Sensory-directed flavor analysis of key odorants compounds development of French fries and oils in the break-in,optimum and degrading frying stage

The flavor is a decisive sensory characteristic that determines the popularity of French fries(FFs).During high-oleic rapeseed oil(RO)frying,the flavor development of FFs showed three noticeable stages including break-in(3.5%-7.5%of total polar compounds(TPC)),optimum(7.5%-22.18%of TPC),and degrading stages(above 22.18%of TPC).Further,in order to distinguish the key aroma compounds in each stage,the FFs prepared in RO at TPC of 3.5%(FF4),14.5%(FF15),and 26.96%(FF27)and their relevant oils(RO4,RO15,RO27)were selected for sensory-directed analysis.The results revealed that the FF4 had low contents of(E,E)-2,4-decadienal(deep-fried odor)which also caused lower sensory score in FF4 sample.The higher contents of(E,E)-2,4-decadienal in FF15 induced its higher deep-fried odor.The FF27 had higher hexanoic acid(sweaty odor),heptanoic acid,nonanoic acid,benzene acetaldehyde(stale odor),and trans-4,5-epoxy-(E)-2-decenal(metallic odor)compared with FF4 and FF15,thus leading to the undesirable flavor of FF27.Moreover,the decrease of 2,5-dimethylpyrazine and 2-ethyl-6-methyl-pyrazine in FF27 induced the lower roasty flavor,which may also lead to the decline of the sensory score.Similarly,the higher contents of(E)-2-undecenal,hexanoic acid,heptanoic acid,and nonanoic acid in RO27 lead to increase its rancid score and thus lower the sensory score.

Structure,Binding Characteristics,and 3D Model Prediction of a Newly Identified Odorant-Binding Protein from the Cotton Bollworm,Helicoverpa armigera (Hübner)

The full-length sequence of the odorant binding protein 5 gene,HarmOBP5,was obtained from an antennae cDNA library of cotton bollworm,Helicoverpa armigera （Hübner）.The cDNA contains a 444 bp open reading frame,encoding a protein with 147 amino acids,namely HarmOBP5.HarmOBP5 was expressed in Escherichia coli and the recombinant protein was purified by affinity chromatography.SDS-PAGE and Western blot analysis demonstrated that the purified protein can be used for further investigation of its binding characteristics.Competitive binding assays with 113 odorant chemicals indicated that HarmOBP5 has strong affinity to some special plant volatiles,including （E）-β-farnesene,ethyl butyrate,ethyl heptanoate,and acetic acid 2-methylbutyl ester.Based on three-dimensional （3D） model of AaegOBP1 from Aedes aegypti,a 3D model of HarmOBP5 was predicted.The model revealed that some key binding residues in HarmOBP5 may play important roles in odorant perception of H.armigera.This study provides clues for better understanding physiological functions of OBPs in H.armigera and other insects.

A conserved odorant receptor identified from antennal transcriptome of Megoura crassicauda that specifically responds to cis-jasmone

Herbivore-induced plant volatiles(HIPVs)play a key role in the interactions between plants and herbivorous insects,as HIPVs can promote or deter herbivorous insects’behavior.While aphids are common and serious phloem-feeding pests in farmland ecosystems,little is known about how aphids use their sensitive olfactory system to detect HIPVs.In this study,the antennal transcriptomes of the aphid species Megoura crassicauda were sequenced,and expression level analyses of M.crassicauda odorant receptors(ORs)were carried out.To investigate the chemoreception mechanisms that M.crassicauda uses to detect HIPVs,we performed in vitro functional studies of the ORs using 11 HIPVs reported to be released by aphid-infested plants.In total,54 candidate chemosensory genes were identified,among which 20 genes were ORs.McraOR20 and McraOR43 were selected for further functional characterization because their homologs in aphids were quite conserved and their expression levels in antennae of M.crassicauda were relatively high.The results showed that McraOR20 specifically detected cis-jasmone,as did its ortholog ApisOR20 from the pea aphid Acyrthosiphon pisum,while McraOR43 did not respond to any of the HIPV chemicals that were tested.This study characterized the ability of the homologous OR20 receptors in the two aphid species to detect HIPV cis-jasmone,and provides a candidate olfactory target for mediating aphid behaviors.

