40 assays (manual) / 400 assays (microplate) / 400 assays (auto-analyser)
Content: | 40 assays (manual) / 400 assays (microplate) / 400 assays (auto-analyser) |
Shipping Temperature: | Ambient |
Storage Temperature: |
Short term stability: 2-8oC, Long term stability: See individual component labels |
Stability: | > 2 years under recommended storage conditions |
Analyte: | Ascorbic Acid |
Assay Format: | Spectrophotometer, Microplate, Auto-analyser |
Detection Method: | Absorbance |
Wavelength (nm): | 578 |
Signal Response: | Increase |
Linear Range: | 0.5 to 30 µg of L-ascorbic acid per assay |
Limit of Detection: | 0.175 mg/L |
Reaction Time (min): | ~ 8 min |
Application examples: | Wine, beer, fruit juices, soft drinks, jam, milk, dairy products (e.g. cheese), dietetic foods, baby foods, processed meat, baking additives, fruit and vegetables (e.g. tomato and potato), pharmaceuticals, feed and other materials (e.g. biological cultures, samples, etc.). |
Method recognition: | Methods based on this principle have been accepted by MEBAK |
The Ascorbic Acid (L-Ascorbate) assay kit is for the specific measurement and analysis of L-ascorbic acid in beverages, meat, flour, dairy and vegetable products.
Note for Content: The number of manual tests per kit can be doubled if all volumes are halved. This can be readily accommodated using the MegaQuantTM Wave Spectrophotometer (D-MQWAVE).
See our full list of our organic acid assay kits.
- Very competitive price (cost per test)
- All reagents stable for > 6 months after preparation
- Mega-Calc™ software tool is available from our website for hassle-free raw data processing
- Standard included
- Suitable for manual, microplate and auto-analyser formats
Megazyme “advanced” wine test kits general characteristics and validation.
Charnock, S. J., McCleary, B. V., Daverede, C. & Gallant, P. (2006). Reveue des Oenologues, 120, 1-5.
Many of the enzymatic test kits are official methods of prestigious organisations such as the Association of Official Analytical Chemicals (AOAC) and the American Association of Cereal Chemists (AACC) in response to the interest from oenologists. Megazyme decided to use its long history of enzymatic bio-analysis to make a significant contribution to the wine industry, by the development of a range of advanced enzymatic test kits. This task has now been successfully completed through the strategic and comprehensive process of identifying limitations of existing enzymatic bio-analysis test kits where they occurred, and then using advanced techniques, such as molecular biology (photo 1), to rapidly overcome them. Novel test kits have also been developed for analytes of emerging interest to the oenologist, such as yeast available nitrogen (YAN; see pages 2-3 of issue 117 article), or where previously enzymes were simply either not available, or were too expensive to employ, such as for D-mannitol analysis.
Hide AbstractGrape and wine analysis: Oenologists to exploit advanced test kits.
Charnock, S. C. & McCleary, B. V. (2005). Revue des Enology, 117, 1-5.
It is without doubt that testing plays a pivotal role throughout the whole of the vinification process. To produce the best possible quality wine and to minimise process problems such as “stuck” fermentation or troublesome infections, it is now recognised that if possible testing should begin prior to harvesting of the grapes and continue through to bottling. Traditional methods of wine analysis are often expensive, time consuming, require either elaborate equipment or specialist expertise and frequently lack accuracy. However, enzymatic bio-analysis enables the accurate measurement of the vast majority of analytes of interest to the wine maker, using just one piece of apparatus, the spectrophotometer (see previous issue No. 116 for a detailed technical review). Grape juice and wine are amenable to enzymatic testing as being liquids they are homogenous, easy to manipulate, and can generally be analysed without any sample preparation.
Hide AbstractVariability of antioxidant compounds and capacities in four wild fruits collected in different years and locations in Mozambique.
Uaila, E., Granfeldt, Y., Khan, M., Guiamba, I., Burleigh, S. & Lazarte, C. E. (2024). Journal of Agriculture and Food Research, 18, 101315.
