Thesis (MScAgric)--Stellenbosch University, 1962. / ENGLISH ABSTRACT: no abstract available / AFRIKAANSE OPSOMMING: geen opsomming

Made available in DSpace on 2014-06-11T19:33:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-15Bitstream added on 2014-06-13T21:06:43Z : No. of bitstreams: 1 santos_lo_dr_jabo.pdf: 961100 bytes, checksum: 071d355b742119430cc25e478c92f43b (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Este trabalho teve como objetivo avaliar o potencial de conservação pós-colheita de tangerinas ‘Fremont’, ‘Satsuma Okitsu’ e ‘Ponkan’, utilizando-se diferentes temperaturas de armazenamento e atmosfera controlada. Avaliou-se também o desverdecimento de tangerinas ‘Satsuma Okitsu’ e ‘Ponkan’ com a utilização do ethephon (ácido 2-cloroetilfosfônico). Foram utilizados frutos recém colhidos em Bebedouro-SP e Monte Alto-SP, nas safras 2008/2009/2010. O trabalho foi dividido em três partes: na primeira avaliou-se o armazenamento a 3 oC e a 7 oC; na segunda, testou-se atmosferas controladas enriquecidas com CO2 (5%) ou com baixas concentrações de O2 (10%); e na terceira, avaliou-se o desverdecimento dos frutos tratados com ethephon (ácido 2-cloroetilfosfônico). Nos experimentos das partes I e II, as avaliações da aparência, perda de massa, taxa respiratória, coloração da casca, e teores de sólidos solúveis, acidez titulável, ácido ascórbico, carboidratos solúveis, pectina total e solúvel, polifenóis totais e atividade antioxidante total foram efetuadas a cada 7 dias de armazenamento e após 3 dias sob a condição de ambiente (22 oC). Nos da parte III as avaliações de perda de massa, coloração da casca, e teores de sólidos solúveis, acidez titulável e ácido ascórbico do suco foram realizadas a cada 3 dias. A vida útil pós-colheita das tangerinas ‘Fremont’, sob as condições refrigeradas (3 ºC ou 7 ºC) e sob atmosfera controlada contendo AR + 5% CO2 e 10% O2 + 5% CO2 foi de 42 dias, limitada pela perda de frescor ou aparência. Nas tangerinas ‘Satsuma Okitsu’ a vida útil, limitada pela aparência... / This work aimed to evaluate the potential post-harvest conservation of 'Fremont', 'Satsuma Okitsu' and 'Ponkan' mandarins, using different storage temperatures and controlled atmosphere. The degreening of 'Satsuma Okitsu' and 'Ponkan' mandarins were also evaluated with the use of ethephon (2- cloroetilfosfônico acid). Fruit was harvested in Bebedouro-SP and Monte Alto-SP, during 2008/2009/2010 seasons. The work was divided in three parts: storage at 3 ºC and 7 ºC, controlled atmosphere enriched with CO2 (5%) or low concentrations of O2 (10%), and as a third part, the degreening of the fruits using ethephon (2-cloroetilfosfônico acid). During the first and the second experiments the fruits were evaluated by appearance, fresh mass, respiratory rate, peel color, and soluble solids, titratable acidity, ascorbic acid, soluble carbohydrates, total and soluble pectin, and total polyphenols content and total antioxidant activity, every 7 days under refrigerated storage and after 3 days under environmental condition (22 ºC). In the third part, were done the fresh mass, peel color, and soluble solids, titratable acidity and ascorbic acid content evaluations every 3 days. The shelf-life of 'Fremont' mandarin under refrigerated conditions (3 ºC or 7 ºC) and controlled atmosphere containing AR + 5% CO2 and 10% O2 + 5% CO2 was 42 days, limited by the freshness or appearance loss. ‘Satsuma Okitsu’ mandarins the shelf-life, limited by appearance, was 35 days at 7 ºC, which was reduced to 28 days at 3 ºC. Under controlled atmosphere (5% CO2 + 10% O2) the shelflife achieved was 42 days, at 7 ºC. The ‘Ponkan’ mandarins, when stored at 3 ºC, the shelf life achieved was 35 days, and 28 days at 7 ºC, also limited by freshness loss... (Complete abstract click electronic access below)

Orientador: Jose Fernando Durigan / Coorientador: Eduardo Sanches Stuchi / Banca: Ben-Hur Mattiuz / Banca: José Maria Monteiro Sigrist / Banca: Rogério Lopes Vieites / Banca: Juliana Sanchez / Resumo: Este trabalho teve como objetivo avaliar o potencial de conservação pós-colheita de tangerinas 'Fremont', 'Satsuma Okitsu' e 'Ponkan', utilizando-se diferentes temperaturas de armazenamento e atmosfera controlada. Avaliou-se também o desverdecimento de tangerinas 'Satsuma Okitsu' e 'Ponkan' com a utilização do ethephon (ácido 2-cloroetilfosfônico). Foram utilizados frutos recém colhidos em Bebedouro-SP e Monte Alto-SP, nas safras 2008/2009/2010. O trabalho foi dividido em três partes: na primeira avaliou-se o armazenamento a 3 oC e a 7 oC; na segunda, testou-se atmosferas controladas enriquecidas com CO2 (5%) ou com baixas concentrações de O2 (10%); e na