Aromatic Character Research Articles

5,18‐Dimesitylorangarin: a Stable Antiaromatic [20]Pentaphyrin(1.0.1.0.0) Displaying Remarkable Oxidative Self‐Coupling Reactions

Abstract5,18‐Dimesitylorangarin and its BF2 complex were synthesized by double SNAr reaction of 3,5‐dibromo‐BODIPY with 2‐pyrrolydipyrrin as the first examples of meso‐aryl‐substituted orangarin. These orangarins, delineated as [20]pentaphyrin(1.0.1.0.0), are strongly antiaromatic but rather stable. The free base orangarin was coupled by oxidation with MnO2 to give a 11,11′‐linked dimer, a cyclooctatetraene(COT)‐centered trimer, and a spiro‐trimer. Fused COT‐centered 3H‐orangarin dimer was oxidized to the corresponding 2H‐orangarin dimer, which was further coupled to give a triply COT‐centered 2H‐orangarin tetramer. 3H‐Orangarin oligomers are all antiaromatic as evinced by extremely low‐field‐shifted 1H NMR signals of the inner NH and ill‐defined absorption spectra with broad tails. In contrast, COT‐centered 2H‐orangarin dimer and tetramer show moderately low‐field‐shifted NH signals and intense NIR absorbance over 900 nm, suggesting effective π‐conjugation through the COT bridge and almost non‐antiaromatic character. These orangarin oligomers exhibit many reversible redox potentials owing to the intramolecular electronic interactions. Regardless of the different aromatic characters, all the orangarin monomers and oligomers exhibit very rapid excited‐state decays.

5,18-Dimesitylorangarin: a Stable Antiaromatic [20]Pentaphyrin(1.0.1.0.0) Displaying Remarkable Oxidative Self-Coupling Reactions.

5,18-Dimesitylorangarin and its BF2 complex were synthesized by double SNAr reaction of 3,5-dibromo-BODIPY with 2-pyrrolydipyrrin as the first examples of meso-aryl-substituted orangarin. These orangarins, delineated as [20]pentaphyrin(1.0.1.0.0), are strongly antiaromatic but rather stable. The free base orangarin was coupled by oxidation with MnO2 to give a 11,11'-linked dimer, a cyclooctatetraene(COT)-centered trimer, and a spiro-trimer. Fused COT-centered 3H-orangarin dimer was oxidized to the corresponding 2H-orangarin dimer, which was further coupled to give a triply COT-centered 2H-orangarin tetramer. 3H-Orangarin oligomers are all antiaromatic as evinced by extremely low-field-shifted 1H NMR signals of the inner NH and ill-defined absorption spectra with broad tails. In contrast, COT-centered 2H-orangarin dimer and tetramer show moderately low-field-shifted NH signals and intense NIR absorbance over 900 nm, suggesting effective π-conjugation through the COT bridge and almost non-antiaromatic character. These orangarin oligomers exhibit many reversible redox potentials owing to the intramolecular electronic interactions. Regardless of the different aromatic characters, all the orangarin monomers and oligomers exhibit very rapid excited-state decays.

Mechanism of the interaction between olfactory receptors and characteristic aroma compounds in sweet orange juice

The aroma compounds of three varieties of orange juice were extracted using solvent-assisted flavor evaporation (SAFE) and stir bar sorptive extraction (SBSE). A total of 41 aroma compounds were identified by gas chromatography-olfactometry (GC-O), among which 10 aroma compounds had an aroma intensity (AI) > 4.5. There were 53 aroma compounds identified by gas chromatography-mass spectrometry (GC-MS), 29 of which had an odor activity value (OAV) higher than 1. The findings indicated that (+)-limonene, linalool, hexanal, citral and myrcene were closely associated with the five characteristic aromas of orange juice. Furthermore, molecular docking was used to analyze the binding energies and interactions between these compounds and olfactory receptors (OR1A1, OR1D2, OR2W1, OR5AC2, OR1A2, and OR5M3). The average binding energies for these compounds at the six receptors were −6.2 kcal/mol, −6.0 kcal/mol, −5.8 kcal/mol, −5.1 kcal/mol, −6.3 kcal/mol and −4.7 kcal/mol, respectively. Hydrophobic interaction was a significant driving force in this process. Key residues such as Leu199 (OR1D2), Ala108 (OR1A2), Gly108 (OR2W1), Pro181 (OR5M3), Tyr261 (OR5AC2), and Val203 (OR1A1) played key roles in binding with characteristic aroma compounds. The formation mechanism of orange juice aroma was revealed, which provides theoretical guidance for the regulation of sweet orange aroma and flavor.