This study investigated the variability of antioxidant compounds and capacity of four wild edible fruits from Mozambique: Adansonia digitata (AD), Dialium schlechteri (DS), Garcinia livingstonei (GL), and Syzygium cordatum (SC), collected over three consecutive years from seven locations. Antioxidant compounds including total polyphenol content (TPC), total flavonoid content (TFC), and vitamin C, as well as the total antioxidant capacity (TAC) by three methods (DPPH, ABTS, and FRAP) were determined by spectrophotometric methods. Results in dry basis for TPC ranged from 42.8 ± 1.05 to 65.4 ± 0.51 mg GAE/g, TFC from 8.6 ± 0.03 to 66.7 ± 1.41 mg RE/g and, vitamin C from 1.7 ± 0.28 to 40.1 ± 0.35 mg/100 g. TAC-DPPH ranged from 53.5 ± 1.80 to 88.3 ± 0.29 μmol TE/g, TAC-ABTS from 52.8 ± 0.50 to 136.7 ± 0.97, μmol TE/g, and TAC-FRAP from 12.4 ± 0.79 to 75.0 ± 2.32 μmol TE/g. AD exhibited the highest TPC and vitamin C, indicating higher antioxidant capacity. Notably, yearly variations had a more pronounced impact on antioxidant compounds than locations. It was found a yearly variation of about 30% for TFC in SC and vitamin C in AD. Despite these variations, these underutilized fruits hold potential nutritional and health benefits and can be used in food product development.
Hide AbstractApplication of a Gallic Acid–Based Oxygen Scavenger Label for the Preservation of L‐Ascorbic Acid in Orange Juice.
Coray, N. M. & Yildirim, S. (2024). Packaging Technology and Science, 37(9), 917-923.
Citrus juices are rich sources of antioxidants, including vitamin C, but are prone to oxidation during storage. We investigated the application of gallic acid (GA), an environmentally friendly reducing agent, as active packaging to mitigate this issue. Orange juice was packaged in airtight glass containers both with and without GA-based oxygen scavenger (GA-OS) label and stored at 20°C and 4°C. During the storage, we monitored oxygen levels in the headspace and dissolved oxygen concentration in the orange juice, vitamin C content and browning. In the presence of GA-OS, oxygen levels in the headspace were reduced by half in under 1 h at 21°C and within 2 h at 4°C. Dissolved oxygen concentration decreased 50% after 8 h at 21°C and after 1.2 days at 4°C. In the absence of GA-OS, vitamin C degraded completely within 30 days at 21°C and 45 days at 4°C. In contrast, GA-OS nearly fully preserved vitamin C for 105 days at both temperatures. Browning, quantified by delta E, escalated in GA-OS-absent samples to 16.79 ± 0.16 at 21°C to 12.19 ± 0.10 at 4°C, whereas GA-OS samples exhibited no significant browning. Our results underscore GA-OS's efficacy in preserving the quality of liquid foodstuffs, exemplified by orange juice, suggesting its broad range applicability as active packaging.
Hide AbstractFormulation of Ascorbic Acid and Betaine-based Therapeutic Deep Eutectic System for Enhanced Transdermal Delivery of Ascorbic Acid.
Song, J. E., Jun, S. H., Ryoo, J. Y. & Kang, N. G. (2024). Pharmaceutics, 16(5), 687.
L-ascorbic acid (AA), a potent antioxidant, is commonly used topically in the pharmaceutical and cosmetic fields. However, the incorporation of AA into topical formulations is difficult because of its highly unstable nature and relatively poor skin permeability. In this study, we propose an alternative strategy for improving the solubility and topical delivery of AA through its conversion to a therapeutic deep eutectic system (THEDES). AA and betaine (Bet)-based THEDESs were prepared at certain molar ratios and characterized using polarized optical microscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry. Solubility tests showed that AA in the form of THEDES was readily soluble in various polyols (glycerin, 1,3-butylene glycol, dipropylene glycol, and 1,3-propanediol) at a high concentration (approximately 40%). Furthermore, compared to AA alone or the physical mixture of AA and Bet, AA-based THEDES significantly enhanced AA delivery through porcine skin. In an in vivo human study, THEDES-containing serum reduced the markers of aging and induced an even skin tone. These findings indicate the utility of AA and Bet-based THEDES as novel transdermal delivery systems for AA. Furthermore, our approach also showed good extension to developing gluconolactone, a well-known natural antioxidant, and Bet-based THEDES, showing potential application in transdermal delivery systems.
Hide AbstractSugar-Triggered Burst Drug Releasing Poly-Lactic Acid (PLA) Microneedles and Its Fabrication Based on Solvent-Casting Approach.
Kang, S., Song, J. E., Jun, S. H., Park, S. G. & Kang, N. G. (2022). Pharmaceutics, 14(9), 1758.
