Sweet Odor Research Articles

Impact of olfactory priming on mental representations of food concepts and subsequent food choice

Previous research suggests that food odors act as a prime and influence food choice outside of awareness. Little is known about how odors prime (healthy) food choices. We hypothesized that odors could activate mental representations of food concepts, interacting with cognitive processes underlying food decision-making. We tested this by examining which concepts (healthy, sensory, or product-specific) are activated by odors and how this impacts subsequent food choices. In a between-subjects design, 112 participants were divided into three conditions: healthy odor (apple or banana), unhealthy odor (chocolate or caramel), and non-odor (control). Participants were exposed to one condition for 5 min and then completed a lexical decision task and a screen-based food choice task. The lexical decision task included four word categories: healthy-related, sensory-related, neutral words, and non-words. Reaction times were recorded and computed for each category. Participants were asked to choose one food they wanted to eat from four (in-)congruent food word options and repeated it four times (one for each odor). Results showed participants responded slower to non-words than other words, and slower to healthy and sensory words than neutral words. However, odor exposure did not influence reaction times, nor did the interaction between odor condition and word category affect reaction times. Participants were more likely to choose unhealthy foods regardless of odor exposure. Thus, ambient sweet odors did not prime food-related information or choice. We recommend additional testing using a broader range of odors and word categories to fully validate the association of an odor with a concept.

UPLC-MS/MS and HS-SPME-GC–MS reveal the flavor profiles of two geographical indications woody vegetables: Staphylea bumalda and Staphylea holocarpa

Staphylea bumalda (SHC) and Staphylea holocarpa (PGG) were recognized as geographical indication agricultural products due to unique flavor. 1218 differential non-volatile compounds and 536 differential volatile compounds were detected and identified through UPLC-MS/MS and HS-SPME-GC–MS methods. In SHC samples, catechins, epicatechins, proanthocyanidins, quinic acid derivatives, and kaempferol glycoside derivatives were the main flavor compounds, with bitter and harsh taste. L-tartaric acid, citraconic acid and citric acid were contributed to increase acidity. 4-Hexen-1-ol acetate, butanoic acid butyl ester, 3-Hexen-1-ol acetate, (E)-, and 3-Hexen-1-ol acetate, (Z)- were identified as characteristic odor compounds with strong floral, fruity and sweet odor. In PGG samples, epicatechin gallate, quercetin glycoside derivatives, L-histidine, and L-tyrosine were the leading contributors to bitter and harsh taste. The spicy, herbal, and bad smell odor were mainly brought by 2-octanol, and 3-Octen-1-ol, (Z)-. Our results offered comprehensive insights into the flavor and quality characteristics differences between PGG and SHC.

Recognition of Davidsoniella virescens on Fagus sylvatica Wood in Poland and Assessment of Its Pathogenicity.

Davidsoniella virescens is so far only known in North America. However, recently in southern Poland, blackish growth consisting of fungal mycelia and sporulation structures was found on the wood of Fagus sylvatica. As a result of isolation, 17 cultures of this fungus were obtained. All cultures produced an intense sweet odor. This fungus, both in situ and in vitro, abundantly produced perithecia with long necks and asexual stage. Particularly characteristic was the production of variable endoconidia in two types of phialophores differing mainly in the width of the collarette. The nucleotide sequences for five gene fragments of representative cultures were used in phylogenetic analyses: 18S; the internal transcribed spacer regions ITS1 and ITS2, including the 5.8S gene (ITS); 28S region of the ribosomal RNA (rRNA), β-tubulin 2 (TUB2) and translation elongation factor 1-α (TEF1). Based on morphological and phylogenetic analyses, the fungus on European beech in Poland was identified as Davidsoniella virescens. The optimal temperature for radial colony growth was 20 °C. However, the differences between colony diameter at 25 °C compared to that at the optimal temperature were not statistically significant. Six D. virescens isolates were used for pathogenicity assay. They were inoculated into wounds on stems of two-year-old seedlings of Fagus sylvatica and Acer saccharum (36 seedlings of each tree species). Final evaluation was performed 4 months after inoculation. No external symptoms were observed in any A. saccharum seedling, neither in the crown nor on the stem. However, 13.9% of F. sylvatica seedlings showed wilting symptoms throughout the entire crown within 3-6 weeks after inoculation. Moreover, after 4 months on the stems of 30.6% beech seedlings, necrotic lesions with a length of 1.3 to 7.2 cm were formed, without any symptoms of wilting. The most noticeable internal symptom was the discoloration of the wood, which was observed in all inoculated seedlings of both tree species. All D. virescens isolates caused greater wood discoloration in F. sylvatica than in A. saccharum. Most of the differences found in the extent of discoloration between host plants were statistically significant. The discoloration caused by all D. virescens isolates in F. sylvatica was significantly greater than in the control. However, none of the isolates tested on A. saccharum caused significantly greater wood discoloration compared to the control. Pathogenicity tests showed that the D. virescens isolates identified in southern Poland may pose a greater threat to native European beech than to foreign sugar maple.

