Orientation ofMicroplitis croceipes (Hymenoptera: Braconidae) to green leaf volatiles: Dose-response curves

FemaleMicroplitis croceipes wasps were tested in a wind tunnel for their ability to orient to various concentrations of eight different green leaf volatile (GLV) substances [hexanal, (E)-2-hexenal, (E)-2-hexen-1-ol, (Z)-3-hexen-1-ol, (E)-2-hexenyl acetate, (Z)-3-hexenyl acetate, (Z)-3-hexenyl propionate, and (Z)-3-hexenyl butyrate]. Overall, the esters elicited the greatest percentage of successful orientation flights, the alcohols elicited an intermediate response, and the aldehydes elicited a low response. The semilog dose-response curves were generally hill-shaped with high responses at medium release rates and low responses at high or low release rates. For the aldehydes, positive responses occurred at all GLV release rates between 0.01 and 100 nl/min. For some alcohols and esters, positive responses occurred at release rates as low as 1 pl/min and as high as 1μl/min. These data show thatM. croceipes wasps are strongly attracted to GLVs and are capable of orienting to GLV concentrations that would occur in nature when a caterpillar feeds on a green leaf. Hence, in nature, GLVs may be important clues, enablingM. croceipes to locate their hosts.     

Aggregation pheromone for the pepper weevil,Anthonomus eugenii cano (Coleoptera: Curculionidae): Identification and field activity

This study describes the identification of an aggregation pheromone for the pepper weevil,Anthonomus eugenii and field trials of a synthetic pheromone blend. Volatile collections and gas chromatography revealed the presence of six male-specific compounds. These compounds were identified using chromatographic and spectral techniques as: (Z)-2-(3,3-dimethylcyclohexylidene)ethanol, (E)-2-(3,3-dimethylcyclohexylidene)ethanol, (Z)-(3,3-dimethylcyclohexylidene)acetaldehyde, (E)-(3,3-dimethylcyclohexylidene)acetaldehyde, (E)-3,7-dimethyl-2,6-octadienoic acid (geranic acid), and (E)-3,7-dimethyl-2,6-octadien-1-ol (geraniol). The emission rates of these compounds from feeding males were determined to be about: 7.2, 4.8, 0.45, 0.30, 2.0, and 0.30µg/male/day, respectively. Sticky traps baited with a synthetic blend of these compounds captured more pepper weevils (both sexes) than did unbaited control traps or pheromone-baited boll weevil traps. Commercial and laboratory formulations of the synthetic pheromone were both attractive. However, the commercial formulation did not release geranic acid properly, and geranic acid is necessary for full activity. The pheromones of the pepper weevil and the boll weevil are compared. Improvements for increasing trap efficiency and possible uses for the pepper weevil pheromone are discussed. A convenient method for purifying geranic acid is also described.The mention of firm names or trade products does not imply endorsement or recommendation by the U.S. Department of Agriculture over other firms or similar products not mentioned. All programs and services of the U.S. Department of Agriculture are offered on a nondiscriminatory basis without regard to race, color, national origin, religion, sex, age, marital status or handicap.     

Oxidation of soybean oil during storage of starch-oil composites

The oxidative deterioration of dry starch-oil composites was investigated by chemical and sensory methods. The composites were stored at 37°C for 63 d, and changes in the hexanal content and odor attributes were monitored. Analysis of the extracted oil showed that the first run through the drum dryer presented higher hexanal concentrations than the subsequent runs. Starch-oil composites from the first run though the drum dryer showed higher metal concentrations and higher odor ratings during storage time than the subsequent runs. There was a significant correlation between odor attributes and hexanal concentration in the first run. Since both the oxidation and the metal content were higher in the first run and decreased in further runs, we concluded that oxidation might have been induced by the presence of metal in the drum dryer. It is likely that during drum drying, the metal drum and knife surfaces became coated with soy oil, reducing both abrasion and metal contact with the product. Since many applications of the starch-oil composite technology require drum drying, it will be necessary to take measures to minimize metal contamination of the product, perhaps by discarding the initial portion of product, which contains the most metal.     

