Dressed, bagged whole chickens from three Oregon and several out-of-state processors were purchased from retail markets in each season in 1988. Birds were stored at 3°C for 6 days. Total aerobic microorganisms, total psychrotrophic microorganisms, pseudomonads and fluorescent pseudomonads were determined by appropriate procedures. Total aerobic microorganisms and psychrotrophic microorganisms were counted on standard plate count agar with incubation at 20°C for 3 days and at 5°C for 7 days, respectively. Two media, King's B medium and CFC medium, were used in counting pseudomonads. Fluorescent colonies were observed on King's medium under ultraviolet light. A simple slime smear test was used to determine the sliminess. Sensory evaluation was done by thirteen panelists using 9-point scales. The flavor of cooked white and dark meat and skin, the flavor intensity of cooked white and dark meat and skin, the aroma of raw and simmered meat, the aroma intensity of raw and simmered meat and raw sliminess were evaluated. Simple regression analysis was used to determine the relationships between the microbial parameters and sensory evaluations. The paired t test was used in determining the difference between counts on King's medium and CFC medium. A significance level of 95% was set for all tests. Correlation coefficients were also calculated. All the microbial counts were at or below 10⁷/cm², which indicated from literature comparisons that most of the fryers purchased from retail markets and stored for six days were of acceptable quality. The season had no significant effect on the microbial counts and sensory qualities. The means of flavor of cooked meat and skin and aroma of raw and simmered meat were all above fair. Only the raw aroma intensity was significantly (p<0.05) and strongly correlated (r=-0.88) to the aroma quality. Relationships between microbial counts and flavor of cooked meat and aroma of raw and simmered meat were all significant but the correlations were weak. The narrow range of microbial counts may explain the weakness of the correlations found. The slime smear tests had a positive relationship (p<0.05) to the raw sliminess score by panelists, total aerobic microorganisms, total psychrotrophic microorganisms, pseudomonads, and fluorescent pseudomonads. / Graduation date: 1990

Our perception of the world is limited by the senses we are endowed with. In the case of taste, its functional fidelity is so critical for our survival that we come into the world with innate preference for sweet and disgust for bitter. These stereotyped behaviors are hardwired at the lowest levels of taste processing and they support the view that taste serves as an arbiter of the chemical world, passing judgement before permitting ingestion. Yet our experience of foods is manifold. This complexity results from distinct contributions from the sights, sounds and smells of the foods we consume. Of these, odors are a co-equal component of flavor and the impairment of olfaction can disrupt enjoyment of eating and alter patterns of consumption. The goal of this thesis is to identify the neural basis of odor-taste perception and to characterize how neural activity is affected by odor-taste integration. In contrast to the discrete and innate categorization performed by the taste system, the sense of smell enables discrimination of thousands of unique odor percepts which have no innate value. At the level of olfactory cortex, odor representations are randomly distributed and have been shown to be conditioned through association with other stimuli. The act of eating produces near simultaneous taste and odor transduction originating from the same source. Yet despite ultimately projecting to neighboring cortical regions, taste and odor pathways are anatomically segregated prior to reaching the cortex. Using viral tracing strategies, we identified Agranular Insular cortex (AIc) as a putative site of odor-taste integration. We then used in vivo two-photon Ca2+ Imaging to characterize odor and taste responsive neurons and identify changes in population activity when these stimuli were simultaneously presented. We next asked whether specific flavor experiences altered activity in AIc compared to naive animals. Finally, we developed a behavioral task to test whether silencing AIc disrupted perception of a flavor compound.

No description available.

No description available.

The taste qualities of acidulants have not been studied in detail despite the fact that they are widely used by the food industry. Studies on characterizing the sensory properties of organic and inorganic acids are very limited. Reported studies are commonly on threshold, equi-sour and the time intensity values of sourness. A series of experiments were conducted to determine the sensory properties of selected acidulants by different sensory and multivariate methods. First, the technique of Free-Choice Profiling was applied in order to characterize the sensory profile of some selected acids (adipic, citric, fumaric, glucono-delta-lactone, hydrochloric, lactic, malic, phosphoric, quinic, succinic, tartaric, citric:fumaric, citric:malic and fumaric:malic) on a weight (0.08% w/v or v/v) basis. Results analyzed through Generalized Procrustes Analysis indicate that on a weight basis (w/v or v/v), acids differed in their flavor and taste dynamics. Likewise, acids were described differently by individual panelists. Second, the sourness power functions of the selected acidulants were generated from five molar concentrations by magnitude estimation involving 16 trained panelists. Equi-sour concentrations were determined by regressing the log of the rescaled response (sensory) on the log of the stimuli (physical). The calculated equi-sour levels ranged from 0.48 ml/L for HCl to 2.34 g/L for glucono-delta-lactone when citric add was set at 1.0 g/L. These theoretical equi-sourness were then tested by using an alternative sensory method, the directional difference from control test. Third, the sensory profile of the acidulants at their equi-sour levels was characterized using two sensory methods, free-choice profiling and the conventional descriptive analysis. The former was analyzed by Generalized Procrustes Analysis while the latter was analyzed by Principal Component Analysis. The two sensory methods gave similar patterns of information regarding the add samples. The similarities of several organic acids and their mixtures were very evident. Hydrochloric and phosphoric acids were astringent while succinic add was bitter and had a monosodium glutamate taste. It was concluded that adds had other sensory properties aside from sourness that must be considered in a given food application. / Graduation date: 1993

