Water solubility of flavor compounds influences formation of flavor inclusion complexes from dispersed high-amylose maize starch

High-amylose maize starch, with and without native lipid, was used to make inclusion complexes with flavor compounds to investigate the effect of water solubility of flavor compounds on inclusion complex formation. Two pairs of terpenes, having high and low water solubility, were used. Aqueous starches were dispersed by heat before adding the flavor compound. The amounts of starch, native lipid, and flavor compound in precipitates were determined, and inferences about the physical state were made using data from X-ray diffraction and differential scanning calorimetry. The water solubility of the flavor compound was related to the extent of inclusion complexation. For the higher water solubility flavor compounds, starch yield and flavor entrapment were higher, producing precipitates with the V 7 pattern. Complex formation with the low-solubility flavor compounds was most effective in the presence of native lipid, producing precipitates with the V 6 pattern. The lipid in native high-amylose maize starch may enhance complexation with low-solubility compounds by forming ternary coinclusion complexes of starch-lipid-flavor.     

The effect of ph on fungitoxic interactions between a solvent and pesticide

The effect of pH on interactions between combinations of the solvent acetone and the pesticide captan was determined using the fungiPythium ultimum, Sclerotinia homeocarpa, andPestalotia sp.. Seven concentrations of the solvent acetone, ranging from 0.1 to 3.0 % (v/v), were interacted with four concentrations of the fungicide captan, ranging from 1.0 to 10.0 ppm (mg L^?1). This interaction procedure was repeated at pH 4.5, 5.5, 6.5, and 7.5, using a temperature of 30 °C. Acetone and captan interacted synergistically towardsP. ultimum andS. homeocarpa, and antagonistically towardsPestalotia sp., regardless of the pH. However, the solvent concentration at which synergism or antagonism was first observed usually decreased as pH increased. The actual pH response obtained was dependent upon both the captan level and culture used. As pH increased from 4.5 to 7.5, the toxicity of captan decreased by up to 40% withS. homeocarpa andPestalotia sp., and 80% withP. ultimum. WithS. homeocarpa andPestalotia sp., the magnitude of synergism or antagonism increased as the captan concentration was raised from 1.0 or 2.5 ppm up to 7.5 or 10.0 ppm. With P. ultimum, the degree of synergism decreased at pH 4.5 and 5.5, but increased at pH 6.5 and 7.5, as the captan concentration was raised from 2.5 to 10.0 ppm. The lowest interaction magnitudes were recorded at pH 4.5 forP. ultimum, but was variable for the other cultures. The greatest interaction magnitudes were obtained at pH 4.5 forS. homeocarpa, 5.5 forPestalotia sp., and 6.5 or 7.5 forP. ultimum.     

Flavor release and perception in hard candy: influence of flavor compound-flavor solvent interactions

The release kinetics of l-menthol dissolved in propylene glycol (PG), Miglyol, or 1,8-cineole (two common odorless flavor solvents differing in polarity and a hydrophobic flavor compound) were monitored from a model aqueous system via atmospheric pressure chemical ionization mass spectrometry (APCI-MS). Breath analysis was also conducted via APCI-MS to monitor release of l-menthol from hard candy that used PG and Miglyol for l-menthol incorporation. The quantities of l-menthol released when dissolved in PG or Miglyol from the model aqueous system were found to be similar and overall significantly greater in comparison to when dissolved in 1,8-cineole. Analogous results were reported by the breath analysis of hard candy. The release kinetics of l-menthol from PG or Miglyol versus from 1,8-cineole were notably more rapid and higher in quantity. Results from the sensory time-intensity study also indicated that there was no perceived difference in the overall cooling intensity between the two flavor solvent delivery systems (PG and Miglyol).     

Influence of flavor solvent on flavor release and perception in sugar-free chewing gum

The influence of flavor solvent [triacetin (TA), propylene glycol (PG), medium chained triglycerides (MCT), or no flavor solvent (NFS)] on the flavor release profile, the textural properties, and the sensory perception of a sugar-free chewing gum was investigated. Time course analysis of the exhaled breath and saliva during chewing gum mastication indicated that flavor solvent addition or type did not influence the aroma release profile; however, the sorbitol release rate was statistically lower for the TA formulated sample in comparison to those with PG, MCT, or NFS. Sensory time-intensity analysis also indicated that the TA formulated sample was statistically lower in perceived sweetness intensity, in comparison with the other chewing gum samples, and also had lower cinnamon-like aroma intensity, presumably due to an interaction between sweetness intensity on aroma perception. Measurement of the chewing gum macroscopic texture by compression analysis during consumption was not correlated to the unique flavor release properties of the TA-chewing gum. However, a relationship between gum base plasticity and retention of sugar alcohol during mastication was proposed to explain the different flavor properties of the TA sample.     

