Inhibition of Listeria in cold-smoked salmon using liquid smoke and isoeugenol

Thesis (M.S.) University of Alaska Fairbanks, 2000Listeria monocytogenes is a foodborne pathogen, ubiquitous in nature and sometimes found in seafood. Cold-smoked salmon products have few barriers to inhibit pathogen growth. This study investigated the antilisterial effects of liquid smoke and the phenolic compound isoeugenol. Five commercial liquid smokes were tested 'in vitro' and the most inhibitory to Listeria monocytogenes ATCC 19115 and L. innocua ATCC 33090 was Charsol Supreme. Chum salmon samples (100-g each) were dipped for 15 seconds at varying concentrations of liquid smoke, processed, and analyzed for L. innocua. Liquid smoke concentrations of 60-100% reduced L. innocua by 3-logs in the final product. Dwell times of 15 seconds to 5 minutes using 60% liquid smoke gradually decreased listerial survival. Isoeugenol was antilisterial 'in vitro, ' but lacked synergism with liquid smoke in cold-smoked salmon. Charsol Supreme formed an antilisterial barrier in cold-smoked salmon, and may be a useful application to commercial products

Formal [3+2] Cycloaddition Reactions of Electron-Rich Aryl Epoxides with Alkenes under Lewis Acid Catalysis Affording Tetrasubstituted Tetrahydrofurans

We report on the regio- and stereoselective synthesis of tetrahydrofurans by reaction between epoxides and alkenes in the presence of a Lewis acid. This is an unprecedented formal [3+2] cycloaddition reaction between an epoxide and an alkene. The chemical reaction represents a very concise synthesis of tetrahydrofurans from accessible starting compounds

Use of Injectable Eugenol for Euthanasia and Anesthesia of American Lobsters (Homarus Americanus) and Similar Species

Crustaceans are economically and ecologically significant, but current treatment and diagnostic protocols for crustacean health are limited. According to standards given by the American Veterinary Medical Association there are no current methods of euthanizing lobsters, nor are there effective methods of quick release anesthesia. The objective of this research demonstrated that eugenol by direct injection is a safe, efficient and reliable method for euthanizing or anesthetizing crustaceans. Anesthetic levels were determined by behavior responses, death was determined by a lack of response to stimuli. The results presented here suggest eugenol can be used as a euthanizing agent for American lobsters (Homarus americanus) and green crabs (carcinus maenas) injected into the sinusoidal circulatory system at a dose of 7µl/g dissolved in a solution of 70% ethanol and sterile sea water injected into the pericardial sac

Biosynthesis of tetrahydrofuran lignans in Virola surinamensis

Através de experimentos de administração in vivo em plântulas de Virola surinamensis, observaram-se as incorporações de fenilalanina e do fenilpropanóide E-isoeugenol no 4-O-metil-5-metoxi-E-isoeugenol (E-isoelemicina) e na lignana tetraidrofurânica verrucosina.The labelled substrates phenylalanine and phenylpropanoid E-isoeugenol were incorporated to 5-methoxy-4-O-methyl-E-isoeugenol (E-isoelemicin) and to the tetrahydrofuran lignan verrucosin in plantlets of Virola surinamensis (Myristicaceae)

Isomerisasi Eugenol Menjadi Isoeugenol Dengan Metode Sonikasi

Isoeugenol merupakan senyawa turunan eugenol yang banyak digunakan di industri farmasi, kosmetik, perisa makanan dan minuman. Konversi eugenol menjadi isoeugenol dilakukan melalui reaksi isomerisasi. Isomerisasi eugenol dapat dilakukan secara konvensional dengan pemanasan pada suhu tinggi, namun tidak efisien sehingga dilakukan dengan metode pemanfaatan gelombang mikro yang memerlukan energi cukup besar. Pada penelitian ini dilakukan isomerisasi dengan memanfaatkan gelombang ultrasonik agar dihasilkan metode yang lebih efisien. Isomerisasi berjalan optimal pada kondisi amplitudo 70% dan 40 menit, menggunakan pelarut etanol, dan dengan perbandingan berat katalis RhCl3 terhadap eugenol sebesar 1 : 2000. Pada kondisi tersebut dihasilkan isoeugenol total hampir 100% dengan komposisi cis isoeugenol sekitar 8,23% dan trans isoeugenol sekitar 91,76%

Primary investigation into the occurrence of Hydroxymethylfurfural (HMF) in a range of smoked products

