This study was aimed at exploring data analysis techniques for generating accurate estimates of the loss in quality of fresh fruits, vegetables and cut flowers in chilled supply chains based on data from advanced sensors. It was motivated by the recent interest in the application of advanced sensors, by emerging concepts in quality controlled logistics, and by the desire to minimise quality losses during transport and storage of the produce. Cut roses were used in this work although the findings will also be applicable to other produce. The literature has reported that whilst temperature was considered to be the most critical post-harvest factor, others such as growing conditions could also be important in the senescence of cut roses. Kinetic modelling was the most commonly used modelling approach for shelf life predictions of foods and perishable produce, but not for estimating vase life (VL) of cut flowers, and so this was explored in this work along with multiple linear regression (MLR) and partial least squares (PLS). As the senescence of cut roses is not fully understood, kinetic modelling could not be implemented directly. Consequently, a novel technique, called Kinetic Linear System (KLS), was developed based on kinetic modelling principles. Simulation studies of shelf life predictions for tomatoes, mushrooms, seasoned soybean sprouts, cooked shrimps and other seafood products showed that the KLS models could effectively replace the kinetic ones. With respect to VL predictions KLS, PLS and MLR were investigated for data analysis from an in-house experiment with cut roses from Cookes Rose Farm (Jersey). The analysis concluded that when the initial and final VLs were available for model calibration, effective estimates of the post-harvest loss in VL of cut roses could be obtained using the post-harvest temperature. Otherwise, when the initial VLs were not available, such effective estimates could not be obtained. Moreover, pre-harvest conditions were shown to correlate with the VL loss but the correlation was too weak to produce or improve an effective estimate of the loss. The results showed that KLS performance was the best while PLS one could be acceptable; but MLR performance was not adequate. In another experiment, boxes of cut roses were transported from a Kenyan farm to a UK distribution centre. Using KLS and PLS techniques, the analysis showed that the growing temperature could be used to obtain effective estimates of the VLs at the farm, at the distribution centre and also the in-transit loss. Further, using post-harvest temperature would lead to a smaller error for the VL at the distribution centre and the VL loss. Nevertheless, the estimates of the VL loss may not be useful practically due to the excessive relative prediction error. Overall, although PLS had a slightly smaller prediction error, KLS worked effectively in many cases where PLS failed, it could handle constraints while PLS could not.In conclusion, KLS and PLS can be used to generate effective estimates of the post-harvest VL loss of cut roses based on post-harvest temperature stresses recorded by advanced sensors. However, the estimates may not be useful practically due to significant relative errors. Alternatively, pre-harvest temperature could be used although it may lead to slightly higher errors. Although PLS had slightly smaller errors KLS was more robust and flexible. Further work is recommended in the objective evaluations of product quality, alternative non-linear techniques and dynamic decision support system.

Made available in DSpace on 2016-05-02T13:53:56Z (GMT). No. of bitstreams: 1 Kellen Cristina Masaro Carvalho-dissertacao.pdf: 1041779 bytes, checksum: 80984a14a959fa109493e4aca6cb7087 (MD5) Previous issue date: 2012-09-27 / The techniques for preserving food, can maintain a large number of natural characteristics of the fruit, making storage and marketing viable for a longer period than what could be achieved with the raw product. The aim of this study was to evaluate the quality of the pulp of red fruits with different concentrations of potassium sorbate. The experiment was conducted at the Federal Institute of Education, Science and Technology in southern Minas Gerais - Campus Machado, using three pulps that were formulated with equal amounts of each fruit (blackberry, raspberry and strawberry) crushed the proportion of sucrose