The shaking and standing processing improve the aroma quality of summer black tea

Black teas harvested during the summer season usually have the defect of low aroma intensity, resulting in unacceptability from consumers. The shaking and standing (SS) process is key to the production of oolong tea and is believed to significantly improve the aroma quality. However, the specific effects of the shaking process on the aroma quality of black tea have not been elucidated. SSBT has a higher aroma intensity than BT, especially floral and sweet odors. By Aroma Extract Dilution Analysis (AEDA), 27 volatiles with flavor dilution factor (FD) above 8 were selected, of which 20 had odor activity values (OAV) values above 1; among them, 9 floral and sweet volatiles with high OAV were linalool (485 for BT, 918 for SSBT), (E)-β-ionone (389, 699), geraniol (315, 493), β-myrcene (25, 62), (E)-2-hexenal (2, 7), phenylacetaldehyde (44, 75), (Z)-3-hexenyl hexanoate (19, 41), 1-hexanol (9, 26), and 2-phenylethanol (2,3). Aroma reconstitution of these 20 volatiles showed reliable results of floral, sweet, fruity, and roasted odors, further validating the aroma and intensity profiles of the key odorants. Overall, our results reveal that the metabolite mechanism of the SS process improves the aroma quality of black tea, providing a theoretical basis and guiding measures for the production of high-aroma black tea.

Antifungal activity of bio-active cell-free culture extracts and volatile organic compounds (VOCs) synthesised by endophytic fungal isolates of Garden Nasturtium

Antimicrobial resistance in fungal pathogens (both human and plant) is increasing alarmingly, leading to massive economic crises. The existing anti-fungal agents are becoming ineffective, and the situation worsens on a logarithmic scale. Novel antifungals from unique natural sources are highly sought to cope sustainably with the situation. Metabolites from endophytic microbes are the best-fitted alternatives in this case. Endophytes are the untapped sources of ‘plants’ internal microbial population’ and are promising sources of effective bio-therapeutic agents. Fungal endophytes were isolated from Tropaeolum majus and checked for antifungal activity against selected plant and human pathogens. Bioactive metabolites were identified through chromatographic techniques. The mode of action of those metabolites was evaluated through various spectroscopic techniques. The production of antifungal metabolite was optimized also. In particular VOCs (volatile organic compounds) of TML9 were tested in vitro for their anti-phytopathogenic activity. Ethyl acetate (EA) extract of cell-free culture components of Colletotrichum aenigma TML3 exhibited broad-spectrum antifungal activity against four species of Candida and the major constituents reported were 6-pentyl-2H-pyran-2-one, 2-Nonanone, 1 propanol 2-amino. The volatile metabolites, trans-ocimene, geraniol, and 4-terpinyl acetate, produced from Curvularia lunata TML9, inhibited the growth of some selected phyto pathogens. EA extract hampered the biofilm formation, minimised the haemolytic effect, and blocked the transformation of Candida albicans (MTCC 4748) from yeast to hyphal form with a Minimum Fungicidal Concentration (MFC) of 200–600 µg mL−1. Central carbohydrate metabolism, ergosterol synthesis, and membrane permeability were adversely affected and caused the lethal leakage of necessary macromolecules of C. albicans. Volatile metabolites inhibited the growth of phytopathogens i.e., Rhizoctonia solani, Alternaria alternata, Botrytis cinerea, Cercospora beticola, Penicillium digitatum, Aspergillus fumigatus, Ceratocystis ulmi, Pythium ultimum up to 89% with an IC50 value of 21.3–69.6 µL 50 mL−1 and caused leakage of soluble proteins and other intracellular molecules. Citrusy sweet odor volatiles of TML9 cultured in wheat-husk minimised the infections of Penicillium digitatum (green mold), in VOC-exposed sweet oranges (Citrus sinensis). Volatile and non-volatile antifungal metabolites of these two T. majus endophytes hold agricultural and pharmaceutical interests. Metabolites of TML3 have strong anti-Candida activity and require further assessment for therapeutic applications. Also, volatile metabolites of TML9 can be further studied as a source of antifungals. The present investigational outcomes bio-prospects the efficacy of fungal endophytes of Garden Nasturtium.

