A standardized descriptive language for Cheddar cheese flavor was developed and validated. Representative Cheddar cheeses (240) were collected. Fifteen individuals from industry, academia, and government participated in a 3-d roundtable discussion to generate descriptive flavor terms. A highly trained descriptive panel (n = 11) refined the terms and identified references. Cheddar cheeses (24) were presented to the panel for validation with the identified lexicon. The panel differentiated the 24 Cheddar cheeses as determined by univariate and multivariate analysis of variance (P < 0.05). Twenty-seven terms were identified to describe Cheddar flavor. Seventeen descriptive terms were present in most Cheddar cheeses. A standard sensory language for Cheddar cheese will facilitate training and communication between different research groups.

The flavor of whey protein concentrates (WPC 80) and whey protein isolates (WPI) was studied using instrumental and sensory techniques. Four WPC 80 and 4 WPI, less than 3 mo old, were collected in duplicate from 6 manufacturers in the United States. Samples were rehydrated and evaluated in duplicate by descriptive sensory analysis. Duplicate samples with internal standards were extracted with diethyl ether. Extracts were then distilled to remove nonvolatile material using high vacuum distillation. Volatile extracts were analyzed using gas chromatography/olfactometry with post peak intensity analysis and aroma extract dilution analysis. Compounds were identified by comparison of retention indices, odor properties, and gas chromatography/mass spectrometry against reference standards. Whey proteins exhibited sweet aromatic, cardboard/wet paper, animal/wet dog, soapy, brothy, cucumber, and cooked/milky flavors, along with the basic taste bitter, and the feeling factor astringency. Key volatile flavor compounds in WPC 80 and WPI were butanoic acid (cheesy), 2-acetyl-1-pyrroline (popcorn), 2-methyl-3-furanthiol (brothy/burnt), 2,5-dimethyl-4-hydroxy-3-(2H)-furanone (maple/spicy), 2-nonenal (fatty/old books), (E,Z)-2,6-nonadienal (cucumber), and (E,Z)-2,4-decadienal (fatty/oxidized). This baseline data on flavor and flavor sources in whey proteins will aid ongoing and future research and will help to identify the most appropriate whey ingredients to use to control or minimize flavor variability in whey enhanced products.

This study investigated the sensory and rheological properties of young cheeses in order to better understand perceived cheese texture. Mozzarella and Monterey Jacks were tested at 4, 10, 17, and 38 d of age; process cheese was tested at 4 d. Rheological methods were used to determine the linear and nonlinear viscoelastic and fracture properties. A trained sensory panel developed a descriptive language and reference scales to evaluate cheese texture. All methods differentiated the cheeses by variety. Principal component analysis of sensory texture revealed that three principal components explained 96.1% of the total variation in the cheeses. The perception of firmness decreased as the cheeses aged, whereas the perception of springiness increased. Principal component analysis of the rheological parameters (three principal components: 87.9% of the variance) showed that the cheeses' solid-like response (storage modulus and fracture modulus) decreased during aging, while phase angle, maximum compliance, and retardation time increased. Analysis of the instrumental and sensory parameters (three principal components: 82.1% of the variance) revealed groupings of parameters according to cheese rigidity, resiliency, and chewdown texture. Rheological properties were highly associated with rigidity and resiliency, but less so with chewdown texture.

The continued popularity of organic and natural foods has generated interest in organic milk, and use of pasture for dairy cattle is a requirement for organic production. This process may improve the health benefits of fluid milk via increases in the unsaturated fatty acid content, including conjugated linoleic acid. Because pasture-based (PB) systems vary in types of forage, it is important to understand the impact of feed on the composition and flavor of fluid milk. The objectives of this study were to compare the chemical and sensory properties of PB milk with conventional fluid milk from Jersey and Holstein cows and to evaluate consumer acceptance of those milks. Fluid milk was collected throughout the 2006 growing season from Holstein and Jersey cows located in 2 herds: one fed a PB diet and one fed a conventional total mixed ration (TMR) diet. Milk was batch-pasteurized and homogenized. Sensory analyses, descriptive profiling, difference testing, and consumer testing were conducted on pasteurized products in separate sessions. Instrumental volatile analysis and fatty acid composition profiling were also conducted. The instrumental and sensory analyses differentiated the PB and TMR milks. Greater percentages of unsaturated fatty acids, including 2 common isomers of conjugated linoleic acid, were measured in PB milks. Trained panelists documented greater intensities of grassy and cowy/barny flavors in PB milks compared with TMR milks when evaluated at 15 degrees C. Volatile compound analysis by solid-phase microextraction and gas chromatography-mass spectrometry separated PB and TMR milk samples. However, analyses showed no compounds unique to either sample. All identified compounds were common to both samples. Consumers were unable to consistently differentiate between PB and TMR milks when evaluated at 7 degrees C, and cow diet had no effect on overall consumer acceptance. These results indicate distinct flavor and compositional differences between TMR and PB milks, but the differences were such that they did not affect consumer acceptance. The current findings are useful to consider as interest in PB dairy production systems grows.