Opto-Chemical Ring Resonator Sensor Based on Morphology Dependent Resonances for Detecting Gas Odorant

A novel Opto-Chemical Ring Resonator （OCRR） has been presented for detecting gas odorant. The sensor is designed based on Morphology Dependent Resonances （MDR） which follows Maxwell＇s electromagnetic equations. In this paper, we have presented a novel technique to integrate chemical science and optical technology by using OCRR. Optical resonances of electromagnetic wave propagations in dielectric micro-ring resonator have been developed based on asymptotic approach. Parametric studies based on developed asymptotic expression have been presented to determine the resonance frequency at particular chemical composition. Finite element simulation is used to predict the performance of the sensor and found encouraging results for odorant sensing. Parametric studies show that present study will help to develop novel OCRR sensors tbr micro/nano technology and biomedical applications.

Identification and functional characterization of female antennae-biased odorant receptor 23 involved in acetophenone detection of the Indian meal moth Plodia interpunctella

The Indian meal moth,Plodia interpunctella(Lepidoptera:Pyralidae),a globally distributed storage pest,relies on odors that are emitted from stored foods to select a suitable substrate for oviposition.However,the molecular mechanism underlying the chemical communication between P.interpunctella and its host remains elusive.In this study,130 chemosensory genes were identified from the transcriptomes of 7 P.interpunctella tissues,and the quantitative expression levels of all 56 P.interpunctella odorant receptor genes(PintORs)were validated using real-time quantitative polymerase chain reaction.The functional characteristics of 5 PintORs with female antennae-biased expression were investigated using 2-electrode voltage clamp recordings in Xenopus laevis oocytes.PintOR23 was found to be specifically tuned to acetophenone.Acetophenone could elicit a significant electrophysiological response and only attracted mated females when compared with males and virgin females.In addition,molecular docking predicted that the hydrogen bonding sites,TRP-335 and ALA-167,might play key roles in the binding of PintOR23 to acetophenone.Our study provides valuable insights into the olfactory mechanism of oviposition substrate detection and localization in P.interpunctella and points toward the possibility of developing eco-friendly odorant agents to control pests of stored products.

Identification of an odorant receptor responding to sex pheromones in Spodoptera frugiperda extends the novel type-I PR lineage in moths

moths,pheromone receptors(PRs)are crucial for intraspecific sexual communication between males and females.Moth PRs are considered as an ideal model for studying the evolution of insect PRs,and a large number of PRs have been identified and functionally characterized in different moth species.Moth PRs were initially thought to fall into a single monophyletic clade in the odorant receptor(OR)family,but recent studies have shown that ORs in another lineage also bind type-I sex pheromones,which indicates that type-I PRs have multiple independent origins in the Lepidoptera.In this study,we investigated whether ORs of the pest moth Spodoptera frugiperda belonging to clades closely related to this novel PR lineage may also have the capacity to bind type-I pheromones and serve as male PRs.Among the 7 ORs tested,only 1(SfruOR23)exhibited a male-biased expression pattern.Importantly,in vitro functional characterization showed that SfruOR23 could bind several type-I sex pheromone compounds with Z-9-tetradecenal(Z9-14:Ald),a minor component found in female sex pheromone glands,as the optimal ligand.In addition,SfruOR23 also showed weak responses to plant volatile organic compounds.Altogether,we characterized an S.frugiperda PR positioned in a lineage closely related to the novel PR clade,indicating that the type-I PR lineage can be extended in moths.