The neural representations of valence transformation in indole processing.

Indole is often associated with a sweet and floral odor typical of jasmine flowers at low concentrations and an unpleasant, animal-like odor at high concentrations. However, the mechanism whereby the brain processes this opposite valence of indole is not fully understood yet. In this study, we aimed to investigate the neural mechanisms underlying indole valence encoding in conversion and nonconversion groups using the smelling task to arouse pleasantness. For this purpose, 12 conversion individuals and 15 nonconversion individuals participated in an event-related functional magnetic resonance imaging paradigm with low (low-indole) and high (high-indole) indole concentrations in which valence was manipulated independent of intensity. The results of this experiment showed that neural activity in the right amygdala, orbitofrontal cortex and insula was associated with valence independent of intensity. Furthermore, activation in the right orbitofrontal cortex in response to low-indole was positively associated with subjective pleasantness ratings. Conversely, activation in the right insula and amygdala in response to low-indole was positively correlated with anticipatory hedonic traits. Interestingly, while amygdala activation in response to high-indole also showed a positive correlation with these hedonic traits, such correlation was observed solely with right insula activation in response to high-indole. Additionally, activation in the right amygdala in response to low-indole was positively correlated with consummatory pleasure and hedonic traits. Regarding olfactory function, only activation in the right orbitofrontal cortex in response to high-indole was positively correlated with olfactory identification, whereas activation in the insula in response to low-indole was negatively correlated with the level of self-reported olfactory dysfunction. Based on these findings, valence transformation of indole processing in the right orbitofrontal cortex, insula, and amygdala may be associated with individual hedonic traits and perceptual differences.

Characterization of key aroma compounds and relationship between aroma compounds and sensory attributes in different quality of high temperature Daqu

Daqu quality is determined by its aroma characteristics. In this study, molecular sensory techniques were used to investigate the sensory attributes of Jiangxiangxing high temperature Daqu, resulting in the development of a sensory wheel. A physicochemical and enzymatic analysis of different grades of Daqu revealed notable differences, especially in acidity. Furthermore, the volatile components of various grades of Daqu were investigated with HS-SPME-GC × GC-TOFMS, resulting in the identification of 524 volatile compounds belonging to 11 distinct classes within Daqu. Univariate analysis demonstrated significant differences in flavor components among Daqu samples of diverse quality grades. By employing GC-O-MS techniques and ROAV≥ 0.1, a comprehensive analysis identified a total of 29 key aroma active compounds that contribute to the overall flavor profile of Daqu. Notably, butyl acrylate and (2E)-2-octenal were found to make substantial contributions to the floral and fruity odor, as well as linalool and benzeneacetaldehyde, which were found to make substantial contributions to sweet odor. These compounds significantly enriched the aroma of Daqu and played a crucial role in enhancing the overall flavor quality of Daqu. In conclusion, these results provide a theoretical base for further investigation of different grades of Daqu, as well as the control and improvement of Daqu quality.

The Flavor Characterization of ‘Huyou’ (Citrus changshanensis) Essential Oils Extracted by Conventional and Novel Methods

The aroma of citrus is among the most appealing natural flavors. ‘Huyou’ (HY) is a hybrid citrus with a unique flavor compared to grapefruit (GF), but few studies have analyzed its characteristic flavor comprehensively. In this study, we extract six essential oils (EOs) from HY and GF peels by cold pressing (CP) and microwave-assisted hydrodistillation (MADH) and spinning cone column (SCC). Further, the flavor of six EOs was investigated by using flavoromics analysis, including e-nose, GC-MS and GC-O combined with chemometric approaches. The results showed that CP EOs exhibited a stronger citrus characteristic flavor, while MADH and SCC EOs contained more diverse volatiles. A total of 23 key odorants were identified in the GC-O-MS analysis, 12 of which were specific to HY. The flavor wheel and partial least squares regression (PLSR) revealed that floral, sweet and fruity odors were positively correlated with linalool, α-terpineol and geraniol, while fatty, green and woody odors with germacrene D, germacrene B and nootkatone. Additionally, based on orthogonal partial least squares discriminant analysis (OPLS-DA), six aroma-active compounds were screened as aroma markers to distinguish HY from GF; i.e., γ-terpinene, D-limonene, germacrene D, nootkatone, germacrene B and terpinolene. The extraction methods and citrus varieties both impact the flavor characterization of citrus EOs, and our study provides guidance on the extraction and application for citrus EOs.