Effect Of Rejected Watermelon Substitution On The Quality Of Choux Paste

This research is motivated by the low utilization of watermelon rejected. Discarded watermelon is a watermelon with a small size or commonly called sub grade fruit with criteria outside the grade including size, shape, color, appearance of imperfect or damaged fruit. Watermelon contains substances that are useful for the body and has a high water content. One of the utilization of watermelon rejected can be used in the innovation of eclairs (Choux Paste). This study aims to analyze the effect of 25%, 50% and 75% watermelon substitution on the quality of color, shape, texture, aroma and taste of the choux paste produced. The type of research used in this research is pure experiment (True Experiment) with the research design used is a complete randomized design (RAL) with 3 repetitions. The type of data used is primary data obtained directly from 3 limited panelists by filling out the organoleptic test format. For hypothesis testing, this study uses analysis of variance (ANOVA) test, if different will be tested with Duncan Multi Ranges Test (DMRT) test. Based on the results of the organoleptic test and continued with the analysis of variance (ANOVA) test, it shows that there is a significant effect on the quality of brown orange color, hollow texture quality, watermelon fragrant aroma quality and watermelon sweet taste quality. There is no significant difference in the shape quality of eclairs with watermelon substitution. From this statement it can be concluded that the indicators of color, texture, aroma and taste Ho is accepted because f count < f table. While on the quality of the shape Ho is rejected because f count > f table. The best research results on the substitution of watermelon rejected on the quality of eclairs are in treatment 2, namely the use of 50% watermelon rejected.

Strawberry Volatile Organic Compounds for Targeted Metabolomics: The AMDIS Strawberry User Library from Korean Germplasm

Strawberry aroma, crucial for determining quality, involves complex volatile compounds which are challenging to identify. This study explores strawberry aroma analysis using Gas Chromatography-Mass Spectrometry (GC-MS) and the Automated Mass Spectral Deconvolution and Identification System (AMDIS). Central to our research is the creation of a bespoke strawberry Volatile Organic Compounds (VOCs) user library using AMDIS, specifically for analyzing strawberry aromas. The library contains VOCs from 61 strawberry cultivars, integrating information on 104 VOCs, including mass spectra, retention index, chemical class, CAS number, formula, odor threshold, and odor description. This custom library significantly outperformed a commercial library by reducing potential false hits by 200, decreasing the size of report files by over 96%, and, most importantly, shortening AMDIS analysis processing time from 31 s to 9 s, representing an approximate 71% reduction. Further, the study demonstrates the library’s practical application by contrasting the aroma profiles of strawberries harvested in winter and spring. This comparison revealed significant VOC variations depending on seasonal temperature changes, offering insights into environmental influences on strawberry aroma. In conclusion, this research marks a significant advance in strawberry aroma quality analysis. The strawberry VOC library developed in this study is expected to greatly aid targeted metabolomics and flavor research in strawberry breeding.

