Dried whey and whey protein are important food ingredients. Functionality of whey products has been studied extensively. Flavor inconsistency and flavors which may carry through to the finished product can limit whey ingredient applications in dairy and nondairy foods. The goal of this research was to determine the flavor and flavor variability of commercially produced liquid Cheddar cheese whey. Liquid Cheddar cheese whey from five culture blends from two different stirred-curd Cheddar cheese manufacturing facilities was collected. Whey flavor was characterized using instrumental and sensory methods. Wide variation in whey headspace volatiles was observed between different manufacturing facilities (P < 0.05). Hexanal and diacetyl were two key volatiles that varied widely (P < 0.05). FFA profiles determined by solid-phase microextraction and degree of proteolysis of the whey samples were also different (P < 0.05). Differences in whey flavor profiles were also confirmed by descriptive sensory analysis (P < 0.05). Differences in liquid whey flavor were attributed to differences in milk source, processing and handling and starter culture blend. The flavor of liquid Cheddar cheese whey is variable and impacted by milk source and starter culture rotation. Results from this study will aid future studies that address the impact of liquid whey flavor variability on flavor of dried whey ingredients.

Several researchers have found anxiety and depression to be indistinguishable in nonclinical samples and have suggested that both constructs may be components of a general psychological distress process. Another possibility is that overlap is due to the psychometric limitations of scales used. A series of exploratory factor analyses were conducted in a nonclinical sample (N = 605) using the Beck Depression Inventory (BDI; Beck, 1978), the State-Trait Anxiety Inventory (STAI; Spielberger, 1983), and the Endler Multidimensional Anxiety Scales (EMAS; Endler, Edwards,& Vitelli, 1991). Both state and trait anxiety and depression could be differentiated with the BDI and the EMAS but not with the STAI. Some theoretical models of negative affectivity or general psychopathology may be premature.

To evaluate the impact of Cheddar cheese starter cultures on the level of free fatty acids in liquid whey, a solid-phase microextraction (SPME) technique was utilized. The determination of response factors relative to an internal standard and the verification of linearity over a wide concentration range allowed for the quantitation of free fatty acids in experimentally produced liquid whey and in a wide range of dry whey ingredients. Results indicated that whey produced with a Lactococcus lactis subsp. lactis starter culture contained the highest level of total free fatty acids with significantly higher levels of lauric, myristic, and palmitic acids. Significant declines in oleic, linoleic, and palmitic acid occurred during storage. Commercial whey ingredients demonstrated a linear increase in free fatty acids with increasing percent protein, except for whey protein isolate, which had the lowest concentration. The use of SPME for the rapid analysis of free fatty acids in whey products should allow for further research to determine the importance of these compounds on the quality and stability of whey products.

One of the factors responsible for the quality deterioration of foods is lipid oxidation. All foods containing fat are susceptible to oxidative rancidity, which can render the food unacceptable to the senses and also reduce nutritional quality.

Commercial enzymes (protease and lipase) were used to produce highly flavored cheese-like hydrolysates from fluid milk. Free fatty acids, free amino acids, degree of proteolysis, and volatile profiles were assessed to suggest the importance of proteolytic and lipolytic activity on cheese flavor development. Free fatty acid liberation was maximized with the combined Flavourzyme TM (protease) and Palatase ® (lipase) treatment incubated at 30 ЊC, most likely due to synergism conferred by the protease. The Flavourzyme/Palatase samples incubated at 45 ЊC generated the highest total concentration of volatile compounds. The addition of Flavourzyme generated free amino acids and low molecular weight peptides (< 1400 MW).