The effect of entrapped air content on heat penetration characteristics in institutional size retortable pouches packed with pears and green beans was investigated. In addition, products processed in pouches and in number 10 cans were compared using several indices of quality (color, texture, total phenolics, ascorbic acid) and sensory panel evaluations. Heat penetration studies were conducted in an FMC Laboratory Retort. Pouches were placed in horizontal orientation, using both constrained and restrained racking methods. For green beans, a retort temperature of 121°C and 0.68 Atm (25 psig) overriding pressure, of steam and air, were used for processing. For pears a retort temperature of 98°C and 0.68 Atm (10 psig) overriding pressure, of air, were used. For both products, thermal processing times were found to increase approximately 15 % for each 100 milliliter increase in entrapped air content, under constrained conditions. When restrained the increases were much larger. A Stock Rotomat laboratory retort which allowed the pouches to be rotated was also used. Two studies were done: first, pouches were rotated at 15 rpm, second, they were still retorted in vertical orientation. When rotated, the processing times were about one-third those obtained in the FMC retort. When the pouches were processed in vertical orientation little change in process time was noticeable even with large amounts of air, entrapped within the pouch. Color of samples was measured by reflectance to obtain Hunter values. An Allo-Kramer shear press was used to measure the texture or firmness of both pears and green beans. Total phenolics were measured using the Folin-Ciocalteu method. The results showed that pears processed in the presence of air will darken. In comparing products from retortable pouches with those from number 10 cans which had been processed from the same processing lot of raw product, it was found that generally the canned products were better than those processed in the pouch, however differences were slight. Results of this study suggested that in order to obtain a better product from institutional size retortable pouches it is necessary to minimize the amount of air entrapped within the pouch. / Graduation date: 1982

No description available.

This thesis considers two broad categories of shape-preserving transformations: physical transformations, in which the chemistry of the as-grown material remains constant but some structural change is introduced (i.e., conversion of dense silicon nanowires into porous silicon nanowires); and chemical transformations, in which the physical structure of the as-grown material remains constant but the chemical composition is changed (i.e., conversion of SiO2 photonic crystal fibers into MgF¬2 photonic crystal fibers). Part I of this thesis focuses on the development of a process which allows for the introduction of porosity into dense silicon nano- and microstructures (a shape preserving net physical transformation, albeit by chemical means), while Part II focuses on conversion of SiO2-based photonic structures, including three dimensional photonic crystals and hollow-core photonic crystal fibers into Mg2Si or MgF2 replicas with more desirable chemical compositions (a shape preserving net chemical transformation) possessing enhanced optical characteristics.

Approximately 200 raw prunes were harvested from each of five Italian prune trees near Corvallis every three days for nine consecutive harvest dates. Forty individual fruit from each tree were drawn at random and subjected to a series of fresh fruit quality tests. For each quality factor which was measured, the experiments were set up as nine by five factorial analysis of variance studies with the numbers of observations in a replication depending upon the factor being studied. The correlation of each objective and subjective test with canned fruit flavor was then calculated. The regression line, standard error of estimate, and 90 percent confidence limits were calculated for each tests which had a correlation of 0.80 or better with canned fruit flavor. Several objective tests were used on raw prunes such as soluble solids-acid ratio, pressure test, percent soluble solids, titratable acidity and color of raw prune flesh measured by the Hunter Color-Color Difference Meter in the order named are significantly correlated with the flavor of the canned Italian prune. Analysis of variance and L.S.D. was used to determine that the first two of these tests show good three-day precision as a guide to harvest maturity. The others appear suitable for longer time intervals. Certain objective tests such as pH values and fresh fruit weight are of little value to predict canned fruit flavor and show poor three-day precision as a guide to harvest maturity. The subjective grading of raw prunes by outer skin appearance does not seem to be a precise way to predict canned fruit quality. The three-day precision as a guide to harvest maturity is poor. Respiration of the fresh fruit shows a definite climacteric and the climacteric appeared at approximately the same time the fruit harvested exhibited optimum canned fruit flavor and color. The remaining lot of fruit after the fresh fruit samples were removed was placed in 32°F. cold storage and held for processing the next day. Fruit from each tree each harvest date were processed in twelve No. 2 fruit enameled cans for use in canned fruit analysis studies. Several canned prune quality factors such as percent transmittance of the canned juice, canned fruit skin color as measured by the Hunter Color-Color Difference Meter and titratable acidity of the canned prune pulp can be used to predict or specify the canned fruit flavor. Other objective tests used on canned prunes such as pH values, cut-out soluble solids and cut-out soluble solids-acid ratio are not highly correlated with canned fruit flavor. Subjective tests used on canned prunes were color and flavor of the fruit. These factors were judged by a statistically selected panel of judges. The correlation between color and flavor of the canned fruit was the highest of the study (r= -.9458). The subjective color measurement seems to be very precise in predicting canned fruit flavor. Every subjective and objective test carried out on the raw and canned prunes were correlated with canned fruit flavor because this factor was felt to be of singular importance in canned prune quality. Regression equations are given. / Graduation date: 1953

No description available.

The removal of phenols from the waste waters of wood preserving plants has always presented problems. The purpose of this paper is to investigate the possibility of employing a biological system to reduce the phenol content of effluent from these plants.

Thesis (Laur. Tech. (Food Technology))--Cape Technikon, 1991. / This dissertation reports on a three prong approach to obtain new knowledge on the interdependent effects which buyers' specifications, peach crop attributes and sieve stack arrangement have on the masses of peach halves sorted into classes of average diameter. Applying statistical methods and using suitable application computer programs a computer-aided system was developed to improve on the manual selection of sieve diameters. It was concluded that size sorting peach halves for the purpose of mass classification is inaccurate and counter-productive. It is suggested that modern technology be employed to develop a method to determine peach half masses individually.

Thesis (Laureatus in Technology ( Food))-- Cape Technikon, 1991 / This dissertation reports on a three prong approach to obtain new knowledge on the interdependent effects which buyers' specifications, peach crop attributes and sieve stack arrangement have on the masses of peach halves sorted into classes of average diameter. Applying statistical methods and using suitable application computer programs a computer-aided system was developed to improve on the manual selection of sieve diameters. It was concluded that size sorting peach halves for the purpose of mass classification is inaccurate and counter-productive. It is suggested that modern technology be employed to develop a method to determine peach half masses individually.

No description available.

Let X be a compact metric space, and Lip(X) is the space of all bounded real-valued Lipschitz functions on X. A linear map T:Lip(X)->Lip(Y) is called disjointness preserving if fg=0 in Lip(X) implies TfTg=0 in Lip(Y). We prove that a biseparating linear bijection T(i.e. T and T^-1 are separating) is a weighted composition operator Tf=hf¡³£p, f is Lipschitz space from X onto R, £p is a homeomorphism from Y onto X, and h(y) is a Lipschitz function in Y.