Related Experiment Video
Updated: May 14, 2026
04:40
The Cultivation, Growth, and Viability of Lactic Acid Bacteria: A Quality Control Perspective
Published on: June 16, 2022
Validation and Application of Quantitative Methods for D-Lactic Acid and L-Lactic Acid Determination in Lactic Acid
Chong Liu1,2, Yiru Liu1,2,3, Xuejian Yu1,2
1China National Research Institute of Food and Fermentation Industries, Beijing 100015, China.
Foods (Basel, Switzerland)
|May 13, 2026
Summary
A new HPLC method accurately measures D- and L-lactic acid in lactic acid bacteria, crucial for infant food safety and regulatory compliance. This validated technique ensures reliable quantification for food cultures.
Area of Science:
- Analytical Chemistry
- Microbiology
- Food Science
Background:
- Accurate quantification of D- and L-lactic acid from lactic acid bacteria is vital for infant food safety.
- Regulatory compliance requires sensitive detection of D-lactic acid in food products.
- Existing methods may lack the specificity or accuracy needed for simultaneous D- and L-lactic acid measurement.
Purpose of the Study:
- To develop and validate a high-performance liquid chromatography (HPLC) method for simultaneous D- and L-lactic acid quantification.
- To ensure the method meets regulatory standards for accuracy, precision, and sensitivity in food applications.
- To assess the method's suitability for analyzing lactic acid bacteria fermentation broths.
Main Methods:
- HPLC analysis was validated for accuracy, precision, specificity, limit of quantification (LOQ), linearity, range, and robustness.
- Measurement uncertainty was evaluated.
- The method was tested on six validated bacterial strains, assessing recovery, relative standard deviations (RSD), and sample stability.
Main Results:
- The method achieved a limit of detection (LOD) of 0.25 µg/mL and LOQ of 0.8 µg/mL for both D- and L-lactic acid.
- Mean recoveries ranged from 93.50% to 105.37%, with low intra-assay (0.90-2.64%) and inter-laboratory (2.56-10.16%) RSD.
- Excellent linearity, accuracy, and precision were confirmed across the 0.8-200.0 µg/mL range, with no interference from media and 48h sample stability.
Conclusions:
- The developed HPLC method is suitable for the accurate identification and quantification of D- and L-lactic acid in lactic acid bacteria fermentation samples.
- The method's robustness and validated parameters make it applicable for assessing D-/L-lactic acid production in food cultures.
- This analytical tool supports regulatory compliance and quality control in the food industry, particularly for infant and young child foods.
Related Concept Videos
01:25Production of Organic Acids
Lactic acid, an important organic acid extensively applied in food, pharmaceutical, and biodegradable polymer industries, is primarily produced via microbial fermentation. This method is favored over chemical synthesis due to its environmental sustainability and capacity for enantiomerically pure product formation. Among various microbial processes, the fermentation of starch-based substrates stands out due to the abundance and renewability of raw materials like corn and potatoes.Hydrolysis of...
01:27Microbes in the Production of Fermented Foods
Lactic acid bacteria (LAB) and molds are instrumental in fermenting plant-based foods to enhance preservation and ensure year-round availability. These microbial processes convert plant carbohydrates into organic acids and other metabolites that inhibit spoilage organisms and contribute to the sensory qualities of the final product.In sauerkraut production, cabbage goes through a microbial succession that starts with cocci such as Leuconostoc mesenteroides. These microbes begin fermentation by...
01:23Microbial Growth Measurement: Direct Methods
Direct methods for measuring microbial populations in a culture are essential tools in microbiology, providing quantitative data for various applications. Among these, microscopic counts, plate counts, and serial dilution are widely used techniques, each with unique principles and applications.Microscopic CountsMicroscopic counting involves the use of a Petroff-Hausser chamber, a specialized microscope slide with a grid and defined depth. By observing a liquid culture under a microscope,...
01:29Microbes in Food Production
Microbial fermentation is central to food biotechnology, enhancing flavor, texture, preservation, and stability. Fermentative microorganisms metabolize carbohydrates into organic acids, alcohols, and other metabolites that inhibit spoilage organisms and improve digestibility while contributing distinctive sensory qualities.In baking, amylases naturally present in flour hydrolyze starch into monosaccharides such as glucose, which Saccharomyces cerevisiae ferments anaerobically. Through...
01:15Data Validation
Method validation is a crucial process in analytical chemistry designed to confirm that a given method consistently produces reliable and high-quality results. This process is essential when a method is applied to different sample matrices or when procedural modifications are made, ensuring that the results meet acceptable standards across various applications.
Key parameters for method validation include:
Key parameters for method validation include:
01:30Methods to Assess Microbial Populations
Assessing microbial populations is crucial for understanding microbial roles in health, ecology, and industry. Various complementary techniques—both culture-based and molecular—enable detailed analysis of microbial abundance, diversity, and function.Viable Plate CountThe viable plate count is a traditional culture-based method used to estimate the number of living microbes in a sample. After serial dilution, the sample is spread onto nutrient agar plates. Each viable cell forms a visible...