Structure and functionality of surface-active amylose-fatty amine salt inclusion complexes.

Novel value-added starch-based materials can be produced by forming amylose inclusion complexes (AIC) with hydrophobic compounds. There is currently little research on AIC use as polymeric emulsifiers, particularly for AIC with fatty amine salt ligands. This work evaluated AIC emulsifiers by studying the structure and functionality of AIC composed of high amylose corn starch and fatty amine salts (10-18 carbons, including a mixture simulating vegetable oil composition) produced via steam jet cooking. X-ray scattering verified successful AIC formation, with peaks located near 7.0°, 12.8° and 19.9° 2θ. AIC were easily dispersed in water (80-85 °C) and remained in suspension at room temperature for weeks, unlike the uncomplexed ligands or starch. AIC were highly effective emulsifying agents, with emulsifying activity indexes of 213-229 m2g-1 at pH 5, and zeta potentials, a measure of electrostatic repulsion, as high as 43.4 mV. AIC dispersions had surface tension ranging from 24 to 41 mN/m and displayed surface-active properties superior to amylose complexes formed from fatty acid salts and competitive with common starch-based emulsifiers. These findings demonstrate that fatty amine salt AIC are effective emulsifiers that can be made from low-cost sources of fatty amine salts, such as vegetable oil derivatives.

Rheological and Micro-Rheological Properties of Chicory Inulin Gels.

As a soluble fiber, inulin is present in many plants and has many applications in food and non-food products. In this work, we investigated the rheological properties of inulin dispersions at seven concentrations. The linear viscoelastic properties of inulin were determined using a conventional mechanical rheometer. At 25 wt%, inulin exhibited fluid-like viscoelastic liquid behavior. However, when concentrations were ≥27.5 wt%, inulin exhibited gel-like viscoelastic properties. The viscoelastic properties (moduli and viscosities) increased with increasing inulin concentration. The high-frequency linear rheological properties of inulin were also investigated using the modern light scattering technique, diffusion wave spectroscopy (DWS). The diffusion wave spectroscopy (DWS) measurements showed the amplitude of complex moduli (|G*(ω)|) of inulin gels (≥27.5 wt%) to be proportional to ½ power law of the frequency, which suggests inulin gels behave similarly to flexible polymers. The non-linear steady shear experiments demonstrated that inulin exhibited shear-thinning behavior that was well fitted by a power law constitutive model. The trend of the power law exponent from the experiments indicated that the shear-thinning extent for inulin was greater as the inulin concentration increased. The results of this work indicated that the properties of inulin gel can be manipulated by altering its concentration. Therefore, the desired inulin product can be designed accordingly. These results can be used to direct further food and non-food applications, such as wound healing materials for inulin gels.

A push-pull strategy to suppress stable fly (Diptera: Muscidae) attacks on pasture cattle via a coconut oil fatty acid repellent formulation and traps with m-cresol lures.

BACKGROUND: Stable flies [Stomoxys calcitrans (L.)] are economically important pests of cattle and other livestock. As an alternative to conventional insecticides, we tested a push-pull management strategy using a coconut oil fatty acid repellent formulation and an attractant-added stable fly trap. RESULTS: In our field trials we found that weekly applications of a push-pull strategy can reduce stable fly populations on cattle as well as a standard insecticide (permethrin). We also found that the efficacy periods of the push-pull and permethrin treatments following on-animal application were equivalent. Traps with an attractant lure used as the pull component of the push-pull strategy captured sufficient numbers of stable flies to reduce on-animal numbers by an estimated 17-21%. CONCLUSIONS: This is the first proof-of-concept field trial demonstrating the effectiveness of a push-pull strategy using a coconut oil fatty acid-based repellent formulation and traps with an attractant lure to manage stable flies on pasture cattle. Also notable is that the push-pull strategy had an efficacy period equivalent to that of a standard, conventional insecticide under field conditions. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of subcritical water flash release processing on buckwheat flour properties.