Structure, dynamics, and stability of beta-cyclodextrin inclusion complexes of aspartame and neotame

Studies of the high-intensity sweetener aspartame show that its stability is significantly enhanced in the presence of beta-cyclodextrin (beta-CyD). At a 5:1 beta-CyD/aspartame molar ratio, the stability of aspartame is 42% greater in 4 mM phosphate buffer (pH 3.1) compared to solutions prepared without beta-CyD. Solution-state (1)H NMR experiments demonstrate the formation of 1:1 beta-CyD/aspartame complexes, stabilized by the interaction of the phenyl-ring protons of aspartame with the H3 and H5 protons of beta-CyD. Inclusion complex formation clearly accounts for the observed stability enhancement of aspartame in solution. The formation of inclusion complexes in solution is also demonstrated for beta-CyD and neotame, a structural derivative of aspartame containing an N-substituted 3,3-dimethylbutyl group. These complexes are stabilized by the interaction of beta-CyD with both phenyl-ring and dimethylbutyl protons. Solid-state NMR experiments provide additional characterization, clearly demonstrating the formation of inclusion complexes in lyophilized solids prepared from solutions of beta-CyD and either aspartame or neotame.     

The effect of SO2 on the production of ethanol,acetaldehyde, organic acids,and flavor volatiles during industrial cider fermentation

SO(2) is widely used in cider fermentation but also in other alcoholic beverages such as wine. Although the authorized limit is 200 ppm total SO(2), the International Organizations recommend its total elimination or at least reduction due to health concerns. Addition of SO(2) to apple juice at levels frequently used in industrial cidermaking (100 mg/L) induced significantly higher acetaldehyde production by yeast than that obtained without SO(2). Although the practical implications of acetaldehyde evolution under cidermaking conditions has been overcome by research and few data are available, this compound reached levels in two 2000 L bioreactors that may have prevented the occurrence of simultaneous alcoholic and malolactic fermentation. It was observed that malolactic fermentation had a positive effect promoting reduction of acetaldehyde levels in cider fermented with juice, SO(2)-treated or not. The addition of SO(2) clearly delayed malolactic fermentation comparing to the control, affecting not the onset of the malolactic fermentation but the rate of malic acid degradation. This compound, however, had a stimulatory effect on alcoholic fermentation.     

Solid inclusion complexes of vanillin with cyclodextrins: their formation, characterization, and high-temperature stability

This study reports the formation of solid vanillin/cyclodextrin inclusion complexes (vanillin/CD ICs) with the aim to enhance the thermal stability and sustained release of vanillin by inclusion complexation. The solid vanillin/CD ICs with three types of CDs (α-CD, β-CD, and γ-CD) were prepared using the freeze-drying method; in addition, a coprecipitation method was also used in the case of γ-CD. The presence of vanillin in CD ICs was confirmed by FTIR and (1)H NMR studies. Moreover, (1)H NMR study elucidated that the complexation stoichiometry for both vanillin/β-CD IC and vanillin/γ-CD IC was a 1:1 molar ratio, whereas it was 0.625:1 for vanillin/α-CD IC. XRD studies have shown channel-type arrangement for CD molecules, and no diffraction peak for free vanillin was observed for vanillin/β-CD IC and vanillin/γ-CD IC, indicating that complete inclusion complexation was successfully achieved for these CD ICs. In the case of vanillin/α-CD IC, the sample was mostly amorphous and some uncomplexed vanillin was present, suggesting that α-CD was not very effective for complexation with vanillin compared to β-CD and γ-CD. Furthermore, DSC studies for vanillin/β-CD IC and vanillin/γ-CD IC have shown no melting point for vanillin, elucidating the true complex formation, whereas a melting point for vanillin was recorded for vanillin/α-CD IC, confirming the presence of some uncomplexed vanillin in this sample. TGA thermograms indicated that thermal evaporation/degradation of vanillin occurred over a much higher temperature range (150-300 °C) for vanillin/CD ICs samples when compared to pure vanillin (80-200 °C) or vanillin/CD physical mixtures, signifying that the thermal stability of vanillin was increased due to the inclusion complexation with CDs. Moreover, headspace GC-MS analyses indicated that the release of vanillin was sustained at higher temperatures in the case of vanillin/CD ICs due to the inclusion complexation when compared to vanillin/CD physical mixtures. The amount of vanillin released with increasing temperature was lowest for vanillin/γ-CD IC and highest for vanillin/α-CD IC, suggesting that the strength of interaction between vanillin and the CD cavity was in the order γ-CD > β-CD > α-CD for solid vanillin/CD ICs.     

