Effects of Different Yellowing Conditions on Neutral Aroma Components and Smoking Quality of Flue-cured Upper Leaves

A heated air circulation standard curing barn was used for baking tobacco leaves, and the effects of different yellowing conditions during the baking process on contents of neutral aroma components and smoking quality of upper leaves were studied by setting different yellowing time and color-fixing time. The results showed that during the baking process, only by prolonging the yellowing time by 24 h on the basis of control, the content of every kind of neutral aroma components in- creased obviously and the content of solanone increased by nearly 2.20 times. It was unfavorable for the degradation and accumulation of aroma components when only prolonging color-fixing time by 24 h. Prolonging both yellowing time and color- fixing time by 24 h mainly promoted the accumulation of chlorophyll degradation product neophytadiene, which increased by 33.24%, while the degradation and ac- cumulation of some aroma components were inhibited, indicating that only prolonging the yellowing time by 24 h could promote the accumulation of various kinds of neu- tral aroma components and improve the quality of tobacco leaves. The regression models were established of neutral aroma components in the first and second prin- cipal components to total aroma content, which were y=x＋0.053 47 （R^2=0.919 7） and y=x＋0.147 5 （R^2=0.698 4）, respectively, and they were verified to be feasible.

Effects of Applying Bio-bacterial Fertilizer on Aroma Components of Flue-cured Tobacco

Objective] This research aimed to investigate the effects of bio-bacterial fertilizer on quality of flue-curved tobacco. [Method] The various concentrations of bio-bacterial fertilizer were applied to flue-cured tobacco as leaf fertilizer and base fertilizer respectively. [Result] The effect of bio-bacterial fertilizer on flue-cured tobac-co differed among different treatments. Compared with the control, the bio-bacterial fertilizer significantly affected the quality of flue-cured tobacco. Among al the treat-ments, Treatment 3（leaf fertilizer） showed the best treatment effect, and it significant-ly improved the quality of flue-cured tobacco. [Conclusion] The bio-bacterial fertilizer showed significant improving effect on quality of flue-cured tobacco if spayed as leaf fertilizer.

Classification and Distribution of Common Aroma Components in Tobacco Leaf Based on Their Physical and Chemical Properties

[Objective] This study was aimed to find a new method for the classification of common aroma components in tobacco leaves. [Method] Sixty-four common aroma components in tobacco leaves were classified by cluster analysis based on their relative molecular weight. The contents and distribution of aroma components in another 71 C3F and 64 B2F tobacco leaf samples were analyzed by using the new method. [Result] The 64 common aroma components were divided into three categories trough the cluster analysis based on their molecular weight. CategoryⅠ consisted of 12 aroma components which had high molecular weight（281.308±21.536on average） and high boiling point（371.311±29.904 ℃ on average）. Category Ⅱ included 27 components which had low molecular weight（103.722 ± 13.115 on average） and low boiling point（176.132±42.342 ℃ on average）. Category Ⅲ included 25components which had middle molecular weight（175.393 ± 24.906 on average） and middle boiling point（250.562±45.431 ℃ on average）. The content of high-molecularweight aroma components in middle leaves（547.344±224.391 μg/g） was much higher than that in upper leaves（477.549±182.066 μg/g）. The content of low-molecularweight aroma component in middle leaves（17.468±3.459 μg/g） was also significantly higher than that in upper leaves（15.936±3.456 μg/g）. The content of middle-molecular-weight aroma component in middle leaves（44.931 ±8.953 μg/g） was extremely significantly higher than that in upper leaves（37.997±6.042 μg/g）. [Conclusion] This study proposed a new way to classify the aroma components in flue-cured tobacco leaves using the relative molecular weight as the index, which will provide theoretical reference for developing special tobacco leaves.

