Internal quality and shelf life of eggs coated with oils from different sources

Selected internal quality and shelf life of eggs coated with oils from differences sources (mineral oil, canola oil, corn oil, grape seed oil, olive oil, soybean oil, and sunflower oil) were evaluated during 5 wk of storage at 25 °C. As the storage time increased, weight loss increased whereas Haugh unit and yolk index values decreased. Throughout the 5 wk of storage, eggs coated with oils, regardless of oil sources, possessed better albumen and yolk quality than the control noncoated eggs. Oil coating minimized weight loss of eggs (<0.8%) compared with that (7.26%) of the noncoated eggs after 5 wk of storage at 25 °C. No significant differences in internal quality (weight loss, Haugh unit, yolk index, and albumen pH) were generally observed among oil-coated eggs during 5 wk of storage. Based on the Haugh unit, the grade of noncoated eggs changed from AA at 0 wk to A at 1 wk and to B after 3 wk whereas that of oil-coated eggs from AA at 0 wk to A at 4 wk and maintained A grade until 5 wk. This study demonstrated that oil coating, irrespective of oil sources, preserved the internal quality, minimized weight loss (<0.8%), and extended the shelf life of eggs by at least 3 wk longer than observed for the noncoated eggs at 25 °C storage. Soybean oil was a more practical option as a coating material for eggs due to its low cost. PRACTICAL APPLICATION: Eggs are highly perishable and susceptible to internal quality deterioration when stored above 7 °C. Refrigeration of eggs may be seldom practiced in some developing regions of the world. Therefore, an alternative method, that is inexpensive yet effective, to preserve the internal quality of eggs and to prevent microbial contamination is needed. Oil coating has been proven to preserve the internal quality, prolong shelf life, and minimize weight loss of eggs. This study demonstrated that, compared with other vegetable oils, soybean oil was a more practical option as a coating material for eggs during 5 wk of storage at 25 °C due to its low cost.     

Spray chilling of lamb carcasses

Two spray-chilling treatments were developed to improve appearance and reduce weight loss during lamb chilling. Rates of cooling and weight loss and meat quality were compared to conventionally chilled carcasses.

The first treatment was an intermittent spray during the first 3 h of chilling. The second consisted of only two sprays at 2 h and 10 h post mortem. The conventional control was a two-stage process, with air at 10°C and 1 m/s up to 10 h post mortem, followed by air at 0°C and 1 m/s for a further 14 h.

Both treatments significantly reduced weight loss at 24 h post mortem compared to conventional, from 2·20% to 0·86% and 1·20%, respectively. During a further 4 days storage, the savings were maintained, with weight losses being 3·97%, 2·97% and 3·19%, respectively.

There were small (<1 h) but significantly reductions in the cooling times of spray-chilled loins and legs, attributed to sustained evaporative cooling of the continually wetted surfaces.

No effects on texture or drip loss and only slight effects on surface lean and fat colour were found. Variation in texture between animals within treatments was far greater than between treatments and could not be accounted for by variations in cooling rates.     

Some characteristics of tungsten filaments operated as cathodes in a gas discharge

Some physical properties of tungsten filaments, when operated as cathodes in a gas discharge, are presented. For a 0.1524-cm-diam tungsten wire, the initiation of a discharge is found to be dependent on the filament geometry. The effect of connecting the discharge power supply to either the positive or negative leg of the filament is examined. When the emission current becomes a sizable fraction of the filament heater current, the filament does not emit uniformly. The temperature distribution indicates that the majority of the electrons are emitted from the negative leg of the filament.     

Effect of metal powder packing on the conductivity of nanometal ink

The power of nanotechnology is realized in its application in numerous areas. One such area is undoubtedly the use of metallic nanoparticles as a direct write application. An effort in this area has resulted in a conductive ink whose conductivity approaches 60-70% that of the bulk copper. Such an ink has been developed by reducing silver, gold, and copper nano-sized powders by a wet method and followed by a heat treatment at less than 400 degrees C. The conductivity of the resulting ink product was found to be very much affected by how various sizes of metal powders are packed when particles were dried and packed on various substrates. The effect of packing and various kinds of metal powders on the eventual conductivity of the final product of the ink has been described and discussed in this paper.     

Direct construction of an open-sandwich enzyme immunoassay for one-step noncompetitive detection of thyroid hormone T4

To establish a sensitive noncompetitive immunoassay for thyroxine (T4), we attempted to isolate anti-T4 antibodies from a phage display library based on a phagemid pDong1 ( Dong et al. Anal. Biochem.2009, 36, 386 ), which was designed to enable open-sandwich enzyme-linked immunosorbent assay (OS-ELISA) after selection on immobilized antigen. After the Fab-displaying phage library made from the splenocytes of T4-KLH immunized mice was subjected to biopanning on T4-BSA, two T4-specific clones were obtained. When they were assayed by indirect competitive ELISA, both clones showed low IC(50) (5-13 ng/mL), indicating their high affinity to T4. When they were used for OS-ELISA that detects antigen-dependency of the interaction between variable domains V(H) and V(L), a clone successfully detected 1 ng/mL of T4 with a working range superior to that of competitive IA. OS-ELISA was also performed with maltose binding protein (MBP)-fused V(H)/V(L) of this clone, which showed a detection limit less than 0.1 ng/mL T4. Moreover, the assay showed cross-reactivity with T3 similar to that of competitive ELISA, and also gave a reasonable total serum T4 concentration (90 ng/mL) from ethanol-extracted sample serum using the recombinant proteins. This is the first direct construction of an OS-ELISA system bypassing hybridoma, which will be applicable to the detection of many other small molecule antigens.