Segregation patterns of several pod shapes of Phaseolus vulgaris L. cv Tendercrop, were studied. The causes of build-up of off-type pods in a seed stock were examined as were possible means of reversing the buildup. Natural selection factors such as germination, vigor, earliness , and ease of threshing, favored the off-types. Careful, selective milling was found to be an aid to roguing in keeping stock seed as free as possible of the off-type pods.

Certain varieties of snap bean, Phaseolus vulgaris L. , seeds are very susceptible to cracks that develop naturally across the cotyledons during pre-harvest, storage, or germination. This phenomenon is commonly known as cotyledonal cracking and may cause serious yield reductions on plants developing from affected seeds. Cotyledonal cracking susceptibility of six white and six colored seeded varieties of snap beans were compared. Considerable differences were found in cracking susceptibility, but there was little or no relationship between seed coat color and cracking susceptibility. An experiment was conducted to determine if a metabolic stress of the plant during the time of pod set could be involved in cotyledonal cracking. Blossoms were tagged on individual plants beginning with the day of first blossom, and tagging was continued for 21 days as blossoms emerged . Individual pods were harvested at maturity and maintained under controlled conditions throughout a simulated weathering treatment to follow. Seeds of each pod were classified according to the amount of cotyledonal cracking sustained. It was concluded that if a stress were involved, it apparently affected the seed several days after pod initiation and that an increase in cotyledonal cracking was negatively correlated to an increase in the number of pods set during one day. Simulated weathering tests were made of seeds remaining in the pod and seeds from the same varieties that were shelled. The results indicated that the pod provides about equal cotyledonal cracking protection for all varieties tested. Apparently the pod is not an important cause of cracking resistance in certain varieties of snap beans. Seed coat permeability was measured and compared for the 12 varieties . A technique was employed by which the bean seed coat served as a semipermeable membrane between a distilled water and a sucrose solution. Sucrose dilution was measured refractometrically and the rate of water penetration calculated. There was little relationship between seed coat permeability and cracking susceptibility among the varieties. The rate of imbibition and drying for seeds of six varieties having varying degrees of cracking susceptibility was tested. Imbibition and drying conditions were closely controlled and weight changes were recorded at regular intervals during imbibition and drying. Results indicated that some of the varieties expressing the most rapid moisture changes were also the most resistant to cracking. It was concluded that the rate of change of seed moisture was not the primary factor controlling cotyledonal cracking susceptibility. Rate of imbibition was tested for two susceptible and two resistant varieties. When the pre-imbibition seed moisture was above 10 percent, a ll varieties imbibed water freely. When pre-imbibition moisture was below 10 percent, several seeds of resistant varieties became slowly permeable while nearly all seeds of the susceptible varieties imbibed freely. This suggested the possibility that a hard seed tendency of the resistant varieties may be one source of protection against cotyledonal cracking. Preliminary data suggested that the seed coats of susceptible varieties remain permeable even at moisture levels below 10 percent, while many seed coats of the resistant varieties become rather impermeable at low moisture levels. Microscopic examination of cotyledonal cracks from four different varieties indicated that the splitting occurred across cotyledonal cell walls more rapidly than between cell walls. This suggested that a weakness of the intercellular middle lamella is not responsible for cotyledonal cracking susceptibility. Further microscopic examination and comparison of the cotyledonal cell structure of two susceptible and two resistant varieties failed to show any structural differences between varieties that could account for differences in cotyledonal cracking susceptibility.