Comparison and identification of aroma components in 21 kinds of frankincense with variety and region based on the odor intensity characteristic spectrum constructed by HS–SPME–GC–MS combined with E-nose

Frankincense is an important seasoning and spice known for its distinctive and intricate flavor profile. Considering the considerable variation in the aromatic quality of frankincense due to geographical origin, species diversity and cultivation conditions, frankincense from major global origins was characterized holistically for the first time. The electronic nose (E-nose) with headspace solid-phase microextraction gas chromatography–mass spectrometry (HS–SPME–GC–MS) and sensory evaluation were implemented to characterize the aroma components of 21 commercial varieties of frankincense from around the world. The results showed that a total of 149 volatile organic compounds (VOCs) of 10 categories were identified in frankincense, among which the numbers of alcohols, terpenes and esters compounds accounted for 22.15 %, 18.79 % and 15.44 % of the total VOCs of frankincense, respectively. The PLS-DA model effectively distinguished frankincense from Oman/Somalia and other origins. Furthermore, the study identified two differential VOCs with VIP > 1 in three Asian countries and five in six African countries. The total VOCs content and sensory characteristic score of “Lemon/Citrus” in Oman frankincense is significantly higher than other regions. The OAV results showed that 61 substances (e.g., Diacety, alpha-Pinene, Camphene, Myrcene) as key aroma compounds and OICS model indicated that p-Cymenol was found to contribute significantly to the citrus aroma in frankincense. This study identified the fundamental components of frankincense flavor and revealed different flavor descriptors of frankincense, which are crucial for reconstructing frankincense flavor and improving flavor quality.

Effect Of Watermelon Albedo Substutution On Quality Of Watermelon Jam

Jam is the result of processing of fruits obtained from the cooking process of fruit juice, puree or fruit pulp with the addition of several ingredients such as acids, sugar water and thickening agents. Jam is used as a filling for pastry products or as a complement in consuming bread. Jam is made from sugar, watermelon pulp, lime juice. This study aims to analyze the effect of 15%, 30% and 45% watermelon albedo substitution on the quality of color, aroma, texture and taste of watermelon jam produced. The type of research used in this research is pure experiment (True Experiment) with the research design used is a complete randomized design (RAL) with 3 repetitions. The type of data used is primary data obtained directly from 3 expert panelists by filling out the organoleptic test format. For hypothesis testing, this study uses statistical analysis of variance (ANOVA) test, if different will be tested with Duncan Multi Ranges Test (DMRT). The results showed that there was a significant effect on the quality of the texture of easy to spread, while the quality of color, aroma and soft texture, sweetness and watermelon flavor did not have a significant difference in watermelon albedo substitution. From this statement it can be concluded that in the indicators of color quality, aroma and soft texture, sweetness and taste of watermelon Ho is accepted because f count, < f table. While in the quality of mudsh texture in the smear Ho is rejected because f count> f table. The best research results are in the best watermelon albedo substitution in treatment 2, namely 30% watermelon albedo

The Effect Of Using Different Rejected Watermelon On The Quality Of Bavarois Pudding

Bavarois pudding is a popular product with a sweet flavor and soft texture. This study aims to determine how the use of sengkaling rejected watermelon, oval rejected watermelon, and striped red rejected watermelon can affect the organoleptic characteristics of bavarois pudding. This type of research is pure experiment, the object of this research is pudding bavarois. The variables of this study include independent variables with 4 factors, namely no watermelon (X0), sengkaling rejected watermelon (X1), oval rejected watermelon (X2), and striped red rejected watermelon (X3). The dependent variable is the quality of bavarois pudding. The type of data is primary data sourced from 3 panelists who answered the organoleptic test format. This research design is a completely randomized design (CRD) with three repetitions. The data obtained were analyzed using analysis of variance (ANOVA), if Fcount > Ftable then continued with the Duncan test. The results showed that the use of rejected watermelon had a significant effect on the characteristics of shape, color, aroma, texture and taste. Striped red rejected watermelon had a significant effect on the characteristics of shape (neat according to the mold), color (pink), and taste of pudding bavarois (sweet watermelon). Oval ripe watermelon gave more prominent results in terms of texture (soft) and aroma (fragrant watermelon).

