Pyrococcus horikoshii OT3 glycogen branching enzyme

In practical applications, the gelatinisation temperature of starch is high. Most current glycogen branching enzymes (GBEs, EC 2.4.1.18) exhibit optimum activity at moderate or low temperatures and quickly lose their activity at higher temperatures, limiting the application of GBEs in starch modification. Therefore, we used the PROSS strategy combined with PDBePISA analysis of the dimer interface to further improve the heat resistance of hyperthermophilic bacteria Pyrococcus horikoshii OT3 GBE. The results showed that the melting temperature of mutant T508K increased by 3.1 °C compared to wild-type (WT), and the optimum reaction temperature increased by 10 °C for all mutants except V140I. WT almost completely lost its activity after incubation at 95 °C for 60 h, while all of the combined mutants maintained >40 % of their residual activity. Further, the content of the α-1,6 glycosidic bond of corn starch modified by H415W and V140I/H415W was approximately 2.68-fold and 1.92-fold higher than that of unmodified corn starch and corn starch modified by WT, respectively. Additionally, the glucan chains of DP < 13 were significantly increased in mutant modified corn starch. This method has potential for improving the thermal stability of GBE, which can be applied in starch branching in the food industry.

Effects of dual modification of lysine and microwave on corn starch: In vitro digestibility and physicochemical properties

The effects of lysine addition and microwave treatment (MC) on the digestibility, physicochemical properties and structure of corn starch were investigated. Among all uncooked samples, unmodified corn starch (CS), microwave modified corn starch (MC-CS) and corn starch mixed with lysine (CS-Lys) contained 15.09 %, 14.82 % and 18.86 % slowly digestible starch (SDS), while up to 30.28 % in microwave-lysine modified corn starch (MC-Lys). In contrast to CS, the peak viscosity, breakdown viscosity, setback viscosity and gel enthalpy of MC-Lys were decreased, while the relative crystallinity was increased. Scanning electron microscopy observation showed that corn starch aggregated with each other and was coated by lysine after MC, the particle size distribution range became wider, and the specific surface area decreased. The results showed that the interaction of starch with lysine in the microwave field increased the ordered and aggregated structure of corn starch, resulting in a significant change in the physicochemical properties and digestibility of corn starch. MC-Lys can be added to foods as a nutritional fortification to meet the needs of specific populations for lysine and low carbohydrate.

Biodegradable foams based on extracted fractions from sorghum by-products

Agricultural by-products comprise abundant, renewable sources of value-added compounds for the food and packaging industries. The production of biodegradable foams can be focused on replacement of polystyrene-foam with biodegradable materials, which are regarded as environmentally friendly. In this study, biodegradable food trays were developed via thermopressing, using modified and unmodified corn starches with additional extracted fractions (celluloses, hemicelluloses, and lignin) from sorghum stalk and bran. The effect of several formulations of extracted fractions from sorghum by-products on bio-foam properties was studied. All trays presented thicknesses between 3 and 4.17 mm, density between 0.16 and 0.64 g cm−3, and moisture content between 5 and 12% (dry basis). The foam trays made from chemically modified starch had lower densities, higher tensile strength and elongation at break than unmodified starch. The increment of cellulose fraction from 2% to 5% and hemicellulose fraction from 1% to 10% had significant effect on the trays’ physical and mechanical properties. All trays exhibited no color and structural changes during storage at 25 °C and 4 °C. The formulation presenting the best properties contained 2% of cellulose and 1% of hemicellulose, had a maximal resistance of 0.77 MPa and 9.46 mJ of total work, attributes which corresponded to a compact, homogenous, and dense microstructure.

