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The novel discovery of p-hydroxyphenylbutan-2-one (berry note) in Riceberry aroma was characterized by gas chromatography-olfactometry and gas chromatography-time-of-flight mass spectrometry. Odor activity values and aroma extract dilution analysis revealed the high potency of this ketone, vanillin, and guaiacol found within the purple rice. Furthermore, ultrapasteurization (UP), high-temperature short-time (HTST) pasteurization, and ultrahigh-temperature (UHT) sterilization effects on rice beverage aroma were analyzed using Riceberry as a sample. Riceberry's key odorants also remained the primary aromatic contributors in beverage models. Although descriptive sensory analysis showed a slightly lower musty note intensity in HTST beverages compared to the UP sample, their flavor dilution chromatograms were similar. Cluster analysis and R-index ranking test further confirmed aroma similarities during storage. Stored samples sterilized via UHT experienced certain potential off-odors, including acetic acid, propanoic acid, and indole, as opposed to the other beverages. UP was therefore superior to HTST and UHT by extending beverage shelf life without any undesirable odors. PRACTICAL APPLICATION: Ultrapasteurization (UP) retains Riceberry aroma characteristic in beverages and requires minimal modifications beyond conventional pasteurization. UP beverages also surpass those of high-temperature short-time and ultrahigh-temperature by extending shelf life with no noticeable off-odors. In addition, the discovery of p-hydroxyphenylbutan-2-one and the other aroma-active compounds of Riceberry aroma should prove valuable for flavor creation, rice breeding, and rice quality standards.

The flavor profile, flavor enhancement, and saltiness modulation of Szechuan pepper (Zanthoxylum simulans) were analyzed to evaluate its effectiveness in lowering salt usage. The saltiness enhancing efficiency of Szechuan pepper and its salt-reduction properties were determined to be 28.74% and 22.32%, respectively. The saltiness enhancers were detected in the polar fraction and taste dilution analysis combined with half-tongue test determined the most potent saltiness enhancing components in chromatographic subfractions. Both spectroscopic analysis and sensory evaluation disclosed NaCl as the unexpected primary contributor of saltiness enhancement in this spice. It is the first known study revealing Szechuan pepper’s high salt content.

In order to use commercial starch for flavor encapsulation, three starches (mungbean, rice, and tapioca) were selected to determine their ability to form inclusion complex with menthone. Mungbean starch had the highest amylose content, followed by rice starch and tapioca starch, respectively. After complexation, appearance and microstructure changes were observed for all starches. Mungbean and tapioca complexes with well-organized V7 crystalline pattern gave similar menthone entrapment (around 4%) which was higher than that of the rice sample (

This study investigated the effects of evaporating temperature during molecular distillation (MD) process employed to deodorizer distillate (DD) on the retention of rice phytochemicals in the unevaporated fraction (UMDs), which were then further used as co-surfactants in the fabrication of water-dispersible vesicles. The pilot-scale MD unit was operated at 120, 140 or 160 °C and 0.1 Pa to concentrate rice phytosterols from 1540.8 mg in 100 g DD to 3990.2-4904.8 mg in 100 g UMDs by evaporating out free fatty acids. Although γ-oryzanol content was increased from 598.9 mg in 100 g DD to 870.0-1018.1 mg in 100 g UMDs when the temperature was raised to 160 °C, such high temperature decreased tocols from 2185.7 mg in 100 g DD to 850.5 mg in 100 g UMDs and antioxidant capacity of UMDs measured as 2,2-diphenyl-1-picrylhydrazyl scavenging capacity. The UMD obtained after distillation at 140 °C was used as co-surfactant with soy lecithin, sucrose palmitate or polyoxyethylene sorbitan monooleate (Tween 80) to fabricate vesicles in pH 7.0 phosphate buffered saline (PBS). This study showed potential use of the UMD as a source of rice phytochemicals and a co-surfactant when used with Tween80 in small vesicle fabrication. The fabricated Tween 80/UMD vesicles in PBS had the size range of 200-300 nm and were stable within a temperature range of 4 to 37 °C for 96 h.

