Gary Beecher - Academia.edu (original) (raw)

Papers by Gary Beecher

The Health Effects of Tea and Tea Components: Opportunities for Standardizing Research Methods

Critical Reviews in Food Science and Nutrition, Sep 1, 2001

ABSTRACT

Human nutrition research : invited papers presented at a symposium held May 6-9, 1979 at the Beltsville Agricultural Research Center (BARC), Beltsville, Maryland 20705

Archives of Physiology and Biochemistry, 2004

Proanthocyanidins, also called condensed tannins, are oligomers and polymers of monomeric flavans... more Proanthocyanidins, also called condensed tannins, are oligomers and polymers of monomeric flavans linked through specific single (B linkages) and double (A linkages) bonds. These secondary plant metabolites have substantial antioxidant activity. They are prevalent in some foods and dietary supplements including several berries, red grapes and their wines, and seeds, baking chocolate, cinnamon, pycnogenol, and Ginkgo biloba. Calculations based on limited food composition data suggest daily intakes of about 54 mg=day per person in the United States. Similar data are unavailable to estimate intakes from dietary supplements. Studies on digestion of proanthocyanidins indicates only monomers and dimers are absorbed; however, preliminary evidence suggests hydroxylated phenolic acids are important products of gastrointestinal microflora activity that also may be absorbed. Several types of investigations support improved vascular health after short-or long-term consumption of proanthocyanidins or foods and supplements that contain them. These effects include vasodilation, presumably as a result of increased NO production, decreased platelet aggregation, reduced sensitivity of low-density lipoproteins (LDL) to oxidization, and modulation of several reactions associated with inflammation. Studies with cranberries and cinnamon, both of which contain uniquely linked proanthocyanidins, support a role for bacterial antiadhesion and improved glucose metabolism in type 2 diabetics, respectively. Results from a variety of experiments indicate proanthocyanidins may modulate several reactions involved in cancer processes. A crucial research need is to identify further biologically active components of proanthocyanidins so that mechanisms of action at the tissue, cellular, and subcellular levels can be elucidated.

Food Chemistry, Oct 1, 2005

The stability of 5-methyltetrahydrofolate (5MTHF) in homogenized fresh fruits and vegetables repr... more The stability of 5-methyltetrahydrofolate (5MTHF) in homogenized fresh fruits and vegetables representing samples for the USDA National Food and Nutrient Analysis Program was evaluated. Samples were homogenized in liquid nitrogen and 5MTHF was measured after 0, 2, 7, 30 days and then at 3-month intervals for a total of 12 months storage at À60 ± 5°C, utilizing extraction by a tri-enzyme treatment, purification by strong anion-exchange solid-phase extraction, and quantification by reverse-phase HPLC. Method validation included analysis of a reference material and interlaboratory analysis of selected samples by HPLC and LC-MS. A canned spinach composite was assayed in each analytical batch to monitor inter-assay precision. No change in 5MTHF content was detected in any of the samples after 12 months. Concentrations ranged from <10 lg/100 g in bananas to >100lg/100 g in spinach. Relative standard deviations were generally <7% within assay and <11% between assays.

Effect of Gamma Irradiation on the B Vitamins of Pork Chops and Chicken Breasts

International Journal of Radiation Biology, 1989

A study was made of the effect of low-dose gamma irradiation on the content of thiamine (B1), rib... more A study was made of the effect of low-dose gamma irradiation on the content of thiamine (B1), riboflavin (B2), niacin, pyridoxine (B6) and cobalamin (B12) in pork chops, and thiamine, riboflavin and niacin in chicken breasts. Gamma irradiation from a caesium-137 source was used to irradiate the samples in a range of 0.49 to 6.65 kGy from -20 to +20 degrees C. Over the range of dose and temperature studied it was possible to derive a mathematical expression for predicting the losses. A calculation was made of the effect of the loss of thiamine, riboflavin and niacin due to irradiation on the overall loss of these vitamins in the American diet. The losses of riboflavin and niacin were of the order of a fraction of a per cent. Pork is an important source of thiamine, but the calculated loss at 1.0 kGy of this vitamin in cooked pork was only 1.5 per cent. There were initial increases with radiation doses up to 2-4 kGy in the measured concentrations of riboflavin and niacin in both pork and chicken. The increases were highly significant, and are of concern both to the study of radiation effects and the chemical method of the determination of these two vitamins.