Nuclear magnetic resonance spectroscopic study of beta-lactoglobulin interactions with two flavor compounds,gamma-decalactone and beta-ionone

Interactions between a well-characterized protein, beta-lactoglobulin, and two flavor compounds, beta-ionone and gamma-decalactone, were studied by 2D NMR spectroscopy. NMR spectra were recorded in aqueous solution (pH 2.0, 12 mM NaCl, 10% D(2)O) under conditions such that beta-lactoglobulin is present in a monomeric state. TOCSY and NOESY spectra were recorded on the protein and the complexes between protein and ligands. The spectra of the NH-CH(alpha) region showed the cross-signals due to the coupling between N- and C-bonded protons in the polypeptide backbone. The observed chemical shift variations in the presence of ligands can be assigned to changes in the protein conformation. It appears that the side chains of several amino acids are affected by binding of gamma-decalactone point into the central cavity (Leu46, Ile56, Met107, and Gln120), whereas binding of beta-ionone affects amino acids located in a groove near the outer surface of the protein (Leu104, Tyr120, and Asp129), as illustrated by molecular visualization. This NMR study provides precise information of the location of binding and confirms the existence of two different binding sites for aroma compounds on beta-lactoglobulin, which was suggested in previous competition studies by fluorometry or affinity chromatography and by structural information obtained from infrared spectroscopy.     

Formation of natamycin:cyclodextrin inclusion complexes and their characterization

Natamycin is a broad spectrum antimycotic with very low water solubility, which is used to extend the shelf life of shredded cheese products. beta-Cyclodextrin (beta-CD), hydroxypropyl beta-cyclodextrin (HP beta-CD), and gamma-cyclodextrin (gamma-CD) were found to form inclusion complexes with natamycin in aqueous solution. The increase in solubility of natamycin with added beta-CD was observed to be linear (type A(L) phase solubility diagram). The 1:1 stability constant of natamycin:beta-CD complex was estimated from its phase solubility diagram to be 1010 M(-1). The phase solubility diagrams of both gamma-CD and HP beta-CD exhibited negative deviation from linearity (type A(N) diagram) and, therefore, did not allow the estimation of binding constants. The water solubility of natamycin was increased 16-fold, 73-fold, and 152-fold with beta-CD, gamma-CD, and HP beta-CD, respectively. The natamycin:CD inclusion complexes resulted in in vitro antifungal activity nearly equivalent to that of natamycin in its free state.     

The effect of interactions between particles on soil infiltrability

Journal of Soils and Sediments - Soil infiltrability is an important topic in environmental and agricultural research and influences plant growth, soil erosion and water runoff. In this study, the...     

Stability of natamycin and its cyclodextrin inclusion complexes in aqueous solution

Aqueous solutions of natamycin and its beta-cyclodextrin (beta-CD), hydroxypropyl beta-cyclodextrin, and gamma-cyclodextrin (gamma-CD) inclusion complexes were completely degraded after 24 h of exposure to 1000 lx fluorescent lighting at 4 degrees C. After 14 days of storage in darkness at 4 degrees C, 92.2% of natamycin remained in active form. The natamycin:beta-CD complex and natamycin:gamma-CD complex were significantly more stable (p < 0.05) than natamycin in its free state in aqueous solutions stored in darkness at 4 degrees C. Clear poly(ethylene terephthalate) packaging with a UV light absorber allowed 85.0% of natamycin to remain after 14 days of storage under 1000 lx fluorescent lighting at 4 degrees C. Natamycin:cyclodextrin complexes can be dissociated for analysis in methanol/water/acetic acid, 60:40:5, v/v/v. Natamycin and its complexes in dissociated form were quantified by reverse phase HPLC with detection by photodiode array at 304 nm.     