Changes of Aroma Components in Hongdeng Sweet Cherry During Fruit Development

To study the changes of aroma components in sweet cherry during fruit development, the aroma components in sweet cherry fruit from the green stage, the color stage, the commercial stage, and the ripe stage were collected using head-space solid phase microextraction （HS-SPME）, and were analyzed using a gas chromatograph-mass spectrophotometer （GC- MS）. A total of 37 compounds were identified from the sample extracts. Aldehydes, alcohols, and esters were the major constituents. The aroma components behaved differently during the fruit developmental period. C6 aldehydes and aromatic aldehydes were the main aldehydes in the sweet cherry fruit. The contents of C6 aldehydes increased quickly to 84.16% in the color stage, then decreased as ripening proceeded, and then, the contents decreased to 59.20 and 55.58% at the commercial stage and the ripe stage, respectively. The aromatic aldehydes （benzaldehyde） increased as ripening proceeded, and the maximum was found at the ripe stage. Alcohols of sweet cherry fruit included C6 alcohols and aromatic alcohols. The content of （E）-2-hexen-l-ol increased as ripening proceeded. The maximum was found at the commercial stage; alcohol was only found at the ripe stage. Ester components included ethyl acetate, butanoic acid ethyl ester, hexanoic acid ethyl ester, which increased as the fruit ripened. Hexanal, （E）-2-hexenal, benzaldehyde, （E）-2-hexen-l-ol, ethyl acetate, and hexanoic acid ethyl ester were the characteristic aroma components of sweet cherry fruit. These aroma components started to form drastically at the color stage, and the main aroma was formed at the commercial stage, which then turned bad at the ripe stage because of the presence of alcohol. So the optimal harvest time of sweet cherry was at the commercial stage.

Judgment of Aroma Types of Middle and Upper Flue-cured Tobacco Leaves Based on Proportions of Aroma Components

[Objective] This study aimed to establish mathematical models for judging the aroma types of flue-cured tobacco leaves from the upper and middle parts of plants. [Method] A total of 128 samples （63 C3F and 65 B2F） from 11 main tobac- co production provinces of China were selected as materials. Stepwise discriminant analysis was applied to samples with different aroma types and discriminant function was expressed with the proportions of 67 aroma components in total aroma con- stituents as the index. [Result] The ratio of most aroma components in clear and full aroma tobacco leaves was higher than that in middle aroma leaves. The ratios of 51, 43 and 40 aroma components of clear, middle and full aroma tobaccos were higher in upper leaves than that in middle leaves. Aroma components dominated certain aroma types differed between middle and upper leaves. The proportions of 18 and 11 aroma components in upper and middle leaves were led in the stepwise discriminant function respectively. Self-validation and cross-validation methods were applied to evaluate the original samples, and the accuracy rates reached 100% and 98.6% on middle leaves, 96.37% and 94.4% on upper leaves. The accuracy rates on some other samples reached 100% on middle leaves and 91.7% on upper leaves predicted with the model. [Conclusion] The ratio of aroma components as discriminant index could improve discriminant accuracy significantly in the middle and upper leaves. It could be used to analyze aroma types objectively, accurately and quickly.

Changes of Aroma Components in 'Keitt' Mango during the Postharvest Period

[ Objective] This study aimed to investigate the ehangos of aroma components in mango fruit at different post-harvest stages. [ Method] The aroma com- ponents in ＇ Keitt＇ mango fruit at 3,6, 9 and 13 d postharvest were extracted using heM-space solid phase mieroextraction （HS-SPME） and analyzed by gas chre- matograph-rnass speetrephotometer （GC-MS）. [ Result] The results showed that a total of 42 aroma compounds were identified from the mango samples at four sta- ges. To be specific, monoterpene and sesquiterpene were the major components; at 3, 6, 9 and 13 d postharvest, the relative contents of terpene were 94.24%, 98.91%, 55.32% and 95.97%, respectively. [ Conclusion] IS-（ ＋ ）-3-earene is the characteristic aroma component in ripe fruit of ＇ Keitt＇ mango. The aroma of mango fruit is also affected by ester, alcohol and aldehyde compounds.