BACKGROUND: Buckwheat (Fagopyrum esculentum) is rich in bioactive components. However, many of these components are trapped within cellular structures, making them inaccessible. Buckwheat flour was hydrothermally modified using subcritical water coupled with a flash pressure release (SCWF). The effects of the SCWF parameters (120, 140, and 160 °C and hold times of 0, 15, and 30 min) on the flour's structure, physicochemical, and functional properties were studied relative to the raw flour. RESULTS: Treatment deepened the flour color with increasing processing temperatures and hold times. Starch content remained unchanged though its granular structure was disrupted. SCWF treatments lowered total phenolic content compared with the raw flour, except for 160 °C-30 min, where total phenolic content increased by 12.7%. The corresponding antioxidant activities were found consistent with phenolic content. Soluble and insoluble dietary fiber amounts were not substantially influenced at 120 and 140 °C, whereas treatments at 160 °C (15 and 30 min hold) decreased soluble dietary fiber while increasing insoluble dietary fiber. Protein content increased 70-109% in some treatments, suggesting greater protein accessibility. Water-holding capacity significantly increased for flour treated at 120 °C, whereas only slight improvements occurred at 140 and 160 °C. CONCLUSIONS: Subcritical water flash processing can modify the compositional and functional properties of buckwheat flour depending on the choice of reaction conditions. Observed changes were consistent with alteration of the flour's cellular structure and allow some components to become more accessible. The resulting SCWF-modified buckwheat flours provide new food ingredients for potential use in ready-to-eat foods and spreads with improved health benefits. Published 2022. This article is a U.S. Government work and is in the public domain in the USA.

Characterization and properties of starch-dicarboxylic acid inclusion complexes prepared by excess steam jet cooking.

A series of dicarboxylic-amylose inclusion complexes (AIC) were prepared by excess steam jet-cooking high amylose corn starch with linear C10, C12, C14, and C16 dicarboxylic acids to examine the influence of two polar head groups on complex formation. The C12, C14, and C16 dicarboxylic acid AIC were prepared in 48-63 % yields and contained 8.9-11.8 % diacid while the C10 AIC gave 30 % and contained 2.6 % diacid. These AIC had V6 helical amylose structures by XRD and complexation was further confirmed by DSC, FTIR, and TGA. SEM of the C12-C16 AIC revealed micron-sized toroidal spherulites while the C10 AIC was predominantly amorphous. DSC showed two AIC related transitions. This work provides a better understanding of the formation and physicochemical properties of these diacid AIC. Preparation by excess steam jet cooking demonstrates practical and commercial utility to prepare AIC as off-the-shelf materials for food and nonfood applications.

Evaluation of Lotions of Botanical-Based Repellents Against Aedes aegypti (Diptera: Culicidae).

Thirteen botanical product repellent compounds such as 2-undecanone, capric, lauric, coconut fatty acids (and their methyl ester derivatives), and catnip oil were formulated in either Coppertone or Aroma Land lotions and evaluated against laboratory-reared Aedes aegypti L. (Diptera: Culicidae) mosquitoes. These formulations contained 7-15 wt/wt of the botanical repellent as the major active ingredient either pure or as mixtures. USDA standard repellent test cages were used to determine the complete protection time (CPT) of the different formulated repellents. Two of the evaluated formulations, a 7% capric acid in Coppertone (CPT 2.7 ± 0.6 h) and 7% coconut fatty acids containing carrylic acid, capric acid, and lauric acid in Coppertone (CPT 2.3 ± 2.0 h), provided strong repellency against mosquitoes up to 3 h, which was equivalent to the (N,N-diethyl-m-toluamide) DEET control (CPT 2.7 ± 0.6 h). This work suggests future potential for these botanical product-based repellents as alternatives to commercial DEET-containing products.

Enzymatic Synthesis and Flash Chromatography Separation of 1,3-Diferuloyl-sn-Glycerol and 1-Feruloyl-sn-Glycerol.

