Thermoluminescence analysis of irradiated oyster shells.

This paper reports the thermoluminescence (TL) analysis performed on the oyster shells powder. TL response of (60)Co gamma-rays irradiated samples were studied in the range from 80 Gy to 8 kGy doses. TL signal of irradiated shell powder was higher as compared to the unirradiated control samples, which allowed to identify the irradiated oysters. Results show that the oyster shells have good TL properties and can be useful for the identification of irradiated seafood as well as for the evaluation of the treatment dose.

Free amino acids in botanicals and botanical preparations.

Numerous studies were carried out about aminoacidic composition of vegetable proteins, but information about the free amino acid pool and the role of these substances is very incomplete. The aim of this paper was to contribute to the scarce knowledge concerning the composition of free amino acids in botanicals and botanical preparations widely used as food, in dietary supplements, and in pharmaceutical products. This work studied the composition of free amino acids, identified the major components of 19 species of plants, and evaluated the influence of different types of extraction on the amino acid profile. Amino acids were determined using an automatic precolumn derivatization with fluorenylmethyl-chloroformate and reversed-phase liquid chromatography with fluorescence and ultraviolet detection. The amounts of total free amino acids varied widely between plants, from approximately 12 g in 100 g of Echinacea pallida extract to less than 60 mg in the same amount of Coleus forskohlii, Garcinia cambogia, and Glycine max. In 13 plants arginine, asparagine, glutamine, proline, and gamma-aminobutyric acid were the free amino acids found in preponderant quantities. The levels of free amino acids above the quantification limit in 36 assayed samples of botanicals, extracts, and supplements are shown.

Free amino acid content in standard infant formulas: comparison with human milk.

OBJECTIVE: To compare the concentration of non-protein nitrogen (NPN) and free amino acids (FAA) in powdered and liquid commercial formulas with that in human milk. METHODS: The non-protein nitrogen and FAAs in pooled breast milk was compared with that in 11 protein-modified starting infant formulas (seven powdered, four liquid whey-predominant formulas) and one powdered soy-formula. Human milk was collected at the end of each feeding (hindmilk) over 24 hours in a group of 40 healthy lactating women after delivery of full-term infants at age one month. RESULTS: In human milk glutamic acid plus glutamine and taurine were the prevalent amino acids, accounting for around 50% total FAA. In the analysed formulas the total FAA fraction was 10% or even less than in human milk, mostly represented by taurine, while methionine was high in soy formula. The sum of glutamic acid and glutamine in all the formulas was much lower than in human milk. CONCLUSIONS: Breastfed infants are supplied with FAA, mainly glutamic acid and glutamine, compared to formula-fed counterparts. The different FAA intake might be the origin of some functional differences at the enteral level between breast- and formula-fed infants.

Free glutamine and glutamic acid increase in human milk through a three-month lactation period.

BACKGROUND: Previous short observational studies on the free amino acid (FAA) content of human milk have shown that glutamine and glutamic acid increase in the first 4 to 6 weeks of life. METHODS: Changes in human milk content of free amino acids (FAAs) was determined at colostrum, 1 month, and 3 months of lactation in 16 healthy lactating women after delivery of full-term infants. Milk was collected at the end of each feeding (hindmilk) during 24 hours. RESULTS: Glutamic acid and taurine were the most abundant FAAs at colostrum. Although taurine remained stable throughout lactation, glutamic acid (the prevalent FAA) and glutamine increased approximately 2.5 and 20 times, respectively, with progressing lactation representing more than 50% of total FAA at 3 months. The content of essential FAA was also stable, so the change in total FAA content was almost entirely due to the changes in glutamic acid and glutamine. CONCLUSIONS: Breast-fed infants are supplied with progressively increasing amounts of glutamine and glutamic acid throughout lactation. The increasing intake of glutamic acid and glutamine could benefit breast-fed infants with molecules that are likely to protect the enteral mucosa and act as neurotransmitters and as a source of nitrogen.

Agglutinating activity of alcohol-soluble proteins from quinoa seed flour in celiac disease.

The edible seeds of the quinoa plant contain small quantities of alcohol-soluble protein which, after peptic-tryptic digestion, are unable to agglutinate K562(s) cells. When separated by affinity chromatography on sepharose-6B coupled with mannan, peptic-tryptic digest separated in two fractions. Fraction B peptides (about 1% of total protein) were shown to agglutinate K562(s) cells at a very low concentration, whereas peptides in fraction A and in the mixed fraction A+B were inactive, suggesting that fraction A contains protective peptides that interfere with the agglutinating activity of toxic peptides in fraction B.

Infant feeding in the first year of age: composition and nutritional influence of the diet.

In recent years there has been a remarkable progress in infant nutrition, thanks to important development in the fields of nutrition, and food preparation and storage. The Istituto Superiore di Sanità (Italian National Institute of Health) has carried out the analytical control of the composition of infant foods present on the Italian market, and verified the nutritional quality and the presence, if any, of undesirable substances. Since 1980 the research has often required the development of specific and accurate analytical methods for these products. Adapted and follow-up formulas, cereal-based weaning products and those meant for subjects in special physiological conditions (premature, coeliac, allergic) have been analyzed, monitoring their qualitative transformation during the years. The main essential nutrients-proteins, lipids and minerals-have been assayed to evaluate whether the nutritional requirements of infants during the first year of life were satisfied. The protein and lipid composition of infant formulas was compared with that of human milk, and the influence of such feedings on plasma amino acid levels and erythrocyte fatty acids was assessed.

Protein and lipid composition of human milk and infant formulas: comparison and nutritional consequences.

This work results from some research carried out by the authors during the last few years in nutrition field. The data collected allowed to compare protein and lipid composition of infant formulas with human milk and to evaluate the influence of such feedings on plasma aminoacid levels and erythrocyte fatty acids. In spite of different infant formula compositions with respect to human milk, our nutritional studies did not demonstrate physiological differences between breast and bottle-fed infants if formulas provide with an adequate intake of protein and linoleic acid.