Coaggregation of mineral filler particles and starch granules as a basis for improving filler-fiber interaction in paper production

The sustainable, efficient use of renewable bio-based additives in the production of various materials fits well into the concept of sustainability. Here, the concept of coaggregation of mineral filler particles and starch granules for improving filler-fiber interaction in paper-based cellulosic networks is presented. Coaggregation of precipitated calcium carbonate filler particles and uncooked, unmodified corn starch granules by cationic polyacrylamide (a cationic high molecular weight polymer flocculant) in combination with bentonite (an anionic microparticle) prior to addition to cellulosic fiber slurry delivered enhanced filler bondability with cellulosic fibers. For instance, under the conditions studied, preaggregation resulted in an increase in filler bondability factor from 9.24 to 15.21 at starch dosage of 1% (on the basis of the dry weight of papermaking stock). The swelling and gelatinization of the starch granules in starch-filler preaggregates or hybrids enabled the “bridging” of the gaps in cellulosic networks, leading to structural consolidation and strength enhancement.

Robust and biodegradable elastomers based on corn starch and polydimethylsiloxane (PDMS).

Designing starch-based biopolymers and biodegradable composites with durable mechanical properties and good resistance to water is still a challenging task. Although thermoplastic (destructured) starch has emerged as an alternative to petroleum-based polymers, its poor dimensional stability under humid and dry conditions extensively hinders its use as the biopolymer of choice in many applications. Unmodified starch granules, on the other hand, suffer from incompatibility, poor dispersion, and phase separation issues when compounded into other thermoplastics above a concentration level of 5%. Herein, we present a facile biodegradable elastomer preparation method by incorporating large amounts of unmodified corn starch, exceeding 80% by volume, in acetoxy-polyorganosiloxane thermosets to produce mechanically robust, hydrophobic bioelastomers. The naturally adsorbed moisture on the surface of starch enables autocatalytic rapid hydrolysis of polyorganosiloxane to form Si-O-Si networks. Depending on the amount of starch granules, the mechanical properties of the bioelastomers can be easily tuned with high elastic recovery rates. Moreover, starch granules considerably lowered the surface friction coefficient of the polyorganosiloxane network. Stress relaxation measurements indicated that the bioelastomers have strain energy dissipation factors that are lower than those of conventional rubbers, rendering them as promising green substitutes for plastic mechanical energy dampeners. Corn starch granules also have excellent compatibility with addition-cured polysiloxane chemistry that is used extensively in microfabrication. Regardless of the starch concentration, all of the developed bioelastomers have hydrophobic surfaces with lower friction coefficients and much less water uptake capacity than those of thermoplastic starch. The bioelastomers are biocompatible and are estimated to biodegrade in Mediterranean seawater within three to six years.

Analysis of the Structural and Mechanical Properties and Micromorphological Features of Polymeric Films Based on Hydrocolloids of Vegetable Origin Used for the Production of Biodegradable Polymers

Modern research and technology approaches to the production of biodegradable polymeric materials based on renewable resources have been reviewed. It has been found that films prepared of cellulose, chitosan, gelatin, polypeptides, casein, soy, wheat, corn, rice, and maize are being commonly used at present. The structural and mechanical properties and micromorphological features of hydrocolloids of vegetable origin promising for the production of biodegradable polymers—starches, pectins, carrageenans, and agar—have been studied. It has been determined that, with respect to strength and suitability for use in films of individual components, all the studied hydrocolloids can be arranged in ascending order as follows: starches, carrageenans, pectins, agar. According to analysis of the structural and mechanical properties of the films, it has been shown that the best parameters are found for the samples based on pectin P1 and agar A2. The breaking stress for these materials is 52 and 77 MPa, respectively. The breaking strain is 11.5 and 8.0%, respectively. Analysis of the micromorphology has revealed the formation of surface microdiscontinuities in the films based on high methoxyl pectins P1 and P4 and unmodified corn starch S3 and the formation of wavy folds in the case of the films of kappa-carrageenan C1; these folds are formed during drying and decrease the tensile strength of the respective films. The found features will be used in the development of technologies for the production of biodegradable polymeric materials based on hydrocolloids of vegetable origin with enhanced performance and processing characteristics.