5-hydroxymethylfurfural (HMF) is produced in foods through many different pathways. Recently, studies have revealed its potential mutagenic and carcinogenic properties. Determination of HMF was originally used as an indicator of both the extent of thermal processing a food had undergone and food quality. It has been identified in a variety of food products such as bread, breakfast cereals, fruit juices, milk and honey. In addition to the thermal processes that lead to the formation of HMF during thermal treatment, food smoking also creates conditions that result in the formation of HMF. This can take place within the food due to the elevated temperatures associated with hot smoking, or by the proximity of the products of the pyrolysis of the wood matrix that is used for smoking (cold smoking). This may lead to further contamination of the product by HMF over and above that associated with the rest of the preparation process. Until now, there have been no studies examining the relation between the smoking procedure and HMF contamination in smoked food. This study is a primary investigation measuring HMF levels in three categories of smoked food products; cheese, processed meat, and fish using HPLC-UV. The amount of HMF found in all three product categories supports our hypothesis that HMF levels are due to both internal pathways during processing and external contamination from smoke generation matrix (wood) employed. The results ranged from 1 ppb (Metsovone traditional Greek smoked cheese) to 4ppm (Hot-smoked ready to eat mackerel). Subsequently for smoked cheese products, a correlation was found between HMF and phenolic compounds generated by the smoking procedures and identified by SPME-GCMS. It was observed that cheese samples that had higher concentrations of HMF were also found to have higher concentrations of syringol and cresols. It is important therefore to understand the smoking procedure’s effect on HMF formation. This will aid in the development of mitigation strategies to reduce HMF formation while retaining the flavour of the smoked products

Responses of fruit flies (Tephritidae: Dacinae) to novel male attractants in north Queensland, Australia, and improved lures for some pest species

Male fruit fly attractants, cue-lure and methyl eugenol (ME), have been successfully used for the last 50 years in the monitoring and control of Dacini fruit flies (Bactrocera and Dacus species). However, over 50% of Dacini are non-responsive to either lure, including some pest species. A new lure, zingerone, has been found to weakly attract cue- and ME-responsive species in Malaysia. In Australia it attracted a weakly cue-responsive minor pest Bactrocera jarvisi (Tryon) and three non-responsive' species. Similar compounds were tested in Queensland and attracted cue- and ME-responsive species and two non-responsive' species. In this study, 14 novel compounds, including raspberry ketone formate (RKF) (Melolure) and zingerone, were field tested in comparison with cue-lure and ME at 17 sites in north Queensland. The most attractive novel lures were isoeugenol, methyl-isoeugenol, dihydroeugenol and zingerone. Several non-responsive' species responded to the new lures: Bactrocera halfordiae (Tryon), a species of some market access concern, was most attracted to isoeugenol; B.barringtoniae (Tryon), B.bidentata (May) and B.murrayi (Perkins) responded to isoeugenol, methyl-isoeugenol and dihydroeugenol; two new species of Dacus responded to zingerone. Bactrocera kraussi (Hardy), a cue-responsive minor pest in north Queensland, was significantly more attracted to isoeugenol than cue-lure. The cue-responsive D.absonifacies (May) and D.secamoneaeDrew were significantly more attracted to zingerone than cue-lure. Bactrocera yorkensisDrew & Hancock, a ME-responsive species was significantly more attracted to isoeugenol, methyl-isoeugenol and dihydroeugenol than ME. The preferential response to RKF or cue-lure was species specific. Six species were significantly more attracted to RKF, including the pests B.tryoni (Froggatt), B.frauenfeldi (Schiner) and minor pest B.bryoniae (Tryon); eight species were significantly more attracted to cue-lure including the pest B.neohumeralis (Hardy). These findings have significance in the search for optimal male lures for pest species elsewhere in the world

Antimicrobial and antioxidant potentials of essential oil and acetone extract of Myristica fragrans Houtt. (aril part)

The antifungal, antibacterial, and antioxidant potentials of essential oil and acetone extract were carried out by different techniques. In poison food medium method, the essential oil showed complete zones of inhibition against Fusarium graminearum at the all tested doses. For other tested fungi and bacteria, they gave good to moderate zone inhibition. The antioxidant activity was evaluated by measuring peroxide, thiobarbituric acid and total carbonyl values of rapeseed oil at fixed time intervals. Both the extract and essential oil showed strong antioxidant activity in comparison with butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). In addition, their inhibitory action in linoleic acid system was studied by monitoring peroxide concentration in emulsion during incubation. The results were well correlated with above values. Their radical scavenging capacity was carried out on 2,2′-diphenyl-1-picrylhydracyl (DPPH) radicalm, and they showed strong scavenging activity in comparison with synthetic antioxidants. Their reducing power was also determined, which also proved strong antioxidant capacity of essential oil and extract. Gas chromatographic-mass spectroscopy studies on essential oil resulted in the identification of 49 components representing 96.49% of the total amount, and the major component was sabinene (20.22%), followed by terpinen-4-ol (12.08%), safrole (10.32%), α-pinene (9.7%), β-phellandrene (6.56%), and γ-terpinene (5.93%). The acetone extract showed the presence of 23 components representing 71.66% of the total amount. The major components were isocroweacin (18.92%), elemicin (17.68%), methoxyeugenol (8.13%), linoleic acid (4.12%), dehydrodiisoeugenol (4.06%), palmitic acid (2.8%), and trans-isoeugenol (2.76%). © 2005 Institute of Food Technologists.Fil: Singh, Gurdip. Deen Dayal Upadhyay Gorakhpur University India; IndiaFil: Marimuthu, P.. Deen Dayal Upadhyay Gorakhpur University India; IndiaFil: De Heluani, Carola S.. Universidad Nacional de Tucumán; ArgentinaFil: Catalan, Cesar Atilio Nazareno. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; Argentin