Determination Of Ascorbic Acid Concentration Research Articles

Determination of Ascorbic Acid Concentration in Commercially Available Fruit Drinks in Bangladesh

Aim: Ascorbic acid (vitamin C) is the most important food constituent because of its antioxidant and functional activity. The study aims to determine the Vitamin C content in commercially available fruit drinks collected from selected shops in Bangladesh.
 Study Design: This study is an experimental study. 
 Place and Duration of Study: The present study was conducted in the food analysis laboratory of Department Food Technology and Nutrition Science, Noakhali Science and Technology University, from January 2019 to May 2019. In the present study, a total of 22 branded different fruit drinks samples (orange, mango, lichi) were collected from the local market of Noakhali, Bangladesh.
 Methodology: Vitamin C was analyzed with the titrimetric method and Sugar content, pH was also successfully determined by refractometer, pH meter respectively.
 Results: The analyzed Vitamin C was found in the range of 2.96 to 70 mg/100 ml. Sugar content, pH was also successfully determined from the samples. The majority of the samples were found less in vitamin C concentration while only two samples (samples 3, 18) were found high the vitamin C concentration.
 Conclusion: From the above study, titrimetric analysis proves itself as a scientific method in the determination of vitamin C concentration in the samples.

Determination of Ascorbic Acid Concentration of Some Commercial Fruits Juices Sold in Ugbokolo Benue State, Nigeria

This research was aimed at investigating the concentration of Ascorbic Acid (Vitamin C) in some commercial fruits juices: ‘5’ Alive, Hollandia yoghurt, Nutri milk, Ribena, Lacasera, Happy hour, Viju milk, Chi exotic and Chi vita sold in Ugbokolo, Benue State, Nigeria by titrimetric method using 2,6-dichlorophenolindophenol (DCPIP) as titrant. The ascorbic acid (AA) content in milligram per 100ml of the various juices investigated is in the order: ‘5’ Alive (11.25) > Ribena (5.47) > nutri milk (5.31) > Happy hour (4.38) > Hollandia yoghurt (1.25) > Lacasera (0.47) ≈ Chi exotic (0.47) >Viju milk (0.31) > Chi vita (0.16). It was observed that half a litre of ‘5’ Alive (56.25 mg AA) a day is suitable for adults and pregnant women, a litre each of Ribena (54.70 mg AA) and Nutri milk (53.10 mg AA) per day for adults, while a litre of Happy hour (43.80 mg AA) per day is suitable for adolescents. It can be concluded that commercial fruits juices when taken in large amount will add to the daily human dietary intake of the vitamin.

Transcriptomic Analysis Reveals the Metabolic Mechanism of L-Ascorbic Acid in Ziziphus jujuba Mill.

Chinese jujube (Ziziphus jujuba Mill.) is the most economically important member of the Rhamnaceae family and contains a high concentration of ascorbic acid (AsA). To explore the metabolic mechanism of AsA accumulation, we investigated the abundance of AsA in the fruit development stages, the leaf and flower of Z. jujuba cv Junzao, and the mature fruit of one type of wild jujube (Z. jujuba var. spinosa Hu, Yanchuan sour jujube). And the expression patterns of genes involved in AsA biosynthesis, degradation, and recycling were analyzed. The result showed that AsA biosynthesis during early fruit development (the enlargement stage) is the main reason for jujube high accumulation. The L-galactose pathway plays a predominant role in the biosynthesis of AsA during jujube fruit development, and the genes GMP1, GME1, GGP, and GaLDH involved in the determination of AsA concentration during fruit development and in different genotypes; the myo-inositol pathway along with the genes GME2 and GMP2 in the L-galactose pathway play a compensatory role in maintaining AsA accumulation during the ripening stage. These findings enhance our understanding of the molecular mechanism in regulating AsA accumulation for jujube.

Analytical characterization of some pasteurized apple juices during storage

Abstract The aim of the study was to assess the effect of three weeks of storage on the chemical and rheological properties of apple juices obtained from Idared and Jonatan apples variety. Total antioxidant activity, levels of bio-active compound groups and the viscosity were measured to characterize the investigated juices. The method applied for the determination of ascorbic acid concentration was with 2, 6-diclorophenolindophenol. Total phenols (TP) in apple juices were determined using the Folin-Ciocalteau method and antioxidant activity by the use of DPPH free radical method. The viscosity of apple juices was investigated by a rotational viscometer, Brookfield viscometer (Brookfield Engineering Inc., Model RV-DV I Prime) with RV spindles. During three weeks of storage, different rates of all measured properties have been observed decreasing for both studied apples varieties juices. The juices from Jonatan apples have higher antioxidant activities that are correlated with the higher content in polyphenols and lower values of viscosity.

A novel ternary system for the determination of ascorbic acid concentration based on resonance Rayleigh scattering

The dienol of ascorbic acid was observed to have a strong reducing power in a 1.44 M HCl buffer solution, and could reduce Fe3+ to Fe2+.

Polyaniline‐Based Sensor Material for Potentiometric Determination of Ascorbic Acid

AbstractPolyaniline (PANI)‐based sensor material for determination of ascorbic acid was synthesized by oxidative chemical polymerization of aniline on a screen‐printed carbon‐paste electrode. The influence of PANI chemical structure formed under various polymerization conditions on the sensor response was investigated. The presence of aniline dimer derivatives in PANI structure was found to induce significant improvement of the limit of detection and the linear dynamic range without a change in sensitivity. The sensor prepared by aniline polymerization in pH 7 buffer leading to the product containing mainly the aniline dimer‐based units showed the best detection limit of 0.1 µM. It was shown that the PANI‐based sensor could be used for ascorbic acid analysis in the presence of citrate and lactate as interfering ions. A quantitative determination of ascorbic acid concentration in beverages and vitamins was performed.

Printed electrochemical sensor for ascorbic acid determination

Simple, strip-type sensors based on 7,7,8,8-tetracyanoquinodimethane-modified graphite were prepared using screen printing techniques. The electrochemical strips operated at low potentials [50 mV at pH 7.0 or 100 mV at pH 4.8 vs. Ag/AgCl (printed)] and had a sensitivity of 3.5–7.1 μA 1 mmol −1 L-ascorbic acid. Determination of ascorbic acid concentration was achieved in 30 s and required samples of ca. 30 μl. The current output of the electrodes was found to be relatively insensitive to variations in pH over the range 5.0–8.5. Between 15 and 35 °C, the temperature coefficient was 2.7% °C −1. The printed electrodes were suitable for single determinations but demonstrated adequate stability for periodic re-use. The ascorbic acid concentration in the juice of fresh fruit was determined using the electrochemical printed electrodes and a commercially available enzymatic test kit. Close agreement was observed between the two methods [ r=0.9997 ( n=12),slope=0.9798]. The limit of detection using the printed sensor for real samples was calculated as 4mg l −1(22 μM).

Ascorbic acid determination in serum and aqueous humour by high-performance liquid chromatography.

High-performance liquid chromatography on a Supelcosil LC-HN2 analytical column in weak anion exchange mode has allowed separation of ascorbic acid, in less than 5 min, from other interfering substances in serum and aqueous humour. UV monitoring at 254 nm enables ascorbic acid to be detected at 20 pmol level. A method for determination of ascorbic acid concentration in serum and aqueous humour is described, and values from 10 cataract patients are reported.