Study on Aroma Components of Six Kinds of Plum Fruits

[Objective] The aim was to study the aromas composition of plum fruit. [Method] The aroma components of six kinds of plum fruits were analyzed by SPME, detected and identified by GC-MS.[Result] 85 kinds of aroma substances were separated and identified, including 40 kinds of common components.The experiments had good reproducibility by strictly controlling the desorption temperature, time and sample holding time.The obtained chromatographic peak retention time and the normalized area variation coefficient CV% values were between 0.03% -0.54% and 5.85% -18.08% by experimenting the five precision of AoLi13.The qualitative and quantitative were fully meet repeatability requirements for test samples. [Conclusion] The study provided scientific basis for the development and process of plum industry in China.

Causes of Deterioration and Changes of Aroma Components in Cigarette Raw Materials

The quality of the favoring agents and fragrances degenerated frequently during the storage and transportation process in a cigarette factory in Yunnan Province, causing huge economic losses. In order to ascertain the causes of deterioration, the microbial population, quantity and aroma components of the raw mate- rials were analyzed in the present study. The results showed that a total of 28 bacterial strains and one fungal strain were isolated and identified, belonging to 13 genera. The 29 strains were Bacillus sp. , Microbacterium sp. , Sphingomonas sp. , Leclercia sp. and Acinetobacter sp. isolated from normal ZY material; Bacil- lus sp. , Microbacterium sp. , Sphingomonas sp. , Brevundimonus sp. , Acinetobacter sp. , Agrobacterium sp. , Ralstonia sp. , Acetobacterium sp. , Saccharomyces sp. and Acidovorax sp. isolated from deteriorated ZY material; Agrobacterium sp. , Microbacterium sp. , Burkholderia sp. , Bacillus subtilis strain, Acetobacterium sp. and Leclercia sp. isolated from normal RZ material ; Agrobacterium sp. , Microbacterium sp. , Bacillus subtilis strain, Acetobacterium sp. , Lec/erc/a sp. , Enter- obacter sp. , Acinetobacter sp. and Saccharomyces sp. isolated from deteriorated RZ material. Microbacterium was the dominant genus by number in normal ZY ma- terial, and the population of this genus accounted for 55.6% of the total. In deteriorated ZY material, Acetobacterium, Bacillus and Saccharomyces were dominant genera, as the population of the three genera occupied 75.0% of the total. The total population of microorganisms in the deteriorated ZY material was 90 times of that in normal ZY material. In normal RZ material, the population of each of Microbacterium, Agrobacterium and Bacillus accounted for 25%, while that of each of Leclercia and Burkholderia accounted for 12.5%. In deteriorated RZ material, the population of Bacillus accounted for 65.0% of the total. The total population of the microorganisms in deteriorated RZ material was 29 times of that in normal RZ material, indicating that the deterioration of the materials was caused by microor- ganisms. The contents of aroma components were detected using two-dimensional gas chromatography-mass spectrometry （GC-MS）. The results showed that in nor- mal ZY material, the content of β-damascone was higher than that of other aroma components. And normal ZY material had higher contents of benzaldehyde, β-damascone, β-damascone, β-damascone, menthol and benzyl benzoate than deteriorated ZY material, and the differences in the contents of β-ddamascone and β-damascone were most significant between the two materials. In normal RZ material, the content of β-damascone was higher than that of other aroma components. And normal RZ material had higher contents of menthol, ethyl capratc, β-damascone, β-damascone and tabanane C than deteriorated RZ material, and the differ- ences in the contents of ethyl caprate and capric acid were most significant between the two materials. The results revealed that aroma components changed greatly in deteriorated tobacco materials.