The American Journal of Clinical Nutrition, 1998

Because premenopausal women experience cyclic fluctuations of plasma carotenoids and their lipopr... more Because premenopausal women experience cyclic fluctuations of plasma carotenoids and their lipoprotein carriers, it is hypothesized that carotenoid concentrations in lipoprotein fractions fluctuate by phase of the menstrual cycle. Nine women ate a standard set of carotenoid-rich foods daily for two cycles under isoenergetic conditions. In the second cycle, hormones and carotenoids in lipoprotein fractions were measured in the early and late follicular and luteal phases. ␣-Carotene concentrations in the LDL fraction were lower in the early than in the late follicular phase (P = 0.03) on the basis of regression analysis. ␤-carotene concentrations in the LDL fraction and the HDL 2 subfraction were higher in the late follicular than in the luteal phase (P = 0.02 and P = 0.04, respectively). Lutein/zeaxanthin concentrations in the LDL and HDL fractions were higher in the late follicular than in the luteal phase (P = 0.03 and P = 0.02, respectively). In each phase, 80% of ␣carotene, 82% of ␤-carotene, 85% of lycopene, and 64% of lutein/zeaxanthin were distributed in the LDL fraction. Among the hydrocarbon cartenoids, 18% of ␣-carotene and of ␤carotene and 13% of lycopene were distributed in the HDL fraction, with slightly more in the HDL 2 than in the HDL 3 subfraction. In contrast 34% of lutein/zeaxanthin was distributed in the HDL fraction with more concentrated in the HDL 3 .than in the HDL 2 subfraction. Less than 4% of any carotenoid was found in the VLDL+IDL (intermediate-density-lipoprotein) fractions. Thus, the hydrocarbon carotenoids were highly concentrated in the LDL fraction and xanthophyll was more evenly distributed in the LDL and HDL fractions. The cyclic fluctuations of these carotenoids in lipoprotein fractions add another dimension to the understanding of their transport and physiologic function.

Separation of carotenol fatty acid esters by high-performance liquid chromatography

Journal of Chromatography A, 1988

Employing isocratic and gradient-elution high-performance liquid chromatography (HPLC) a number o... more Employing isocratic and gradient-elution high-performance liquid chromatography (HPLC) a number of straight-chain fatty acid esters (decanoate, laurate, myristate, palmitate) of violaxanthin, auroxanthin, lutein, zeaxanthin, isozeaxanthin, and beta-cryptoxanthin, prepared by partial synthesis, have been separated on a C18 reversed-phase column. Several chromatographic conditions were developed that separated a mixture of di-fatty acid esters (dimyristate, myristate palmitate mixed ester, dipalmitate) of violaxanthin, auroxanthin, lutein, and zeaxanthin in a single chromatographic run. Hydroxycarotenoids such as lutein, zeaxanthin, and isozeaxanthin that are not easily separated by HPLC on C18 reversed-phase columns, can be readily separated after derivatization with fatty acids and chromatography of their esters. Chromatographic conditions for optimum separation of carotenoids from various classes are discussed.

Simultaneous determination of radioactivity and o-phtalaldehyde derived fluorescence in low levels of amino acids

Journal of Chromatography A, Jul 1, 1979

Whole grains as a source of antioxidants

Cereal Foods World, Sep 1, 2002

Journal of Food Science, 1968

A Comparison of the Light and Dark Portions of a Striated Muscle SUMMARY-The levels of physio'ogi... more A Comparison of the Light and Dark Portions of a Striated Muscle SUMMARY-The levels of physio'ogically related muscle constituents were determined in the light (white) and dark (red) portions of a striated muscle from the pig (SW domcsticus). Myoglobin level, percent red fibers and succinic dehydrogenase activity were twofold higher in the semitendinosus dark portion whereas ADP and inorganic phosphate levels were similar in both portions. Phosphorus levels were higher and sodium levels lower in the semitendinosus light portion than in the semitendinosus dark portion. Zinc and iron contents were greater in the dark portion than in the light portion; calcium, nickel, boron and potassium levels were similar in both portions. The semitendinosus light portion also had more lipid and more sarcoplasmic nitrogen than did the semitendinosus dark portion. These data suggest that the light (white) and dark (red) portions within the semitendinosus have physio-chemical properties similar to uniformly white and uniformly red muscles, respectively.