used was 1/6 and water 1/6 with respect to the total mass of crushed red fruits. The heat treatment was 100 ° C for 10 minutes. The concentration of potassium sorbate used was 0%, 0.05% and 0.1%. After cooling, the pulps were packaged in plastic containers containing 150 mL. The packages containing the pulps were sealed, identified and stored at 25 ° C in BOD incubator for 60 days. The microbiological, chemical and physical performed every 30 days, were as follows: yeast and mold, coliforms at 35 º C and 45 º C, analysis of Salmonella sp, vitamin C, pH, titratable acidity, soluble solids, color analysis (values L *, a *, b *, C * and h °). The experiment was conducted in a completely randomized design (CRD) with three replications. Treatments were arranged by a 3 x 3 factorial, being constituted by factors concentration of potassium sorbate (0%, 0.05% and 0.1%) and storage time (0, 30 and 60 days), respectively. The experimental plot consisted of a plastic satisfaction 150 mL of red fruit pulp. The pulp of red fruits with no added potassium sorbate stored at 25 º C for 30 days showed a count of yeasts and molds above the limit specified by Brazilian law. The red fruit pulps treated with 0.05% and 0.1% potassium sorbate were enough to ensure the stability of physical, chemical and microbiological during the 60 days of storage at 25 ° C. As the red fruit pulps with addition of 0.05% and 0.1% potassium sorbate have substantially similar results it is recommended to use in production of the fruit pulp red adding 0.05% potassium sorbate as preservative Red fruit pulp for economy product. Results were subjected to analysis of variance, after the comparison test of means, with a statistically significant difference of 5%. / As técnicas de conservação de alimentos, mantêm um grande número possível das características naturais das frutas, tornando seu armazenamento e comercialização viáveis por um período de tempo superior ao que se conseguiria com o produto in natura. O objetivo deste trabalho foi avaliar a qualidade da polpa de frutas vermelhas com diferentes concentrações de sorbato de potássio. O experimento foi realizado no Instituto Federal de Educação, Ciência e Tecnologia do Sul de Minas Gerais - Campus Machado, utilizando três polpas que foram formuladas com quantidades iguais de cada fruta (amora-preta, framboesa e morango) trituradas, a proporção de sacarose usada foi de 1/6 e de água 1/6 em relação à massa total das frutas vermelhas trituradas. O tratamento térmico foi de 100ºC por 10 minutos. A concentração de sorbato de potássio usada foi 0%, 0,05% e 0,1%. Após o resfriamento, as polpas foram envasadas em embalagens plásticas contendo 150 mL. As embalagens contendo as polpas foram seladas, identificadas e armazenadas à temperatura de 25ºC em câmara incubadora BOD, por 60 dias. As análises microbiológicas, químicas e físicas realizadas, a cada 30 dias, foram as seguintes: bolores e leveduras, coliformes a 35ºC e a 45ºC, análise de Salmonella sp, vitamina C, pH, acidez titulável, sólidos solúveis, análise da cor (valores de L*, a*, b*, hº e C*). O experimento foi conduzido em delineamento inteiramente casualisado (DIC), com três repetições. Os tratamentos foram dispostos por um fatorial 3 x 3, sendo constituídos pelos fatores concentração de sorbato de potássio (0%, 0,05% e 0,1%) e tempo de armazenamento (0, 30 e 60 dias), respectivamente. A parcela experimental foi constituída por uma embalagem plástica contento 150 mL de polpa de frutas vermelhas. A polpa de frutas vermelhas sem adição de sorbato de potássio armazenada a 25 ºC, por 30 dias, apresentou a contagem de bolores e leveduras acima do limite especificado pelo legislação brasileira. As polpas de frutas vermelhas tratadas com 0,05% e 0,1% de sorbato de potássio foram o suficiente para garantir a estabilidade física, química e microbiologica durante os 60 dias de armazenamento sob temperatura de 25ºC. Como as polpas de frutas vermelhas com adição de 0,05% e 0,1% de sorbato de potássio apresentam resultados praticamente semelhantes, é indicado usar na produção da polpa de frutas vermelhas a adição de 0,05% de sorbato de potássio como conservante de polpa de frutas vermelhas por questão de economia do produto. Os resultados foram submetidos à análise de variância, posteriormente ao teste de comparação de médias, com diferença estatística significativa de 5%.