Progress in Research on Insect Olfactory Perception of Habitat Odor Molecules

A highly sensitive olfactory system allows insects to precisely identify and position volatile compounds from different sources in their habitats,and plays a crucial role in their foraging,mating,and oviposition activities.During evolution,insects have successfully developed a large and complex olfactory system to adapt to heterogeneous environments,enabling the maintenance of inset population.A comprehensive examination of the olfactory system of insects may therefore yield novel insights into the development of innovative pest control and prevention strategies,as well as the study of olfactory mechanisms in vertebrates and even humans.This paper outlines the current state of research into the signal transduction mechanism by which insects perceive the olfactory molecules of their habitats.The aim of this review is to provide a reference point for future studies into the olfactory perception mechanism and its potential applications in pest management.

Identification and functional characterization of an odorant receptor in pea aphid,Acyrthosiphon pisum

The sensitive olfactory system is necessary for survival of insects.Odorant receptors (ORs)are located on the dendrites of olfactory receptor neurons and play a critical role in odor detection.Insect ORs are functionally analyzed via heterologous expression in a Xenopus oocyte system using a two-electrode voltage-clamp (TEVC)electrophysiological recording.Here,we have identified a novel OR in the pea aphid,Acyrthosiphon pisum,then we cloned and named it ApisOR4.We analyzed the ApisOR4 tissue expression patterns and found expression only in antennae tissues.Further functional analysis using TEVC revealed that ApisOR4 is broadly tuned to eight volatiles,which elicit electrophysiological response in pea aphid antennae.This study provides an initial functional analysis of aphid ORs and identifies candidate volatiles to be used in developing new strategies for aphid control.

Identification and expression profiling of putative odorant-binding proteins in the malaria mosquitoes, Anopheles gambiae and A. arabiensis

Olfaction plays a major role in host-seeking behaviour of mosquitoes. An informat- ics-based genome-wide analysis of odorant-binding protein (OBP) homologues is under- taken, and 32 putative OBP genes in total in the whole genome sequences of Anopheles gam- biae are identified. Tissue-specific expression patterns of all A. gambiae OBP candidates are determined by semi-quantitative Reverse Transcription (RT)-PCR using mosquito actin gene a internal expression control standard. The results showed that 20 OBP candidates had strong expression in mosquito olfactory tissues (female antennae), which indicate that OBPs may play an important role in regulating mosquito olfactory behaviours. Species-specific expression pat- terns of all putative anopheline OBPs are also studied in two of the most important malaria vec- tors in A. gambiae complex, i.e. A. gambiae and A. arabiensis, which found 12 of the putative OBP genes examined displayed species-differential expression patterns. The cumulative relative expression intensity of the OBPs in A. arabiensis antennae was higher than that in A. gambiae (the ratio is 1441.45:1314.12), which might be due to their different host preference behaviour. While A. gambiae is a highly anthropophilic mosquito, A. arabiensis is more opportunistic (Vary- ing from anthropophilic to zoophilic). So the latter should need more OBPs to support its host selection preference. Identification of mosquito OBPs and verification of their tissue- and spe- cies-specific expression patterns represent the first step towards further molecular analysis of mosquito olfactory mechanism, such as recombinant expression and ligand identification.

Application of Cydia pomonella expressed sequence tags： Identification and expression of three general odorant binding proteins in codling moth

The codling moth, Cydia pomonella, is one of the most important pests of pome fruits in the world, yet the molecular genetics and the physiology of this insect remain poorly understood. A combined assembly of 8？341 expressed sequence tags was generated from Roche 454 GS-FLX sequencing of eight tissue-specific cDNA libraries. Putative chemosensory proteins （12） and odorant binding proteins （OBPs） （18） were annotated, which included three putative general OBP （GOBP）, one more than typically reported for other Lepidoptera. To further characterize CpomGOBPs, we cloned cDNA copies of their transcripts and determined their expression patterns in various tissues. Cloning and sequencing of the 698？nt transcript for CpomGOBP1 resulted in the prediction of a 163 amino acid coding region, and subsequent RT-PCR indicated that the transcripts were mainly expressed in antennae and mouthparts. The 1？289 nt （160 amino acid） CpomGOBP2 and the novel 702 nt （169 amino acid） CpomGOBP3 transcripts are mainly expressed in antennae, mouthparts, and female abdomen tips. These results indicate that next generation sequencing is useful for the identification of novel transcripts of interest, and that codling moth expresses a transcript encoding for a new member of the GOBP subfamily.