Application of a C-45-.beta.-carotene as an internal standard for the quantification of carotenoids in yellow/orange vegetables by liquid chromatography

Journal of Agricultural and Food Chemistry, Sep 1, 1987

... Frederick Khachik* and Gary R. Beecher ... Recently a method for the detection of cis-trans c... more ... Frederick Khachik* and Gary R. Beecher ... Recently a method for the detection of cis-trans carotene isomers by two-dimensional thin-layer and high-perform-ance liquid chromatography has been reported by Schwartz and Patroni-Killam (1985). ...

Journal of Agricultural and Food Chemistry, Mar 1, 1992

The major carotenoid constituents of extracts from several raw and cooked green vegetables (brocc... more The major carotenoid constituents of extracts from several raw and cooked green vegetables (broccoli, green beans, spinach), red ripe tomatoes, and tomato paste have been identified and quantified by high-performance liquid chromatography on a CIS reversed-phase column. The predominant carotenoids in raw green vegetables were neoxanthin, violaxanthin, lutein epoxide, lutein, a-carotene, and P-carotene. The carotenoids in tomatoes and tomato paste were lutein, 5,6-dihydroxy-5,6-dihydrolycopene, lycopene 1,2-epoxide, lycopene 5,6-epoxide, lycopene, neurosporene, y-carotene, (-carotene, @-carotene, phytofluene, and phytoene. The effect of various means of cooking on the levels of carotenoids in raw and cooked (microwaved, boiled, steamed, stewed) green vegetables and tomatoes has been extensively studied. It was shown that while the epoxycarotenoids were somewhat sensitive to heat treatment, lutein and hydrocarbon carotenoids such as neurosporene, a-and P-carotene, lycopene, {-carotene, phytofluene, and phytoene survived the heat treatments.

Evaluation of vitamin A and carotenoid data in food composition tables

PubMed, Dec 1, 1984

Vitamin A and carotenoid data in food composition tables have been generated with the use of the ... more Vitamin A and carotenoid data in food composition tables have been generated with the use of the Association of Official Analytical Chemists procedures. These procedures fractionate complex mixtures of retinoids and carotenoids into only three fractions, e.g., retinoids, carotenes, and xanthophylls. Food tables lack uniformity in the presentation of vitamin A and carotenoid data. For example, the revisions of Agriculture Handbook, No. 8 (Washington, D.C.: U.S. Govt Print Off, 1963), report both international units and retinol equivalents of vitamin A in foods. Food tables published in the United Kingdom (Paul AA, Southgate DA. McCance and Widdowson's: The composition of foods. Amsterdam: Elsevier/North-Holland, 1978) report preformed vitamin A as retinol and carotenoids as carotene on a weight basis (micrograms/100 g food). The vitamin A and carotenoid data currently available in food composition tables allow only the intake of total vitamin A activity to be estimated. Information about the intake of specific species of retinoids or carotenoids is not available and could not be calculated from existing food tables. Limited applications of new separation techniques and chemical instrumentation have demonstrated the potential for generating detailed analytic information in regard to the retinoid and carotenoid contents of foods.

Journal of Food Science, Jul 1, 1965

Journal of Food Science, May 1, 1965

Effect of cholecalciferol, 1,25(OH)2D3 and zinc on bone metabolism in the rat

Nutrition Research, Feb 1, 1987

... of Poultry Science and Nutritional Sciences Program University ofMaryland, College Park, MD 2... more ... of Poultry Science and Nutritional Sciences Program University ofMaryland, College Park, MD 20742 and GR Beecher, CE Bodwell, and J. Cecil Smith, Jr ... I01:597-604, 1971.Murray, EJ, Messer, HH: Turnover of bone zinc during normal and accelerated bone loss in rats, J. Nutr.Iii ...