Made available in DSpace on 2016-05-02T13:55:21Z (GMT). No. of bitstreams: 1 Kellen Cristina Masaro Carvalho-dissertacao.pdf: 1041779 bytes, checksum: 80984a14a959fa109493e4aca6cb7087 (MD5) Previous issue date: 2012-09-27 / The techniques for preserving food, can maintain a large number of natural characteristics of the fruit, making storage and marketing viable for a longer period than what could be achieved with the raw product. The aim of this study was to evaluate the quality of the pulp of red fruits with different concentrations of potassium sorbate. The experiment was conducted at the Federal Institute of Education, Science and Technology in southern Minas Gerais - Campus Machado, using three pulps that were formulated with equal amounts of each fruit (blackberry, raspberry and strawberry) crushed the proportion of sucrose used was 1/6 and water 1/6 with respect to the total mass of crushed red fruits. The heat treatment was 100 ° C for 10 minutes. The concentration of potassium sorbate used was 0%, 0.05% and 0.1%. After cooling, the pulps were packaged in plastic containers containing 150 mL. The packages containing the pulps were sealed, identified and stored at 25 ° C in BOD incubator for 60 days. The microbiological, chemical and physical performed every 30 days, were as follows: yeast and mold, coliforms at 35 º C and 45 º C, analysis of Salmonella sp, vitamin C, pH, titratable acidity, soluble solids, color analysis (values L *, a *, b *, C * and h °). The experiment was conducted in a completely randomized design (CRD) with three replications. Treatments were arranged by a 3 x 3 factorial, being constituted by factors concentration of potassium sorbate (0%, 0.05% and 0.1%) and storage time (0, 30 and 60 days), respectively. The experimental plot consisted of a plastic satisfaction 150 mL of red fruit pulp. The pulp of red fruits with no added potassium sorbate stored at 25 º C for 30 days showed a count of yeasts and molds above the limit specified by Brazilian law. The red fruit pulps treated with 0.05% and 0.1% potassium sorbate were enough to ensure the stability of physical, chemical and microbiological during the 60 days of storage at 25 ° C. As the red fruit pulps with addition of 0.05% and 0.1% potassium sorbate have substantially similar results it is recommended to use in production of the fruit pulp red adding 0.05% potassium sorbate as preservative Red fruit pulp for economy product. Results were subjected to analysis of variance, after the comparison test of means, with a statistically significant difference of 5%. / As técnicas de conservação de alimentos, mantêm um grande número possível das características naturais das frutas, tornando seu armazenamento e comercialização viáveis por um período de tempo superior ao que se conseguiria com o produto in natura. O objetivo deste trabalho foi avaliar a qualidade da polpa de frutas vermelhas com diferentes concentrações de sorbato de potássio. O experimento foi realizado no Instituto Federal de Educação, Ciência e Tecnologia do Sul de Minas Gerais - Campus Machado, utilizando três polpas que foram formuladas com quantidades iguais de cada fruta (amora-preta, framboesa e morango) trituradas, a proporção de sacarose usada foi de 1/6 e de água 1/6 em relação à massa total das frutas vermelhas trituradas. O tratamento térmico foi de 100ºC por 10 minutos. A concentração de sorbato de potássio usada foi 0%, 0,05% e 0,1%. Após o resfriamento, as polpas foram envasadas em embalagens plásticas contendo 150 mL. As embalagens contendo as polpas foram seladas, identificadas e armazenadas à temperatura de 25ºC em câmara incubadora BOD, por 60 dias. As análises microbiológicas, químicas e físicas realizadas, a cada 30 dias, foram as seguintes: bolores e leveduras, coliformes a 35ºC e a 45ºC, análise de Salmonella sp, vitamina C, pH, acidez titulável, sólidos solúveis, análise da cor (valores de L*, a*, b*, hº e C*). O experimento foi conduzido em delineamento inteiramente casualisado (DIC), com três repetições. Os tratamentos foram dispostos por um fatorial 3 x 3, sendo constituídos pelos fatores concentração de sorbato de potássio (0%, 0,05% e 0,1%) e tempo de armazenamento (0, 30 e 60 dias), respectivamente. A parcela experimental foi constituída por uma embalagem plástica contento 150 mL de polpa de frutas vermelhas. A polpa de frutas vermelhas sem adição de sorbato de potássio armazenada a 25 ºC, por 30 dias, apresentou a contagem de bolores e leveduras acima do limite especificado pelo legislação brasileira. As polpas de frutas vermelhas tratadas com 0,05% e 0,1% de sorbato de potássio foram o suficiente para garantir a estabilidade física, química e microbiologica durante os 60 dias de armazenamento sob temperatura de 25ºC. Como as polpas de frutas vermelhas com adição de 0,05% e 0,1% de sorbato de potássio apresentam resultados praticamente semelhantes, é indicado usar na produção da polpa de frutas vermelhas a adição de 0,05% de sorbato de potássio como conservante de polpa de frutas vermelhas por questão de economia do produto. Os resultados foram submetidos à análise de variância, posteriormente ao teste de comparação de médias, com diferença estatística significativa de 5%.