Ethyl ferulate was transesterified with Enova Oil (a soy-based vegetable oil containing 80-85% diacylglycerol) using Novozym 435 at 60 °C. The resultant feruloylated vegetable oil reaction product produced a precipitate (96.4 g, 4.02 wt%) after 7 d of standing at room temperature. Preliminary characterization of the precipitate identified the natural phenylpropenoids 1,3-diferuloyl-sn-glycerol (F2G) and 1-feruloyl-sn-glycerol (FG) as the major components. A flash chromatography method was developed and optimized (e.g., mass of sample load, flow rate, binary solvent gradient slope, and separation run length) using a binary gradient of hexane and acetone mobile phase and silica gel stationary phase to separate and isolate F2G and FG. The optimized parameters afforded F2G (1.188 ± 0.052 g, 39.6 ± 1.7%) and FG (0.313 ± 0.038 g, 10.4 ± 1.3%) from 3.0 g of the transesterification precipitate, n = 10 trials. Overall, all flash chromatography separations combined, F2G (39.1 g, 40.6%) and FG (9.4 g, 9.8%) were isolated in a combined yield of 48.5 g (51.4%), relative to the 96.4 g of transesterification precipitate collected. The optimized flash chromatography method was a necessary improvement over previously reported preparative HPLC and column chromatography methods used to purify milligram to low gram quantities of F2G and FG to be able to process ~100 g of material in a timely, efficient manner.

Spatial repellency, antifeedant activity and toxicity of three medium chain fatty acids and their methyl esters of coconut fatty acid against stable flies.

BACKGROUND: Stable flies are one of the most detrimental arthropod pests to livestock. With changing climates and agronomic practices, they expand their roles as pests and disease vectors as well. Their painful bites reduce livestock productivity, annoy companion animals, and interfere with human recreational activities. Current management technologies are unable to effectively control stable flies. The present study reports new results concerning the contact, spatial repellency, and toxicity of a bio-based product, coconut fatty acid and their methyl ester derivatives of free fatty acids of C8:0 , C10:0 and C12:0 to stable flies. RESULTS: Three medium chain fatty acid methyl esters (C8:0 , C10:0 and C12:0 ) showed strong antifeedant activity against stable flies and their strengths were dose-dependent. Only the C8:0 acid, C8:0 - and C10:0 methyl esters elicited significant antennal responses. Laboratory single cage olfactometer bioassays revealed that coconut fatty acid and C8:0 methyl ester displayed active spatial repellency. All three methyl esters showed strong toxicity against stable flies. CONCLUSION: Antifeedant activity is the main method through which coconut fatty acid deters stable fly blood-feeding. The C8:0 , C10:0 and C12:0 methyl esters act not only as strong antifeedants, but also possess strong toxicity against stable fly adults. Limited spatial repellency was observed from coconut fatty acid and C8:0 methyl ester. © 2019 Society of Chemical Industry.

Starch-Flavor Complexation Applied to 2-Acetyl-1-pyrroline.

The pleasant popcorn-like smelling compound 2-acetyl-1-pyrroline (2AP) occurs naturally in many foods but is scarcely used as a flavoring agent due to its great instability. In this work, we evaluate the potential of high amylose corn starch to complex and stabilize 2AP. The methodology was first optimized using model compounds, 2-acetylpyridine and 2-acetyl-2-thiazoline, and then applied to 2AP. Complexes were successfully prepared and characterized using X-ray diffraction, gas chromatography, and differential scanning calorimetry. Loadings of up to 0.504 (±0.071)% 2AP were achieved, and storage studies showed that over half of the flavor was retained after 2 weeks at 0% relative humidity. To our knowledge, this is the first demonstration that 2AP can form amylose inclusion complexes and may lead to a method to effectively stabilize this labile aroma compound.

Better than DEET Repellent Compounds Derived from Coconut Oil.

Hematophagous arthropods are capable of transmitting human and animal pathogens worldwide. Vector-borne diseases account for 17% of all infectious diseases resulting in 700,000 human deaths annually. Repellents are a primary tool for reducing the impact of biting arthropods on humans and animals. N,N-Diethyl-meta-toluamide (DEET), the most effective and long-lasting repellent currently available commercially, has long been considered the gold standard in insect repellents, but with reported human health issues, particularly for infants and pregnant women. In the present study, we report fatty acids derived from coconut oil which are novel, inexpensive and highly efficacious repellant compounds. These coconut fatty acids are active against a broad array of blood-sucking arthropods including biting flies, ticks, bed bugs and mosquitoes. The medium-chain length fatty acids from C8:0 to C12:0 were found to exhibit the predominant repellent activity. In laboratory bioassays, these fatty acids repelled biting flies and bed bugs for two weeks after application, and ticks for one week. Repellency was stronger and with longer residual activity than that of DEET. In addition, repellency was also found against mosquitoes. An aqueous starch-based formulation containing natural coconut fatty acids was also prepared and shown to protect pastured cattle from biting flies up to 96-hours in the hot summer, which, to our knowledge, is the longest protection provided by a natural repellent product studied to date.