SINTESIS PATI JAGUNG TERFOSFORILASI MELALUI TEKNIK GELOMBANG MIKRO

SINTESIS PATI JAGUNG TERFOSFORILASI MELALUI TEKNIK GELOMBANG MIKRO [Microwave-Assisted Synthesis of Phosphorylated Corn Starch ] Atep Dian Supardan*, Suminar Setiati Achmadi dan Tun Tedja Irawadi Departemen Kimia, Fakultas Matematika dan Ilmu Pengetahuan Alam, Institut Pertanian Bogor, Bogor Diterima 28 Maret 2013 / Disetujui 24 Februari 2014 ABSTRACT Phosphorylated starch is a type of modified starches which is most ly imported. Commonly, starch to be modified must contain more than 25% of amylose. This study aimed to synthesize phosphorylated starch and evaluate its potency as a heavy metal adsorbent. Corn starch was subjected to phosphorylation through microwave-assisted reaction with a mixture of sodium dihydrogen orthophosphate and disodium hydrogen phosphate. The experiment was designed to optimize the pH, microwave radiation power, and phosphorylation time. The results showed that the maximum phosphate subtitution degree was obtained at pH of 6, microwave radiation of 500 W, and a reaction time of 10 minutes. The degree of subtitution ranged from 0.567 to 0.787. The physicochemical properties of the product i.e. swelling capacity, solubility, water binding capacity, and paste clarity were significantl y different than that of the unmodified corn starch. The infrared spectrum showed a high peak absorption at the wavelength of 1651 cm -1 , indicating hydrogen bond formation of phosphoric group-water- phosphoric group. In the fingerprint area, there were two new absorption peaks at 12 00 and 99 0 cm -1 , which were assigned for the P = O and C-O-P vibrations, respectively. The phosphorylated corn starch adsorbed methylene blue up to 73.3% and mercury up to 73.6%, suggesting the prospect of the microwave - assisted synthetic phosphorylated corn starch as an effective adsorbent for heavy metals.

Characteristics of Starch Paste for Conservation of Paper Properties (Part 1) - The Nature and Adhesive Strength of Starch Paste -

This study was carried out to investigate the characteristics of starch paste which was used for the conservation of paper properties. Three kinds of commercial corn starch and five kinds of fermented wheat starch were examined on the contents of amylose and amylopectin, shapes of particles, and viscosity and pH of paste. And adhesive strength on the drying, accelerated aging, and wetting treatments were measured. The contents of amylopectin of oxidized corn starch were higher those of cationic corn starch, unmodified corn starch, and fermented wheat flour. In case of fermented wheat flour, increasing of a fermentation period was resulted in increasing of amylopectin contents. The particle shapes of commercial corn starch showed with a uniform polygon, but fermented wheat flour showed with a mixture of small and large oval types. The viscosity of oxidized corn starch were very lower those of cationic corn starch and unmodified corn starch. And increasing of a fermentation period of wheat flour was resulted in increasing of viscosity. The pH of commercial corn starch were 3.6-7.5 and fermented wheat flour were 3.6-5.2. Through the examination on the nature and adhesive strength of starch paste, the oxidized corn starch 60 cps which is the name of products and wheat flour which had fermented for 5 years were considered that most suitable for conservation of paper properties.

Structure and physical properties of EVA/starch precursor materials for foaming applications

AbstractThe use of biodegradable materials to develop polymeric blends visioning distinct applications is desirable and nowadays is an important research field. In this work, blends of an ethylene‐vinyl acetate copolymer (EVA) and 30, 50, and 70% in weight of an unmodified corn starch have been successfully fabricated. The structure of these blends have been characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). It was found that the original starch particles are kept in the blends forming a separate phase from EVA. The FTIR confirmed that EVA and starch comprise a physical mixture in the blends. Besides, the blends were found very homogenous and mainly amorphous with the EVA melting temperature being independent of the starch content. The melt flow index (MFI) decreased for higher contents of starch, revealing that starch acts as a filler in the blends. Physical properties such as density, hardness, and thermal conductivity were found to increase with the content of starch in the blends. Considering one of the goals of this research, which is producing foams using these blends as precursor materials, the structural and physical characteristics determined here are very satisfactory and open good perspectives in this sense. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Starch–cassia gum interactions: A microstructure – Rheology study