terceira, avaliou-se o desverdecimento dos frutos tratados com ethephon (ácido 2-cloroetilfosfônico). Nos experimentos das partes I e II, as avaliações da aparência, perda de massa, taxa respiratória, coloração da casca, e teores de sólidos solúveis, acidez titulável, ácido ascórbico, carboidratos solúveis, pectina total e solúvel, polifenóis totais e atividade antioxidante total foram efetuadas a cada 7 dias de armazenamento e após 3 dias sob a condição de ambiente (22 oC). Nos da parte III as avaliações de perda de massa, coloração da casca, e teores de sólidos solúveis, acidez titulável e ácido ascórbico do suco foram realizadas a cada 3 dias. A vida útil pós-colheita das tangerinas 'Fremont', sob as condições refrigeradas (3 ºC ou 7 ºC) e sob atmosfera controlada contendo AR + 5% CO2 e 10% O2 + 5% CO2 foi de 42 dias, limitada pela perda de frescor ou aparência. Nas tangerinas 'Satsuma Okitsu' a vida útil, limitada pela aparência... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work aimed to evaluate the potential post-harvest conservation of 'Fremont', 'Satsuma Okitsu' and 'Ponkan' mandarins, using different storage temperatures and controlled atmosphere. The degreening of 'Satsuma Okitsu' and 'Ponkan' mandarins were also evaluated with the use of ethephon (2- cloroetilfosfônico acid). Fruit was harvested in Bebedouro-SP and Monte Alto-SP, during 2008/2009/2010 seasons. The work was divided in three parts: storage at 3 ºC and 7 ºC, controlled atmosphere enriched with CO2 (5%) or low concentrations of O2 (10%), and as a third part, the degreening of the fruits using ethephon (2-cloroetilfosfônico acid). During the first and the second experiments the fruits were evaluated by appearance, fresh mass, respiratory rate, peel color, and soluble solids, titratable acidity, ascorbic acid, soluble carbohydrates, total and soluble pectin, and total polyphenols content and total antioxidant activity, every 7 days under refrigerated storage and after 3 days under environmental condition (22 ºC). In the third part, were done the fresh mass, peel color, and soluble solids, titratable acidity and ascorbic acid content evaluations every 3 days. The shelf-life of 'Fremont' mandarin under refrigerated conditions (3 ºC or 7 ºC) and controlled atmosphere containing AR + 5% CO2 and 10% O2 + 5% CO2 was 42 days, limited by the freshness or appearance loss. 'Satsuma Okitsu' mandarins the shelf-life, limited by appearance, was 35 days at 7 ºC, which was reduced to 28 days at 3 ºC. Under controlled atmosphere (5% CO2 + 10% O2) the shelflife achieved was 42 days, at 7 ºC. The 'Ponkan' mandarins, when stored at 3 ºC, the shelf life achieved was 35 days, and 28 days at 7 ºC, also limited by freshness loss... (Complete abstract click electronic access below) / Doutor

Orientadores: Marcos David Ferreira, Oscar Antonio Braunbeck / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-12T21:40:12Z (GMT). No. of bitstreams: 1 Atarassi_MarciaEiko_M.pdf: 1960343 bytes, checksum: 9d61529cd30a1a4960b9778fd37effa7 (MD5) Previous issue date: 2008 / Resumo: As normas de classificação garantem o mesmo padrão para produtores, atacadistas e consumidores finais, facilitando a comercialização, valorizando os produtos e diminuindo as perdas. O objetivo deste trabalho foi avaliar um sistema de classificação por diâmetro de tomates in natura, por meio de cilindros rotativos divergentes. Os cilindros avaliados foram: cilindro com cerdas de Tereftalato de Polietileno (PET); cilindro liso de tubo de PVC (Policloreto de Vinila); e cilindro de PVC com helicóide de borracha (altura de 0,01 m e passo de 0,10 m). Primeiramente, foram realizados ensaios para definir as faixas de aberturas de cada classe de tamanho, variando os tratamentos (dois cilindros com cerdas - CC; um cilindro com cerda e um cilindro liso - CL; e um cilindro liso e outro com helicóide - LH) e a velocidade de rotação (50, 100, 150, 200 e 250 rpm). Depois foi avaliada a classificação realizada pelo sistema. Na segunda etapa avaliou-se a incidência de danos mecânicos nos tomates da cultivar 'Carmen' submetidos à classificação nas duas velocidades de maior eficiência de classificação de cada tratamento. Na terceira etapa realizou-se um ensaio de eficácia de limpeza dos frutos com os tratamentos dois cilindros com cerdas (CC) e um cilindro com cerda e outro liso (CL), nas duas velocidades de maior eficiência de classificação. A classificação com cilindros divergentes apresentou conformidade em mistura permitida, para a classe 60, nos tratamentos CC (200 rpm), CL (50 e 100 rpm), LH (100 e 150 rpm) e para a classe 80, para os tratamentos CC (50, 150 e 250 rpm), CL (100 e 250 rpm), LH (50, 100, 150 e 250 