Effects of Different Fermentation Methods on Flavor Quality of Liupao Tea Using GC-Q-TOF-MS and Electronic Nose Analyses.

To further develop Liupao tea products and enhance their flavor, this study investigated the effects of different fermentation methods on the aroma quality of Liupao tea. The aroma quality of Liupao tea was comprehensively analyzed using HS-SPME in combination with GC-Q-TOF-MS, electronic nose, and sensory evaluations. Electronic nose detection showed that the aroma fingerprints of Liupao tea samples with different fermentation methods were different. Sulfides, alcohols, ketones, and methyls were the main aroma categories affecting the aroma of the four groups of Liupao tea samples. GC-Q-TOF-MS analysis revealed significant differences in the composition of aroma components among the four fermentation methods of Liupao tea (p < 0.05). Furthermore, the total amount of aroma compounds was found to be highest in the group subjected to hot fermentation combined with the inoculation of Monascus purpureus (DMl group). Based on the OPLS-DA model, candidate differential aroma components with VIP > 1 were identified, and characteristic aroma compounds were selected based on OAV > 10. The key characteristic aroma compounds shared by the four groups of samples were 1,2,3-Trimethoxybenzene with a stale aroma and nonanal with floral and fruity aromas. The best sensory evaluation results were obtained for the DMl group, and its key characteristic aroma compounds mainly included 1,2,3-Trimethoxybenzene, nonanal, and cedrol. The results of this study can guide the development of Liupao tea products and process optimization.

Influence of thermal processing on sensory profile of crayfish meat

The present study examined the outcomes of boiling (BO), air frying (AF), and boiling combined with air frying (BO-AF) methods on the appearance, texture, taste, and flavor of crayfish meat through a combination of sensory and instrumental analyses. The Free Choice Profiling and Check-All-That-Apply results showed that the BO-AF group had the highest overall acceptability. The BO-AF group presented an attractive golden color, crispy outside, and tender inside characteristics in appearance and texture. However, there was a loss of umami and sweetness in crayfish meat from the AF and BO-AF groups compared to the control (CK) and BO groups. Crayfish meat was identified as containing 42 volatile compounds. Among them, aldehydes and heterocyclic compounds were the main volatile compounds in the AF and BO-AF groups. In particular, the pyrazine compounds were produced by the thermal decomposition of methionine and cysteine. They gave the crayfish meat of the AF and BO-AF groups their characteristic roasted aroma and good color. However, compared to the AF group, the BO-AF group had the characteristic baking aroma of the AF group, as well as a floral and fruity aroma due to the presence of the boiling treatment.

Innovative insights into the roasting-driven transformation of volatile compounds and quality markers in flaxseed (Linum usitatissimum L.) oil.

Roasting is essential for developing the characteristic aroma of flaxseed oil (FSO), yet its impact on oil quality remains underexplored. This study employed headspace-gas chromatography-mass spectrometry coupled with multivariate analysis to elucidate the dynamic changes in volatile compounds and quality characteristics of FSO subjected to varying roasting temperatures. Our findings revealed that seven key aroma compounds, identified through the variable importance in the projection scores of partial least square-discrimination analysis models and relative aroma activity value, served as molecular markers indicative of distinct roasting temperatures. These compounds included 2,5-dimethylpyrazine, 2-pentylfuran, (E)-2-pentenal, 2-ethyl-3,6-dimethylpyrazine, heptanal, octanal, and 2-hexenal. Notably, roasting at 200°C was found to enhance oil stability and antioxidant capacity, with phenolic compounds and Maillard reaction products playing synergistic roles in bolstering these qualities. Network analysis further uncovered significant correlations between these key aroma compounds and quality characteristics, offering novel perspectives for assessing FSO quality under diverse roasting conditions. This research not only enriched our understanding of the roasting process's impact on FSO but also provided valuable guidance for the optimization of industrial roasting practices. This study would provide important practical applications in aroma regulation and process optimization of flaxseed oil. .