O aproveitamento de proteína de pescado como coprodutos do processo de industrialização, constitui-se em uma alternativa para a elaboração de produtos com elevada qualidade nutricional. A carne mecanicamente separada (CMS), produzida a partir de carcaças do descarte do processamento de tilápia híbrida vermelha (CMSV), Oreochromis niloticus var. Red Stirling e de tilápia preta (CMSP), Oreochromis niloticus, foram caracterizadas física, química, microbiológica e sensorialmente. Em um primeiro estudo avaliou-se a eficiência de dois tipos de equipamentos de extração mecânica da CMS, rosca- sem-fim e cinta-tambor. Posteriormente, avaliou-se a qualidade da CMS congelada durante 90 dias de armazenamento. Em seguida avaliou-se os atributos sensoriais de cor, odor e aparência da CMSV e CMSP congelada. Para a avaliação do sabor da CMS, foi adicionado ao molho de tomate com CMSV armazenada por 15 e 90 dias e a aceitação avaliada por consumidores. Foi realizado um estudo para avaliação das características de funcionalidade da CMS reestruturada da tilápia híbrida vermelha. O separador tipo rosca-sem-fim apresentou melhor rendimento de extração e controle da temperatura do processo, quando comparado ao separador do tipo cinta-tambor, embora ambos os processos tenham permitido a obtenção de CMS com teores de umidade, proteína e lipídeo adequados para o processamento de coprodutos. A avaliação da vida útil indicou que coprodutos da tilápia híbrida vermelha (CMSV) e tilápia preta (CMSP) apresentaram padrões microbiológicos, valores de pH e oxidação lipídica aceitáveis ao longo do estudo, mesmo apresentado uma descoloração ao longo do armazenamento. A avaliação sensorial para o estabelecimento da vida útil (teste de diferença do controle com provador treinado) foi realizada em períodos até 90 dias. Aos 15 dias de armazenamento, os provadores detectaram diferença significativa, porém o limite sensorial estabelecido pelos provadores (moderadamente diferente do controle) foi atingido aos 60 dias para a CMS da tilápia preta e aos 90 dias para a CMS de tilápia vermelha. A aceitação teve boa resposta, porém a intenção de compra apresentou queda de 19% para o molho adicionado de CMS estocada durante 90 dias. A CMSV é uma matéria prima, com elevado teor proteico (12%) e elevado teor lipídico (15%) e pode ser utilizada para elaboração de diferentes coprodutos. Foi possível obter produto reestruturado com boa funcionalidade tecnológica com adição de 100% de CMS de tilápia híbrida vermelha, o que demonstra a viabilidade de sua utilização, onde apresentaram respostas satisfatórias de rendimento, capacidade de retenção de água e força de penetração no reestruturado. Conclui-se que a CMS das variedades de tilápia estudadas representam um coproduto de qualidade a ser aproveitado pela indústria. Além de contribuir para para fornecer dados, junto a outros trabalhos, para se criar um padrão de identidade e qualidade da CMS de pescado, o que é de suma importância para o controle de qualidade da indústria processadora do coproduto. / The use of fish protein resulting from the industrial process constitutes an alternative to the development of co-products with nutritional quality. Mechanically recovered meat (MRM), produced from carcasses of Red hybrid tilapia, Oreochromis niloticus var. Red Stirling and black tilapia Oreochromis niloticus were characterized in terms of physical, chemical, microbiological and sensory aspects. The first study evaluated the efficiency of two mechanical extraction devices of MRM, the screw type and the belt and drum type. Later assessed the quality of frozen MRM for 90 days of storage. Then it was evaluated the sensory attributes of color, odor and appearance of defrozen MRM. The resulting MRM was used in the development of a tomato sauce and its acceptance with consumers was analyzed. A performance study of MRM restructured of red hybrid tilapia was conducted. The worm screw-type separator presented better extraction yield when compared to belt-drum type separator, but both processes allowed obtaining MRM with levels of moisture, protein and lipids suitable for processing co-products. Both MRM presented microbiological and oxidative stability after 90 days of storage. The sensory analysis of control difference for up to 90 days showed significant difference to that at 15 days of storage. The team of tasters set the value 4 (appearance, color and odor moderately different from the control) as limiting MRM shelf life to 60 days for MRM of the Nile tilapia and 90 days for MRM of the red tilapia. The tomato sauce with the addition of tilapia formulated with MRM of the red tilapia stored for 15 and 90 days was well accepted by consumers, but purchase intent dropped 19% for the product obtained from MRM with 90 days of storage. The MRM from the red hybrid tilapia is a raw material with high protein content, average 12%, and high lipid content, average 15%, and can be used to prepare different co-products of tilapia. It was possible to obtain restructured product with addition of 100% of MRM from the red hybrid tilapia with good processing characteristics, which shows viability of production with satisfactory responses of performance, water retention capacity and penetration force of restructured fish meat. We conclude that the CMS of the studied tilapia varieties represent a quality co-product to be used by the industry. Besides contributing to to provide data , along with other works , to create a standard of identity and quality of fish CMS , which is of paramount importance for the quality control of the co-product processing industry.

