scholarly journals Accumulation of Antioxidants in Apple Peel as Related to Preharvest Factors and Superficial Scald Susceptibility of the Fruit

1994 ◽  
Vol 119 (2) ◽  
pp. 264-269 ◽  
Author(s):  
Cynthia L. Barden ◽  
William J. Bramlage
Keyword(s):  
Ascorbic Acid ◽  
Low Temperature ◽  
Light Intensity ◽  
Phosphonic Acid ◽  
Malus Domestica ◽  
Water Soluble ◽  
Total Water ◽  
Superficial Scald ◽  
Apple Peel ◽  
Conjugated Trienes

Antioxidants are believed to protect against the oxidation of α-farnesene to conjugated trienes in apple (Malus domestica, Borkh.) peel, thus providing resistance against superficial scald development. We conducted three experiments in which apples were a) harvested weekly, during which they were exposed to increasing hours at <10C during ripening; b) induced to ripen with no hours at <10C by applying ethephon; and c) enclosed in paper bags as they ripened. Inducing ripening with ethephon increased total water-soluble reducing compounds and percentage inhibition of lipid oxidation of peel extracts, increased concentrations of α-tocopherol, carotenoids, and ascorbic acid in peel, but only slightly reduced scald. Delayed harvests increased all of these antioxidants except ascorbic acid and greatly reduced scald development. Bagging fruit before ripening decreased α-tocopherol, carotenoid, and ascorbic acid concentrations, decreased total water-soluble reducing compounds, and increased scald development. We conclude that changes in these antioxidants probably are affected more by ripening and light intensity than by low temperature before harvest. Chemical name used: (2-chloroethyl)phosphonic acid (ethephon).

scholarly journals PREHARVEST CONDITIONS, ENDOGENOUS ANTIOXIDANTS AND SCALD DEVELOPMENT

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1159c-1159
Author(s):  
Cynthia L. Barden ◽  
William J. Bramlage
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Water Soluble ◽  
The Other ◽  
Cool Temperature ◽  
Total Water ◽  
Apple Peel ◽  
Endogenous Antioxidants ◽  
Reducing Capacity ◽  
Lipid Soluble Antioxidant

During the harvest season apples ripen and develop scald resistance. In the Northeast they usually are also exposed to cool temperatures as they mature and ripen. Experiments were conducted to study the effects of cool temperature, light and maturity on the endogenous antioxidants and subsequent scald development in Cortland and Delicious apples. Total lipid-soluble antioxidant activity in apple peel at harvest generally increased as scald incidence after storage decreased. Yet, α tocopherol, ascorbic acid and total water-soluble reducing capacity were not closely related to scald development. The absence of light (bagged fruit) decreased all measured antioxidants and increased scald development. However, ethephon applied in mid-August to induce ripening increased the levels of these antioxidants but had little effect on scald incidence in the absence of cool temperatures (hours <10°C). Cool temperatures, which decreased scald susceptibility, increased lipid-soluble antioxidant activity but had little influence on the other measured antioxidants. These data suggest that the endogenous antioxidants may be only partly responsible for natural scald resistance.

scholarly journals Volatile Cuticular Components Involved in Superficial Scald

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 605a-605
Author(s):  
S. Wee ◽  
R.M. Beaudry
Keyword(s):  
Gas Chromatography ◽  
Mass Spectroscopy ◽  
Malus Domestica ◽  
Apple Fruit ◽  
Superficial Scald ◽  
Conjugated Trienes ◽  
Gas Chromatography Mass Spectroscopy

Autoxidation products alpha-farnesene of have been implicated in superficial scald induction for apple (Malus domestica cv. Cortland Apple) fruit. We suspect the apple cuticle acts as a sink where α-farnesene can accumulate and eventually autoxidize into hydroperoxides, conjugated trienes, 6-methyl-5-hepten-2-one (ketone), and other compounds. These oxidized byproducts may diffuse back into the peel, thereby initiating the scald process. Cortland apples were stored at 0.8°C. Volatile cuticular components were analyzed at 2-week intervals by gas chromatography–mass spectroscopy. Only two scald-related volatiles were found, 6-methyl-5-hepten-2-one and α-farnesene. The identification of these compounds may allow the determination of cuticular involvement in superficial scald, as well as a possible correlation between the volatiles and apple scald development. α-farnesene concentrations initially increased and was followed by a decline, possibly due to its autoxidation.