Discriminative analysis of aroma profiles in diverse cigar products varieties through integrated sensory evaluation, GC-IMS and E-nose

Cigars, treasured for their rich aromatic profiles, occupy a notable segment in the global consumer market. The objective of this study was to characterize the volatile aroma compounds that shape the flavor profiles of six distinct varieties of Great Wall cigars, contributing to the understanding of cigar aroma analysis. Utilizing HS-GC-IMS and sensory evaluation, the study discerned the aroma profiles of GJ No. 6 (GJ), Animal from the Chinese zodiac (SX), Range Rover No. 3 Classic (JD), Miracle 132 (QJ), Sheng Shi No. 5 (SS), and Red 132 (HS) cigars. The analysis uncovered a spectrum of characteristic aromas, including tobacco, creaminess, cocoa, leather, baking, herbaceous, leathery, woodsy, and fruity notes. A total of 88 compounds were identified, categorized into 11 chemical classes, with their quantities varying among the cigars in a descending order of QJ, JD, GJ, SS, HS, and SX. 24 compounds, such as 2-heptanone, n-butanol, 2,6-dimethylpyrazine and 2-furfuryl methyl sulfide were considered as key differential components. The volatile components were effectively differentiated using principal component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA), and cluster analysis, revealing correlations between sensory attributes, key components, and electronic nose (E-nose). This research introduces a novel method for analyzing volatile aroma components in cigars, offering insights to enhance cigar quality and to foster the development of new products with unique aroma profiles.

Characterization of the volatile components in the processing of Citri Exocarpium Rubrum black tea based on HS-SPME and GC/MS.

Citri Exocarpium Rubrum black tea (CER tea) is a novel blend tea infusion combining tea and CER. Due to its potential health benefits and unique flavor, it has gained popularity among consumers. Nevertheless, the aroma characteristics and key odorants of it remain to be distinguished and cognized. The HS-SPME and GC/MS techniques were employed to analyze the alterations in volatile constituents throughout the critical stages of CER tea production. A total of 200 chemical compounds exhibited notable disparities during the processing procedures. Among them, terpenes and esters were the most abundant compounds in CER tea, which might be the key material basis for the aroma quality of CER tea. It is worth noting that 124 metabolites were significantly increased in the kneading stage and drying stage, including benzeneacet aldehyde, trans-nerolidol, and D-limonene, with contained floral and fruity odors, which might be closely related to the aroma of CER tea. Monoterpenes might be important contributors to the aroma of CER tea. This study provided a theoretical basis for the quality improvement of CER tea.

Borospherene in the Nanohoop: Complexation and Aromaticity of Neutral and Dioxidized Cycloparaphenylene Supramolecules with B40 and C60 Fullerenes.

Supramolecular complexes of carbon nanohoops with fullerenes play a key role for the design of novel nanomaterials with technological applications. Herein we investigate with density functional theory (DFT) methods the capability of neutral and dioxidized cycloparaphenylenes (CPPs) to encapsulate all-boron fullerene B40. Our results show that [9]CPP and [10]CPP are feasible host candidates to encapsulate B40 displaying comparable complexation energies with the all-carbon analog [10]CPP⊃C60. Upon dioxidation the host-guest interactions are not affected, whereas the positive charge is delocalized on the CPPs leading to global aromatic character of the hosts. Consequently, the dicationic complexes [n]CPP2+⊃B40 and [10]CPP2+⊃C60 display augmented global shielding cones that strongly shield the guests, as manifested by large upfield shifts in 11B-NMR and 13C-NMR signals. Hence, CPP complexes with carbon fullerenes can be extended borospherene B40 host-guest complexes, as well as to doubly oxidized species stabilized by global host aromaticity, expanding our understanding of carbon nanohoop complexes to boron-based fullerenes.

