Serum antioxidant capacity in neurological, psychiatric, renal diseases and cardiomyopathy.

The role of free radicals (FR) in the pathogenesis and in the progression of many diseases has been often discussed, but not widely investigated. However, the total antioxidant capacity in the serum seems to be of great evidence. Total antioxidant capacity was determined using oxygen absorbance capacity assay (ORAC) in serum of patients suffering from depression, schizophrenia, Alzheimer's disease (AD), anorexia nervosa, Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), Aids-encephalopathy, diabetic polyneuropathy (PNP), cardiomyopathy (CM), renal disease, and healthy individuals as controls (C). The results showed that the total antioxidant capacity in serum decreased significantly (p < 0.01) by 24, 20, 13, and 17% for anorexia nervosa, Aids-encephalopathy, PNP and CM respectively. In serum of patients with renal disease significantly elevated antioxidant capacity was found. The data indicated that increased oxidative stress can be involved in the pathogenesis or in the progression of PNP and CM. Decrease of serum antioxidant capacity in patients with anorexia nervosa and Aids-encephalopathy are probably due primarily to malnutrition and secondly to insufficient antioxidant and immune system. In renal disease, the accumulation of urea in serum seems to be responsible for high antioxidant capacity. In contrast, there were no changes in PD, AD, depression syndrome and schizophrenia.

[Chemical and microbiological studies of microwave-treated milk]. / Chemische und mikrobiologische Untersuchungen an mikrowellenbehandelter Milch.

Pasteurized milk was treated with microwaves for 2.5 minutes (2450 MHz, 650 W). Important chemical components (vitamin A, beta-carotin, vitamins B1, B2, C, E; activity of peroxidase, xanthinoxidase; content of fat and peroxides, percentage of solids, content of raw protein, content of all microorganisms and storage stability were examined. Ascorbic acid (reduction of 36%) and alpha-tocopherol (reduction of 17%) were influenced by microwave treatment, whereas other chemical parameters, odor and flavor remained unchanged. The content of microorganisms was reduced from about 10(4) to 10(2) per milliliter. Untreated milk had a content of 10(7) microorganisms per milliliter after 10 days storage at 8 degrees C and a taste of acidity, whereas in milk treated with microwaves only 10(4) microorganisms per ml were identified and no organoleptic changes could be observed after 14 days storage at 8 degrees C.

[The migration of acetaldehyde from polyethylene terephthalate bottles for fresh beverages containing carbonic acid]. / Untersuchungen zur Migration von Acetaldehyd aus Polyethylenterephthalat-Flaschen für kohlensäurehaltige Erfrischungsgetränke.

The migration of acetaldehyde from polyethylene terephthalate (PET) under various conditions was analysed by headspace gas chromatography and flame ionisation detection. The residual amounts of new PET bottles were about 6.3 mg/kg with a migration value of 200 micrograms/l. On studying the migration at different temperatures and times, behaviour curves characteristic of packing materials made from plastics are obtained. The amount of acetaldehyde diffusing from PET at a temperature of 40 degrees C reached a constant level after 4 days which was about 10% of the residual value of acetaldehyde. On increasing the temperature by 20 degrees C, this level was raised up to 50%. The results of the analysis of acetaldehyde in soft drinks containing carbonic acid show that the migration in fact is not sufficiently high to influence the taste of these soft drinks. A negative effect on the taste may be recognized with mineral waters and soda when they are exposed to higher temperatures (e.g. 40 degrees C or more) over a longer period of time.

[The antioxidant activity of citrus fruit peels]. / Uber die antioxidative Aktivität von Zitrusfruchtschalen.

The antioxidant properties of freeze-dried citrus fruit peels (orange, lemon, grapefruit) and methanolic extracts from the peel were studied. Freeze-dried orange peel showed the highest, lemon peel somewhat less and grapefruit peel the lowest but still remarkable antioxidant activity. This could be significantly improved by preparing methanolic extracts of the peels. Comparative examinations and autoxidation studies with the flavanon glycosides hesperidin and naringin as well as with their aglycones hesperetin and naringenin showed that the former are mainly responsible for the antioxidative activity of the citrus peel and extracts. In order to compare their antioxidative activity with that of the commercially available natural antioxidants alpha-tocopherol and ascorbylpalmitate, the freeze-dried citrus peels and their methanolic extracts should be used in higher concentrations, in consideration of their peculiar properties and complex natural composition. Furthermore, aspects of the correlation between antioxidant activity and molecular structure of the flavanones were discussed.