Flavor release and perception in hard candy: influence of flavor compound-compound interactions

The influence of flavor compound-compound interactions on flavor release properties and flavor perception in hard candy was investigated. Hard candies made with two different modes of binary flavor delivery, (1) L-menthol and 1,8-cineole added as a mixture and (2) L-menthol and 1,8-cineole added separate from one another, were analyzed via breath analysis and sensory time-intensity testing. Single-flavor candy containing only L-menthol or 1,8-cineole was also investigated via breath analysis for comparison. The release rates of both L-menthol and 1,8-cineole in the breath were more rapid and at a higher concentration when the compounds were added to hard candy separate from one another in comparison to their addition as a mixture (conventional protocol). Additionally, the time-intensity study indicated a significantly increased flavor intensity (measured as overall cooling) for hard candy made with separate addition of these flavor compounds. In conclusion, the flavor properties of hard candy can be controlled, at least in part, by flavor compound-compound interactions and may be altered by the method of flavor delivery.     

Enantiomeric synthesis of (S)-2-methylbutanoic acid methyl ester, apple flavor, using lipases in organic solvent

Enantiomeric selective synthesis of (S)-2-methylbutanoic acid methyl ester, which is known as a major apple and strawberry flavor, was performed from racemic 2-methylbutanoic acid using lipases in organic solvent. Among 20 lipases, lipase IM 20 (immobilized lipase of Rhizomucor miehei), lipase AP (Aspergillus niger), and lipase FAP-15 (Aspergillus javanicus) exhibited higher enzymatic activities and enantioselectivities and were selected for the synthesis of (S)-2-methylbutanoic acid methyl ester. Using these enzymes, the reaction conditions such as temperature and lyophilizing pH were optimized, and kinetic parameters were determined. All of the reactions were performed in isooctane, which was identified as the best reaction media for nonaqueous systems. At 20 degrees C maximum enantiomeric excess was observed, while synthetic activity increased as the temperature increased. Only lipases lyophilized at pH 5.5, 6. 0, 6.5, and 7.0 showed synthetic activity. In this pH range, enantioselectivities were not influenced by the lyophilizing pH. The K(M,S) and K(M,R) values for ester synthetic activity of lipase were 1120 and 1240 mM, respectively. Enzyme activity was inhibited by (S)-2-methylbutanoic amide, and its K(i) was calculated as 84 mM. (S)-2-Methylbutanoic amide acted as a competitive inhibitor.     

Sweetener/sweetness-induced changes in flavor perception and flavor release of fruity and green character in beverages

Green leaf volatile (GLV) mixtures, commercial orange flavors, and commercial strawberry flavors were applied to beverage bases in which concentrations of citric acid as well as a sweetener (sucrose or aspartame/acesulfame-K) were varied. Sensory profiling showed that flavor-specific fruity character increased as perceptible sweetness increased, independent of whether the sweetness resulted from sucrose (a change from 9 to 12 Brix) or aspartame/acesulfame-K (a change from 0.2 to 0.4 Brix). Sweetness was affected only by the tastants in the base and not by the flavors, although flavor-specific interactions between sweetener type and sweetener level occurred. Flavor release from the sucrose bases was compared to flavor release from bases containing aspartame/acesulfame-K by static headspace measurements and by MS-Nose measurements using an artificial throat. These measurements showed greater flavor volatility from bases having low Brix (fewer soluble solids). This negative Brix effect was also evident in the sensory data for perception of some GLV green notes. The headspace data could not support a positive Brix effect, the typical salting out, which would correspond to the observed perceptual enhancement of fruity notes.     