Silencing of odorant binding protein gene AlinOBP4 by RNAi induces declining electrophysiological responses of Adelphocoris lineolatus to six semiochemicals

Odorant binding proteins （OBPs） are believed to be important for transporting semiochemicals through the aqueous sensillar lymph to the olfactory receptor cells within the insect antennal sensilla. Here, we injected AlinOBP4-siRNA into the conjunctivum between prothorax and mesothorax of the lucerne plant bug, Adelphocoris lineolatus and evaluated the silencing of AlinOBP4 by reverse transcription polymerase chain reaction （RT-PCR） analysis, quantitative real-time PCR （qPCR） test and electroantennogram （EAG） assay. The combination of RT-PCR and qPCR analyses revealed that the levels of mes- senger RNA transcript were significantly reduced ~95% in AlinOBP4-siRNA-treated A. lineolatus males and ~75% in RNAi-treated females within 48 hours. It was found that there are different EAG responses between male and female bugs when the AlinOBP4 gene was silenced by RNAi. The EAGs of A. lineolatus to two plant volatiles, tride- canal and hexyl alcohol, were reduced 9.09% and 79.45% in RNAi-treated males, 62.08% and 62.08% in RNAi-treated females compared to the controls, separately. Antennae of RNAi-treated bugs showed significantly lower electrophysiological responses to four sex pheromone analogs, butyl butanoate, 1-hexyl butyrate, （E）-2-hexenyl butyrate and hexyl hexanoate. The EAG recordings were reduced 35.43%, 35.24%, 39.96% and 78.47% in RNAi-treated males and 64.52%, 18.13%, 36.88% and 49.52% in RNAi-treated females, respectively. The results suggested that AlinOBP4 might play dual-roles in the identifi- cation of plant volatiles and sex pheromones. It was suspected that AlinOBP4 may have different functions in odor perception between male and female A. lineolatus.

The general odorant receptor GmolOR9 from Grapholita molesta (Lepidoptera: Tortricidae) is mainly tuned to eight host-plant volatiles

Grapholita molesta is one of the most destructive fruit pests distributed worldwide.Odorant receptors(ORs)located on the dendritic membrane of chemosensory neurons are deemed to be key molecules for sensing exogenous chemical signals.In this study,GmolOR9,a general OR from G.molesta,was functionally characterized.Quantitative real-time polymerase chain reaction revealed that GniolOR9 was more highly expressed in adults than in other stages,including eggs,larvae,and pupae.GmolOR9 expression was highly significantly more in the antennae of females than in those of males,and the highest level occurred in the antennae of 3-day-old female adults.GmolOR9 was broadly tuned to eight of 47 odorant components tested including(Z)-3-hexenyl acetate,butyl propionate,ethyl hexanoate,ethyl heptanoate,1-hexanol,(Z)-3-hexenol,2-ethyl-1-hexanol,and linalool,by in vitro heterologous expression.Furthermore,electroantennogram responses indicated that the efTects of dsOR9-injected females to(Z)-3-hexenyl acetate dramatically decreased.These results suggested that GmolOR9 might be involved in detecting hostplant volatiles.Moreover,(Z)-3-hexenyl acetate might serve as a potential attractant for the biological control of G.molesta.

cDNA cloning and recombinant expression of the general odorant binding protein Ⅱ from Spodoptera litura