The alteration of the profile of volatiles of canned coconut milk was monitored during storage at ambient temperature. Canned coconut milk was thermally processed (121 °C for 5 min), and then stored at ambient temperature (32 to 35 °C) for 6 mo. Volatile compounds were assessed monthly using direct solvent extraction (diethyl ether), followed by high-vacuum distillation and gas chromatography-mass spectrometry analysis. Six groups of compounds consisting of alcohols, aldehydes, ketones, acids, esters, lactones, and others were identified. Two stages of major changes in profile of volatiles were observed. The 1st occurred after 2 mo as indicated by a high abundance of alcohols, acids, and lactones. The 2nd was observed after 5 mo and corresponded to a large increase in lactones, short-chain free fatty acids, 3-methyl-2(5H)-furanone, and phenol. Acetic and butyric acids observed after 5 mo could contribute to the potential of off-odor development in the product as indicated by their high odor activity values. Lactones increased approximately 10-fold. Identification of 3-methyl-2(5H)-furanone indicated that Maillard reaction had occurred in conjunction with the development of a coconut, toffee-like, and caramel odor.

This study investigated the roles of rice mono- and diacylglycerol (rice MDG) and commercial MDG on solid structure formation of rice bran oil (RBO) and RBO-anhydrous milk fat (AMF) blends after the crystallized blends were aged at 5°C for 12 or 24 h and stored at 30°C for 12 or 24 h. The rice MDG was prepared using a pilot-scale molecular distillation (MD) unit to evaporate out the free fatty acids from deodorizer distillate (DD) at 120, 140 and 160°C at 0.1 Pa. It was found that increasing the distillation temperature during MD process from 120°C to 140°C resulted in higher contents of rice MDG and γ-oryzanol in the unevaporated fraction (UMD) compared to those in DD. Although UMD increased solid fat content in RBO-UMD blend, it could not stabilize the solid fat phase in the RBO-UMD or RBO-AMFUMD oleogel at 30°C storage. In the presence of UMD, RBO-AMF-UMD blends remained in a liquid state although it contained a high content (38.54%) of saturated fatty acids. On the other hand, with the addition of commercial MDG rich in palmitic acid, RBO-MDG and RBO-AMF-MDG blends were able to retain the volume of solid fat phase in the oleogels provided that the RBO-MDG and RBO-AMF-MDG oleogels were aged at 5°C for at least 12 h. This study implicated that the presence of 1% MDG surfactant having different acyl chains from the major fatty acids in the bulk oil phase, as well as aging regime, could be used to assist solid structure forming process of RBO and RBO-AMF oleogels.

Summary Volatile compounds of fresh and dried kaffir lime leaves were analysed by gas chromatography–mass spectrometry (GC–MS). Fifty-four volatile compounds were identified in fresh kaffir lime leaf with citronellal being the most abundant, followed by l-linalool, hexanal, sabinene and β-citronellol. Aroma active compounds were determined by gas chromatography–olfactory (GC–O). Thirty-seven aroma active compounds were reported along with their odour descriptions and Log3 FD. On the basis of high values of their Log3 FD and odour characteristics together with odour activity value (OAV), the concentrations of selected eleven key odourants were compared between fresh and dried samples. Three drying temperatures at 50, 60 and 70 °C for 6 h were applied for hot air-drying. The concentrations of most compounds in 50 °C dried samples were not much different from those in fresh samples. Drying at 60 and 70 °C brought substantial losses of some key odourants. However, concentrations of citronellal and l-linalool, as key aroma compounds of kaffir lime leaves, in 60 and 70 °C dried kaffir lime leaves were not significantly different.

Protein crosslinking via the Maillard reaction has been shown to alter the functional properties of several food proteins, but the potential to use this chemistry to alter the functional performance of cocoa proteins has yet to be fully explored. This study investigated the potential of employing cocoa protein crosslinking during processing. Cocoa protein solutions were extracted from dried cocoa beans and the resulting cocoa protein solutions were treated with 2–300 mM glutaraldehyde and methylglyoxal, which established model compounds for Maillard crosslinking chemistry. SDS–PAGE analysis showed remarkably few crosslinks of the cocoa protein solutions, although lysine and particularly arginine availability were both reduced during the incubations. These results suggest that cocoa proteins are not greatly susceptible to intermolecular cross-linking via Maillard chemistry, perhaps due to non-cross-linking modifications to the arginine residues, and/or to interference from high levels of polyphenols in the cocoa bean.