Study on Extraction of Effective Aroma Components from Formula Tobacco by the Supercritical CO2 Extraction Method and Its Aroma Composition

[Objectives]This study was conducted to improve the sensory quality and industrial availability of tobacco extracts.[Methods]The L9(34)design was adopted to carried out an extraction experiment,in which formula tobacco was extracted using supercritical CO2,and the extract was concentrated by vacuum distillation.Through sensory evaluation and chemical analysis,the function determination and chemical composition analysis of the tobacco extracts were carried out,and the optimal supercritical fluid extraction process was finally determined.[Results]The obtained optimal supercritical fluid extraction conditions were as follows:extraction temperature 55℃,extraction pressure 25 MPa,CO2 flow rate of 20 L/h,and entrainer of 95%ethanol.The tobacco extract obtained under the optimal conditions endowed the cigarettes with full and delicate aroma,less irritation and clean aftertaste and made the flavor of the cigarettes overall coordinated and softer,so the sensory quality was significantly improved.[Conclusions]The tobacco extract obtained by the supercritical CO2 extraction method from formula tobacco can effectively improve the quality of cigarettes.

Effects of ultrasonic-assisted extraction on bioactive compounds,volatile flavors and antioxidant activities of vine tea water extracts

Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in China.In vine tea processing,a large amount of broken tea is produced,which has low commercial value.Methods:This study investigates the influence of different extraction methods(room temperature water extraction,boiling water extraction,ultrasonic-assisted room temperature water extraction,and ultrasonic-assisted boiling water extraction,referred to as room temperature water extraction(RE),boiling water extraction(BE),ultrasonic assistance at room temperature water extraction(URE),and ultrasonic assistance in boiling water extraction(UBE))on the yield,dihydromyricetin(DMY)content,free amino acid composition,volatile aroma components,and antioxidant properties of vine tea extracts.Results:A notable influence of extraction temperature on the yield of vine tea extracts(P<0.05),with BE yielding the highest at 43.13±0.26%,higher than that of RE(34.29±0.81%).Ultrasound-assisted extraction significantly increased the DMY content of the extracts(P<0.05),whereas DMY content in the RE extracts was 59.94±1.70%,that of URE reached 66.14±2.78%.Analysis revealed 17 amino acids,with L-serine and aspartic acid being the most abundant in the extracts,nevertheless ultrasound-assisted extraction reduced total free amino acid content.Gas chromatography-mass spectrometry analysis demonstrated an increase in the diversity and quantity of compounds in the vine tea water extracts obtained through ultrasonic-assisted extraction.Specifically,69 and 68 volatile compounds were found in URE and UBE extracts,which were higher than the number found in RE and BE extracts.In vitro,antioxidant activity assessments revealed varying antioxidant capacities among different extraction methods,with RE exhibiting the highest DPPH scavenging rate,URE leading in ABTS•+free radical scavenging,and BE demonstrating superior ferric ion reducing antioxidant activity.Conclusion:The findings suggest that extraction methods significantly influence the chemical composition and antioxidant properties of vine tea extracts.Ultrasonic-assisted extraction proved instrumental in elevating the DMY content in vine tea extracts,thereby enriching its flavor profile while maintaining its antioxidant properties.

Analysis of Volatile Components in Strawberry Cultivars Xingdu 1 and Xingdu 2 and Their Parents

To study differences and genetic trends of volatiles in Xingdu 1 and Xingdu 2, the strawberry cultivars, with their parents, the volatile components were analyzed by head space-solid phase microextraction and gas chromatography-mass spectrometry. The results indicated that a total of 50 compounds were identified in Xingdu 1 cultivar, including hexanoic acid methyl ester and hexanoic acid ethyl ester, butanoic acid methyl ester, and butanoic acid ethyl ester, octanoic acid methyl ester and octanoic acid ethyl ester, isomyl hexanoate. And there were 71 compounds in Xingdu 2, which were similar to that of Xingdu 1. About 55 volatiles were identified in Allstar （female parent）, including acetone, acetic acid 1- methylethyl ester, 1-octanol, hexanoic acid ethyl ester and butanoic acid methyl ester. And 43 volatiles were identified in Toyonoka （male parent）, including hexanoic acid ethyl ester, nerolidol, 1-octanol, hexanoic acid methyl ester, acetic acid octyl ester, isomyl hexanoate and octanoic acid methyl ester. Consequently, hexanoic acid methyl ester and hexanoic acid ethyl ester, butanoic acid methyl ester, and butanoic acid ethyl ester and isomyl hexanoate in twins might be affected both sides of their parents. In the family, male parent （Toyonoka） had the highest concentrations of fragrance alcohols, such as nerolidol, linalool and 1-octanol, but which couldn＇t be transmitted to the descendants. Acetone, acetic acid 1- methylethyl ester of the twins originally came from matrilinear inheritance, as the contents of the two compounds were very high in Allstar but little in Toyonoka. Genetic trends of butanoic acid methyl ester, butanoic acid ethyl ester, hexanoic acid ethyl ester, hexanoic acid methyl ester and isomyl hexanoate were affected by both sides of parents.

