Overview
For rapid, direct determination of malic acid concentrations in food and beverage samples as well as biological samples. The assay uses Visual for signal readout. Compatible sample input includes Wine, beer, milk, etc. Typical stated assay timing is Approximately 15 min.
Key elements and design rationale
- Readout format: Visual supports plate-based signal acquisition and consistent comparison across matched samples.
- Sample compatibility: The stated sample scope includes Wine, beer, milk, etc, which is useful when aligning matrix type with calibration and control design.
- Workflow timing: The listed assay time of Approximately 15 min helps frame batch planning, replicate handling, and plate throughput.
- Feature emphasis: Fast and sensitive. Use of 20 or 100 µL sample. Semi-quantitative measurement between 0-500 mg/L (undiluted) malic acid.
Additional feature notes highlight Convenient. No expensive lab equipment needed; Sample treatment and assay can be performed in under 15 minutes. Available format information for this listing includes 10 Tests.
Biological background
This product is centered on measurement of quantiquik malic acid quick test strips within the matrices described for the assay. In practice, datasets from this type of format are typically interpreted by comparing relative signal, activity, or abundance across matched control and experimental groups rather than relying on a single value in isolation. Careful alignment of sample matrix, incubation window, and calibration strategy is important when comparing results across plates, operators, or study days.
More details
L-MALIC ACID, or L-malate, is a dicarboxylic acid that is made by all living organisms and plays an important role in the Calvin and Krebs Cycle. Malic acid is frequently used in food and beverage industries as an additive in products such as wine, beer, candies, etc. It can be used as an acidity regulator, preservative, or simply added for flavor. In the wine industry, decreasing levels of L-malic acid and increasing levels of L-Lactic Acid are monitored during malolactic fermentation. As L-malic acid is converted to L-lactic acid, the overall acidity of the wine is reduced which can lead to the improvement of the flavor of the wine.BioAssay Systems QuantiQuik™ L-Malic Acid Test Strips are based on L-malate dehydrogenase catalyzed oxidation of L-malic acid in which the formed NADH reduces a chromogenic reagent. The intensity of the product color is directly proportional to the L-malic acid concentration in the sample.
Detection method
Visual.
Procedures and timing
Stated procedure or timing information: Approximately 15 min.
Research relevance and current trends
- Plate-based quantification and side-by-side group comparison remain central use cases for this assay format.
- The description supports intervention-focused study designs in which researchers compare baseline and perturbed conditions.
- Short assay timing and plate compatibility support time-course or repeated-measure collection plans when handling is kept consistent.
Common research applications
- Screen quantiquik malic acid quick test strips in wine, beer, milk using strip-based detection.
- Compare threshold or presence-call outcomes across matched sample groups.
- Monitor routine or field-collected batches with consistent collection timing.
Interpretation is usually strongest when signal changes are assessed alongside matrix-matched controls, replicate agreement, and the assay's stated analytical window.
Notes for experimental interpretation
- Matrix composition, background signal, and sample handling can influence apparent response; compare like-with-like whenever possible.
- Use appropriate blanks, controls, and replicate wells to distinguish biological differences from plate, reagent, or handling variability.
What samples have you tested?
The strips have been tested on red wine, white wine, homogenized whole milk, cultured buttermilk, almond milk, yogurt, beer, apple juice, lemonade, grape juice, orange juice, cranberry juice, lime and lemon juice.
My sample turns the strip very dark purple, how can I determine the D-lactate concentration?
Very dark purple indicates that the diluted sample concentration is greater than 500 mg/L. To obtain a more accurate concentration, the sample should be further diluted and retested. For example, if the sample was diluted 5×, try diluting 21×.
I don’t have access to a pipetteman. How can I accurately measure out my samples?
We offer exact volume transfer pipettes as an accessory. For samples requiring a 21× dilution, order the 20 µL transfer pipettes (TP20). For samples requiring a 5× dilution, order the 100 µL transfer pipettes (TP100).
In your product information about the QuantiQuik L-Lactic Quick Test Strips, you indicate that there is information on how to prepare yogurt products for analysis with the Quick Test strips. How do I prepare my yogurt sample?
Previously, we have tested the QQLLAC test strips with greek yoghurt and buttermilk. Since yoghurt is a solid sample, it cannot be diluted in the same way as liquids, so sample spoons with defined volumes were used to measure the amount of sample to dilute in water. If you have access to a scale, you can also weigh out your sample. Our yoghurt required a 5x dilution, but different samples may vary.
I am working with Sour Beer samples and the edges are dark purple while the center is pale yellow. Is this normal? I tried D-Lactic & L-Lactic and had similar results
The color on the strip should be uniform. Sometimes the strip will not develop a uniform color if the sample is too acidic, and I suspect that this is your problem. In this case, you can either dilute your sample further than 5x, or if you have access to pH measuring equipment and a strong base like NaOH, you can adjust the pH of your sample to ~7 and rerun the sample.
Can I store unused reagents for future use?
Yes, unused reagents can be stored according to the assay protocol. The strips should be kept in a dry, cool location and protected from light.
For laboratories requiring additional technical capacity, we provide scientific support services including assay execution, method guidance, product sourcing, and customization to align the assay with specific experimental objectives. If you need assistance selecting the appropriate kit configuration, adapting the workflow to your application, or identifying related research services, please click Talk to a Scientist, email support@biohippo.com, or review our Research Services; a member of our scientific team will follow up with recommendations tailored to your study.