A cDNA encoding the general odorant binding protein Ⅱ(GOBP Ⅱ) was isolated from the antennae of Spodoptera litura(SlGOBP Ⅱ,GenBank Accession No.EU086371) by homologous cloning and rapid amplification of cDNA ends(RACE).Sequencing and structural analyses revealed that the open reading frame(ORF) of SlGOBP Ⅱ was 489 bp,encoding 162 amino acids with a predicted MW of 18.2 kD and pI of 5.72.SlGOPB Ⅱ shared typical structural features of odorant binding proteins with other insects,including the six conservative cysteine residues.The deduced amino acid sequence of SlGOPB Ⅱ shared significant identity with the GOBP Ⅱ from S.frugiperda and S.exigua.RT-PCR and Northern blot analyses showed that SlGOBP Ⅱ was specifically expressed in the antennae.cDNA encoding SlGOBP Ⅱ was constructed into the pET-32a vector and the recombinant protein was highly expressed in Escherichia coli BL21(DE3) after induction with IPTG.SDS electrophoresis and Western blot analysis confirmed the molecular weight of the recombinant SIGOBPⅡ i.e,32 kD,which has a 6×His tag at the N-terminus.The recombinant SlGOBP Ⅱ was purified by single-step Ni-NTA affinity chromatography and used to raise antiserum in rabbits.ELISA showed that the titer of antiserum was 1:12800,while Western blot analysis showed that the recombinant SlGOBP Ⅱ was recognized as anti-SlGOBP Ⅱ antiserum.

No evidence of predator odor avoidance in a North American bird community

Recent advances in our understanding of avian chemical communication have highlighted the importance of olfaction in many aspects of avian life.Prior studies investigating predator avoidance behaviors in response to predator odor cues have produced mixed results across species and contexts.Here we assess if a community of birds in eastern Pennsylvania displays avoidance behaviors towards predator odor cues in a natural foraging setting.We use clay caterpillars to measure foraging activity by birds in the presence of predator(bobcat)urine,non-predator(rabbit)urine,and water controls in two different environmental contexts(field vs.forest).Although we detected a weak trend for birds to forage less at predator urine-treated sites,we found no significant difference in avian foraging between the site types.We did find that foraging rates between environmental contexts changed significantly over the course of the experiment,with forest sites showing decreasing foraging rates and field sites showing increasing foraging rates.Our results reinforce the published literature that avoidance of predator odors by birds may not be ubiquitous across contexts and species.

Volatile Solid and Bury Period Influence on Odorous Material Production in Simulating Landfill Treatment

Odor pollution in landfill area has attracted more social attention in China. It is very important to control the generation of odor pollutants in situ. Analyzing odorous materials production form buried waste, simulated columns of different volatile solid (VS) content and different buried period waste were designed. Gas compounds produced from the columns were collected and analyzed by comprehensive two-dimensional gas chromatography (GC × GC) method. It has remarkable relationship between VS content and concentrations of odorous material. When VS content more than 40%, the total amount of odorous compounds increases remarkably. It can be inferred that reduced VS content of original waste may effective decreasing odorous materials production in landfill area. The old rubbish produced more odorous compounds than that of fresh one in simulated columns.

20 ppm Anhydrous Ammonia Odor Agent Proposed for Hydrogen Fuel for Safe Detection of Leaks

Preferably 20 ppm anhydrous ammonia (NH3) is proposed to be added to hydrogen fuel (H) made from renewable energy sources (green hydrogen), so that H leaks may be easily detectable by smell, but not dangerously toxic. Including this odor agent, would allow H to be distributed safely in pipes, as required by law, and it would allow H to be safely stored, transported, and exported for sale, and widely commercialized. Further research is suggested to identify optimum pressure, temperature, and automated technique for injecting NH3 into H, and to chart the minimum concentration needed, as a function of temperature and humidity. An application to make hypersonic H burning aircraft safer for ground maintenance crews is proposed. An ability to make, store and distribute H, made from local sources of renewable energy, would reduce a need for fossil fuels, especially in poor, remote communities, where it could improve their economy by creating an export product for sale, while reducing pollution.

