Factors influencing formation of cholesterol oxidation products (COPS) in spray-dried whole eggs, particularly free radicals generated during the combustion process, were investigated. Total COPS formed in products dried in the presence of free radicals (by using a gas burner or addition of prooxidants into an electric heating system) were approximately 2-5 times greater than those in powders processed by an electric heating system. Addition of antioxidants (tertiary butylhydroquinone and oleoresin rosemary) did not significantly affect (P < 0.05) the formation of COPS in eggs spray-dried with direct gas-fired heating during processing and/or storage. Room temperature storage significantly promoted (P < 0.05) further formation of COPS regardless of the initial content of COPS in the egg powders. The pathway of cholesterol oxidation initiated by oxides of nitrogen appeared to be similar to the hydroperoxide-induced free radical reaction.

Deposition of carotenoids in saponified paprika (SP) and unsaponified oleoresin paprika (OP) in egg yolks as well as the dietary level for desired pigmentation were evaluated. Sixty‐four hens on a carotenoid‐depletion diet were divided into two replicated groups of each of eight dietary treatments containing from 0 to 16 mg paprika carotenoids per kg feed. Colour and the carotenoid content of egg yolk increased linearly (P<0·01) with the amounts of paprika carotenoids in the diets. The colours of egg yolks from hens fed similar concentra‐tions of OP or SP were not significantly different (P<0·01). A low dose (4 mg kg−1) of OP or SP provided yolk colour equivalent to the colour of eggs in supermarkets. High‐performance liquid chromatographic analyses showed that carotenoids deposited in the yolk are in the free alcohol form, regardless of the form of carotenoids in the diet. Capsanthin, the predominant carotenoid in paprika, was deposited in egg yolk less efficiently than zeaxanthin and lutein.

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In this study, we investigated temporal changes in galanin receptor type 2 (GalR2) expression in NF200-, galanin-, neuropeptide Y (NPY)-, and neuronal nitric oxide synthase (nNOS)-like immunoreactive (LI) dorsal root ganglion (DRG) neurons after median nerve chronic constriction injury (CCI), and the effects of GalR2 on c-Fos expression in the cuneate nucleus (CN). Double immunofluorescence labeling methods were used to appraise changes in GalR2 expression in NF200-LI, galanin-LI, NPY-LI, and nNOS-LI DRG neurons after CCI. The von Frey assay was used to assess the efficiency of intraplantar administration of saline, M871 (a GalR2 antagonist), or AR-M1896 (a GalR2 agonist) on neuropathic signs of rats with CCI. The effects of alterations in c-Fos expression were assessed in all treatments. The percentage of GalR2-LI neurons in lesioned DRGs increased and peaked at 1 week after CCI. We further detected that percentages of GalR2-LI neurons labeled for NF200, galanin, NPY, and nNOS significantly increased following CCI. Furthermore, M871 remarkably attenuated tactile allodynia, but the sensation was slightly aggravated by AR-M1896 after CCI. Consequentially, after electrical stimulation of the CCI-treated median nerve, the number of c-Fos-LI neurons in the cuneate nucleus (CN) was significantly reduced in the M871 group, whereas it increased in the AR-M1896 group. These results suggest that activation of GalR2, probably through NPY or nitric oxide, induces c-Fos expression in the CN and transmits mechanical allodynia sensations to the thalamus.

The effects of dietary α‐tocopherol and/or oleoresin paprika (OP) on cholesterol and carotenoid stability in egg powders during spray drying and subsequent storage were investigated. Cholesterol oxidation and loss of carotenoids in eggs dried with a direct gas‐fired spray dryer were greater (P<0·05) than in eggs dried using an indirect (electric) heating system. Dietary supplementation of α‐tocopherol acetate (200 mg kg−1 feed) significantly increased (P<0·01) the oxidative stability of cholesterol and carotenoids in eggs dried with the direct heating system. Supplementation of OP (7·5 μg g−1 egg lipids) through diet or by direct addition to liquid eggs did not affect the formation of cholesterol oxidation products (COPS) during storage. However, increased concentrations of OP in liquid eggs (15 and 30 μg g−1 lipids) suppressed the formation of COPS during processing and subsequent storage.