Lactic acid: recent advances in products, processes and technologies — a review

Abstract

Lactic acid, the most widely occurring hydroxycarboxylic acid, is an enigmatic chemical. It was discovered a long time ago and its use in food preservation and processing and as a specialty chemical has grown over the years with current production of about 120 000 t yr −1 . Its potential as a major chemical feedstock, derived from renewable carbohydrates by sustainable technologies, to make plastics, fibers, solvents and oxygenated chemicals, had also been recognized. Recently, new technologies have emerged that can overcome major barriers in separations and purification and processing. Advances in electrodialysis (ED) and bipolar membranes and one particular process configuration termed the 'double ED' process, a specific combination of desalting ED followed by 'water-splitting' ED with bipolar membranes, has given very promising results, showing a strong potential for an efficient and economic process for recovery and purification of lactic acid without generating a salt waste. For the production of polymers, several advances in catalysts and process improvements have occurred in the technology to produce dilactide and its polymerization to produce plastics and fibers by Natureworks LLC, which is the leader in lactic polymer technology and markets. Other advances in esterification technology with pervaporation and development of biosolvent blends also have a high potential for 'green' solvents in many applications. Recently, a considerable amount of pioneering effort in technology, product development and commercialization has been expended by several companies. To overcome the barriers to replace long-established petroleum-derived products, further real support from consumer, regulatory and government organizations is also needed.

Influence of Residual Sugars on the Purification of Lactic Acid Using Short Path Evaporation

“…Therefore, development of an efficient and low-cost separation process is very important, as this can reach up to 50% of the total cost (Wasewar et al 2002;Datta and Henry 2006;Chanukya et al 2013).…”

Production of Food Grade β-Galactosidase from Artisanal Yogurt Strains

“…It is well known that lactic acid is an economically valuable product with different applications in the pharmaceutical, chemical, textile, and food industries. The current worldwide production (including polymer uses such as formation of linear polyesters, lactoyllactic acid, and higher polylactic acids) is estimated to be around 120,000 ton per year (Datta and Henry, 2006). Existing commercial lactic acid production processes mainly use homolactic organisms including L. delbrueckii, L. amylaphilus, L. bulgaricus, and L. leichmanii (Datta and Henry, 2006).…”

“…The current worldwide production (including polymer uses such as formation of linear polyesters, lactoyllactic acid, and higher polylactic acids) is estimated to be around 120,000 ton per year (Datta and Henry, 2006). Existing commercial lactic acid production processes mainly use homolactic organisms including L. delbrueckii, L. amylaphilus, L. bulgaricus, and L. leichmanii (Datta and Henry, 2006). Therefore, in the last decade, lactic acid production has increased considerably due to the development of new applications, and the production technology is currently based on microbial fermentation, which emphasizes the demand for the discovery of new microbial sources with novel characteristics (Datta and Henry, 2006).…”

“…Existing commercial lactic acid production processes mainly use homolactic organisms including L. delbrueckii, L. amylaphilus, L. bulgaricus, and L. leichmanii (Datta and Henry, 2006). Therefore, in the last decade, lactic acid production has increased considerably due to the development of new applications, and the production technology is currently based on microbial fermentation, which emphasizes the demand for the discovery of new microbial sources with novel characteristics (Datta and Henry, 2006). Furthermore, these artisanal strains can also be considered as starter cultures with unique characteristics for dairy industry.…”

Microbial conversion of sugars from plant biomass to lactic acid or ethanol

“…This review focuses on the development of biocatalysts for conversion of hexoses and pentoses derived from lignocellulosic biomass. Other reviews have focused on the microbial production of various other commodity chemicals, such as succinate, acetate and butanol from biomass (Datta and Henry, 2006;Hahn-Hä gerdal et al, 2006;Lynd et al, 2005;McKinlay et al, 2007;Narayanan et al, 2004;Ragauskas et al, 2006;Singh et al, 2006;Wyman, 2003). Naturally occurring lactic acid bacteria (LAB) ferment hexose sugars, such as glucose, by oxidizing NADH generated during glycolysis, with pyruvate serving as the electron acceptor, to form lactic acid as the major product ( Figure 2).…”