Thesis--Wisconsin. / Vita. Includes bibliographical references (leaves 33-44).

[No abstract available] / Land and Food Systems, Faculty of / Graduate

[No abstract submitted] / Land and Food Systems, Faculty of / Graduate

No description available.

No description available.

Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 45-47). Also available on the World Wide Web.

The elucidation of the structure of the red pigments of the black raspberries. Monger variety, was achieved. The components of the pigment of the berries were (a) cyanidin-3-glucoside, (b) cyanidin-3, 5-diglucoside, (c) cyanidin-3-diglucoside and (d) cyanidin-3-rhamnoglucosido- 5-glucoside. The elucidation was carried out after isolation, purification, concentration and chromatographic separation of the components. Further analysis by paper chromatographic techniques and spectrophotometric methods were carried out on the pigments and their products after specific chemical degradations. The degradation of the major anthocyanin component, cyanidin- 3-diglucoside, was further studied in buffered model systems of various pH values at 50°C. As the pH of the medium decreased the anthocyanin stability increased. The same was true for total crude pigment and the anthocyanin in the juice. Nitrogen atmosphere enhanced the stability of cyanidin-3- diglucoside as compared to an oxygen atmosphere. This held for the crude pigment and juice as well. Cyanidin in buffered model systems at 50°C was much more unstable than cyanidin-3-diglucoside under the same conditions. Nitrogen atmosphere resulted in improvement of the pigment retention over that in atmospheric conditions. The thermal degradation of cyanidin-3-diglucoside in model systems followed first order kinetics. The rate constants of the reaction at various pH levels under air and nitrogen were determined. The effect of the presence of various sugars and their degradation products on the destruction of cyanidin-3-diglucoside was studied in buffered model systems of pH 3.25 at 50°C. All of these additives increased the rate of pigment destruction. No differences were revealed among the sugars glucose, fructose, xylose and sucrose, which were used. All reactions followed first order kinetics and the rate constants were determined. When these reactions were carried out in the presence of nitrogen instead of air, a marked decrease in the rate of the pigment destruction was detected. Ascorbic acid in model buffered systems of pH 3.25 at 50°C markedly accelerated the destruction of cyanidin-3-diglucoside. Metal ions and atmospheric oxygen acted synergistically with ascorbic acid in the destruction of this anthocyanin. When the action of either of these synergists was blocked, the stability of the pigment was increased. EDTA was found to improve the retention of cyanidin-3-diglucoside by means of its ability to chelate the metal ions present, thus indirectly inhibiting the effect of ascorbic acid. When nitrogen was used instead of air, an improvement of the stability of anthocyanin in this system resulted. The degradation of cyanidin-3-diglucoside and the disappearance of ascorbic acid followed the same pattern. The same observations were also true for the anthocyanins of the juice. Cyanidin-3-diglucoside in buffer at pH 6.5 was acted upon by tyrosinase. This activity was low but nevertheless demonstrable. When catechol was added to this system, a rapid decolorization of anthocyanin was produced. This effect was further investigated and a scheme of the enzymatic reaction was proposed. Protocatechuic acid and tyrosine were able to couple with cyanidin-3-diglucoside and enhance the destructive action of tyrosinase on anthocyanins. The rate of the decolorization of the anthocyanin was lower in these systems than in the coupling with catechol. / Graduation date: 1966

Raspberry growers in the lower mainland of British Columbia are contending with increasing production costs and are facing problems in obtaining seasonal labour for fruit picking. Since cost of hand harvesting represents a large proportion of the total production cost, the purpose of this research was to investigate the feasibility of mechanical raspberry harvesting and to design a mechanical harvesting system suitable for the lower mainland of British Columbia. A systematic design procedure, oriented toward design and testing of a bio-machine system, was employed and the selected design was based upon the physical and mechanical properties of the raspberry plant and its fruit. An economic analysis, comparing the mechanical harvesting system to present hand harvesting methods was used to determine the necessary relationships among machine cost, machine capacity and machine efficiency. The selected design for a mechanical raspberry harvesting system included tools for feeding, cane orientation, selective harvesting, fruit collection, fruit conveying and fruit storage. Mathematical models for these tools were constructed, based on a series of tests determining pertinent physical and mechanical properties of the raspberry plant and fruit. In addition, tests to define fruit quality were undertaken and the relationships among fruit quality and selective harvesting parameters were investigated. The use of chemical growth, regulator's to alter fruit retention force was also investigated. Force-deformation moduli, resulting from flat plate compression tests of raspberry fruit, were found to be good indicators of fruit quality. Correlations among force-deformation moduli and fruit properties indicated that either fruit retention force or F/W ratio could be used as control variables for a selective harvesting tool. Prototype units for feeding, cane orientation and selective harvesting tools were designed and fabricated. The selective harvesting tool was a fixed displacement shaker designed to apply equal maximum acceleration to all fruiting portions of the plant, independent of plant properties. F/W ratio was used as the control variable for selective harvesting. Limited field testing indicated that the tools for feeding, cane orientation and selective harvesting could satisfactorily be used in a mechanical raspberry harvesting system. Results also indicated that mechanical harvesting could be substantially more profitable than hand harvesting. The Willamette variety of raspberries as commonly grown in British Columbia was found not especially suitable for mechanical harvesting. Due to the high ratio of fruit retention force to fruit stem strength in the Willamette variety, the quality of machine harvested fruit must be lower than the quality of hand harvested fruit. Since fruit retention force is dependent upon fruit variety, investigation of physical properties of other suitable raspberry varieties should be undertaken in order to find a variety having properties more compatible with mechanical harvesting methods. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

No description available.

Field performance of micropropagated (MP) and conventionally propagated (CP) red raspberry (Rubus idaeus L. cv. Comet and Festival) was examined under hedgerow and stool cane management systems for 3 seasons (1989 to 1991). All MP plants established well compared to 58% survival rates 45 days after planting and 92% survival rates after replanting for CP plants. The MP plants were more vigorous compared with the CP plants for the duration of this study as indicated by more and taller canes. MP 'Festival' in 1990 yielded 2.2 MT$ cdot$ha$ sp{-1}$, almost half the yield of established commercial plantings in Quebec, while yields from CP 'Festival' and MP and CP 'Comet' were negligible. The MP 'Festival' crop (8.42 MT$ cdot$ha$ sp{-1}$) also outyielded CP 'Festival' (6.8 MT$ cdot$ha$ sp{-1}$) and both MP (5.72 MT$ cdot$ha$ sp{-1}$) and CP (4.91 MT$ cdot$ha$ sp{-1}$) 'Comet' in the second fruiting year. Propagation method had no effects on winter hardiness, photosynthetic capacity nor leaf and stem morphology of either cultivar. The results indicated that MP plants were superior to CP plants for both nursery propagation and fruit production due to their more consistent establishment and increased vigor. Red raspberry plantlets were successfully hardened in vitro on low-sucrose or sucrose-free media through CO$ sb{2}$ enrichment (1500 ppm) and relative humidity reduction (90%) using a forced ventilation system in specially constructed plexiglass chambers. Enriched CO$ sb{2}$ significantly increased general vigor, root formation, root growth, plantlet growth and plantlet photosynthetic capacities. Sucrose in the medium promoted plantlet growth but depressed photosynthesis. In vitro relative humidity at 90% decreased stomatal apertures and improved plantlet ex vitro performance but did not affect the CO$ sb{2}$ uptake rates of cultured plantlets or ex vitro transplants. The maximum CO$ sb{2}$ uptake rates of plantlet leaves were about 52-69% that of greenhouse control pla