The content of sensory active compounds and flavour of several types of yogurts

Abstract

The aim of this work was to identify and quantify several sensory active compounds in various types of yogurts using gas chromatography and simultaneously to judge their influence on flavour of yogurts using sensory analysis. In total 4 types of white and 10 types of flavoured yogurts (creamy and low-fat) with various flavourings, produced in Dairy Valašské Meziříčí, Ltd., were analysed. The highest content of sensory active compounds (P < 0.05) was found in strawberry yogurts, with high amount of ethyl butyrate. Excepting ethanol no significant differences (P < 0.05) were found between low-fat and creamy varieties. The total content of sensory active compounds in white yogurts was significantly (P < 0.05) lower than in flavoured fruit types. The highest content was in low-fat and lowest in white bio yoghurts. Flavour of yogurts was evaluated sensorially using scale and ranking test. All creamy yogurt varieties were evaluated as significantly (P < 0.05) more tasty than low-fat ones. Similarly in case of white yogurts creamy yogurts were evaluated as the most tasty and low-fat ones as the worst. Bio yogurts were evaluated equally tasty as classic yogurts with the same fat content.

Recent analyses using solid phase microextraction in industries related to food made into or from liquids

“…For dairy products, fatty acid esters were usually formed though enzyme activity, especially in cheeses (Bergamini et al, 2010;Delgado et al, 2010Delgado et al, , 2011Wolf et al, 2010), or added as a flavoring in milks and yoghurt through direct addition or enzyme production (Erkaya & Ş engül, 2011;Gioacchini et al, 2010;Majcher et al, 2010;Soukoulis et al, 2010;Verzera et al, 2010;Vítová et al, 2010;. In fruit and vegetable processing, fatty acid esterification was identified from SPME analyses of cooked and stored potatoes (Blanda et al, 2010).…”

“…2). Ester concentrations reported between January 2010 and May 2011 varied between 1 ng/g for ethyl octanoate in melons (Verzera et al, 2011) up to 1413 mg/kg in yoghurt (Vítová et al, 2010). Esters in food produce a variety of aromas including cheese and fruit smells (Leksrisompong et al, 2010;Torrea et al, 2011).…”

“…However, small molecular weight (approximately 100 g/mol) aldehydes are desirable in fermented dairy products. SPME analyses were used to monitor the concentrations of benzaldehyde, acetaldehyde and various acetones (Verzera et al, 2010;Vítová, Babák, Moká nová, Hýsková, & Zemanová, 2010). Acetaldehyde was considered the strongest contributor to yoghurt aroma (Soukoulis et al, 2010), as well as being the most concentrated aldehyde in some cheeses (Bergamini et al, 2010;Cais-Sokoli nska & Majcher, 2010;Majcher et al, 2010).…”

“…Even unprocessed milk was found to contain a range of straight chain and methylated alcohols identified with a DVB-CAR-PDMS SPME fiber . For yoghurts (Vítová et al, 2010) and Italian "Fossa" cheese (Gioacchini et al, 2010), alcohols were identified as the second most common group of volatile chemical compounds after esters. Cheese was the most common dairy product that has been investigated for alcohols with SPME analyses (Barba et al, 2010).…”