Vacuum freeze drying combined with catalytic infrared drying to improve the aroma quality of chives: Potential mechanisms of their formation

This study aimed to investigate the effect of vacuum freeze drying combined with catalytic infrared drying (FD-CIRD) process on aromas, free amino acids, reducing sugars and free fatty acids in chive leaves and stems. Gas chromatography-mass spectrometry combined with multivariate data analysis revealed that dipropyl disulfide was the key aroma that distinguished the differences between chive leaves and stems. The key aromas benzeneacetaldehyde, decanal and 1-octen-3-ol enhanced FD-CIRD chive leaves and stems aromas. The free amino acid content was highest at FD-CIRD stage in all samples except for the control (FD), while the reducing sugar content was lowest. The content of unsaturated fatty acids gradually decreased at FD stage and increased at FD-CIRD stage. Additionally, correlation analysis revealed that phenylalanine was a potential precursor of benzacetenealdehyde, oleic and linolenic acids were potential precursors of decanal and 1-octen-3-ol. Therefore, FD-CIRD technique helps to improve the sensory profile of dried chives.

Mechanism of aroma formation in white tea treated with solar withering

Withering is a crucial process that determines the quality of white tea (WT). Solar withering (SW) is reported to contribute to the aroma quality of WT. However, the mechanism by which aroma is formed in WT subjected to SW remains unclear. In this study, through headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC–MS) and transcriptomics, we found that 13 key genes enriched in the mevalonic acid and methylerythritol phosphate pathways, such as those of 1-deoxy-D-xylulose-5-phosphate synthase and terpineol synthase, were significantly upregulated, promoting the accumulation of α-terpinolene, geraniol, and nerolidol, which imparted floral and fruity odors to WT subjected to SW. Additionally, the significant upregulation of lipoxygenases enriched in the lipoxygenase pathway promoting the accumulation of hexanol, 1-octen-3-ol, (E, Z)-3,6-nonadien-1-ol, and nonanal, which contributed to the green and fresh odor in WT subjected to SW. This study provided the first comprehensive insight into the effect mechanism of SW on aroma formation in WT.

Identification of characteristic compounds of sweet orange oil and their sweetening effects on the sucrose solution with sweetness meter, sensory analysis, electronic tongue, and molecular dynamics simulation

The characteristic aroma compounds of five-fold sweet orange oil were analyzed using gas chromatography–mass spectrometry combined with the odor aroma value (OAV) method. The results indicated that limonene, linalool, dodecanol, (E,E)-2,4-decadienal, (E)-citral, linalool, (E)-2-decenal, and geraniol are important contributors. The sweetening effects of key compounds on sucrose solutions were experimentally investigated. The results showed that the sweetness effects of five compounds (limonene, citronellal, geraniol, β-sinensal and β-caryophyllene) were better than those of (E)-citral, linalool and octanal. Molecular dynamics implied that the hydrogen bonding residues of the T1R2/T1R3-sucrose system were converted from LYS65, GLU302, ASP278, and SER144 to ASP278, SER144, ASP142, and ASP213 after the addition of limonene. Meanwhile, the hydrophobic interaction forces of the system are significantly enhanced. The total energy of the T1R2/T1R3-sucrose system decreased from −32.08 kcal/mol to −63.57 kcal/mol. The synergistic sweetening mechanism of characteristic aroma compounds of sweet orange oil on sucrose was revealed.

ABIOTIC STRESS GENE 1 mediates aroma volatiles accumulation by activating MdLOX1a in apple.