O caldo de cana é uma bebida saborosa, energética, não alcoólica que conserva todos os nutrientes presentes na cana-de-açúcar, muito apreciado no Brasil que, se devidamente explorado, pode alcançar um mercado consumidor com proporções ainda maiores. O presente trabalho teve como objetivos avaliar o grau de aceitação do mercado consumidor e a estabilidade do caldo de cana puro e adicionado de suco de frutas, submetido ao processamento térmico (70&#176;C/ 25 min) e/ ou à radiação gama (2,5 kGy), armazenado em garrafas de polietileno de alta densidade sob refrigeração (5 &#177; 1&#176;C). O teste de mercado do caldo de cana processado e embalado foi avaliado através da aplicação de 350 questionários em seis municípios paulistas. A qualidade do caldo de cana foi avaliada através dos parâmetros: microbiológicos (contagem de aeróbios psicrotróficos, bactérias lácticas e fungos filamentosos e leveduriformes), físico-químicos (pH, cor, acidez titulável, teor de sólidos solúveis, ratio e atividade da polifenoloxidase) e sensoriais (teste hedônico). Foi determinada a composição centesimal das bebidas elaboradas analisando-se: umidade, valor calórico, carboidratos totais, açúcares totais e redutores, extrato etéreo, proteínas, teor de ácido ascórbico, cinza e minerais. A vida útil foi determinada a cada 7 dias analisando o produto armazenado sob refrigeração durante 42 dias. Os resultados foram avaliados através de análise de variância e comparação das médias pelo teste de Tukey (p<0,05). Entre as 350 pessoas entrevistadas, mais da metade interessa-se e preocupa-se com a segurança de sua alimentação habitual e rotineira e apresenta receio em se alimentar em comércio de alimentos de rua. Os lanches foram os alimentos citados como os rotineiramente consumidos, seguidos pelo caldo de cana e pastel. Entre os entrevistados, 80% mencionaram apreciar caldo de cana, não havendo correlação entre idade e escolaridade e a preferência pela forma de consumo foi com adição de suco de limão. Cerca de 55% dos entrevistados mencionaram que consumiriam com maior freqüência o caldo de cana puro ou adicionado de suco de frutas, processado e embalado. Os processamentos aplicados ao caldo de cana não alteraram significativamente o aroma e o sabor da bebida. O teste sensorial para a escolha das melhores concentrações de suco de frutas a ser adicionado ao caldo de cana elegeu a adição de 4% de suco de limão e 10% de suco de abacaxi. A adição dos sucos de frutas ao caldo de cana nas concentrações propostas não alterou sua composição centesimal. No entanto, a adição do suco de abacaxi ao caldo de cana incrementou significativamente o teor de manganês e o de açúcares redutores quando comparado com o caldo de cana puro e adicionado de suco de limão. Considerando os resultados do teste de mercado, elegeu-se o caldo de cana adicionado de suco de limão como o preferido entre os provadores para a análise da vida útil do produto. As bebidas elaboradas pela mistura de caldo de cana e suco de limão submetidas à irradiação, pasteurização combinada com radiação e pasteurização mantiveram qualidade microbiológica, físico-química e sensorial satisfatória durante os períodos de 28, 35 e 42 dias, respectivamente, após o processamento. O tratamento térmico isolado foi considerado a melhor forma de conservação da bebida. / Sugarcane juice is a taste drink, energetic, no alcoholic that conserves all the nutrients in cane sugar. It was very appreciated by the Brazilian population and its production has been shown to be a highly lucrative business. This research had the following objectives: evaluate the acceptance of the consuming market and the stability of pure sugarcane juice or added with natural fruit juices, submitted of heat treatment (70&#176;C/ 25 min) and/ or gamma radiation (2,5 kGy) and stored in high density polyethylene bottles, under refrigeration (5 &#177; 1&#176;C). Sugarcane juice market test was evaluated through the application of 350 questionnaires on six São Paulo cities. Sugarcane juice stability was evaluated through microbiological (psicrothrophic count, lactic bacteria and yeasts and molds count), physical-chemical (pH, color, titratable acidity, soluble solids, ratio and polyphenoloxidase activity) and sensory (hedonic test) parameters. Centesimal composition was determined analyzing: humidity, caloric value, total carbohydrates, total and reducing sugars, lipids, proteins, ascorbic acid, ash and minerals. Sugarcane juice