Chemical vs. biotechnological synthesis of C13-apocarotenoids: current methods, applications and perspectives

Abstract

Apocarotenoids are natural compounds derived from the oxidative cleavage of carotenoids. Particularly, C13-apocarotenoids are volatile compounds that contribute to the aromas of different flowers and fruits and are highly valued by the Flavor and Fragrance industry. So far, the chemical synthesis of these terpenoids has dominated the industry. Nonetheless, the increasing consumer demand for more natural and sustainable processes raises an interesting opportunity for bio-production alternatives. In this regard, enzymatic biocatalysis and metabolically engineered microorganisms emerge as attractive biotechnological options. The present review summarizes promising bioengineering approaches with regard to chemical production methods for the synthesis of two families of C13-apocarotenoids: ionones/dihydroionones and damascones/damascenone. We discuss each method and its applicability, with a thorough comparative analysis for ionones, focusing on the production process, regulatory aspects, and sustainability.

Engineering the oleaginous yeast Yarrowia lipolytica to produce the aroma compound β-ionone

“…Therefore, improving the efficiency of the product extraction and capture is necessary to ensure successful production on an industrial scale. We will continue work on enzyme engineering to address the encountered issues as well as improving the means of product extraction and capture, aiming to achieve the break-even point of 1 g/L for commercial production [14]. …”

“…A second method for obtaining natural β-ionone involves using in vitro enzymatic processes (i.e., the biotransformation of β-carotene to β-ionone). However, the enzymatic bio-transformations often lead to a variety of undesirable byproducts [11, 14]. These specific limitations motivate research into new reliable production processes for obtaining natural β-ionone.…”

Techniques for the recovery of volatile aroma compounds from biochemical broth: A review

“…Most naturally occurring aromas are secondary metabolites, with a low odour threshold, present at minor concentrations in natural sources . Low product concentrations, which make natural extraction expensive, combined with seasonal, climatic, and even political fluctuations in the quality and availability of natural stock, have led to most aroma molecules being produced chemically nowadays . However, chemical production is non‐sustainable, energy consuming, involves several reaction steps with expensive chiral educts and (expensive) catalysts and, if non chiral educts are used, results in a racemic mixtures of the desired product.…”

“…Furthermore, chemically produced F&Fs are perceived as somehow artificial . In recent years the ‘chemophobia’ of consumers has increased the call for replacing aromas produced from chemical stock with aromas extracted from natural sources . For this reason biochemical production is becoming an attractive alternative to chemical synthesis or natural extraction .…”

“…For this reason biochemical production is becoming an attractive alternative to chemical synthesis or natural extraction . It can be carried out in mild conditions, and renewable substrates such as sugar or organic residual streams can be used for fermentation or biotransformation, yielding high enantioselectivity without any toxic waste . Despite all of the advantages of biochemical production, finding an appropriate technique for industrial product recovery from fermentation broth could present a hurdle on the way to the production of commercially competitive biochemical aromas.…”