scholarly journals A Modified Hypothesis on the Role of Conjugated Trienes in Superficial Scald Development on Stored Apples

1993 ◽  
Vol 118 (6) ◽  
pp. 807-813 ◽  
Author(s):  
Zhanyuan Du ◽  
William J. Bramlage
Keyword(s):  
Absorption Spectra ◽  
Malus Domestica ◽  
Ultraviolet Absorption ◽  
Superficial Scald ◽  
The Poor ◽  
Metabolic Products ◽  
Conjugated Trienes ◽  
Conjugated Triene ◽  
Experimentally Induced

Three experiments were conducted using `Cortland' and `Delicious' apples (Malus domestica Borkh.). Fruit varying widely in superficial scald susceptibility, because of either endogenous or experimentally induced conditions, were stored for various intervals at 0C and evaluated for scald development at 20C. Samples were extracted periodically in hexane, and ultraviolet absorption spectra of the extracts were used to evaluate α-farnesene and conjugated triene (CT) relationships to scald development. CT concentrations were calculated using each of the three CT absorption maxima (258-290 nm, 269-290 nm, and 281-290 nm) and expressed accordingly as CT258, CT269, and CT281. The poor association of CT281 concentrations with scald development led us to propose that metabolic products of CT281 species are more likely to be associated with scald development than the species themselves.

scholarly journals THE PIGMENT-PROTEIN COMPOUND IN PHOTOSYNTHETIC BACTERIA

1940 ◽  
Vol 23 (4) ◽  
pp. 469-481 ◽  
Author(s):  
C. S. French
Keyword(s):  
Ascorbic Acid ◽  
Light Intensity ◽  
Soluble Protein ◽  
Photosynthetic Bacteria ◽  
Water Soluble ◽  
Photochemical Oxidation ◽  
Distilled Water ◽  
Neutral Solution ◽  
Water Suspension ◽  
Water Soluble Protein

1. Photosynthetic bacteria in water suspension break open when treated with supersonic vibration thus liberating the cell contents, including a water soluble protein to which is attached the otherwise water insoluble pigments, bacteriochlorophyll and carotinoids. Both types of pigments appear to be combined with the same protein. 2. The protein pigment compound is insoluble in the region of pH 3.0 to 4.5 and in neutral solution can be completely precipitated by 0.5 saturated (NH4)2SO4. It is soluble in distilled water and adsorbable on fullers' earth. 3. Supersonic extracts of photosynthetic bacteria do not have the ability to carry on photosynthesis, but will act as a photocatalyst for the oxidation of ascorbic acid with visible or infrared radiation. The rate of the photochemical oxidation is proportional to the light intensity.

Light Intensity: the Role Player in Cucumber Response to Cold Stress

2021 ◽  
Author(s):  
Tahereh Ashrestaghi ◽  
Sasan Aliniaeifard ◽  
Aida Shomali ◽  
Shiva Azizinia ◽  
Jahangir Abbasi Koohpalekani ◽  
...  
Keyword(s):  
Low Temperature ◽  
Light Intensity ◽  
Cold Stress ◽  
Low Temperatures ◽  
Warm Season ◽  
Water Soluble ◽  
Photon Flux ◽  
Soluble Carbohydrate ◽  
Dependent Manner ◽  
Biochemical Traits

Abstract Low temperatures are an important limitation for geographic distributions of warm-season crops like cucumber (Cucumis sativus L.). Tolerance to low temperatures varies among different plant species and genotypes when changes in normal environmental cues occur. To cope with low temperature, biochemical and biophysical events should be coordinated to form a physiological response. We examined how light intensity influences the effects of low temperature on photosynthesis machinery and some biochemical traits. We used chlorophyll fluorescence imaging and polyphasic fluorescence transient (OJIP) to analyze cold stress (4 ºC) damage to photosynthetic electron transport chain (ETC) under different Photosynthetic Photon Flux Densities (PPFDs; 0, 300 and 600 μmol m-2 s-1), in four accessions of cucumber. The results showed that, the negative effects of cold stress are PPFD-dependent. The adverse effect of cold stress on ETC was more pronounced in plants exposed to 600 μmol m-2 s-1 compared to the control and dark-exposed plants; indicated by disturbance in ETC and higher energy dissipation. Moreover, biochemical traits including H2O2 content, ascorbate peroxidase activity and electrolyte leakage, and water-soluble carbohydrate was increased under low temperature by increase in PPFD, while chlorophyll and carotenoid contents decreased under low temperature by PPFD elevation. Low temperature induced H2O2 accumulation via suppressing APX activity in a PPFD-dependent manner. In conclusion, high PPFDs exacerbate the adverse effects of low temperature on the cucumber seedlings.

