A sample of 243 Willamette Valley households participated in personal interviews and kept 7-day records of all foods brought into the household but not consumed by human household members. Their reason for discarding the foods, the amounts of discard, and their assessment of the safety of the foods were compared to household characteristics. Age of the major food preparer and the presence of children had a marked effect upon the discard patterns of the household. Households with children younger than 10 years discarded an average of $3.60 (1185 g) in a 7 consecutive day period, households with children 10-18 years of age discarded an average of $4.36 (2743 g), and childless households discarded an average of $2.11 (1195 g). In a sample of 50 households, as the household refrigerator temperature (as determined during the personal interview) increased from 35°F (2°C) to 68°F (20°C), the amount of discards also increased (r [subscript cost] = .82, r [subscript g] = .80). Food which was being discarded due to poor quality or because it was judged unsafe to eat by the householder was collected daily over a 3-day period for a subsample of 50 of the households. These collected discards were evaluated by a trained panel for degree of off-color, off-odor, and off-texture compared to the normal product standards, and also were microbiologically analyzed. When the householder's estimate of amount of food discarded was converted from their household measures to grams using food composition tables, the householder's estimate was 97% of the actual grams of food as weighed in the laboratory. Both studies found consumer confusion between solely quality changes in a food and environmental conditions that allow the possibility of pathogen growth in foods. In 62% of the microbiologically analyzed foods, the householder did not make correct safety assessments. In 9% of the microbiologically analyzed foods, an assessment of safe was made by the householder for foods which were determined to be at risk. Uncoded dates on packaged foods were the basis for the householder's discard decision for 17% of the total foods appearing on the 7-day records. Householders often stated they felt it would be unsafe to consume this food. Educational programs which give the householder criteria for the evaluation of food safety are recommended. / Graduation date: 1985

Abstract Cold-tolerant bacteria, also known as psychrotrophic bacteria, are notorious contaminants of milk in the refrigerated dairy food chain. These organisms, especially the pseudomonads, may produce heatresistant enzymes that are responsible for the breakdown of proteins and lipids in milk and dairy products. Such reactions result in a variety of defects in the raw or unprocessed milk that may affect the suitability of such milk for further processing. The enzymes produced may cause defects in long-life dairy products such as cheese, butter and long-life milk. In the present study, a range of 18 yellow pigmented psychrotrophic bacteria, collectively known as flavobacteria, were isolated from local dairy products. One aim of this study was to identify these bacteria to species level using molecular techniques. A second aim was to determine the spoilage potential of these organisms based on profiles generated by the BIOLOG system (that may relate to hydrolytic enzymes produced). Of the 18 isolates, 14 belonged to the genus Chryseobacterium while 4 were identified as Empedobacter isolates. The most active spoilage organisms in this group were shown to be C. bovis, C. shigense and E. brevis. These findings illustrate that enzymatically catalysed defects in dairy products should not be attributed solely to acknowledged psychrotrophic bacteria such as the pseudomonads, but that flavobacterial species may also be actively involved.

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Graduation date: 1971

Thesis (M.S.) in Food Science and Human Nutrition--University of Maine, 2007. / Includes vita. Includes bibliographical references (leaves 69-73).