lactic acid

  1. a colorless or yellowish, syrupy, water-soluble liquid, C3H6O3, produced during muscle contraction as a product of anaerobic glucose metabolism, abundant in sour milk, prepared usually by fermentation of cornstarch, molasses, potatoes, etc., or synthesized: used chiefly in dyeing and textile printing, as a flavoring agent in food, and in medicine.

Origin of lactic acid

First recorded in 1780–90 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use lactic acid in a sentence

  • Cheese makers also often add cultures or lactic acid to their milk to keep it from spoiling during fermentation.

    Why We Love Stinky Cheese | Stacey Slate | January 14, 2010 | THE DAILY BEAST
  • The presence of phenol causes a deep amethyst-blue color, as in Uffelmann's test for lactic acid.

    A Manual of Clinical Diagnosis | James Campbell Todd
  • Its disadvantage is that it introduces, with the bread, a variable amount of lactic acid and numerous yeast-cells.

    A Manual of Clinical Diagnosis | James Campbell Todd
  • The presence of lactic acid is the most suggestive single symptom of gastric cancer.

    A Manual of Clinical Diagnosis | James Campbell Todd
  • These same lactic acid bacteria may be useful when they sour the milk for the cheese maker.

    A Civic Biology | George William Hunter

British Dictionary definitions for lactic acid

lactic acid

  1. a colourless syrupy carboxylic acid found in sour milk and many fruits and used as a preservative (E270) for foodstuffs, such as soft margarine, and for making pharmaceuticals and adhesives. Formula: CH 3 CH(OH)COOH: Systematic name: 2-hydroxypropanoic acid

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for lactic acid

lactic acid

[ lăktĭk ]

  1. A syrupy, water-soluble organic acid produced when milk sours or certain fruits ferment. It is also produced in the body during the anaerobic metabolism of glucose, as in muscle tissue during exercise, where its buildup can cause cramping pains. A synthetic form of lactic acid is used as a flavoring and preservative, in dyeing and textile printing, and in pharmaceuticals. Chemical formula: C3H6O3.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.