Orientadores: Kil Jin Park, Jose Maria Monteiro Sigrist / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-04T08:24:34Z (GMT). No. of bitstreams: 1 Spagnol_WigbertoAntonio_D.pdf: 1868736 bytes, checksum: 6f96b6c038ec83ef28aec9e47331b2bc (MD5) Previous issue date: 2005 / Resumo: Apesar dos consumidores associarem frutas e hortaliças como uma dieta saudável, por outro lado, estão mais exigentes, requerendo o aprimoramento da qualidade e a praticidade para seu consumo. Para atender esta expectativa dos consumidores, as hortaliças processadas minimamente necessitam de aplicação de tecnologias, a fim de evitar a perda de qualidade causada pelas várias operações unitárias inerentes ao processamento. O presente trabalho teve como finalidade caracterizar os efeitos da temperatura, da modificação da atmosfera através da aplicação de filme plástico e de atmosferas ativas com altos teores de O2 e CO2, visando atingir a segurança, a alta qualidade e a conveniência no consumo de produtos processados minimamente (PM). O conceito de aplicação de fatores de preservação combinados envolve um enfoque mais amplo da preservação da qualidade, tanto na prevenção do crescimento de microrganismos de deterioração e/ou tóxicos, mas também para a conservação de outros atributos (cor, sabor, odor, textura). Em cenoura e vagem processadas minimamente, considerando um sistema com fluxo de ar contínuo, um acréscimo de 10ºC na temperatura causou um aumenta na taxa respiratória de 3,0 vezes em cenouras e, para vagens aumentou de 3,78 a 4,71 vezes. As condições climáticas de produção, verão e inverno, afetaram a taxa de respiração de vagens, sendo em torno de 50% maior para as vagens colhidas na época de inverno em relação às vagens colhidas no verão. O sintoma de dano pelo frio foi constatado à temperatura de 1ºC, sendo possível mantê-las a esta temperatura no máximo durante 4 dias. Foi observada uma diferença de 3 ciclos logUFC.g-1 no atraso de crescimento de microrganismos de deterioração a 1ºC quando comparado a 11ºC, para as cenouras embaladas em filmes plásticos. A aplicação de altos teores de O2 e CO2 em cenoura e vagem PM, considerando um sistema experimental aberto, com fluxo da mistura de gases contínuo, causou uma diminuição do crescimento de bactérias aeróbias psicrotróficas e mesófilas em torno de 2 ciclos log ao longo do período de 10 dias de armazenamento tanto para as cenouras mantidas a 11ºC como para as vagens a 5ºC. O alto teor de CO2 (30 kPa) em sinergia com alto teor de O2 (50 a 60 kPa) apresentou uma maior eficiência na inibição do crescimento das bactérias. A presença de altos teores de CO2 também evitaram a ocorrência de escurecimento enzimático nas vagens, evitando a perda de sua coloração verde durante o período de armazenamento / Abstract: Although the consumers associate fruits and vegetables to a healthy diet, they are more demanding about their quality and facility, on the other hand. The minimally processed vegetables need some technology to satisfy the consumer's expectations and in order to avoid the loss of the quality caused by many different operations concerned to minimally processing food. This work has the purpose to characterize the temperature effects, to modify the atmosphere by using plastic films and active atmospheres with high concentration of CO2 and O2. It aims to get safety, high quality and the convenience in consuming minimally processed products.The combination of preservation factors applied to minimal processing of foods concept involves a wider focus of quality preservation as prevention of the microorganisms deterioration growth and toxics microorganisms: and also for the conservation of other qualities (color, flavour, odor, texture). The minimally processing carrots and snap beans submitted to an open experimental system with the continuous air flux, an increase of 10ºC in the temperature has caused an increase of the respiration rate from 2 to 3 times in carrots and from 4 to 5 times on snap beans, being around 50% higher to snap beans harvested in the summer. The chilling injury symptoms on the snap beans were verified at the temperature of 1ºC. It is possible to maintain then at this temperature during only four days. It was observed a difference of 3 cycles log UFC.g-1 in the growth lag of deterioration microorganisms at 1ºC when compared to 11ºC, for the plastic films packaged carrots. The application of high concentration on the MP carrots and snap beans considering an experimental open system, with mixture flux of continuous gases, caused a decrease of psicotrofic and mesofile aerobic bacteria around 2 cycles log during 10 days of storage either carrots at 11ºC or snap beans at 5ºC. The high concentration of CO2 (30kPa) in synergy with high level of O2 (50 to 60 kPa) presented bigger efficiency in inhibition of the bacteria growth. The presence of high concentration of O2 also CO2 also avoided the occurrence of enzymatic browning on the snap beans, besides the loss of the green coloration during the storage period. The high concentration of O2 and CO2 didn¿t caused statistics alteration on C vitamin when compared to the air / Doutorado / Tecnologia Pós-Colheita / Doutor em Engenharia Agrícola