Physical and chemical properties of pyrolyzed biosolids for utilization in sand-based turfgrass rootzones.

Biosolids are several forms of treated sewage sludge that are intended for use as soil conditioners for horticultural, agricultural and industrial crops. The objectives of this research were to determine the chemical and physical properties of biosolids pyrolyzed at several different temperatures, and their effect on perennial ryegrass seed germination and growth. Biosolids were thermally treated in an oxygen-free (nitrogen atmosphere) retort oven at 300, 400, 500, 700 and 900 °C. As pyrolysis temperatures increased, bulk densities, total surface areas, micropore surface areas, % minerals and pH values of the pyrolyzed biosolids increased, while carbon percentage decreased compared to untreated biosolids. Fourier-transform infrared spectroscopy analysis showed decreased surface functionality as pyrolysis temperature increased. Perennial ryegrass (Lolium perenne L. 'Nui') plants were grown in mixtures of 10% (v/v) biosolids or 10% (v/v) of the various pyrolyzed biosolids and 90% coarse sand. Ryegrass plants grown in the biosolids and the 300 °C pyrolyzed biosolids mixture had the greatest shoot heights of any of the treatments after 4 weeks of growth. These results indicate that pyrolyzing biosolids at 300 °C would produce material with excellent potential as a long-term peat replacement for water and nutrient retention in sand-based rootzones.

Formation of inclusion complexes between high amylose starch and octadecyl ferulate via steam jet cooking.

Amylose-ligand inclusion complexes represent an interesting approach to deliver bioactive molecules. However, ferulic acid has been shown not to form single helical inclusion complexes with amylose from high amylose maize starch. To overcome this problem a lipophilic ferulic acid ester, octadecyl ferulate, was prepared and complexed with amylose via excess steam jet cooking. Jet-cooking octadecyl ferulate and high amylose starch gave an amylose-octadecyl ferulate inclusion complex in 51.0% isolated yield. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) confirmed that a 61 V-type inclusion complex was formed. Amylose and extraction assays showed the complex to be enriched in amylose (91.9±4.3%) and contain 70.6±5.6mgg(-1) octadecyl ferulate, although, minor hydrolysis (∼4%) of the octadecyl ferulate was observed under the excess steam jet-cooking conditions utilized. This study demonstrates that steam jet cooking is a rapid and scalable process in which to prepare amylose-octadecyl ferulate inclusion complexes.

Preparation and properties of films cast from mixtures of poly(vinyl alcohol) and submicron particles prepared from amylose-palmitic acid inclusion complexes.

The use of starch in polymer composites for film production has been studied for increasing biodegradability, improving film properties and reducing cost. In this study, submicron particles were prepared from amylose-sodium palmitate complexes both by rapidly cooling jet-cooked starch-palmitic acid mixtures and by acidifying solutions of starch-sodium palmitate complexes. Films were cast containing poly(vinyl alcohol) (PVOH) with up to 50% starch particles. Tensile strength decreased and Young's modulus increased with starch concentration, but percent elongations remained similar to controls regardless of preparation method or starch content. Microscopy showed particulate starch distribution in films made with rapidly cooled starch-palmitic acid particles but smooth, diffuse starch staining with acidified sodium palmitate complexes. The mild effects on tensile properties suggest that submicron starch particles prepared from amylose-palmitic acid complexes provide a useful, commercially viable approach for PVOH film modification.

Amylose-potassium oleate inclusion complex in plain set-style yogurt.