Color characteristics and pyrolysis volatile properties of main colored fractions from the Maillard reaction models of glucose with three amino acids

The effects of hydrosoluble colored fractions generated in the Maillard reaction models on the volatiles of pyrolytic Maillard reaction products was investigated. The hydrosoluble colored fractions obtained by reaction of glucose with glycine (Gly-Glc), proline (Pro-Glc) and phenylalanine (Phe-Glc) respectively at 125 °C were separated using Sephadex LH-20 Gel column. The colored fraction with large molecular weight had a higher contribution to the overall color and more glucose residue structures in main skeleton than that with small molecular weight in the same model. Gel permeation chromatography analysis indicated that these colored fractions had continuous relative molecular weight distribution (1000–80000 Da). Pyrolysis - gas chromatography - mass spectrometry determination (pyrolysis temperature: 160∼900 °C) suggested that furans and pyrroles were the main volatiles of two Gly-Glc fractions after pyrolysis, and the key pyrolysis volatiles of Pro-Glc fraction were furans, pyrroles, pyran, indole and cyclopentenes, which gave a freshly baked bread, nutty, coffee-like and sweet caramel-like odor. Especially phenyl-containing compounds seemed typical indicators of Phe-Glc fraction pyrolysis products, exhibiting a benzene-like, tallowy, sweet, balsamic and floral odor. The hydrosoluble colored fractions produced by different Maillard reactions had different pyrolytic volatile properties and were suitable for the development of bakery food improver with different color and flavor requirements.

Estimation of Lipid Profile in CCl4 Induced Toxicity in Albino Rats

The combination of chlorine and chloroform in the presence of light produces carbon tetrachloride (CCl4), a colorless, volatile, non-inflammable liquid. It is a clear liquid with a sweet odor that can be perceived at low levels and does not occur naturally. It poses a significant hazard to one's health and is also one of the leading sources of toxicity in critical organs such as the lungs, kidneys, liver, and brain. Objectives: To determine the lipid profile with CCl4-induced in albino rats. Methods: The research was conducted at the University of Okara, Department of Zoology. The experiment was conducted at the animal home of the Department of Zoology, University of Okara. Albino Rats were the intended targets. There were two groups created: a control group and an experimental group. To test the harmful effect on the lipid profile, the rats were fed 30 per cent diluted carbon tetrachloride, with normal saline as a control group. This was accomplished through a 12-day trial. Sampling or dissection was done after 12 days to determine serum Total Cholesterol, Triglycerides, high-density lipoprotein (HDL), and low-density lipoprotein (LDL). Rats were dissected, and their hearts were punctured to obtain a blood sample and organs. After sampling was taken by puncturing the Rats' hearts, the samples were examined by a machine called Micro-Lab 300. Results: Total Cholesterol, Triglycerides, HDL, and LDL levels were higher than usual. Conclusions: The study indicated that CCl4 has a toxic effect on the lipid profile of rats.

Investigating the Link between Eating Attitudes, Taste and Odour Preferences and the Chemical Senses.

To examine if higher degrees of pathological eating attitudes in a non-clinical sample are associated with odour and taste perception and preferences based on psychophysical ratings. A total of 80 female university students completed the eating attitudes test (EAT-26), followed by four chemosensory measures including olfactory and gustatory perception plus perceptual ratings and preferences for food odours and tastes. There were no significant correlations between EAT-26 scores and measures of olfactory and gustatory perception. However, a significant interaction effect indicated higher degrees of pathological eating attitudes may be associated with differential sensitivity to sweet and fatty food odours compared to those with lower levels of pathological eating attitudes. This was the first study to examine pathological eating attitudes using food stimuli with a non-clinical sample. The results remain preliminary until replication. However, the findings highlight the need for development of measures of disordered eating attitudes and behaviours that go beyond caloric restriction.

Microbiomics and volatile metabolomics-based investigation of changes in quality and flavor of oat (Avena sativa L.) silage at different stages.