Fruit aroma is an important organoleptic quality, which influences consumer preference and market competitiveness. Aroma compound synthesis pathways in plants have been widely identified, among the lipoxygenase pathway is crucial for fatty acid catabolism to form esters in apple. However, the regulatory mechanism of this pathway remains elusive. In this study, linear regression analysis and transgene verification revealed that the lipoxygenase MdLOX1a is involved in ester biosynthesis. Yeast one-hybrid library screening indicated that a protein, MdASG1 (ABIOTIC STRESS GENE 1), was a positive regulator of MdLOX1a and ester production based on yeast one-hybrid and dual-luciferase assays, as well as correlation analysis among eight different apple cultivars. Overexpression of MdASG1 in apple and tomato stimulated the lipoxygenase pathway and increased the fatty acid-derived volatile content, whereas the latter was decreased by MdASG1 silencing and CRISPR/Cas9 knockout. Furthermore, MdASG1 overexpression enhanced the salt-stress tolerance of tomato and apple 'Orin' calli accompanied by a higher content of fatty acid-derived volatiles compared to that of non-stressed transgenic tomato fruit, while MdASG1-Cas9 knockdown calli do not respond to salt stress and promote the biosynthesis of fatty acid-derived volatiles. Collectively, these findings indicate that MdASG1 activates MdLOX1a expression and participates in the lipoxygenase pathway, subsequently increasing the accumulation of aroma compounds, especially under moderate salt stress treatment. The results also provide insight into the theory for improving fruit aroma quality in adversity.

Exploring Corbières red wine typicity: evaluation of the impact of winemaking processes on the chemical composition and organoleptic properties of wines from different terroirs

Aromatic and polyphenolic compounds play an important role in the quality of red wines, contributing not only to flavour, but also to colour, astringency and bitterness. To explore the influence of climate and oenological practices on the chemical and sensory profile of wines, red blends from five terroirs of the Corbières appellation were analysed, taking into account two production years (2018 and 2019). The wines were a blend of at least two of four main grape varieties: Syrah, Grenache, Carignan and Mourvèdre. Volatile compounds were evaluated by HS-SPME-GC-MS, while wine pigments and derived pigments were evaluated by spectrophotometric measurements. In addition, the wines were compared using a quantitative descriptive analysis sensory profile method. The percentage of the blend significantly influenced the polyphenolic and aromatic characteristics of the wines, showing distinct 'typicity' characteristics between sub-regions. Maceration techniques, on the other hand, did not did not allow us to discriminate between sub-regions, but enabled a better understanding of chemical and sensory differences between samples.

Impact of Harvesting Time on Grain Yield, Physicochemical Attributes, and 2-Acetyl-1-pyrroline Biosynthesis in Aromatic Rice

Achieving a consistent grain yield while preserving persistent aroma remains a substantial challenge in aromatic rice production in Bangladesh. To address this challenge, a field experiment was conducted at the agronomy research area of Sher-e-Bangla Agricultural University, Dhaka-1207, between 15 June 2022, and 25 November 2022 (Aman season). This study aimed to evaluate the influence of harvesting time on aromatic rice performance. The experiment, following a randomized complete block design with three replications, involved two factors: factor 1 comprised various rice varieties [Bangladesh Rice Research Institute (BRRI) dhan34, BRRI dhan70, BRRI dhan80, and Tulshimala], and factor 2 comprised three harvesting times [3, 4, and 5 weeks after flowering (WAF)]. Results revealed significant impacts of variety and/or harvesting time on grain yield, physicochemical characteristics, and aroma of aromatic rice. Notably, Tulshimala and BRRI dhan80 exhibited superior milling quality, biochemical properties, and aroma characteristics among the aromatic rice types. BRRI dhan70 and BRRI dhan80 displayed higher grain yield when harvested at 5 WAF. However, Tulshimala and BRRI dhan80 showed superiority in grain 2-acetyl-1-pyrroline (2-AP) concentration when harvested 3 or 4 WAF. Earlier harvesting at 3 and 4 WAF resulted in higher percentages of grain 2-AP (60.22% and 53.96%, respectively) compared with later harvesting at 5 WAF (used as check). In conclusion, varying harvesting times markedly impact the yield, physiochemical characteristics, and aroma of aromatic rice varieties, with earlier harvesting beneficial for aroma retention in Tulshimala and BRRI Dhan80 and later harvesting for increased economic yield in BRRI dhan70 and BRRI dhan80.