scholarly journals Analysis of the bioavailability of tea species

2021 ◽  
Vol 291 ◽  
pp. 02005
Author(s):  
Pavel Maslennikov ◽  
Mikhail Zorin ◽  
Anna Seregina
Keyword(s):  
Ascorbic Acid ◽  
Green Tea ◽  
Water Soluble ◽  
Biologically Active Substances ◽  
Biologically Active ◽  
Biological Availability ◽  
Total Water ◽  
Low Level ◽  
Initial Content ◽  
Active Substances

In samples of different tea brands the content of biologically active substances (total water-soluble antioxidants content, ascorbic acid, rutin, polyphenols, anthocyanins) was determined. The water-soluble antioxidant biological availability of the studied tea samples was evaluated. Green Tea with Lemon and Ceylon Baikhovi Black Spiced Tea is characterized by similar levels of antioxidant bioavailability. After the consumption of both beverages, there was a definite increase in the content of antioxidants in saliva of individuals with an initially low content of antioxidants. Amaranth Phytotea antioxidants were characterized by low level of bioavailability. The consumption of this beverage did not change the level of antioxidants in saliva, regardless of their initial content.

scholarly journals Effect of Heat or 1-Methylcyclopropene on Antioxidative Enzyme Activities and Antioxidants in Apples in Relation to Superficial Scald Development

2003 ◽  
Vol 128 (5) ◽  
pp. 761-766 ◽  
Author(s):  
Zohar Shaham ◽  
Amnon Lers ◽  
Susan Lurie
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Enzymes ◽  
Enzyme Activities ◽  
Total Activity ◽  
Water Soluble ◽  
Ascorbate Oxidase ◽  
Superficial Scald ◽  
Control Fruit ◽  
Apple Peel ◽  
Antioxidative Enzyme Activities

`Granny Smith' apples [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] were harvested in two seasons and stored at 0 °C air storage with no pretreatment (control), after heating for 4 d at 38 °C, or after treating for 16 hours at 20 °C with 1 μL·L-1 1-methylcyclopropene (1-MCP). The effects of the two treatments on superficial scald development were consistent over both seasons. Scald began to appear after 8 weeks in control fruit, after 16 weeks in heated fruit but not on 1-MCP treated fruit. α-Farnesene accumulation and oxidation were slower in the skin of heated than in control fruit, and almost entirely absent in 1-MCP treated fruit. The activities of five antioxidant enzymes, ascorbate peroxidase, catalase, glutathione reductase, peroxidase and superoxide dismutate, were measured at two-week intervals in the apple peel, quantitatively as total activity and qualitatively by isozyme analysis. Enzyme activities either increased or remained stable during 16 weeks of storage, except for superoxide dismutase activity, which decreased. Ascorbate oxidase activity was higher in heated than control apples and there was an additional peroxidase isozyme present in activity gels. The activities of antioxidant enzymes were lower in 1-MCP treated fruit except for catalase during the first month of storage. Lipid soluble antioxidant activity was higher in 1-MCP treated fruit than the fruit of the other treatments, and water soluble antioxidant activity was higher in both treatments than in control fruit during the time that scald was developing in control apples. Both free and total phenol contents in the peel fluctuated during storage but no consistent trend was detected. The differences in enzyme activity and antioxidant content of the peel of 1-MCP and heated apples may play a role in preventing or delaying the appearance of superficial scald.

