RESUMEN

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.

Asunto(s)

RESUMEN

The physicochemical properties and the flavor retention ability of the dried mungbean starch film formed in the presence of calcium ions under alkaline pH were analyzed. Treating starch in a NaOH or Ca(OH)2 solution at pH 12 induced the formation B-type starch crystal. However, the starch film made with Ca(OH)2 (Ca-film) was more effective than starch film made with NaOH (Na-film) in entrapping 1,8-cineole, menthone and citonellol. Entrapment efficiency of citonellol in Ca-film which had B-type starch crystal structure was close to that of the V-type starch film formed at neutral pH using distilled water (DW-film). 1,8-cineole, menthone, and citronellol were entrapped in dried Ca-films for 5.07%, 1.52%, and 30.84%, respectively. Physical entrapment of flavor compounds by alkaline-treated starch and high water solubility (24.4-46.7 %) of Ca-films could help designing a novel controlled flavor release systems.

RESUMEN

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.

RESUMEN

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.

Asunto(s)

RESUMEN

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.

Asunto(s)

RESUMEN

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.

Asunto(s)

RESUMEN

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.

Asunto(s)