We present for the first time the interactions of starch and cassia gum – a novel galactomannan recently approved for use in food processing. Viscoelastic, pasting and microstructural characterization of various starches (waxy; high amylose; normal; cross-linked waxy corn starch; potato starch) containing different levels of the cassia gum was carried out. Significant changes were observed in the morphology of granule remnants formed during gelatinization in the starch pastes prepared with and without the addition of cassia gum. The freeze-dried starch–cassia gum pastes presented a shrunken and tight arrangement of the starch granule remnants, when studied by scanning electron microscopy. A significant reduction in the granule remnant size was also calculated using laser diffraction particle size analysis. The extent of interaction with cassia gum differed significantly among the various starch types. All the unmodified corn starches recorded an increase in peak viscosity at all levels of the cassia gum addition. An increase in the final viscosity of these starches was also observed by the addition of cassia gum, with high amylose and normal corn starch showing the maximum. Similarly, the extent of breakdown and setback viscosity also differed among the different starch types. Ranges of dynamic rheological measurements (temperature, time and frequency sweeps) were performed within the viscoelastic zones. Rheological parameters, such as storage modulus ( G′), loss modulus ( G″) and the gelatinization temperature ( T gel), of the corn starches during the heating cycle were observed to increase, when cassia gum was present at lower levels. The starch–gum systems also exhibited higher tan δ values during both the heating and the cooling cycles, indicating the dominance of the viscous modulus. The G′ and G″ of all the corn starch gels containing cassia gum showed higher values throughout the frequency sweep range. However, the increase in G′ and G″ of different starches was not always consistent with the increase in cassia gum levels. The changes in rheological behaviour during storage of the starch gels, aged on the plate of the rheometer and then studied through time sweeps at 5 °C and frequency sweeps at 25 °C, suggested that the starch gels containing cassia gum had less pronounced changes in the rheological parameters than had their control counterparts.

Improvement of paper strength with starch modified clay

AbstractIn order to improve the strength properties of high filler filled papers, a new technique of coating starch on the clay surface was developed. The stability of the coated starch and its effects on paper properties were studied. It was found that the starch coated on the clay surface swelled in water. This swelled starch film on the filler surface contributes significantly to the filler–filler bonding. The strength properties of handsheets made from starch coated clay, even with unmodified corn starch, could be increased by more than 15% versus those from the traditional method of adding cationic or amphoteric potato starch directly to 50% bleached softwood pulp/50% bleached hardwood pulp. This research suggests that the starch coated filler can be used to make high filler content paper products. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 44–50, 2005

Preparation and properties of biodegradable poly(propylene carbonate)/starch composites

AbstractBiodegradable composites of poly(propylene carbonate) (PPC) reinforced with unmodified cornstarch were compounded in a batch mixer followed by compression molding. The effects of reinforcement on the morphology, static and dynamic mechanical properties, as well as thermal properties of PPC/starch composites, were investigated. Tensile tests showed that incorporation of starch improves the stiffness and tensile strength of composites significantly. Scanning electron microscopic examination revealed the existence of good interfacial adhesion between the fillers and PPC matrix. Moreover, experimental results indicated that the starch addition leads to a significant improvement in the thermal stability of the composites. This paper demonstrates that the incorporation of low‐cost and biodegradable cornstarch into PPC provided a practical way to produce completely biodegradable and cost‐competitive composites with good mechanical properties. Polym. Eng. Sci. 44:2134–2140, 2004. © 2004 Society of Plastics Engineers.