Sorbitol enhances the physicochemical stability of B12 vitamers

2020 ◽  
Vol 90 (5-6) ◽  
pp. 439-447 ◽  
Author(s):  
Andrew Hadinata Lie ◽  
Maria V Chandra-Hioe ◽  
Jayashree Arcot
Keyword(s):  
Ascorbic Acid ◽  
Uv Light ◽  
Heat Exposure ◽  
Water Soluble ◽  
Uv Exposure ◽  
Physicochemical Stability ◽  
Before And After ◽  
The Stability

Abstract. The stability of B12 vitamers is affected by interaction with other water-soluble vitamins, UV light, heat, and pH. This study compared the degradation losses in cyanocobalamin, hydroxocobalamin and methylcobalamin due to the physicochemical exposure before and after the addition of sorbitol. The degradation losses of cyanocobalamin in the presence of increasing concentrations of thiamin and niacin ranged between 6%-13% and added sorbitol significantly prevented the loss of cyanocobalamin (p<0.05). Hydroxocobalamin and methylcobalamin exhibited degradation losses ranging from 24%–26% and 48%–76%, respectively; added sorbitol significantly minimised the loss to 10% and 20%, respectively (p < 0.05). Methylcobalamin was the most susceptible to degradation when co-existing with ascorbic acid, followed by hydroxocobalamin and cyanocobalamin. The presence of ascorbic acid caused the greatest degradation loss in methylcobalamin (70%-76%), which was minimised to 16% with added sorbitol (p < 0.05). Heat exposure (100 °C, 60 minutes) caused a greater loss of cyanocobalamin (38%) than UV exposure (4%). However, degradation losses in hydroxocobalamin and methylcobalamin due to UV and heat exposures were comparable (>30%). At pH 3, methylcobalamin was the most unstable showing 79% degradation loss, which was down to 12% after sorbitol was added (p < 0.05). The losses of cyanocobalamin at pH 3 and pH 9 (~15%) were prevented by adding sorbitol. Addition of sorbitol to hydroxocobalamin at pH 3 and pH 9 reduced the loss by only 6%. The results showed that cyanocobalamin was the most stable, followed by hydroxocobalamin and methylcobalamin. Added sorbitol was sufficient to significantly enhance the stability of cobalamins against degradative agents and conditions.

Ascorbic Acid does not Improve Endothelium-Dependent Flow-mediated Dilatation of the Brachial Artery in Patients with Raynaud’s Phenomenon Secondary to Systemic Sclerosis

2003 ◽  
Vol 73 (1) ◽  
pp. 3-7 ◽  
Author(s):  
M. E. Mavrikakis ◽  
J. P. Lekakis ◽  
M. Papamichael ◽  
K. S. Stamatelopoulos ◽  
Ch. C. Kostopoulos ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Smooth Muscle ◽  
Systemic Sclerosis ◽  
Endothelial Dysfunction ◽  
Brachial Artery ◽  
Raynaud’S Phenomenon ◽  
Raynaud's Phenomenon ◽  
Water Soluble ◽  
Placebo Administration ◽  
Flow Mediated Dilatation

Previous studies have shown that patients with Raynaud’s phenomenon secondary to systemic sclerosis present abnormal endothelial function; the mechanisms responsible for the endothelial dysfunction are unknown but increased vascular oxidative stress could be a possible cause. The hypothesis that a potent water-soluble antioxidant can reverse endothelial dysfunction in these patients was tested in the present study. We examined 11 female patients with Raynaud’s phenomenon secondary to systemic sclerosis and ten healthy control women by ultrasound imaging of the brachial artery to assess flow-mediated (endothelium-dependent) and nitrate-induced (endothelium-independent) vasodilatation. Flow-mediated dilatation and nitrate-induced dilatation were significantly reduced in patients with Raynaud’s phenomenon, indicating abnormal endothelial and smooth muscle cell function. Patients with Raynaud’s phenomenon entered a double-blind, randomized, crossover placebo-controlled trial and received orally 2 g of ascorbic acid or placebo; vascular studies were repeated two hours after ascorbic acid or placebo administration. Flow-mediated dilatation did not improve after ascorbic acid (1.6 ± 2.2% to 2.2 ± 2.5%, ns) or placebo administration (1.2 ± 1,9% to 1.7 ± 1.4%, ns); also nitrate-induced dilatation was similar after ascorbic acid or placebo (16 ± 7.4% vs 17 ± 8%, ns), suggesting no effect of ascorbic acid on endothelial and vascular smooth muscle function. In conclusion, ascorbic acid does not reverse endothelial vasomotor dysfunction in the brachial circulation of patients with Raynaud’s phenomenon secondary to systemic sclerosis. The use of different antioxidants or different dosing of ascorbic acid may be required to show a beneficial effect on endothelial vasodilator function.

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