This study aimed to analyze the fermentation quality, microbial community, and volatile metabolites of oat silage harvested at two different stages, while examining the correlation between microorganisms and volatile metabolites. Oats were harvested at two growth stages (pre-heading [PRH] and post-heading [POH] stages), followed by 90 days of natural fermentation, with 6 replicates per treatment. Pre- and post-silage samples were randomly selected for nutrient composition, fermentation parameters, microbial population, and high-throughput sequencing analysis. Volatile metabolomics analysis was also performed on samples after 90 days of fermentation to detect differences in flavor quality after silage. The effect of growth stage on the nutrient content of oats was significant, with pre-heading oats having higher crude protein and post-heading oats having higher water soluble carbohydrates content (p < 0.05). Following a 90-day fermentation period, the pH and ammonia nitrogen/total nitrogen levels in the PRH-90 (silage from pre-heading oats after 90 days of fermentation) group demonstrated a significant decrease (p < 0.05), whereas the lactic acid content was notably higher compared to the POH-90 (silage from post-heading oats after 90 days of fermentation) group (p <0.05). Lactiplantibacillus dominated in the PRH-90 group and Enterococcus dominated in the POH-90 group, with abundances of (> 86%) and (> 87%), respectively. The differential volatile metabolites of the two treatment groups were dominated by esters and terpenoids, and the differences in flavor were mainly concentrated in sweet, green, and fruity odors. The results of Kyoto encyclopedia of genes and genomes pathway enrichment analysis demonstrated three major metabolic pathways: phenylpropanoid biosynthesis, phenylalanine metabolism, and biosynthesis of secondary metabolites. Specific microorganisms were significantly correlated with flavor indicators and flavor metabolites. Lactiplantibacillus was significantly positively correlated with flavor substances indicating sweet and fruity flavors, contributing to good flavor, while Enterococcus was significantly and positively correlated with flavor substances indicating bad flavors. In summary, growth stage had significant effects on nutritional components, fermentation parameters and flavor quality of oats, with the fermentation process dominated by Lactiplantibacillus leading to good flavor, while the fermentation process dominated by Enterococcus led to the development of poor flavor.

Effects of pile-fermentation on the aroma quality of dark tea from a single large-leaf tea variety by GC × GC-QTOFMS and electronic nose

Aroma is one of the significant quality factors of dark tea (DT). However, for a single large-leaf tea variety, there are few studies analyzing the effect of pile-fermentation on the aroma quality of DT. The GC × GC-QTOFMS, electronic nose (E-nose) and GC-olfactometry (GC-O) techniques were employed to analysis the difference of tea products before and after pile-fermentation. A total of 149 volatile metabolites (VMs) were identified, with 92 VMs exhibiting differential characteristics. Among these, 31 VMs with OAV > 1.0 were found to be correlated with E-nose results (|r| > 0.8). Additionally, GC-O analysis validated seven major differential metabolites. Notably, naphthalene, 2-methylnaphthalene, and dibenzofuran were found to enhance the woody aroma, while (Z)-4-heptenal, 2-nonenal and 1-hexanol were associated with an increase in mushroom, fatty and sweet odors, respectively. Moreover, 1-octen-3-ol was linked to reducing pungent fishy smell. These findings could provide a certain theoretical basis for understanding the influence of pile-fermentation on the aroma quality of dark tea.

Enfluran Metoda oznaczania w powietrzu na stanowiskach pracy z zastosowaniem chromatografii gazowej1

Enflurane is an inhaled general anaesthetic and is a positional isomer of another anaesthetic, namely isoflurane. At room temperature, it is a colourless, transparent liquid with a faint, sweet odour. In occupational exposure, enflurane is often used in a mixture with other inhalation anaesthetics, so symptoms are difficult to attribute to the effects of any one substance. Symptoms such as eye and skin irritation, central nervous system depression, cardiovascular disorders, and liver and kidney damage have been reported in workers exposed to anaesthetic mixtures. The aim of this research work was to develop and validate a method for the determination of enflurane in air at workplaces. This enflurane determination method is based on the adsorption of substance vapours on the ‘Petroleum Charcoal’ activated carbon, extraction with toluene and chromatographic analysis of the resulting solution. The tests used a gas chromatograph coupled with a mass spectrometer (GC-MS) fitted with a capillary polar column ZB-WAXplus (60 m length, 0.25 mm diameter and 0.5 µm stationary phase film thickness). The SIM mass spectrometer readings as a function of enflurane concentration within the tested concentration range (10.0–400 µg/ml) are linear. The analytical method developed enables the determination of enflurane in air at workplaces in the presence of other inhalation anaesthetics. The method is precise and accurate and it meets the requirements of PN-EN 482 for the determination of chemicals. The method developed for the determination of enflurane in air at workplaces has been recorded as an analytical procedure (see Appendix). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering studies.