Journal of Chromatography A, Oct 1, 1981

High-performance liquid chromatography (HPLC) provides a powerful tool for the separation and qua... more High-performance liquid chromatography (HPLC) provides a powerful tool for the separation and quantitation of biologically important compounds that are * Vitamin B, compounds have been abbreviated, according to published recommendations (IUPAC-IUB Commission on Biochemical Nomenclature, 1970) as follows: PMP = pyridoxamine phosphate; PM = pyridoxamine; PNP = pyridoxine phosphate; PN = pyridoxine; PLP = pyridoxal phosphate; PL = pyridoxal. PIC has been used as an abbreviation for pyridoxic acid while HOP is used for the internal standard, 3-hydroxypyridine.

Life Sciences, Jul 1, 1977

Experiments were conducted to investigate the infl amts of endurance exercise training on protein... more Experiments were conducted to investigate the infl amts of endurance exercise training on protein synthesis in skel~tal muscle, heart, and liver. Training decreased incorporation of [ C]-leucine into proteins of the stromal fraction of muscle but there was no change in amino acid incorporation into protein of the sarcoplasmic and myofibrillar fractions. Incorporation of [~4C]-leucine into the proteins of heart, liver, and plasma was depressed in trainsd rats compared to untrained rats. The specific radioactivity of [ 14C]leucine was similar in tissues of trained and untrained rats and thus the depressed amino acid incorporation represents a decrease in the rate of protein synthesis. These observations demonstrate that the adaptation of muscle protein metabolism to endurance training is quite different than the alterations Buring work-induced hypertrophy of muscle. The difference in adaptation probably relates to the functional differences between the types of exercise. However depression of protein synthesis in trained rats is a general effect in several tissues and not an effect localized in muscle tissue. * Mention of a trademark of proprietary product does not constitute a guarantee or warranty of the product by the U. S. Department of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as refl ecting the views of the Department of the Army or the Department of Defense. In conducting the research described in this report, the investigators adhered to the "Guide for Laboratory Animal Facilities and Care," as promulgated by the Committee on the Guide for Laboratory Animal Facilities and Care of the

Bovine Muscle Tenderness as Related to Protein Solubility

Journal of Food Science, Mar 1, 1971

ABSTRACT— The longissimus (modest degree of marbling) from forty beef ribs selected 48–56 hr post... more ABSTRACT— The longissimus (modest degree of marbling) from forty beef ribs selected 48–56 hr post‐mortem was used in two trials. Trial I involved A, C and E maturity ribs (10 each classification). Each rib was subjectively scored for texture (fresh) and adjacent longissimus samples were removed for the determination of protein solubility (fresh) and tenderness. Tenderness (cooked muscle) was measured with a Warner‐Bratzler shear and taste panel. Protein solubilities were determined using 0.154M Krebs‐Ringer‐Bicarbonate buffer, 0.2M KCl + 0.01M K phosphate buffer, 1.1M Kl + 0.1M K phosphate buffer, and 0.03M K phosphate buffer. Trial II involved 10 A maturity ribs. The 0.2M KCl, 1.1M Kl and 0.03M K phosphate buffers as described for trial I were used for protein extraction. Additionally, sarcomere length was measured in formalin. Multiple regression equations were developed to predict tenderness in trial II. Protein solubilities were not significantly different between the carcass maturity groups although there were trends toward increased solubility as maturity increased. Tenderness tended to decrease from A to E maturity indicating a negative relationship between protein solubility and tenderness. Several significant negative correlations between protein solubility and tenderness were found in trial I (A maturity group) and trial II. Additionally, several significant negative correlations between texture and solubility were calculated. Correlations within the C and E maturity groups were variable and showed no definite trends. Multiple regression analyses showed that a combination of protein solubilities, texture score and sarcomere length accounted for 88% of the variation in shear force and 72% of the variation in taste panel tenderness.