Shallow Trench Isolation for the 45-nm CMOS Node and Geometry Dependence of STI Stress on CMOS Device Performance

In the present work, a high aspect ratio process (HARP) using a new O₃/TEOS based sub atmospheric chemical vapor deposition process was implemented as STI gapfill in sub-65-nm CMOS. Good gapfill performance up to aspect ratios greater than 10:1 was demonstrated. Since the HARP process does not attack the STI liner as compared to HDP, a variety of different STI liners can be implemented. By comparing HARP with HDP, the geometry dependence of nand p-FET performance due to STI stress is discussed     

Continuous Hydrolysis of Cuphea Seed Oil in Subcritical Water

Cuphea seed oil (CSO) is a source of decanoic acid which is useful in the preparation of estolide lubricants among other applications. Decanoic acid and other free fatty acids (FFA) can be hydrolyzed from CSO using a catalyst like KOH, followed by neutralization with HCl and extraction with hexane. This procedure, however, uses caustic materials, hazardous solvents and generates waste salt streams. This study investigated the use of water without catalysts to hydrolyze CSO in a continuous flow tubular reactor. Parameters such as the interaction of pressure and temperature, temperature, water to cuphea oil fatty acid residue (H₂O:COFAR) molar ratio, and flow rate were examined. The lowest conversions of CSO to FFA were at the lowest temperature (i.e., 300 °C) and the hydrolysis was ca. 90% at 350 °C and 13.8 MPa and ca. 80% at 365 °C and 13.8 MPa. Hydrolysis increased with pressure and leveled off at 13.8 MPa. Hydrolysis increased with temperature and leveled off at ca. 330 °C. The optimal H₂O:COFAR molar ratio was found to be 6:1. Conversion rates were inversely proportional to flow rate with 95% conversion at the lowest flow rate (i.e., 0.25 mL/min) corresponding to the longest residence time (i.e., ca. 45.2 min). These results demonstrate a continuous subcritical water process for hydrolyzing CSO to FFA that is effective, requires no catalysts and does not generate a waste salt stream.     

Phenolic content and antioxidant capacity of supercritical carbon dioxide-treated and air-classified oat bran concentrate microwave-irradiated in water or ethanol at varying temperatures

Oat bran concentrate (OBC) was defatted with supercritical carbon dioxide (SCD), then microwave-irradiated (MI) at 50, 100 or 150 °C for 10 min in water, 50% or 100% ethanol, and extract pH, soluble solids, phenolic content (PC) and antioxidant capacity (AC) were analysed. OBC was air-classified into five fractions and MI in water at 150 °C. OBC without SCD and microwave irradiation was extracted at 22 °C. Most effective temperature during microwave irradiation for maximising extraction of PC and AC was 150 °C. Defatted OBC in 50% ethanol and MI at 150 °C extracted greatest PC and AC. SCD treatment slightly reduced PC and AC. OBC extracted in water or 50% ethanol at 22 °C without microwave irradiation had similar PC and AC than OBC MI at 150 °C, but much higher levels were observed for latter heat treatment using absolute ethanol. Air-classification shows potential to enhance PC and AC.     

Antioxidant Activity and Sensory Evaluation of a Rosmarinic Acid‐Enriched Extract of Salvia officinalis

An extract of Salvia officinalis (garden sage) was prepared using supercritical carbon dioxide (SC‐CO₂) extraction, followed by hot water extraction. The resulting extract was enriched in polyphenols, including rosmarinic acid (RA), which has shown promising health benefits in animals. The extract contained RA at a concentration of 28.4 mg/g, representing a significant enrichment from the RA content in sage leaves. This extract was incorporated into oil‐in‐water emulsions as a source of lipid antioxidants and compared to emulsions containing pure rosmarinic acid. Both treatments were effective in suppressing lipid oxidation. The extract was evaluated by a trained sensory panel in a tea formulation. While the panel could discriminate among extract‐treated and control samples, panelists demonstrated high acceptability of the sage extract in a tea.     

Determination of dehydroacetic acid and its sodium salt in food products and polymeric packing materials

HPLC method of determination of dehydroacetic acid and its sodium salt in food products and polymeric packing materials has been developed. The migration of DGA from food-contacting materials to food matrix has been investigated.