Utilization of Various Carbohydrate Sources as Affected by Age in the Chick

In 3 experiments, New Hampshire × Columbian male chicks were fed carbohydrate-soybean meal (SBM) or casein diets from 0 to 21 d of age, and MEn was determined at 0 to 2, 3 to 4, 7, 14, and 21 d of age. Carbohydrate sources evaluated in experiment 1 were dextrose (D-glucose), conventional cornstarch, dextrinized cornstarch, corn-syrup solids, pregelatinized unmodified cornstarch, pregelatinized tapioca starch, tapioca dextrin, high-amylose starch, and polycose (mixed glucose polymers). Carbohydrate sources evaluated in experiments 2 and 3 were conventional corn, waxy corn, high-oil corn, corn flour, rice flour, dextrose, and sucrose. In experiment 1, chicks fed the dextrose diet had the highest weight gains, and the chicks fed high-amylose starch and pregelatinized unmodified cornstarch diets had the lowest weight gains. The MEn values varied among carbohydrate sources with MEn being highest for the dextrose diet and lowest for the high amylose starch diet. In experiment 2, chicks fed waxy corn, high-oil corn, or dextrose-SBM diets had (P < 0.05) higher growth rates than chicks fed conventional corn, corn flour, or rice flour. The MEn values increased with age for all diets except the dextrose-SBM, which was consistently high at all ages. In experiment 3, the dextrose diets (SBM or casein) yielded higher growth performance and MEn values than the sucrose-diets, and the differences were greater at younger ages. The MEn values were also much higher for the casein than the SBM diets, and MEn of the SBM diets increased with increasing age. The results of this study indicate that MEn, varies among carbohydrate sources and increases with age for most carbohydrate-SBM diets.

Effect of processing conditions on intrinsic viscosity of extruded cornstarch

Unmodified cornstarch from dent corn was used in this study to determine the effect of twin-screw extrusion conditions on the intrinsic viscosity of this polysaccharide and water. The study focused on the intrinsic viscosity of the cornstarch as a function of the key variables. Primary variables examined were temperature (75, 100, and 125°C), starch concentration or consistency (35, 50, and 65%), and screw speed (100, 200, and 300 rpm) during the extrusion processing. The most favorable conditions examined were the extrusion of the cornstarch at 35% consistency, 100°C, and 200 rpm. Two-thirds of the original intrinsic viscosity of the unmodified starch was retained upon extrusion at 35% consistency at all temperatures and the screw speeds (200 and 300 rpm) examined. Also, similar values were observed at 50% consistency for 75°C at 100 and 200 rpm and for 100°C at all three screw speeds. © 1996 John Wiley & Sons, Inc.

Chemical properties influencing rate of release of starch encapsulated herbicides: Implications for modifying environmental fate

Starch encapsulation is a controlled release technology which may reduce a chemical's environmental contamination potential. Effectiveness of starch encapsulation in modifying environmental fate is not uniform for all herbicides. We quantified the time required for complete release of herbicides encapsulated in unmodified cornstarch (amylopectin:amylose ratio approximately 3:1) by an extrusion process. These herbicides exhibited a range of chemical properties. Time required for complete release of herbicides, encapsulated using this technology, was strongly correlated with water solubility of the encapsulated chemical. As water solubility of the encapsulated chemical decreased, time required for complete release increased exponentially. Results of field scale experiments suggests that starch encapsulation influences the environmental fate of an encapsulated herbicide when the time required for complete release is from 14 to 21 days. Results suggest that starch encapsulation will provide a satisfactory rate of release for herbicides that have water solubilities of 20 to 300 mg l −1.

Hydrophilic foams containing corn products for horticultural use

AbstractPolyurethane foams containing equal amounts of commercial unmodified cornstarch and a polyisocyanate‐terminated polyether exhibit properties suitable for horticultural applications. The use of cornstarch in the foam formulation increased the volume by one‐fourth as compared to the foam without cornstarch. This volume increase represents an economic advantage of 20% savings based on material cost. When cornstarch or corn flour is added to the foam formulation, the foams are more resistant to compressive force. Upon wetting and draining, the foams prepared with no auxiliary blowing agent and containing corn products exhibit higher volumes than do the unfilled foams. Radish seeds planted inside 25 mm cubes of foams began to sprout after 1 day. Early developmental growth for the plants was similar in the control and cornstarch‐filled foams. Spectroscopic analyses of the starch‐containing foams revealed that 60–70% of the cornstarch was metabolized within 4–5 weeks by a microbial consortium. Control polyurethane foams were not affected by the microorganisms tested. © 1994 John Wiley &amp; Sons, Inc.This article is a U.S. Government work and, as such, is in the public domain in the United States of America.