Microneedles have emerged as a novel transdermal delivery tool that enables the delivery of various products such as drugs, vaccines, or cosmetic ingredients. Although the demand for solid microneedles composed of biocompatible polymer is increasing, the manufacture of microneedles using poly-lactic acid (PLA) with rapid drug-releasing is yet to be established and the process is still in its infancy. Here, we propose a novel strategy for the fabrication of PLA solid microneedles which enable a drug to be burst-released based on a solvent-casting process. This approach offers extreme simplicity, broad geometric capability, cost-effectiveness, and scalability based on high fidelity-replicas. It was verified that microneedles of various heights (250–500 μm) could be fabricated with appropriate mechanical strength to penetrate the stratum corneum layer of skin. By adding sugar in the composition of PLA microneedle, it was observed that both hydrophilic and hydrophobic drugs can be rapidly released within 30 min. Our burst drug-releasing PLA microneedle having both characteristics of solid microneedle and soluble microneedle and its fabrication approach based on solvent-casting will contribute to getting microneedle technology close to commercialization and beyond existing technical limitations.
Hide AbstractEvaluation of physicochemical, sensory, and antimicrobial properties of small-scale produced fruit vinegars.
Benedek, C., Szakolczi, O., Makai, G., Kiskó, G. & Kókai, Z. (2022). Acta Alimentaria, 51(1), 1-10.
Hungarian fruit vinegars were characterised in terms of physicochemical attributes (total polyphenol content, antioxidant characteristics/FRAP, CUPRAC, ABTS/, ascorbic acid content, pH, total soluble solids), sensory profiles, and antimicrobial properties. Both compositional and sensory profiles showed distinct patterns depending on the type of vinegar (Tokaj wine, balsamic or apple) and the additional fruit used. Balsamic vinegars maturated on rosehip, sea buckthorn, and raspberry showed outstanding antioxidant performances. Rosehip, raspberry, and quince vinegars, as well as vinegars produced from Tokaji aszú and balsamic apple obtained high scores for fruity and sweet notes. Antimicrobial activities were tested on Gram-negative and Gram-positive organisms, including probiotic bacteria. Generally, only weak activities were obtained, which was attributed to the natural sugar content of the samples, depending on the type of the vinegar and the fruit. Similar results, but more pronounced bacterial growth inhibitions were obtained for probiotic strains, however, some probiotic strains were resistant to at least two of the vinegars. Based on these, balsamic apple, raspberry, rosehip, quince, and sea buckthorn may qualify as potential functional components of probiotic preparations containing some of the strains tested.
Hide AbstractRipening assessment of ‘Ortanique’ (Citrus reticulata Blanco x Citrus sinensis (L) Osbeck) on tree by SW-NIR reflectance spectroscopy-based calibration models.
Pires, R., Guerra, R., Cruz, S. P., Antunes, M. D., Brázio, A., Afonso, A. M., Daneil, M., Panagopoulos, T., Goncalves, I. & Cavaco, A. M. (2022). Postharvest Biology and Technology, 183, 111750.
The aim of this study was the non-destructive assessment of ‘Ortanique’ (Citrus reticulata Blanco x Citrus sinensis (L) Osbeck) ripening, based on the prediction of internal quality attributes (IQA) by short-wave near-infrared reflectance spectroscopy (SW-NIRS) calibration models. Spectra from fruit of 50 trees located in two different orchards, were acquired on tree using a customized portable visible near-infrared (vis-NIR) system. Partial least squares (PLS) was used to build the various IQA calibration models. The models were tested through internal validation (IV) and external validation (EV). Generally, the IV results were always superior to those of EV: regarding IV, a high regression coefficient (R2) and low root mean square error of prediction (RMSEP) were achieved, revealing a good predictive performance for juice pH (R2 = 0.80; RMSEP = 0.10; SDR = 2.23), soluble solids content (SSC) (R2 = 0.79; RMSEP = 0.75 %; SDR = 2.27), titratable acidity (TA) (R² = 0.73; RMSEP = 0.24 % citric acid; SDR = 1.94) and the maturation index (MI) (R2 = 0.80; RMSEP = 1.38; SDR = 2.2). The best EV predictions were obtained for TA (R2 = 0.69; RMSEP = 0.38 % citric acid; SDR = 1.24), and MI (R2 = 0.69; RMSEP = 2.07; SDR = 1.49). Calibration models for glucose, fructose and sucrose showed medium-coarse predictions for both validation strategies. A detailed investigation of MI models was performed, to understand the causes of their poor EV results. In the context of EV, model updating strategies were explored by using some validation samples to improve the calibration model. The methods of bias correction and spiking were tested, showing a clear improvement in the predictions.
