Agreement between analytical values and label declarations of sodium content of processed packaged foods.

As part of the Food Labeling and Product Surveillance Program of the Food and Drug Administration, samples from 1982, 1984, and 1986 surveys of processed packaged foods (canned, frozen, and dry packaged) were analyzed to determine how closely the foods' actual sodium content matched their label claims for sodium. Samples were classified into three groups: "sodium-free" products (less than 5 mg sodium per serving), and "very-low-sodium" products (5 to 35 mg per serving), and a larger group of products that were labeled as containing more than 35 mg sodium per serving. In the third group, the distribution of actual sodium content fell around 100% of label claims for sodium. For the three survey years, analyzed sodium averaged 101% of label claim (standard deviation [SD] = 25%) for 1982 samples (20 products), 99% of label claim (SD = 28%) for 1984 samples (108 products), and 94% of label claim (SD = 21%) for 1986 samples (265 products). Products labeled "very low sodium" were treated separately because sodium analyses varied widely from the label declarations. However, most "very-low-sodium" products were well under 35 mg sodium per serving. Results indicated that consumers receive reasonably accurate information about the sodium content of processed packaged foods from label claims.

Determination of selenium in infant formula and enteral formula by dry ash graphite furnace atomic absorption spectrometry with deuterium background correction.

A method was developed to determine selenium in infant formula using a graphite furnace equipped with deuterium background correction after dry ashing. The method circumvents the use of perchloric acid, 2,3-diaminonapthalene (DAN) and hydride generation without the use of Zeeman background correction. Twelve commercial infant and enteral formulas and corresponding spiked products (30-500 ng) were analyzed in triplicate for Se to evaluate this method. All test portions were digested on a hot plate after addition of magnesium nitrate-nitric acid. Following heating, digests were evaporated to dryness and placed in a 500 degrees C muffle furnace for 30 min to complete ashing. All Se was converted to Se+4 by dissolving the ash in HCl (5 + 1) and holding the solution for 20 min in a 60 degrees C water bath. Se+4 was subsequently reduced to Se(zero) with ascorbic acid and collected on a membrane filter. The membrane filters were digested in a small volume of nitric acid in a microwave oven. Following digestion, contents of the vessels were diluted and analyzed for Se by graphite furnace atomic absorption spectrometry. Selenium standards in starch or in unfortified formula containing trace levels of Se were carried through the entire process. The recovery range for Se was 85-127%, and analyzed reference materials fell within their certified range for Se. This method is as sensitive (detection limit 0.44 ng Se/g) as methods reported in the literature and may be applicable to other foods.

Extension of dry ash atomic absorption and spectrophotometric methods to determination of minerals and phosphorus in soy-based, whey-based, and enteral formulae (modification of AOAC Official Methods 985.35 and 986.24): collaborative study.

Eight laboratories participated in a collaborative study of AOAC Official Method 985.35, Minerals in Ready-to-Feed Milk-Based infant Formula and Pet Foods, Atomic Absorption Spectrophotometric Method; and 7 laboratories participated in a study of AOAC Official Method 986.24, Phosphorus in Milk-Based infant Formula, Spectrophotometric Method, to extend these methods to infant formulae (other than milk-based) and enteral products. Three ready-to-feed soy-based formulae and 2 soy-based powder formulae were chosen to represent the plant matrix. A whey-based formula and a casein-based enteral formula were also included in the study. Soy formulae containing nearly identical concentrations of particular elements were matched, and an application of the Youden "closely matched pair" approach was used to estimate repeatability parameters. Average reproducibility values were as follows: calcium, 9.3%; copper, 9.7%; Iron, 5.5%; potassium, 4.0%; magnesium, 5.2%; manganese, 10.6%; sodium, 4.7%; phosphorus, 10.5%; and zinc, 7.3%. At similar analyte concentrations, the between-laboratory variabilities compared well with those reported for the official methods. Most repeatability and reproducibility parameters compared well with the original collaborative study. AOAC Official Methods 985.35 and 966.24 have been modified to extend their applicability to infant formulae (other than milk-based) and enteral products.

Supplementation of rats with a lutein mixture preserved with vitamin E reduces tissue phylloquinone and menaquinone-4.

The modulation of tissue concentrations of vitamin K by a lutein supplement preserved with natural vitamin E was studied in Fischer 344 rats. Vitamin K is necessary for blood coagulation and may be essential for tissue and bone health. Weanling male rats were fed the AIN-93G diet (control) or modified AIN-93G diets containing 0.3, 0.6, 1.2, 2.4 and 4.8 g supplement/100 g diet for 8 weeks. The supplement contained 5% lutein, 0.22% zeaxanthin and 2.2% natural vitamin E as a preservative. Concentrations of trans-phylloquinone in the plasma (nmol/mmol triglycerides) and heart were significantly reduced (P < or = 0.05) in rats fed the supplement. The reductions in trans-phylloquinone in the heart ranged from approximately 20 to 60% of the control. Concentrations of phylloquinone in the liver were significantly lower in the rats fed the supplement at levels > or = 1.2 g/100 g diet than in the control rats. Ratios of cis/trans phylloquinone in liver and heart increased and concentrations of menaquinone-4 in heart decreased as the dietary level of the lutein supplement increased. The results suggest that the lutein supplement affected the absorption, tissue uptake and/or turnover rate of vitamin K. The presence of other components in the supplement confounded the interpretation of the biological effects of lutein alone on vitamin K metabolism.

Chemical peel of nonfacial skin using glycolic acid gel augmented with TCA and neutralized based on visual staging.

BACKGROUND: Until recently, standard techniques for laser or chemical peeling have not always provided consistent results when applied to the nonfacial skin. OBJECTIVE: The author describes a more controlled chemical peel technique for nonfacial skin using 70% glycolic acid gel combined with 40% trichloroacetic acid (TCA). The method has given consistently good results on the skin of the neck, chest, arms, hands, back, and other nonfacial skin. METHODS: More than 3100 patients were given skin peels of the neck, chest, and other areas of the body as indicated. Seventy percent glycolic acid gel was applied to the areas to be peeled, then immediately augmented with 40% TCA. Each area was carefully monitored for the end point and then neutralized with copious amounts of 10% sodium bicarbonate solution. The end point was determined by visual observation using a six-stage classification to determine the degree of peeling. RESULTS: Clinical results were excellent, with smoother skin texture, decreased wrinkling and striae, and fading of lentigines and other pigmentary abnormalities. There was excellent blending into peeled facial skin and into adjacent areas of nonpeeled skin. Complications were minimal. CONCLUSION: This technique can provide the benefits of skin peeling to nonfacial skin with excellent cosmetic results and minimal complications.

Inductively coupled plasma emission spectroscopic determination of nine elements in infant formula: collaborative study.

Results from a collaborative study of a method for the determination of 9 elements in infant formula, using inductively coupled plasma emission spectroscopy, are reported. Six collaborators analyzed 6 infant formulas for native and spiked levels of Ca, Cu, Fe, Mg, Mn, P, K, Na, and Zn. The within-laboratory and between-laboratory coefficients of variation were generally (69 of 108 samples) below 9% for all elements determined in all samples. Most of the average recoveries of the elements from spiked samples ranged from 90 to 105%. The method has been adopted official first action for determining Ca, Cu, Fe, Mg, Mn, P, K, Na, and Zn in infant formula.