Digestion of starch granules by α-amylases from the rice weevil, Sitophilus oryzae: effect of starch type, fat extraction, granule size, mechanical damage, and detergent treatment

In vitro digestion of raw starch granules by α-amylases from the rice weevil, Sitophilus oryzae (L.), was studied. Digestion of starch granules isolated from ball-milled cereals, especially corn and wheat, was extremely slow. Relative to intact starch granules of rice, corn, and wheat, gelatinized samples were 550-, 2000-, and 3300-fold, respectively, more susceptible to enzyme action. Among commercial starch samples tested, granular potato starch was most resistant to α-amylases from S. oryzae. Relative to granular potato starch, activity against other tested starches ranged from 2.1-fold greater for tapioca starch to 15.9-fold greater for an unmodified corn starch. Size distribution of granules of an unmodified wheat starch was determined by sequential passage through a series of nylon screens. Larger granules (15–20 μ) were 2.4-fold more susceptible than smaller granules (5–10 μ) to α-amylase. Defatted granules were slightly more susceptible than nondefatted granules to enzymatic degradation. α-Amylase activity against intact starch granules purified from soft wheat kernels (“Florida 302”) was increased 119-fold when the granules were extensively homogenized in a ground glass homogenizer. Activity against granules damaged by grinding in a mortar and pestle or a mechanical grinder was also increased. Presence of a detergent (Triton X-100) in the grinding buffer gave only a slight increase (14%) in susceptibility. Studies comparing the activity of α-amylase and crude gut homogenates of S. oryzae indicated that α-amylase is the primary enzyme that attacks granular starch in the gut. In addition, we could find no evidence that α-amylases from S. oryzae bind for a relatively long duration to intact or mechanically damaged granules from Florida 302. Based on these results, in our view, the precise mechanisms and efficiencies of the enzymatic conversion of granular starch to utilizable nutrients in vivo cannot be adequately assessed from in vitro assays with gelatinized starch and thus remain to be determined. A hypothesis for the in vivo digestion of granular starch by phytophagous insects is presented.

Reactive extrusion vs. batch preparation of starch–g–polyacrylonitrile

AbstractAcrylonitrile (AN) was graft polymerized onto unmodified cornstarch by a continuous reactive extrusion process and, for comparison, by a typical batch reaction process. The effect of AN/starch weight ratios, level of ceric ammonium nitrate (CAN) initiator, starch in water concentration, reaction temperature, reaction time, and extruder screw speed in the reactive extrusion process was studied. Add‐on, reaction efficiency, grafting frequency, weight average molecular weight (MW) and MW distribution of polyacrylonitrile (PAN), and water absorbency of the saponified copolymers were determined. Processing times in the twin‐screw extruder (ZSK) were 2–3 min, and total reaction time was about 7 min before reaction of the extruded material was terminated, compared to a reaction time of 2 h used in the typical batch procedure. The continuous reactive extrusion process was found to be a rapid and efficient means of preparing St‐g‐PAN with high add‐on (% PAN of the grafted product). For example, 42% add‐on was achieved within the 7‐min reaction period using an AN/starch weight ratio of 1.0 (3.5% CAN, starch weight basis), as compared to 38–49% for the 2‐h batch process (0.75–1.5 AN/starch ratio). Percentages of homopolymer of the copolymers were low for both extrusion and batch processes. Grafting frequencies were substantially higher while MWs were significantly lower for grafts from the extrusion process. Water absorbency of the saponified St–g–PAN products was somewhat greater for the products prepared by the batch process.

Oxidation of Starch Catalyzed by Persulfate

AbstractOxidation of unmodified corn starch in the presence of persulfates under different conditions has been studied. The method using silver catalyzed persulfate led to a grey colored oxidation product containing equal carbonyl but less carboxyl contents as compared to an industrial oxidized starch sample. Air‐oxidation of starch in the presence of persulfate gave a colorless oxidation product possessing low carboxyl but high carbonyl contents. Irradiation, by ultraviolet light during this oxidation procedure had little effect on the degree of oxidation. Ammonium persulfate was found to be a better oxidant than potassium persulfate.