Health and wellness aspirations of U.S. consumers continue to drive the demand for lower fat from inherently beneficial foods such as yogurt. Removing fat from yogurt negatively affects the gel strength, texture, syneresis, and storage of yogurt. Amylose-potassium oleate inclusion complexes (AIC) were used to replace skim milk solids to improve the quality of nonfat yogurt. The effect of AIC on fermentation of yogurt mix and strength of yogurt gel was studied and compared to full-fat samples. Texture, storage modulus, and syneresis of yogurt were observed over 4 weeks of storage at 4 °C. Yogurt mixes having the skim milk solids partially replaced by AIC fermented at a similar rate as yogurt samples with no milk solids replaced and full-fat milk. Initial viscosity was higher for yogurt mixes with AIC. The presence of 3% AIC strengthened the yogurt gel as indicated by texture and rheology measurements. Yogurt samples with 3% AIC maintained the gel strength during storage and resulted in low syneresis after storage for 4 wk.

Preparation and properties of amylose complexes prepared from hexadecylamine and its hydrochloride salt.

Amylose inclusion complexes were prepared from jet-cooked aqueous mixtures of high amylose corn starch and 1-hexadecylamine (HDA). Slow-cooling produced torus/disc-shaped spherulites, whereas aggregates of smaller spherulites were obtained by rapid-cooling in ice. The morphologies and 61V X-ray diffraction patterns of these spherulites were similar to those of spherulites obtained previously with palmitic acid, indicating that spherulite morphology is influenced largely by the hydrophobic structure of the carbon chain of the complex-forming ligand and to a lesser extent by the nature of the more polar head group. Water soluble, cationic amylose inclusion complexes were prepared by adding an aqueous solution of the HCl salt of HDA to a jet-cooked dispersion of high amylose starch. The cationic nature of these HDA·HCl complexes suggests possible applications as flocculating agents for water purification and as retention aids in papermaking.

Effect of amylopectin on the rheological properties of aqueous dispersions of starch-sodium palmitate complexes.

Aqueous dispersions of normal and high-amylose corn starch were steam jet cooked and blended with aqueous solutions of sodium palmitate to give starch containing amylose-sodium palmitate inclusion complexes. Partial conversion of complexed sodium palmitate to palmitic acid by addition of acetic acid led to the formation of gels. Blends of inclusion complexes prepared from normal and high-amylose corn starch were used to vary the amylose:amylopectin ratio of the gels, and the linear viscoelastic moduli were found to decrease with decreasing amylose:amylopectin ratio. Precipitation of the complexed starch at low pH showed that most of the amylopectin was not part of the gel network. The elastic modulus of the gels was shown to decrease sharply between 74 and 85 °C, and the transition temperature increased strongly with decreasing amylose:amylopectin ratio.

Preparation of starch-stabilized silver nanoparticles from amylose-sodium palmitate inclusion complexes.

Starch-stabilized silver nanoparticles (AgNP) were prepared from amylose-sodium palmitate helical inclusion complexes by first converting sodium palmitate within the amylose helix to silver palmitate by an ion-exchange reaction with silver nitrate, and then reducing the complexed silver palmitate salt with NaBH(4). This process yielded stable aqueous solutions that could be dried and then re-dispersed in water for end-use applications. Reaction products were characterized by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), UV-VIS spectroscopy, X-ray diffraction, TEM, SEM and light microscopy. Addition of acid to reduce the pH of aqueous starch-AgNP solutions produced an increase in viscosity, and nearly quantitative precipitation of starch-AgNP was observed at low pH. Smaller AgNP and higher conversions of silver nitrate to water-soluble starch-AgNP were obtained in this process, as compared with a process carried out under similar conditions using a commercial soluble starch as a stabilizer.

Free radical addition of butanethiol to vegetable oil double bonds.

Butanethiol was used in ultraviolet-initiated thiol-ene reaction with canola and corn oils to produce sulfide-modified vegetable oils (SMVO). The crude SMVO product was successfully purified by solvent extraction, vacuum evaporation, and silica gel chromatography. The SMVO products were characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy. Further product characterization and analysis was conducted using GC and GC-MS on the fatty acid methyl esters obtained by the transesterification of the SMVO products. Investigation of the effect of reaction conditions showed that high yield and high conversion of double bonds into thiol were favored at low reaction temperatures and high butanethiol/vegetable oil ratios. Canola and corn oils gave similar double-bond conversions and yields of the desired SMVO product even though they have big differences in the relative numbers of single and multiple double bonds in their structures. Under best reaction conditions, up to 97% of double-bond conversion and 61% isolated yields of the purified SMVO products were attained.