Hide AbstractAntioxidant properties and sensory evaluation of microgreens from commercial and local farms.
Tan, L., Nuffer, H., Feng, J., Kwan, S. H., Chen, H., Tong, X. & Kong, L. (2020). Food Science and Human Wellness, 9(1), 45-51.
Microgreens are young and tender vegetables or herbs that provide attractive color, flavor, and nutrition. The purpose of this study was to evaluate the nutritional and sensory qualities of broccoli microgreens grown by different methods (hydroponically vs. soil grown) and from different sources (commercial vs. local farm). No significant difference in total phenolic concentration and antioxidant capacity was found in all broccoli microgreens, but a significantly higher chlorophyll concentration was found in farm microgreens than the commercial ones. Moreover, the soil-grown farm microgreens possessed a significantly higher vitamin C concentration than hydroponically-grown farm sample and commercial sample. Participants in the sensory study favored farm samples regardless of growing method, and their overall liking was significantly correlated with taste of the microgreens. In addition, six other microgreens from the local farm were analyzed for their nutritional quality. These conclusions suggested a potential for consumers to still benefit nutritionally by purchasing commercial microgreens at a lower cost; however, it may be worthwhile for consumers to purchase microgreens from local farms for a better sensory experience.
Hide AbstractImpact of heat treatment and flavorings on the antioxidant capacity of black and green tea.
Bodor, Z., Pergel, B. & Benedek, C. (2020). Progress in Agricultural Engineering Sciences, In Press.
The high antioxidant capacity of tea is well-known, but the effect of flavorings like honey or lemon has been less studied. Their antioxidants can interact with each other, the global result being also affected by the brewing temperature. The combined effect of heat (55 and 80°C) and flavorings (acacia and honeydew honeys, lemon juice) on the total polyphenol, total flavonoid content and antioxidant capacity of black and green teas was studied. In many cases higher antioxidant capacity was obtained at 80°C. Teas flavored with honeydew honey had higher antioxidant capacity than those containing acacia honey. Addition of lemon decreased the antioxidant capacity of tea with honey. No synergies were confirmed in any of the compositions investigated. Vitamin C content of lemon-containing black tea was reduced by half at 80°C compared to tea brewed at 55°C; while honey was shown to partly prevent this loss of ascorbic acid.
Hide AbstractFermentation of blackberry with L. plantarum JBMI F5 enhance the protection effect on uvb-mediated photoaging in human foreskin fibroblast and hairless mice through regulation of MAPK/NF-κB signaling.
Kim, H. R., Jeong, D. H., Kim, S., Lee, S. W., Sin, H. S., Yu, K. Y., Jeong, S-I. & Kim, S. Y. (2019). Nutrients, 11(10), 2429.
Chronic and extensive exposure of ultraviolet (UV)-irradiation causes human skin sunburn, inflammation, or photoaging, which is associated with downregulated collagen synthesis. This study investigated the effects of fermented blackberry (Rubus fruticosus B., FBB) by Lactobacillus plantarum JBMI F5 (LP) on UVB-induced photoaging in human foreskin fibroblast (Hs68) as well as in SKH-1 hairless mice. FBB pretreatment inhibited UVB-mediated type-1 procollagen degradation, matrix metalloproteinase (MMP)-1 and MMP-2 protein expression, and suppressed nuclear factor-κB (NF-κB) activation as well as mitogen-activated protein kinase (MAPK) phosphorylation in Hs68. In addition, FBB administration diminished the wrinkle formation in dorsal skin and epidermal thickening in UVB-irradiated hairless mice. Moreover, UVB-induced Type-1 procollagen reduction and antioxidant enzyme inactivation were reversed by FBB administration. These results suggest that FBB may have antiphotoaging effects on UVB-induced wrinkle formation by maintaining the extracellular matrix density in the dermis, which occurs via regulation of reactive oxygen species and related MAPK and NF-κB signaling. Therefore, FBB can be a potential candidate for protecting skin aging against UV irradiation.
