The impact of agglomeration on flavor and flavor stability of whey protein concentrates 80% (WPC80) and whey protein isolates (WPI) has not been widely addressed. This study examined the impact of agglomeration on the flavor and flavor stability of commercial WPC80 and WPI across 18 mo of storage. Duplicate agglomerated and nonagglomerated WPC80 and WPI were collected from 4 facilities and stored at 21• C, 50% relative humidity. Volatile analysis using solid phase microextraction (SPME) with gas chromatography-mass spectrometry (GC-MS) and descriptive sensory analysis were conducted every 2 mo. Solubility index, bulk volume, dispersibility, moisture, and color (L, a, b) were tested every 3 or 6 mo. Consumer acceptance testing with protein beverages was conducted with fresh and stored whey proteins. Higher intensities and more rapid development of lipid oxidation flavors (cardboard, raisin/brothy, cucumber, and fatty) were noted in agglomerated powders compared to nonagglomerated powders (P < 0.05). Volatile analysis results confirmed sensory results, which indicated increased formation of aldehydes and ketones in agglomerated products compared to nonagglomerated powders (P < 0.05). Consumer acceptance scores for protein beverages were lower for beverages made with agglomerated WPC80 stored for 12 mo and agglomerated or nonagglomerated WPI stored for 18 mo compared to fresh products while trained panelists detected differences among beverages and rehydrated proteins earlier. Agglomeration with or without lecithin decreased the storage stability of whey proteins. These results indicate that the optimum shelf life at 21• C for nonagglomerated whey proteins is 12 to 15 mo and 8 to 12 mo for agglomerated whey proteins.

Chevre-style goat cheeses were characterized by descriptive sensory analysis as exhibiting sweet dairy flavors as well as a characteristic waxy/animal flavor. Aroma-active compounds (> 80) with high intensities identified by gas chromatography/olfactometry and gas chromatography/mass spectrometry included 2,3-butanedione (buttery), 1-octen-3-one (mushroom), o-aminoacetophenone (grape), lactones (coconut, peach), octanoic acid (sour/waxy), as well as 4-methyl and 4-ethyl octanoic acids (waxy/animal). Subsequent sensory analysis with model cheese systems confirmed that 4-methyl and 4-ethyl octanoic acids were responsible for the characteristic waxy/animal flavor.

This study identified and explored the sensory characteristics that drive consumer liking of butter. A trained descriptive panel evaluated 27 commercial butters using a defined sensory language. Two focus groups were conducted with butter consumers to gain an understanding of consumer use and consumption habits. Six representative butters and 2 vegetable oil spreads were selected for consumer acceptance testing. Both internal and external preference mapping techniques were applied to interpret consumer data. Key discriminating sensory characteristics of butters included color intensity; diacetyl, cooked, grassy, and milk fat flavors; and salty taste. From focus groups and quantitative consumer testing, the key butter features were a desirable flavor and a natural image. Negative aspects included price and cholesterol. Five consumer clusters with distinct butter and spread flavor likes and dislikes were identified. Butter is a desirable product to consumers. Sensory expectations of butter vary among consumers, and butters with specific sensory characteristics could be marketed to specific target market segments.

Umami plays an important role in the flavor of many cheese varieties. The purpose of this study was to identify the compound(s) responsible for umami taste in Cheddar and Swiss cheeses. Four Cheddar and 4 Swiss cheeses (two with low umami intensity and two with high umami intensity from each type) were selected using a trained sensory panel. Monosodium glutamate (MSG), disodium 5'-inosine monophosphate (IMP), disodium 5'-guanosine monophosphate (GMP), sodium chloride, lactic acid, propionic acid, and succinic acid were quantified in the cheeses instrumentally. Taste thresholds (best estimate thresholds, BETs) were determined for each compound in water. Subsequently, a trained descriptive sensory analysis panel evaluated each compound in odor-free water across threshold concentrations to confirm that the thresholds were based on umami and not some other stimuli. Model system studies with trained panelists were then conducted with each compound individually or all compounds together. Comparison of analytical data and sensory thresholds indicated that IMP and GMP thresholds were 100-fold higher than their concentrations in cheese. All other compounds contributed some umami taste within their concentration range in umami cheeses. Sensory analysis of model cheeses revealed that glutamic acid played the largest role in umami taste of both Cheddar and Swiss cheeses while succinic and propionic acids contributed to umami taste in Swiss cheeses. Knowledge of the key compounds associated with umami taste in cheeses will aid in the identification of procedures to enhance formation of this taste in cheese.

There is considerable interest in the aquaculture of southern flounder, Paralichthys lethostigma, because of its worldwide market appeal, high market value and ability to grow in fresh or brackish water. This study was conducted to identify and define sensory properties of wild (WF), freshwater farm-raised (FFF) and saltwater farm-raised (SFF) southern flounder. In addition, consumer acceptance of these three sources of southern flounder was determined. A defined sensory lexicon for southern flounder (appearance, flavor, texture) was identified. Descriptive sensory differences were documented among the three types of flounder (P Ͻ 0.05). FFF flounder was differentiated by an earthy flavor. WF and SFF flounder were characterized by medicinal and fresh fish flavors, respectively. Consumer acceptance scores for SFF were significantly higher in all attributes compared with WF or FFF flounder (P Ͻ 0.05). Consumers preferred SFF Ͼ WF Ͼ FFF flounder (P Ͻ 0.05). SFF flounder may be a viable alternative to WF flounder.