Characterization and metabolism pathway of volatile compounds in walnut oil obtained from various ripening stages via HS-GC-IMS and HS-SPME-GC–MS

Volatile organic compounds (VOCs) of walnut oil (WO) samples obtained from 5 ripening stages were analyzed by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and HS-solid phase microextraction-GC-mass spectrometry (HS-SPME-GC–MS). A total of 75 VOCs were identified in WO, of which 24 VOCs were found to be the key aroma-active compounds for WO by using odor activity values (OAVs) analysis. Based on chemometrics methods, flavor of WO samples can be characterized into three categories, i.e., early, mid-, and late stages. WO from early ripening stage had stronger green and sweet odor due to 1,8-cineole (OAV 280) and ethanol (OAV 134.5). While nonanal (OAV 181.82), (E)-2-octenol (OAV 160), and hexanal (OAV 103.78) were sources of intense fatty and oily odor in mid-ripening stage. For WO of later ripening stage, the flavor was affected by nonanal (OAV 192.28), 1-heptanol (OAV 150), heptanal (OAV 71.11) and some organic acids.

The Impact of Different Cooking Methods on the Flavor Profile of Fermented Chinese Spicy Cabbage.

Chinese spicy cabbage (CSC) is a common traditional fermented vegetable mainly made of Chinese cabbage. In addition to eating raw, boiling and stir-frying are the most common cooking methods for CSC. To identify the impacts of boiling or stir-frying on the quality of CSC, the physicochemical properties, flavor compounds, and sensory properties of CSC were analyzed. A total of 47 volatile flavor compounds (VFCs) were detected by gas chromatography-mass spectrometry. Sulfide was determined as the main flavor compound of CSC, mainly contributed by cabbage, garlic, and onion odors. The content of sulfide decreased significantly after cooking. Nonanal, geranyl acetate, and linalool were newly generated after boiling with odor activity value (OAV) > 1, and contributed fatty, sweet, fruity, and floral odors to BL-CSC. 1-Octen-3-one, 1-octen-3-ol, octanal, nonanal, and (E)-2-nonenal were newly generated after stir-frying with OAV > 1, and contributed mushroom, fatty, and green odors to SF-CSC. Diallyl trisulfide, nonanal, (E)-β-ionone, β-sesquiphellandrene, and (E)-2-decenal were considered as the potential key aroma compounds (KACs) to distinguish the CSCs after different heat treatment. After cooking, the total titratable acidity of CSC increased and the sensory properties changed significantly. This study provides valuable information and guidance on the sensory and flavor changes of thermal processing fermented vegetables.

Physico-Chemical Characteristics and Acceptability of Graded Levels of Ensiled Cabbage Waste and Wheat Offals as Ruminants’ Supplemental Diet

Animal nutritionists are now searching for new non-traditional feed sources to enhance ruminants’ diets due to price increases and the unavailability of some unconventional feed ingredients. In a Completely Randomized Design, wheat offal was substituted with cabbage waste silage in diets 1 to 5 at 0, 10, 20, 30, and 40%, respectively for 30 days to assess the physicochemical characteristics and acceptability of the new diets by Yankasa rams. Temperatures of 29.00 ± 0.14 and 28.05 ± 0.78 °C, respectively, were noticeably lower in diets 4 and 5. Diets 4 (4.26) and 5 (4.38) considerably lowered (P &gt; 0.05) the pH. All of the diets had good silages based on color, smell, and texture, with diet 5 having a firm and wet texture. Diets 4 and 5 had sweet aromatic odour. With increasing the amount of cabbage waste in the silage, the dry matter dropped, going from 80.11 to 46.88% in diets 1 and 5, respectively. Diet 4’s lowest CP of 12.68%, is sufficient for ruminant feeding. In diet 4, the values of crude fiber and ether extract significantly (P &lt; 0.05) increased. Although there were substantial differences (P &lt; 0.05) in each diet’s fiber content, the NDF, ADF, and ADL all fell within the acceptable range for excellent silage. All the silages made in diets 1 to 5 were acceptable by Yankasa rams, but diet 5 ranked highest in terms of coefficient of preference (CoP). According to all findings, cabbage waste could be a valuable silage additive in ruminants’ diets. Wheat offal can be replaced by cabbage waste up to 30% and 40% in the diet of ruminants with good silage formation and better CoP.