Hide AbstractFlorkiewicz, A., Socha, R., Filipiak‐Florkiewicz, A. & Topolska, K. (2018). Journal of the Science of Food and Agriculture, In Press.
BACKGROUND: Vegetables are important components of the human diet. The processing method is crucial for nutritional quality of ready to eat product. The purpose of this study was to assess whether Sous‐vide method could be an alternative for traditional cooking of Brassica vegetables. RESULTS: Sous‐vide method appeared to be the most advantageous technique in relation to vitamin C preservation, both directly after processing and during storage of processed vegetables. Among studied phytochemicals, p‐coumaric and gallic acids were the most stable in vegetables cooked by this method. CONCLUSION: Sous‐vide method should be considered as an optimal technique of Brassica vegetables thermal treatment.
Hide AbstractBădărău, L. C., Nina, B., Maria, Ș. & Radu, H. (2017). Journal of Hygienic Engineering and Design, 19, 58-63.
Being a staple food crop, the potato provide basic nutrition to many people and offer several nutritional benefits. Despite valued as carbohydrate source, tubers with higher levels of bioactive compounds (as vitamin C) could have a positive impact on the people health. The goal of this research was to evaluate the behavior of 10 potato varieties with different L ascorbic acid content after inoculation with potato virus Y (necrotic strains). Another goal of this study was to elucidate the biochemical basis responsible for different reaction to infection with potato virus Y necrotic strains PVYN among several varieties which differ in their susceptibility or resistance to this pathogen. The potato varieties, including new Romanian and commercial cultivars evaluated for L ascorbic acid content, were the following: Christian, Roclas, Red Lady, Marvis, Castrum, Brasovia, Hermes, Sante, Riviera and Carrera. The vitamin C content was estimated using an enzymatic method (L-ascorbic test kit, Megazyme Ltd., Bioreba). The L ascorbic acid content was analyzed in the flesh only, with variety Hermes showing the highest content (746 mg/kg-1 DW) in tubers after inoculation. Significant differences in vitamin C content were observed across the cultivars before and after virus inoculation. Excepting the cultivars Christian, Riviera and Sante, which were very resistant and resistant to mechanical inoculation, all the other varieties presented 48.6 - 100% infected plants. After 3 months from harvesting, the frequency of tubers with symptoms was between 8.2 - 34.7% for varieties Roclas, Marvis, Castrum, Brasovia and for Red Lady, Carrera, Hermes varieties this percentage was higher (69.2-98.2%). This study provides information on level of important micronutrients as L ascorbic acid in a range of several health and PVYN infected potato cultivars.
Hide AbstractMonteiro, N., Martins, A., Pires, R. A., Faria, S., Fonseca, N. A., Moreira, J. N., Reis, R. L. & Neves, N. M. (2016). RSC Advances, 6(115), 114599-114612.
Delivery systems may be designed to protect and control the release kinetics of growth/differentiation factors in a spatiotemporal manner. Liposomes are examples of biological-based bioactive agent delivery systems. In this work, ascorbic acid (AscA) was encapsulated in the inner compartment of the liposome and dexamethasone (Dex) was encapsulated within the lipid bilayer in order to develop a dual release system of these bioactive agents involved in the osteogenic differentiation of mesenchymal stem cells (MSCs). The particle size (~150 nm) of the prepared liposomes showed a monodisperse distribution. The bioactive agent release study showed that Dex was released more rapidly from the liposomes than AscA. The Dex release profile showed an initial burst release within 12 h; afterwards, a slower and sustained release was observed until 21 days. The release of AscA from the liposomes was not detected until 6 h; afterwards, a linear release was observed from 24 h until 21 days. The effect of Dex-AscA-loaded liposomes on the viability, proliferation and osteogenic differentiation of human bone marrow-derived MSCs (hBMSCs) were assessed. The cell culture results showed that the Dex-AscA-loaded liposomes (in a single dose or in repeated doses) do not have any cytotoxic effect. Dex-AscA-loaded liposomes given once did not promote induction of hBMSCs differentiation into the osteogenic lineage. However, Dex-AscA-loaded liposomes given repeatedly promoted the hBMSCs differentiation into the osteogenic lineage, both in basal medium and complete osteogenic medium. These results were genotypically demonstrated by the expression of osteoblastic markers. In conclusion, Dex-AscA-loaded liposomes represent a biological nanoparticle strategy with potential safety and efficacy for bone tissue engineering approaches.
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