shelf life period was determinate ever 7 days over a period of 42 days stored under refrigeration. The data were submitted to the variance analysis and compared by Tukey&#39;s test (p<0,05). Among the 350 interviewed people, more of the half one is interested about its habitual food safe and care about street foods. Sandwiches had been cited foods as routinely consumed, followed for the sugarcane juice and &#34;pastel&#34;. Among the interviewed ones, 80% had mentioned to appreciate sugarcane juice. It had not correlation between age and school age and the preference for the consumption form was with lemon juice addition. About 55% of the interviewed ones had mentioned that would more frequently consume sugarcane juice processed and packed. Sugarcane juice processament didn&#39;t modify the flavor and taste of the drink. It was concluded from the sensory analyses that the best mixture was that formulated with sugarcane juice and 4% of lemon juice as well as 10% of pineapple juice. Sugarcane juice centesimal composition wasn&#39;t altered by fruit juice concentration addition. However, sugarcane juice added with 10% pineapple juice incremented manganese and reducing sugars when compared with pure sugarcane juice and added with 4% lemon juice. The market test prefered mixture was shown to be that containing sugarcane juice and natural lemon juice for evaluation the shelf life. Sugarcane juice added with 4% of lemon juice submitted to gamma radiation, heat treatment combinated with gamma radiation and heat treatment remaining satisfactory microbiological, sensory and physicalchemical characteristics until 28, 35 and 42 days respectively, after processing. These results indicated that the heat treatment was effective for sugarcane juice preservation.

Este trabalho teve como objetivo avaliar o efeito de revestimentos comestíveis na qualidade de mamão \'Formosa\' minimamente processado durante armazenamento a 5°C por 15 dias. Os tratamentos foram: o controle, e os seguintes revestimentos: amido de arroz 3%, alginato de sódio 0,5% e carboximetilcelulose 0,25%. O uso de revestimentos causou alterações nos parâmetros físicos, físico-químicos e microbiológicos do mamão minimamente processado, quando comparado ao controle. As alterações mais importantes foram: menor contagem de coliformes totais; menor respiração dos mamões tratados com amido de arroz e maior dos tratados com carboximetilcelulose, ao longo do tempo; menor descoloração da polpa dos frutos ao longo do armazenamento; maior manutenção da firmeza das amostras tratadas com carboximetilcelulose; e redução do teor de sólidos solúveis e aumento da acidez titulável. Os revestimentos não afetaram os atributos sensoriais. Como a maioria dos efeitos positivos das coberturas ocorreu no 12° e 15° dias e, considerando o custo da tecnologia relacionado ao preço dos revestimentos, a melhor opção, até 9 dias de armazenamento, consiste em fazer apenas uma boa sanitização dos frutos, como feito no controle. No entanto, se o interesse for preservar a vida útil dos mamões por um período maior, até 15 dias, os revestimentos testados podem ser utilizados com resultados satisfatórios. / This study aimed to evaluate the effect of edible coatings on the quality of minimally processed \'Formosa\' papaya during storage at 5°C for 15 days. The treatments were: the control, and the following coatings: rice starch 3%, sodium alginate 0.5% and carboxymethylcellulose 0.25%. The use of coatings caused changes in the physical, physicochemical and microbiological parameters of minimally processed papaya, when compared to control. The most important changes were: lower counts of total coliforms; lower respiration of papayas treated with rice starch and higher of those treated with carboxymethylcellulose over time; less fruit pulp discoloration during storage, increased firmness maintenance of samples treated with carboxymethylcellulose; and reduction of soluble solids and increased acidity. The coatings did not affect the sensory attributes. Since most of the positive effects of the coatings occurred at the 12th and 15th days, and considering the technology cost related to the price of coatings, the best option, until 9 days of storage, is just to do a good sanitization of fruits such as that of control samples. However, if the interest is to preserve the shelf life of papayas for a longer period, up to 15 days, the coatings tested could be used with satisfactory results.