The objective of the study was to determine growth performance, physico-chemical attributes, oxidative stability and sensory quality of pork from pigs fed one of three dietary treatments, eac containing 0%, 2.5% or 5% (T1, T2 and T3, respectively) Moringa oleifera leaf meal (MOLM). Dietary treatments were formulated to be isonitrogenous and isoenergetic for weaner (6 – 8 weeks) and grower (9 – 13 weeks) phases. Twelve Large White (LW) and 12 Kolbroek (KB) male pigs at 6 weeks of age, initially weighing an average 10 kg, were randomly allocated to one of the dietary treatments, each with four replicates, in individual pens. Feed and water were offered ad libitum. The Longissimus thoracis et lumborum (LTL) muscle of each carcass (n = 24) was sampled for meat quality and fatty acid analyses. Breed differences in measured parameters were observed. In pigs receiving 5% MOLM, the LW had significantly the highest ADFI (P<0.05) than KB pigs. In pigs receiving 2.5% and 5% MOLM, backfat thickness was significantly highest (P<0.05) compared to those receiving 0% MOML. Dietary inclusion of MOLM had no significant effects (P>0.05) on the physico-chemical quality of pork from LW pigs; although it significantly (P<0.05) increased a* and reduced WBSF values in pork from KB pigs. Pork from LW pigs receiving 5% MOLM had significantly increased (P<0.05) n-3 content of the subcutaneous tissue of LW pigs compared to KB, and also when compread to other treatment groups. In both breeds, the composition of PUFA: SFA and n-6: n-3 in the subcutaneous adipose tissue was significantly (P<0.05) lower in T2 and T3 than in T1. The n-3 levels for pork muscle from LW pigs receiving 2.5% and 5% MOLM, and from KB pigs receiving 5% MOLM, were significantly (P<0.05) lower. Inclusions of MOLM significantly (P<0.05) reduced the n-6: n-3 fatty acids in pork from both LW pigs and KB pigs. Consumer scores on sensory attributes (aroma intensity, initial impression of juiciness, first bite, sustained impression of juiciness, muscle fibre and overall tenderness and overall flavor intensity) significantly (P<0.05) increased as the level of MOLM inclusion in the diet increased; and higher scores were observed in fried meat than in boiled for most sensory attributes. It may be concluded that inclusion of MOLM in pig diets up to 5% improved the ADFI, a*, tenderness of pork without adversely affecting the FCR and other physico-chemical quality attributes; and resulted in desired increase in levels of n-3 and reduced the n-6: n-3 fatty acid ratio.

American lambs are often over-finished and lack consistent quality. It has been suggested that the use of intact ram lambs can decrease USDA YG and improve growth efficiency. However, ram lamb carcasses are underutilized because of potential issues, the most crucial being off-flavor development. Our hypothesis for this study is that U.S. producers can take advantage of intact ram lamb growth and performance with no detriment to product quality, as long as lambs are slaughtered before the attainment of puberty. Three breeds (Hampshire, Dorset, and Columbia), three slaughter weights (light, medium, and heavy) and two sexes (rams and wethers) were evaluated. Results indicate that ram lambs can provide a satisfactory eating experience, however, in one of our studies compounding of maturity and slaughtering intact rams increased incidence of off-flavors. It remains undetermined whether the small differences in sensory characteristics would be detectable by everyday consumers.

No description available.

However, interferences by inhaled volatile compounds are not the aim of the present study. The objective of this report is to determine if common food stuffs would cause an interference with the CMI Intoxilyzer. It has been theorized that if one has been eating while drinking alcoholic beverages, the food might cause an elevated breath-alcohol test result. Odorous foods were chosen on the theory that if it could be smelled on one's breath, it would perhaps elicit a reading on the instrument. The list of foods was further narrowed to those commonly found in eating and drinking establishments (i.e. pizza shops) or those foods taken in an attempt to conceal the presence of ethanol in the breath (i.e. mints and candies).

The taste of a preferred food, pizza, was adulterated with quinine sulfate and the effects of taste experience on subsequent measures of palatability were measured. The measures of palatability were salivary responses to the thought and presentation of pizza. Additional measures were latency to start eating, amount eaten, meal duration, rate of eating and preference ratings of the pizza's taste, aroma and appearance. Thirty-six subjects received access to regular and/or adulterated pizza over two experimental sessions. The resulting groups of nine subjects each received either adulterated and adulterated, adulterated and regular, regular and regular, or regular and adulterated pizza over the two sessions. In a third session all subjects received regular pizza. In session two, groups which had received regular pizza in session one showed a reliably greater salivary response on the presentation trial than on the thought trial. Groups which had received adulterated pizza showed minimal differences in salivation between these trials. In session three, groups which had received regular pizza in session one yielded reliably greater salivation on the presentation trial than did groups which had received adulterated pizza in session one. Furthermore, nonshift groups, which had received the same pizza condition over sessions one and two, showed a greater difference between thought and presentation trial responses than did shift groups, which had received different pizza conditions over sessions one and two. An approach-avoidance conflict model of behavior was applied to the salivation data. Preference ratings of the pizza's taste, the amount eaten and the rate of eating data yielded reliably greater responses for groups which received regular pizza than for groups which received adulterated pizza in sessions one and two. Positive and negative contrast effects were also evidenced by these data. The meal duration and latency to start eating data yielded highly similar responses among groups over days. / M.S.