Effect of Conventional and Microwave Heating on Protein and Odor Profile in Soymilk Powder

Soymilk contained serine protease enzymes with inhibitory activity against trypsin, causing a negative effect on nutritional absorption. This project aimed to investigate the effects of conventional heating (100 °C/20 min) and microwave heating (360–900 W/1–6 min) on trypsin inhibitor, protein digestibility, and odor profiles. Soymilk contained 46–47% protein, regardless of heating conditions. Using scanning electron microscopy, it can be seen that the conventionally heated sample had a smooth surface and a porous structure, whereas microwave-heated samples contained a protein matrix in clusters with rough surfaces. The molecular weight of proteins in SDS-PAGE was reduced to 19 kDa and &lt;16 kDa after conventional and microwave heating, respectively, resulting in the reduction of trypsin inhibitor from 36.66 to 0.91 and 0.56–0.66 mg/g, respectively. Protein digestibility was significantly improved when either the conventional heating at 100 °C for 20 min or the microwave heating at 900 W for 6 min was applied. From e-nose analysis, the beany flavor was reduced after the microwave heating for 3–6 min, and the highest intensity of the sweet odor compounds were observed after the microwave heating at 600 W for 1 min. Due to the short processing time, microwave heating was then recommended for inhibition of trypsin inhibitors and improving protein digestibility.

Improvement of the sensory characteristics of Dancong tea using a dry-heating post-treatment approach

Dancong tea is famous for floral aroma and strong, sweet aftertaste. Dry-heating post-treatment (DHP treatment) is used to decrease astringency and bitterness in oolong teas, but the effects of it on the taste and aroma profiles of Dancong teas are unknown. Here, the sensory and biochemical characteristics of two differently-scented Dancong tea varieties (YS and LH) were assessed both before and after DHP treatment. Overall, DHP treatment improved the taste and aroma of the infusions. The concentrations of theasinensins and theaflavins, which contribute to tea infusion colour and taste, varied significantly between varieties and as a result of DHP treatment. Treated samples showed a marked decrease in the abundance of volatile compounds such as alcohols, aldehydes, and ketones. Hotrienol and β-ionone were the primary aroma-active volatile components shared by all samples (both varieties, both before and after DHP treatment). DHP treatment generated β-myrcene and limonene, enhancing the characteristic Dancong aroma profiles and endowing treated samples with sweet and lemony odours, respectively. Heptanol and cis-2-heptenal were identified as the strongest contributors to the fresh, greenish aromas of untreated samples, and degraded by DHP treatment. This study offers an effective, economical, and implementable method of improving the quality of bitter, astringent teas.

Identification of aroma‐active components from cultivated agarwood ‘Qi‐Nan’ based on GC‐O‐MS combined with aroma extract dilution analysis

AbstractAgarwood ‘Qi‐Nan’ is commonly regarded as the highest quality agarwood, and has been highly valued for its fragrance. With the increasing amount of cultivated agarwood ‘Qi‐Nan’ in recent years, evaluation of the aroma compounds was drawn attention. Therefore, the volatile compounds in three cultivated ‘Qi‐Nan’ agarwood samples were extracted by simultaneous distillation‐extraction (SDE) and analysed by GC‐O‐MS, combined with aroma extract dilution analysis (AEDA). A total of 70 volatile compounds were identified from three samples, in which sesquiterpenes and aromatics were characterized as key aroma‐active components. Nine compounds were considered as common aroma‐active volatiles in these three essential oils according to their flavour dilution (FD) activity and relative flavour activity (RFA) value, and among them, dihydro‐β‐agarofuran and 4‐methoxy‐benzaldehyde were the most important aroma‐active compounds. Additionally, three ‘Qi‐Nan’ agarwood samples showed different aroma specificity. TD agarwood was characterized by sweet sandalwood odour due to the dominant aroma‐active compound of β‐Santalol. WS agarwood was distinguished by its woody odour because α‐kessyl acetate was its primary aroma. HQ agarwood was featured by woody, spicy and balsamic odour on account of its main aroma compounds of agarospirol and β‐elemene.