Diacetyl levels and volatile profiles of commercial starter distillates and selected dairy foods

• Published in: Journal of dairy science Vol. 95; no. 3; pp. 1128 - 1139
• Main Authors: Rincon-Delgadillo, M.I., Lopez-Hernandez, A., Wijaya, I., Rankin, S.A.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.03.2012; Elsevier
• Subjects: acetaldehyde; acetic acid; acetoin; alcohols; Animal productions; bacteria; benzaldehyde; Biological and medical sciences; butyric acid; Chromatography, High Pressure Liquid; citrates; cottage cheese; Dairy Products - analysis; diacetyl; Diacetyl - analysis; distillates; esters; fermentation; flavor; Flavoring Agents - analysis; Food industries; Food Technology - methods; formic acid; Fundamental and applied biological sciences. Psychology; furfural; gas chromatography; good manufacturing practices; GRAS substances; headspace analysis; ingredients; Lactococcus lactis subsp. lactis bv. diacetylactis; lactones; Leuconostoc; margarine; mass spectrometry; Milk and cheese industries. Ice creams; odors; Plant Oils - analysis; processed cheeses; propionic acid; solid phase microextraction; sour cream; starter cultures; starter distillate; Terrestrial animal productions; toxicity; vegetable oil; Vertebrates; volatile compounds; Volatile Organic Compounds - analysis; United States; toxicity; diacetyl; starter distillate; Volatile compound; Toxicity; Dairy industry
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2011-4834

Starter distillates (SDL) are used as ingredients in the formulation of many food products such as cottage cheese, margarine, vegetable oil spreads, processed cheese, and sour cream to increase the levels of naturally occurring buttery aroma associated with fermentation. This buttery aroma results, in part, from the presence of the vicinal dicarbonyl, diacetyl, which imparts a high level of buttery flavor notes and is a key component of SDL. Diacetyl (2,3-butanedione) is a volatile product of citrate metabolism produced by certain bacteria, including Lactococcus lactis ssp. diacetylactis and Leuconostoc citrovorum. In the United States, SDL are regarded as generally recognized as safe ingredients, whereby usage in food products is limited by good manufacturing practices. Recently, diacetyl has been implicated as a causative agent in certain lung ailments in plant workers; however, little is published about the volatile composition of SDL and the levels of diacetyl or other flavoring components in finished dairy products. The objective of this work was to characterize the volatile compounds of commercial SDL and to quantitate levels of diacetyl and other Flavor and Extract Manufacturers Association-designated high-priority flavoring components found in 18 SDL samples and 24 selected dairy products. Headspace volatiles were assessed using a solid-phase microextraction and analyzed by gas chromatography-mass spectrometry. In addition to diacetyl (ranging from 1.2 to 22,000μg/g), 40 compounds including 8 organic acids, 4 alcohols, 3 aldehydes, 7 esters, 3 furans, 10 ketones, 2 lactones, 2 sulfur-containing compounds, and 1 terpene were detected in the SDL. A total of 22 food samples were found to contain diacetyl ranging from 4.5 to 2,700μg/100g. Other volatile compounds, including acetaldehyde, acetic acid, acetoin, benzaldehyde, butyric acid, formic acid, furfural, 2,3-heptanedione, 2,3-pentanedione, and propanoic acid, were also identified and quantified in SDL or food samples, or both. The results obtained in this work summarize the volatile composition of commercial SDL and the approximate levels of diacetyl and other Flavor and Extract Manufacturers Association-designated high-priority flavoring components found in SDL and selected dairy foods.