rpm). Em todos estes tratamentos a mistura foi apenas de classes imediatamente superiores e/ou inferiores no mesmo lote, em acordo com a norma brasileira de classificação de tomates. Entretanto, para a classe 70 não houve nenhum tratamento em conformidade com a tolerância permitida de 10% de frutos de outras classes. As maiores eficiências de classificação foram obtidas no tratamento LH a 150, 200 e 250 rpm, com valores variando de 74 a 80%. A maior perda de massa foi no tratamento CL 50 rpm, devido ao giro do fruto em torno do eixo equatorial, que causou maior abrasão na casca do fruto. A atividade respiratória dos frutos em todos os tratamentos foi similar aos frutos não classificados, após 4 horas de classificação. A eficácia no processo de limpeza foi maior para o tratamento CC, com índices de limpeza de 33 e 38%, a 50 e 100 rpm, respectivamente. Os cilindros divergentes apresentaram potencial para a classificação de tomate, contudo, são necessários ajustes para classificar os frutos da classe 70. A melhor classificação de tomates foi para o tratamento LH 150 rpm, que apresentou a maior eficiência e capacidade de classificação, sem alterar a qualidade dos frutos. Para realizar a etapa de limpeza e a classificação juntas, poderia se empregar cilindros de cerdas mais adequadas, com eficácia de limpeza maior e que não prejudicassem a qualidade do tomate / Abstract: Size standards guarantee the same classification for producers, wholesalers and consumers, facilitating trade, enhancing products value and reducing losses. The main goal of this work was to evaluate a grading system of fresh tomatoes by rotating divergent cylinders. The evaluated cylinders were: cylinder with bristles of Polyethylene Terephthalate (PET); smooth cylinder of PVC (Poly Vinyl Chloride) tube; and PVC cylinder with helical rubber (height of 0.01 m and step of 0.10 m). First, it was defined the range openings of each grading, varying treatments (two cylinders with bristles - CC; bristles cylinder and a smooth cylinder - CL; and smooth cylinder and cylinder with a helical - LH) and speed rotation (50, 100, 150, 200 and 250 rpm). After, the sorting system was assessed. In a second step, it was evaluated mechanical damage incidence in 'Carmen' cultivar tomatoes, subject to treatments in two speeds with better sorting efficiency. In a third step it was tested cleaning effectiveness on tomatoes submitted to two cylinders with bristles (CC) and bristles cylinder and a smooth cylinder (CL), at the two best sorting efficiency speeds. Tomatoes graded with divergent cylinders presented accordance with standards allowed mixture for grade 60, at treatments CC (200 rpm), CL (50 and 100 rpm), LH (100 and 150 rpm) and for grade 80 for treatments CC (50, 150 and 250 rpm), CL (100 and 250 rpm), LH (50, 100, 150 and 250 rpm). In all these treatments classes mixture was only just above and/or less at the same batch, in accordance with the Brazilian grading standard for tomatoes. However, for grade 70 there was no treatment in accordance for a grade tolerance allowing 10% fruit out-of-size. The greatest sorting efficiencies were obtained at LH treatment, at 150, 200 and 250 rpm, with values ranging from 74 to 80%. The highest weight loss was at LC 50 rpm treatment, due to the tomato spin around the equatorial axis, which caused more abrasion on the fruit skin. The respiratory activity of the fruits in all treatments was similar to the fruit no grading, after 4 hours of classification. Effectiveness in cleaning process was higher for CC treatment, with cleanliness index of 33 and 38% for 50 to 100 rpm, respectively. The diverging cylinders could be used for classification of tomatoes; however, adjustments are necessary to grade the class 70 fruits. The best tomatoes classification was for LH 150 rpm treatment, which had the highest efficiency, without changing the fruit quality. To achieve the cleaning and classification stage together, could employ cylinders of bristles more appropriate for tomatoes / Mestrado / Tecnologia Pós-Colheita / Mestre em Engenharia Agrícola

