A Thorough Dissection on Lactic Acid Enantiomers

Abstract

The fermentation process is a wonder of nature. It has been applied by our ancestors for transforming food, such as converting milk to yogurt and cheese, grapes to wine, and wheat to beer. In this study, three brands of store-bought yogurt, Ahmoulé, Junlebao, and Classy Kiss, will be analyzed to quantitatively determine the total lactic acid (LA) concentration in yogurt, as well as the ratio of L to D lactic acid enantiomers using liquid and gas chromatography. The novelty of this paper lies in the versatility of lactic acid and its enantiomers. Understanding lactic acid also stems out into the environmental and medical fields. In the environmental aspect, the polymerized form of lactic acid, polylactic acid, is proficient for producing biodegradable plastics, alleviating urgent issues like plastic waste. In the medical aspect, lactic acid enantiomers can be studied to improve medicine and medical polylactic acid (PLA) can be used in various ways, such as drug-controlled release materials. The conclusions drawn from the sample preparation of the total lactic acid concentrations supported previously published results. However, there was a shocking discovery in the data regarding the L to D enantiomer ratio in commercially available yogurts that differed from past studies, showing significant progress that manufacturers have made in the nutritional value of yogurt. These novel findings and routes of thinking about how to fully utilize lactic acid are beneficial advancements for the scientific field.