After an induction period, crystallization of cocoa butter under dynamic conditions at 26.5°C occurs in two stages, primary and secondary. The primary stage involves nucleation, crystal growth, aggregation, and sintering. Crystals formed during the primary stage were slightly or non-birefringent, and had long, irregular-shaped filaments. The secondary stage was initiated by the formation of spherulites. Total crystallization time may depend upon the crystal growth rate in the primary stage and the time that coca butters take to form the spherulitic crystals in the secondary stage. After the spherulitic crystals formed, the crystal growth rates were rapid. Cocoa butters crystallized into two fractions during the primary and secondary stages. The low-melting fractions had onset melting temperatures similar to those of polymorphs IV and V of cocoa butter. The high-melting fractions, which were observed at the latter stages of crystallization, had differential scanning calorimetry endotherms with peak maxima at approximately 34–36°C (Form VI). The concentrations of 1,3-stearoyl-2-oleoylglycerol (SOS) in the crystals during growth were higher than those in the original cocoa butter. As crystallization progressed, crystals increased in their proportions of SOS in the triacylglycerol fraction. Concentrations of the C18 free fatty acids were lower during early crystallization as compared to the original cocoa butter.

Six cocoa butters with different crystallization induction times and their seed crystals were analyzed for simple lipid composition. The rapid-nucleating cocoa butter samples had higher concentrations of 1-palmitoyl-2-oleoyl-3-stearoylglycerol and 1,3-stearoyl-2-oleoylglycerol (SOS), and lower concentrations of the diunsaturated triacylglycerols, 1-palmitoyl-2,3-oleoylglycerol and 1-stearoyl-2,3-oleoylglycerol, as well as higher stearic acid concentrations within their diacylglycerol fractions when compared to the slow-nucleating samples. At the early stages of crystallization, under agitation conditions at 26.5°C, cocoa butters solidified into two fractions, high-melting and low-melting. The low-melting fractions were composed of polymorphs IV and V of cocoa butter, as indicated by the onset melting temperatures of the endotherms from differential scanning calorimetry. The high-melting fractions, which had wide melting ranges, had peak maxima of 38.5–52.2°C. Seed crystals isolated at the early stage of crystallization were characterized by high concentrations of complex lipids, saturated triacylglycerols, saturated fatty acid-rich diacylglycerols, and monoacylglycerols. The rapid-nucleating seed crystals had higher concentrations of SOS when compared to their respective cocoa butters. The slow-nucleating seed crystals did not exhibit this characteristic.

Three forms of Thai fried chili pastes (CP) were prepared, consisting of an unheated CP (UH-CP), a CP heated at 100 degrees C for 25 min (H25-CP, typical product), and a CP excessively heated for 50 min (H50-CP). The potent odorants in the CPs were investigated by two gas chromatography-olfactometry methods: dynamic headspace dilution analysis (DHDA) and aroma extract dilution analysis (AEDA). DHDA revealed that the predominant odorants in heated CPs were mainly sulfur-containing compounds, followed by lipid-derived compounds, Strecker aldehydes, and Maillard reaction products. Dimethyl sulfide, allyl mercaptan, 2- (or 3-) methylbutanal, ally methyl sulfide, 2,3-butanedione, 3,3'-thiobis(1-propene), and methyl propyl disulfide were among the most potent headspace odorants detected by DHDA. By AEDA, 2-vinyl-4 H-1,3-dithiin and diallyl trisulfide had the highest FD factors in H25-CP. On the basis of their high FD factors by both GCO methods, the predominant odorants in H25-CP were 3-vinyl-4 H-1,2-dithiin, allyl methyl disulfide, and allyl methyl trisulfide. Furthermore, dimethyl trisulfide and diallyl disulfide had the highest odor activity values in H25-CP, suggesting that these were also potent odorants in CP. In addition, methional, 3-methylbutanoic acid, 4-hydroxy-2,5-dimethyl-3-(2 H)-furanone, and 3-hydroxy-4,5-dimethyl-2( 5H)-furanone (sotolon) were indicated as potent thermally derived odorants of H25-CP.

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.

Twenty-four commercially pressed cocoa butters and 39 laboratory solvent extracted cocoa butters were evaluated. A rapid method using differential scanning calorimetry (DSC) was used to evaluate the hardness of small quantities of cocoa butter. In the DSC thermogram of a quenched sample, the percentage area under the polymorph II endotherm had a positive correlation (r=0.74) with the mechanical hardness. Soft cocoa butters were characterized by high POO, SOO content (P=palmitic acid, O=oleic acid, S=stearic acid), high iodine value, low percentage, area under the polymorph II endotherm from the DSC scanning, and low SOS. Hard cocoa butters displayed opposite characteristics. In general, South American cocoa butters were the softest and had a 37.03 iodine value, a total of 9.1% POO and SOO, and a 26.4% area under the polymorph II endotherm. Cocoa butters from Asia and Oceania were the hardest and had a 34.74 iodine value, a total of 4.1% POO and SOO, and a 35.65% area under the polymorph II endotherm. North and Central American and African cocoa butters were intermediate in hardness characteristics.