Differential inhibitory effects of organic acids on pear polyphenol oxidase in model systems and pear puree

The profile of 18 heterocyclic amines from seven categories (including β-carbolines) in tea leaves during green and black tea processing procedures, as well as commercial tea products was screened by ultrahigh-performance liquid chromatography with tandem mass spectrometry.

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Solubility of Iron in Model Systems Containing Organic Acids and Lignin

Journal of Food Protection ◽

10.4315/0362-028x-55.11.893 ◽

1992 ◽

Vol 55 (11) ◽

pp. 893-898 ◽

Cited By ~ 13

Author(s):

TAKESHI SUZUKI ◽

FERGUS M. CLYDESDALE ◽

TIRA PANDOLF

Keyword(s):

Ascorbic Acid ◽

Organic Acids ◽

Model Systems ◽

Molar Ratio ◽

Soluble Form ◽

Enhancing Effect ◽

Gastrointestinal Ph ◽

Soluble Iron ◽

Ph Values ◽

Ph Conditions

The effect of six organic acids, ascorbic, citric, fumaric, lactic, malic, and succinic, alone and in combination, at a 1:1.9 molar ratio (Fe+2:ligand) on the solubility of iron was evaluated in the presence of lignin under simulated gastrointestinal pH conditions. The enhancing effect, evaluated under two systems of preparation at two pH values, was in the following order: citric>malic>ascorbic>lactic,fumaric>succinic. Citric acid solubilized 80 and 81% of iron under both pH conditions. When ascorbic acid was mixed with fumaric, lactic, and succinic acids, a higher percentage of soluble iron was retained than with these three acids alone. In the case of citric and malic acids, the addition of ascorbic acid reduced the soluble iron. The percentage of soluble iron obtained when prepared at the endogenous pH (2.5–3.1) was higher than that at pH 5.5. These results indicated that ascorbate bound less iron in a soluble form than citrate or malate but more than fumarate, lactate, or succinate. Also, combinations of citric with malic acid did not demonstrate a synergistic effect.

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Modeling the inhibitory effects of organic acids on bacteria

International Journal of Food Microbiology ◽

10.1016/s0168-1605(99)00012-4 ◽

1999 ◽

Vol 47 (3) ◽

pp. 189-201 ◽

Cited By ~ 95

Author(s):

Chang-Ping Hsiao ◽

Karl J Siebert

Keyword(s):

Organic Acids ◽

Inhibitory Effects

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Influence of preharvest treatment with some organic acids on polyphenol oxidase and peroxidase activities and blossom end browning incidence in ‘Anna’ apples

Acta Horticulturae ◽

10.17660/actahortic.2018.1194.72 ◽

2018 ◽

pp. 493-498

Author(s):

M.Z. Sultan ◽

M. El-Danasoury ◽

H. Yossif ◽

M. Elbagoury

Keyword(s):

Organic Acids ◽

Polyphenol Oxidase

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Sodium iron EDTA and ascorbic acid, but not polyphenol oxidase treatment, counteract the strong inhibitory effect of polyphenols from brown sorghum on the absorption of fortification iron in young women

British Journal Of Nutrition ◽

10.1017/s0007114513002705 ◽

2013 ◽

Vol 111 (3) ◽

pp. 481-489 ◽

Cited By ~ 22

Author(s):

Colin I. Cercamondi ◽

Ines M. Egli ◽

Christophe Zeder ◽

Richard F. Hurrell

Keyword(s):

Ascorbic Acid ◽

Polyphenol Oxidase ◽

Young Women ◽

Inhibitory Effect ◽

Inhibitory Effects ◽

Fe Isotopes ◽

Absorption Studies ◽

Oxidase Enzyme ◽

Strong Inhibitory Effect

In addition to phytate, polyphenols (PP) might contribute to low Fe bioavailability from sorghum-based foods. To investigate the inhibitory effects of sorghum PP on Fe absorption and the potential enhancing effects of ascorbic acid (AA), NaFeEDTA and the PP oxidase enzyme laccase, we carried out three Fe absorption studies in fifty young women consuming dephytinised Fe-fortified test meals based on white and brown sorghum varieties with different PP concentrations. Fe absorption was measured as the incorporation of stable Fe isotopes into erythrocytes. In study 1, Fe absorption from meals with 17 mg PP (8·5 %) was higher than that from meals with 73 mg PP (3·2 %) and 167 mg PP (2·7 %;P< 0·001). Fe absorption from meals containing 73 and 167 mg PP did not differ (P= 0·9). In study 2, Fe absorption from NaFeEDTA-fortified meals (167 mg PP) was higher than that from the same meals fortified with FeSO4(4·6v.2·7 %;P< 0·001), but still it was lower than that from FeSO4-fortified meals with 17 mg PP (10·7 %;P< 0·001). In study 3, laccase treatment decreased the levels of PP from 167 to 42 mg, but it did not improve absorption compared with that from meals with 167 mg PP (4·8v.4·6 %;P= 0·4), whereas adding AA increased absorption to 13·6 % (P< 0·001). These findings suggest that PP from brown sorghum contribute to low Fe bioavailability from sorghum foods and that AA and, to a lesser extent, NaFeEDTA, but not laccase, have the potential to overcome the inhibitory effect of PP and improve Fe absorption from sorghum foods.

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