Determination of Aroma Composition of Santalum album Linn by Solid-phase Microextraction-Gas Chromatography-Mass Spectrometry

[Objectives]This study aimed to determine the volatile components in Santalum album Linn and gradually clarify the aroma composition of S.album Linn.[Methods]Solid-phase microextraction method was used to obtain the volatile components of S.album Linn.The aroma components were analyzed by gas chromatography-mass spectrometry and their relative contents were calculated using the area normalization method.[Results]In a dry state at room temperature,39 chemical components were identified from S.album Linn,mainly olefins(91.15%),alkanes(3.00%),alcohols(2.56%),esters(2.19%),ketones(0.55%),aldehydes(0.41%)and heterocyclics(0.14%).[Conclusions]This method has the advantages of low sample consumption,easy operation,rapid identification of aroma components and high sensitivity,and can effectively separate and determine volatile components in S.album Linn,realizing the rapid identification of different S.album Linn varieties and providing technical support for further research on Chinese medicinal materials.

Characteristics of traditional Chinese acidic rice soup(rice-acid)prepared with different fermentation methods

Rice-acid,a Chinese traditional acidic rice soup(rice-acid),is widely accepted by consumers due to its unique flavor and anti-oxidation,anti-aging and immunity enhancement functions.This study confirmed that L-lactic acid and malic acid were the main organic acids in rice-acid.Low-temperature rice-acid samples produced by enterprises had the highest signal intensity of sour taste.The total content of free amino acids in different fermented rice-acid samples were in the range of 0.003-0.468 mg/g.42 key volatile flavor compounds were identified in rice-acid.8 volatile compounds with a higher contribution to the aroma of rice-acid were respectively acetic acid,1-octen-3-ol,2-heptanol,ethyl acetate,propyl propionate,hexanal,nonanal,and2,3-butanedione.The interaction between lactic acid bacteria(3.00×10^(3)-7.02×10^(6) CFU/mL)and yeasts(5.04×10^(4)-2.25×10^(8) CFU/mL)affected the formation of taste and aroma components in rice-acid.The physicochemical characteristics including titratable acidity,pH,reducing sugars,amino acid nitrogen,gammaaminobutyric acid showed significant differences between low-temperature fermentation samples and hightemperature fermentation samples.In addition,relationships linking all data through Pearson coefficient correlation were also reported.In summary,the study can be used to improve the quality of rice-acid products.

Preparation and chemical characterization of banana/orange composite wine

Banana/orange composite wine was brewed in the lab by liquid fermentation using angel yeast and lactic acid bacteria as the fermentation strains,and characterized by chemical analyses.It was found that the best ratio of banana juice to navel orange juice was 1:2,and the optimum alcohol fermentation parameters were as follows:28~30℃,22%initial sugar content,6%yeast,and 6 days of fermentation to reach an alcohol concentration of 11.63%v/v.The free amino acids in the composite wines were tested by automatic amino acid analyzer,and the flavor components of the composite wine were determined and analyzed by gas chromatography-mass spectrometry(GC-MS).Seven types of trace elements in the composite wine were measured by atomic absorption spectrometry.Results showed that there were 17 free amino acids,and their total concentration was up to 897.6 mg/L.A total of 16 key compounds were identified in the composite wine,11 of which were ester,4 of which were alcohols and 1 of which was acid.Magnesium,iron,copper and manganese elements were relatively rich in the wine,while lead was extremely low.