## 1 Introduction  
Lactones are one of the most important groups of substances that shape the sensory properties of food and cosmetic products. They exhibit a pleasant, fruity-floral scent and are a group of compounds that are often isolated from the natural environment. However, the possibilities of using industrial extraction from natural sources are limited, as the sensory-relevant plant components are often present in low concentration, and therefore, isolating and obtaining them in sufficiently large amounts is usually expensive. The technically troublesome and economically unprofitable isolation of cyclic esters from the natural environment, with the simultaneous willingness to meet consumer trends for a healthy lifestyle and interest in what is natural, contributed to the dissemination of the research on the biotechnological method of synthesizing these compounds [1, 2]. In the last two decades, a particularly great interest has been noted in the biotechnological synthesis of gamma-decalactone (GDL), a compound with a characteristic peach fragrance used in the production of confectionery, cakes, wafers, chewing gums, and granulated and powder beverages [3]. The research conducted by the scientists from France ([PERSON], [PERSON], [PERSON]) [4; 5; 6], Belgium ([PERSON], [PERSON]) [7; 8], Portugal ([PERSON], [PERSON], [PERSON]) [9; 10], and Brazil ([PERSON], [PERSON]) [11; 12] has provided extensive knowledge on the biotransformation of fatty acids to gamma-decalactone, based on \(\beta\)-oxidation, which takes place in yeast cell peroxis. Particular attention was paid to the \(\beta\)-oxidation process of ricinoleic acid [(\(R\))-12-hydroxy-9-octadecanoic acid], which is the main component (80-90%) of castor oil obtained from castor bean seeds (_Ricinus communis_). The conversion of this acid into GDL involves cleavage from the carboxy terminus of the eight-carbon fragment as a result of four \(\beta\)-oxidation cycles. From the 18-carbon chain, the final 10-carbon compound (4-hydroxydecanoic acid) is obtained, which is then cyclized in an acidic environment to gamma-decalactone [13]. Many microorganisms show the capability of the biosynthesis of GDL (_Candida, Pichia, Sporobolus, Rlodorula, Yarrowia_) and are highly active in the process of \(\beta\)-oxidation and reduction of the unsaturated bond in ricinoleic acid (gamma-decalactone precursor) [6; 7; 13; 14; 15; 16]. Among them, _Yarrowia lipolytica_ yeast is characterized by the highest production efficiency, especially when castor oil is used as a substrate in the reactions. This is due to the high extracellular lipolytic activity of this yeast induced by hydrophobic substrates [17; 18]. The numerous studies conducted so far on the biotechnological synthesis of GDL have mainly focused on the improvement of reaction efficiency through the selection and optimization of individual process parameters, as well as the selection of the appropriate strain, which is often subject to additional genetic modifications [12; 19; 20; 21]. However, these studies have been mostly carried out on a small scale, and the reaction efficiency, at the level of a few grams of lactone per liter of the culture medium, has been estimated on the basis of chromatographic or spectrophotometric determinations without separating a product from the mixture. The most frequently used analytical methods include GC [19; 22; 23; 24], GC-MS [7; 9; 25; 26], solid-phase microextraction in combination with GC-MS (SPEME-GC-MS) [27], and less often, a spectrophotometric method based on the ferric hydroxamate reaction [28]. So far, only a few research papers on the possibility of separating GDL from the culture medium have been published. Generally, the recovery of products in the bioprocesses that involve microorganisms is a difficult stage, especially for fragrances, due to their volatility and low solubility as well as the complexity of the biotransformation medium itself. Liquid-liquid extraction (LLE), adsorption, or pervaporation are most often used to extract fragrances [29; 30; 31].