Characterization of the key aroma compounds in four varieties of pomegranate juice by gas chromatography-mass spectrometry(GC-MS),gas chromatography-olfactometry(GC-O),odor activity value(OAV),aroma recombination,and omission tests

P omegranate(Punica granatum L.)has attracted considerable attention in world markets due to its valuable nutrients and highly appreciated sensory properties.The aroma profiles of 4 varieties of pomegranate juice,including Dahongtian(DP),Jingpitian(JP),Luyudan(LP),and Tianhonngdan(TP),were investigated via gas chromatography-mass spectrometry(GC-MS)and gas chromatography-olfactometry(GC-O)analyses.A total of 43 volatile compounds were identified by using GC-MS.Among these compounds,16 were considered as potential aroma-active compounds as detected by GC-O.These compounds belonged to the classes of terpinenes,alcohols,and aldehydes.Eleven volatile compounds were defined as the main contributors to the overall aroma of pomegranate juice due to their high odor activity values(OAVs≥1).Aroma recombination and omission tests confirmed thatβ-myrcene,1-hexanol,and(Z)-3-hexen-1-ol were the key aroma compounds,and limonene,1-octen-3-ol,linalool,and hexanal were important aroma-active compounds in DP samples.

Study on the Antibacterial and Deodorization Effect of 4,4-Dichloro-2-Hydroxydiphenyl Ether in Laundry Gel Beads

In the formulation development of laundry gel beads,4,4-dichloro-2-hydroxydiphenyl ether(HP-100)was used as a bacteriostatic agent,and the effect of HP-100 dosage on the bacteriostatic rate of laundry gel bead samples with different formulation systems was examined by the suspension quantification method;the long-lasting bacteriostatic performance of laundry gel bead samples added with HP-100 was investigated by the absorption method for evaluating the antimicrobial performance of textiles;the effect of HP-100 on the odor control of laundry gel bead samples was investigated by filling out surveys and questionnaires using the actual measurement method.Questionnaire was used to investigate the effect of HP-100 on odor control.The test results showed that the antibacterial rate of the two laundry gel samples against S.aureus increased with the increase of HP-100 dosage,and the antibacterial rate of Formula 1 reached 99.9%when the dosage of HP-100 was 0.3%;the antibacterial rate of cotton cloth washed with the laundry gel sample of Formula 1+0.3%HP-100 was more than 50%after 24 h,and still had the antibacterial effect;the antibacterial rate of cotton cloth washed with the sample of laundry gel with HP-100 was more than 50%after 24 h,and still had the antibacterial effect;the antibacterial effect of the sample with HP-100 was more than 50%after 24 h,and still had the antibacterial effect.The fabrics washed with HP-100 added laundry gel beads had better odor control than those treated with laundry gel beads without HP-100,and the addition of HP-100 to laundry gel beads could have antibacterial and deodorizing effects.

Age Differences in Behavioral Responses of Male Giant Pandas to Chemosensory Stimulation

Chemical communication plays an important role in survival and reproductive success in mammalian species. In the present study, we examined the ontogenetic pattern of behavioral responses of male giant pandas （Ailuropoda melanoleuca ） to urine odors of conspecific individuals. Our data showed that exposure to the urine of adult females induced a significant increase in sniffing and environmental sniffing/licking behaviors, but a decrease in biting behavior, in males. Males of different ages displayed specific behaviors to female urine odors. Adult males spent more time licking than juvenile and sub-adult males. Further, sub-adult and adult males displayed high levels of environmental sniffing/licking, which was absent in the juvenile males. Juvenile males displayed scent rubbing behavior significantly more frequently than sub-adult and adult males, and also spent more time showing biting behavior than sub-adult males. Finally, juvenile and sub-aduh males showed no difference in response to female and male urine odors. Together, these data suggest that chemosensory cues from conspecific urines induce age-specific responses in male giant pandas.

非接触式人体气味标志化合物的定性研究

As a base research on intelligentized search technique in seismic ruins,we study on human odor by a portable GC-MS.Qualitative analysis experiment demonstrate that isoprene,acetone and 6-methyl-5-heptene-2-one are symbol of human odor.This research give important data to search survival base on artificial olfaction technique in seismic ruins.