O efeito da injeção do lactato de potássio associado ao uso de atmosfera modificada com alto oxigênio sobre músculos Longissimus lumborum de bovinos machos inteiros foi avaliado. Foram utilizados animais anelorados (com características fenotípicas de Nelore) com diferentes faixas de pH final (pHf - 48h post mortem). Foram coletados 18 músculos e divididos em 3 grupos, sendo eles: baixo (controle; 5,4 < pHf < 5,8), intermediário (5,81 < pHf < 6,3) e alto (pHf > 6,3). Na primeira etapa, foi injetada em cada músculo uma solução de lactato de potássio a 2,5%, em seguida foram cortados em bifes, embalados em atmosfera modificada contendo 80% de oxigênio e 20% de gás carbônico e estocados no escuro a 2 ± 1ºC durante 5 dias. Posteriormente, estes seguiram para um expositor refrigerado com iluminação e temperatura controlada (2 ± 1ºC), onde permaneceram por 9 dias, completando 14 dias de vida útil. Análises de composição gasosa, pH, composição centesimal, sensorial de odor, avaliação microbiológica, oxidação lipídica e cor instrumental foram realizadas nos dias: 0, 5, 8, 11 e 14. Os resultados estatísticos obtidos foram analisados pelo método de medidas repetidas no tempo e também utilizando análise não-paramétrica. A oxidação lipídica foi menor (P < 0,05) e apresentou maior estabilidade em músculos com pHf alto. Não houveram diferenças (P > 0,05) na análise sensorial de odor entre os grupos. A contagem microbiana permaneceu dentro dos limites aceitáveis para consumo humano. Os grupos de pHf intermediário e alto apresentaram uma maior (P < 0,05) estabilidade da cor (maiores valores de a*, croma e oximioglobina). Nas condições do presente estudo, a injeção do lactato de potássio associada à atmosfera com alto oxigênio atuou beneficamente na estabilidade da cor e vida útil de músculos de pHf intermediário e alto. Pode-se concluir que a injeção desta solução é uma alternativa viável para tornar a aparência de bifes provenientes de músculos L. lumborum mais atrativa para o consumidor por meio da estabilização da cor, sem prejudicar a vida útil mesmo nas condições de embalagem utilizadas. / The effect of potassium lactate enhancement in a high oxygen modified packaging on bulls\' Longissimus lumborum was studied. Zebu animals (with phenotypic characteristics of Nellore) animals with different range of ultimate pH (pHu - 48h post mortem) were used. Eighteen muscles were collected and segregated into three groups, wich were: low (control; 5.4 < pHu < 5.8), intermediate (5.81 < pHu < 6.3) and high (pHu > 6.3). In the first stage, a 2.5% potassium lactate solution was injected into each muscle, then they were cut into steaks, packaged in a modified atmosphere containing 80% oxygen and 20% carbon dioxide and stored in the dark at 2 ± 1ºC for 5 days. Later, they were displayed with light and controlled temperature (2 ± 1ºC), where remained for 9 days, completing 14 days of shelf life. Gas composition, pH, proximate analysis, odor sensory, microbiological evaluation, lipid oxidation and instrumental color analysis were performed on days: 0, 5, 8, 11 and 14. The statistical results were analyzed by the method of repeated measurements over time and also using non-parametric analysis. The lipid oxidation decreased (P < 0.05) and showed greater stability on high pHu treatment. There were no differences (P > 0.05) between the treatments on odor sensory analysis. Microbial counts remained within acceptable limits for human consumption. The intermediate and high pHu groups had a higher (P < 0.05) color stability (higher values of a*, chroma and oxymyoglobin). Under the conditions of this study, the potassium lactate enhancement associated with high oxygen atmosphere (Hi-Ox MAP) can be an alternative to increase color stability and shelf life of intermediate and high pHu muscles. It can be concluded that the injection of this solution is a viable alternative to make L. lumborum steaks appearance more attractive to the consumer through the color stabilization, without sacrificing shelf life even under packaging conditions used.