Master of Science / Food Science Institute / Sara E. Gragg / Leafy greens have been recognized as vehicles for transmission of foodborne pathogens and an effective pre-harvest intervention to control them is currently lacking. After harvest, lettuce is often subjected to chlorinated water to reduce the microbial load in the water and on the lettuce tissue. While moderately effective, there is also a need for improved postharvest interventions. The purpose of Objective I was to 1) determine potassium bisulfate efficacy at reducing populations of Escherichia coli (E. coli) and Listeria innocua (L. innocua) when applied pre-harvest to lettuce, and 2) assess the impact on product quality at harvest. Potassium bisulfate reduced E. coli populations on inoculated lettuce by 1.32 log₁₀ CFU/g (P=0.0002) and L. innocua by 1.18 log₁₀ CFU/g (P=0.0017). No detectable differences were observed in color (P>0.05); however, brown spots were observed on various leaves sprayed with potassium bisulfate. The purpose of Objective II was to employ a blend of benzalkonium chloride, acetic acid, and methyl paraben (BAM) as a postharvest wash on romaine and iceberg lettuce and to 1) determine efficacy at reducing populations of Listeria monocytogenes (L. monocytogenes), E. coli O157:H7 and Salmonella, 2) measure changes in aerobic bacteria throughout the shelf life, and 3) quantify benzalkonium chloride and methyl paraben residues post-washing. To quantify efficacy of BAM reducing pathogenic bacterial populations, fresh-cut romaine and iceberg lettuce were inoculated with L. monocytogenes, E. coli O157:H7, or Salmonella and washed in BAM at concentrations of 0%, 1%, 2% or 3% for one or five minutes. When plated on recovery media, contact time and wash concentration was not significant (P>0.05) for Salmonella on either product. Concentration was significant (P=0.0189) for L. monocytogenes on romaine; however, the greatest reduction observed was <1.0 log₁₀ CFU/g. The 3% wash significantly reduced E. coli O157:H7 on romaine by 1.75 log₁₀ CFU/g, which is 0.66 log₁₀ CFU/g better than the 0% wash. Following washing, wash water was analyzed and data demonstrate that all wash concentrations significantly (P≤0.05) reduced each foodborne pathogen by >2.0 log₁₀ CFU/g in the wash water. To quantify benzalkonium chloride and methyl paraben residues, as well as changes in aerobic bacteria and product quality, fresh-cut romaine and iceberg lettuce were subjected to a 1 minute wash in BAM at concentrations of 0%, 1%, 2%, or 3% and immediately sampled to determine aerobic populations and product quality. Concentrations 0% and 2% were also packaged into retail storage bags and sampled on days 0, 3, 5, and 7. Residues were quantified on these days as well. On day 0, aerobic populations did not vary according to wash concentration (P>0.05). With regards to shelf-life data, the 2% wash significantly reduced (P=0.0203) aerobic bacteria on romaine lettuce; however, no significant difference was observed on iceberg lettuce (P=0.0819). With regards to overall visual appearance of romaine or iceberg lettuce, no significant difference was detected between 0% and 2% BAM washes for each day throughout the shelf-life study (P>0.05). Methyl paraben and benzalkonium chloride residues were <5.0 and <10.0 ppm, respectively, on both products on each sampling day.

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The Food Safety Modernization Act (FSMA), specifically the Produce Safety Rule (PSR), requires growers to clean and sanitize food-contact surfaces to protect against produce contamination. The ATP monitoring device is a potential sanitation tool to monitor the efficacy of an on-farm cleaning and sanitation program that could help growers meet regulatory expectations mandated by PSR. The ATP device uses bioluminescence to detect all ATP (found in bacteria and produce matter cells) from a swabbed surface. Little work has been done to test the efficacy of these tools under postharvest conditions. The present study evaluated ATP measurement for postharvest surface cleanliness evaluation. Concentrations of leafy greens (spinach, romaine, red cabbage) (with/without L. innocua) were used as organic matter inocula onto stainless steel, HDPE plastic, and bamboo wood coupons to represent postharvest surfaces. The ATP levels on the coupons were measured using swabs and ATP monitoring device. Results showed that the concentration of L. innocua and leafy greens on a surface had a highly significant effect on the ATP device reading (PL. innocua at 4.5 log CFU/coupon where the ATP device could no longer detect ATP from L. innocua. The type of leafy green on a food-contact surface did not affect the ATP reading (P=0.88). Leafy greens with L. innocua had a higher ATP reading when compared to saline and L. innocua, demonstrating the presence of leafy green matter contributes to ATP reading when combined with L. innocua. The different food-contact surfaces had different ATP readings (P=0.03) and the ATP device did not detect bacterial or leafy green ATP from bamboo wood surfaces (P=0.16). Based upon our results, ATP measurement is an appropriate tool to measure produce or bacterial contamination on stainless steel or HDPE plastic surfaces, however it is not recommended for wood surfaces.