The role of fat in flavor perception: effect of partition and viscosity in model emulsions

Decreasing the fat content of a food, while maintaining the same aroma content, changes both aroma release (due to partition effects) and the viscosity of the food. To understand the relative contribution of these two factors on flavor perception, a series of flavored emulsions were prepared to control aroma release and viscosity using different aroma, oil, and hydroxypropyl methyl cellulose (HPMC) contents. Samples were formulated to deliver the same aroma-release in vitro and in vivo, and their viscosity was measured using the Kokini oral shear stress parameter. Despite the in vivo aroma release being constant, there were perceptual differences between the samples, and the flavor intensity decreased as in-mouth viscosity increased. For these iso release samples, the Kokini oral shear stress parameter correlated well with the decrease in perception, suggesting that there may be a viscosity stimulus or that the viscosity affects release of tastant and hinders aroma-taste interactions.     

Electrochemical investigation of the effect of pH and solvent on amitraz stability

The widespread use of the pesticide amitraz for pest control of crops, livestock and honeybees has warranted several studies aimed at understanding the degradation of this compound during storage and use. In particular the degradation of amitraz and the nature of the toxicologically significant intermediates formed owing to pH and solvent type has been examined. In this study we report on the use of electrochemical methods to monitor amitraz degradation and to identify the major intermediates formed. While this study examines the use of rapid voltammetric methods for such analyses, it also resolves earlier studies showing the rapid degradation of amitraz to 2,4-dimethylaniline without formation of intermediates first, and also suggests that the degradation of amitraz to 2,4-dimethylphenylformamide and to 2,4-dimethylaniline is more rapid than previously observed at pH above 3. These studies also showed that amitraz degrades to dimethylphenylformamide in ethanol and methanol, and is stable in both acetonitrile and dimethylsulphoxide.     

植物精油与环糊精包合物的制备及对柑橘绿霉病的抑制作用

植物精油及其活性组分能降低柑橘采后病害且不影响果实品质,是一种潜在的生物杀菌剂,但存在易挥发和不稳定等问题,限制了其实际应用。将植物精油与环糊精包合能有效克服上述缺陷,提高植物精油的应用效果。为了提升植物精油组分反式-2-己烯醛对柑橘绿霉病菌的控制效果,该研究拟采用饱和水溶液法制备反式-2-己烯醛与α-环糊精（α-CD）、β-环糊精（β-CD）、γ-环糊精（γ-CD）和羟丙基-β-环糊精（HP-β-CD）包合物,并考察包合物对指状青霉的离体和活体控制效果,在此基础上解析效果较优包合物的结构特点和包合模式。结果显示,通过饱和水溶液法成功制备了反式-2-己烯醛与α-CD、β-CD、γ-CD和HP-β-CD的4种包合物（α-CDTH、β-CDTH、γ-CDTH和HP-β-CDTH）。外观形态结果显示,α-CDTH、β-CDTH和γ-CDTH粉末细腻绵密,HP-β-CDTH粉末粗糙,颗粒分明。4种环糊精包合物均能有效抑制P.digitatum菌丝体的生长且具有浓度依赖性,β-CDTH和γ-CDTH抑制P.digitatum菌丝体生长的最小杀菌浓度（Minimum Fugicide Concen...     

Characterization of soluble non-covalent complexes between bovine serum albumin and beta-1,2,3,4,6-penta-O-galloyl-D-glucopyranose by MALDI-TOF MS

Beta-1,2,3,4,6-penta-O-galloyl-D-glucopyranose (PGG) and soluble complexes of PGG with bovine serum albumin (BSA) were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). PGG was also characterized by electrospray ionization mass spectrometry (ESI-MS). Similar fragmentation patterns of PGG were found in ESI-MS and MALDI-TOF MS. The apparent stoichiometries of non-covalent BSA-PGG complexes were determined by MALDI-TOF MS.     

Use of catalyst in a 3D-QSAR study of the interactions between flavor compounds and beta-lactoglobulin

This paper reports a 3D-QSAR study using Catalyst software to explain the nature of interactions between flavor compounds and beta-lactoglobulin. A set of 35 compounds, for which dissociation constants were previously determined by affinity chromatography, was chosen. The set was divided into three subsets. An automated hypothesis generation, using HypoGen software, produced a model that made a valuable estimation of affinity and provided an explanation for the lack of correlation previously observed between the hydrophobicity of terpenes and the affinity for the protein. On the basis of these results, it appears that aroma binding to beta-lactoglobulin is caused by both hydrophobic interactions and hydrogen bonding, which plays a critical role. Catalyst appears to be a reliable tool for the application of 3D-QSAR study in aroma research.