Süperkritik Karbondioksit Ekstraksiyon Yöntemi ile Konsantre Çedar ve Küflü Peynir Aroması Eldesi

Abstract

The increasing awareness of consumers towards the consumption of natural products has led to the focus on obtaining additives in natural ways rather than through chemical/synthetic ways. Although recent studies have focused on the obtaining and optimization of such value-added additives through innovative ways, more detailed studies are needed. Therefore, this thesis was carried out in order to obtain natural Cheddar and mouldy cheese flavors which have the possibility to be widely used and show the potential in order to offer an alternative solution to industrial large-scale applications. Within the scope of the thesis, as raw materials; Cheddar cheese and Roquefort cheese, and enzyme-modified cheeses (EMCs); Cheddar and Roquefort were used. Supercritical carbon dioxide extraction (SC- CO2) were conducted under three different temperature (35, 45, 55 °C) and pressure (100, 200, 300 bar) conditions at a constant time (90 min) and CO₂ flow rate (20 g/min). A total of 36 extractions were carried out for four cheese samples as a combination of each parameter. Basic composition, urea-PAGE, total free amino acid, total free fatty acid, flavor and sensory analyzes were made in cheese raw material, extracts and cheese pellets after extraction. Considering the dry matter analysis results, it was determined that dry matter partially decreased after extraction in all cheese varieties, and the average decrease in Cheddar cheese pellets and EMC cheddar cheese pellets was determined as 12% and 3%, respectively. Dry matter change was observed limited in Roquefort and EMC Roquefort cheese. The highest fat changes (%) in Cheddar and Roquefort cheese pellets were observed in AXM (35 °C, 300 bar) and DZM (55 °C, 300 bar) samples, respectively, and the rates were determined as 53.71% and 19.64%. In EMC Cheddar and EMC Roquefort cheese pellets, the % fat changes in BYL (45 °C, 200 bar) and CZK (35 °C, 100 bar) samples were determined at the highest rate and were observed as 15.88% and 12.72%, respectively. Considering temperature and pressure, no significant differences were observed in pH values. In terms of % protein in Cheddar cheese and Roquefort cheese pellets, an increase in % of protein values were observed depending on the decreased % of the fat amount in the pellets. Protein values in cheddar cheese pellets were found 32.16%, 33.05%, and 33.75% in the samples AXK (35 °C, 100 bar), AYK (45 °C, 100 bar), and AZK (55 °C, 100 bar), respectively. It has been determined that the protein values increase at increasing temperatures of the same pressure, and this situation is similar in Roquefort cheese pellets at 200 bar and 300 bar pressure. UREA-Polyacrylamide Gel Electrophoresis (UREA-PAGE) analysis revealed that the effect of the extraction on the casein fractions was insignificant. Free fatty acid (FFA) analysis was performed by gas chromatography (GC) in pellets and extracts and found that FFA concentration was decreased in all pellets compared to the raw material. It was observed that FFA composition generally decreased in accordance with the samples with high-fat content (%) change in the pellets.

In all cheeses, similar sensory qualities to the raw materials were also detected in the extracts which shows that similar flavor profiles can be obtain effectively by using supercritical extraction method. As a result, according to data obtained within this thesis, it is seen that natural Cheddar and moldy cheese aromas can be obtained within the SC-CO2 method and this study may contribute to the industrial-scale integration and production of aroma compounds, as well as shed light on similar studies to be carried out in the future.