The increasing market demand for fresh produce promotes a keen interest in developing a rapid, sensitive and reliable method for monitoring plant health and determining the shelf-life of postharvest produce. The objective of this study is to explore the capability of Surface-enhanced Raman spectroscopy (SERS) in these applications. SERS integrates Raman spectroscopy which measures molecular vibrations and nanotechnology which enhances the weak Raman signals. Herein, we developed two SERS methods based on a surface detection approach using nanoparticles solution and a headspace detection approach using gold nanoparticles (AuNPs) fibers, to detect biochemical changes during postharvest storage of arugula leaves. Compared with surface detection, the headspace detection revealed significant spectral changes during the storage, particularly in the shifts around 500, 950 and 1030 cm-1. These changes analyzed using principal component analysis (PCA) to establish a prediction model for shelf-life determination. Through analyzing reference standard compounds, we identified the dimethyl disulfide (DMDS), 1-propanethiol and methanethiol (MT) were most likely to account for the signature spectra of headspace arugula at the late storage period due to the activities of spoilage bacteria. The headspace detection method was also applied to monitor the stress responses of living basil to abiotic stresses (pesticide/salinity). However, the volatile analysis of the basil plants response to abiotic stresses (pesticide/salinity) showed indistinctive results. In conclusion, the headspace detection based on SERS provides a new strategy for quality monitoring of fresh produce in the food industry.

Thesis (M.Sc. Agriculture (Horticulture)) -- University of Limpopo, 2022 / The most common postharvest limitation of litchi fruit is pericarp browning, which leads to consumer rejection of the solid fruit in the market even when the edible portion is not affected. Previously, sulphur dioxide (SO2) fumigation was used to control the browning and extend shelf life of litchi fruit. However, SO2 fumigation leaves undesirable residues, alters the fruit taste and may results in health hazards for consumers. An alternative method, namely, minimal processing was used to control pericarp browning and curb postharvest losses in litchi. Litchi fruit were harvested at two maturity stages (early harvest; 120 days after full bloom (DAFB), late harvest; 130 DAFB), peeled and immersed for two (2) minutes in three (3) solutions that represented treatments, namely 1) 1% citric acid 2) 1% calcium lactate and 3) a combination of citric acid and calcium lactate both at 1% measure. The untreated arils were dipped in sodium hypochloride (NaOCl) solution for 1 minute and represented the control samples. The treated arils were packed in sterilized clamshell containers and stored at 1±0.5°C and 95% relative humidity for 12 days, then held at 10±0.5°C for 2 days for shelf life study. As a result of the interaction effect of harvest stages and postharvest pre-treatments, least mass loss percentage (1.32%), juice leakage (1.8 ml per 120 g of fruit) and pH (4.18) was observed in litchi arils harvested late and treated with 1% citric acid only under cold storage. Under shelf life study, H2 control samples presented lower mass loss (2.8%) and juice leakage (4.2 ml per 120 g of fruit). At the end of cold storage, litchi arils harvested early and treated with 1% citric acid combined with 1% calcium lactate presented better tissue strength (56.0 N) and radical scavenging activity (36.6 mmol AAE/mL), while those harvested late presented higher ascorbic acid content (72.9 µg/mL), least microbial population and total colour change (3.5). However, at the end of shelf life storage, litchi arils harvested early and treated with 1% citric acid combined with 1% calcium lactate presented lower (3.1) total change in colour. Overall, harvesting the fruit late and treating with citric acid alone or combined with calcium lactate showed the potential of maintaining better aril quality with least microbial population for up to 12 days under 1±0.5°C storage, whereas harvesteing the fruit early and treating with citric acid alone or combined with calcium lactate showed the potential of maintaining better aril quality under shelf life storage. Keywords: Litchi chinesis sonn; calcium lactate; citric acid; maturity; fresh-cut. / Agricultural Research Council (ARC), National Research Foundation (NRF) and Agri-Seta

No description available.