Growing consumer awareness of the health benefits associated with fruits and vegetables and demand for easy to prepare products has prompted the development of a wide variety of minimally processed fruits and vegetables. Minimally processed fruits and vegetables are often peeled, cut, or diced which compromise the produces’ natural protective barriers, exposing a nutrient rich medium and providing an ideal environment for the growth of microorganisms, including foodborne pathogens. The germination conditions of sprout vegetables consisting of relatively high temperatures and humidity, low light and abundance of nutrients are also conducive to the proliferation of foodborne pathogens. Recent outbreaks and recalls indicate additional measures are needed to improve food safety and maintain the integrity of the food industry. The objective of this research was to evaluate the efficacy of Lactic Acid Bacteria (LAB) against E. coli O157:H7, L. monocytogenes, and Salmonella spp. on apple slices and alfalfa sprouts and it’s influence on product quality. Apple slices inoculated with E. coli O157:H7, L. monocytogenes, and Salmonella spp. (each at 104 CFU/g) were treated with Lb. plantarum alone and in combination with Pediococcus acidophilus and P. pentosaceus (LPP) (107 CFU/g) while alfalfa seeds were inoculated with L. monocytogenes and Salmonella spp. (each at 101 CFU/g and 103 CFU/g) and treated with LPP (107 CFU/g). The growth of the microorganisms on the apple slices was assessed during five and seven days of storage at 4◦C and 20◦C, respectively. Growth on alfalfa seeds was reported during five days of sprouting at 20◦C. Populations of LAB were maintained between 7.0 log CFU/g and 8.0 log CFU/g throughout storage and sprouting on the sliced apples and alfalfa seeds, respectively. Although LAB had no significant effect on pathogen populations on apple slices during storage at 4°C (p > 0.05), populations were significantly different at 20°C (p < 0.05). Populations of L. monocytogenes in the presence of Lb. plantarum and LPP were 1.84 log CFU/g and 2.84 log CFU/g less than the controls after five days of storage at 20°C (p < 0.05). Populations of E. coli O157:H7 in the presence of Lb. plantarum and LPP were 1.83 log CFU/g and 1.86 log CFU/g less than the control after one and three days of storage, respectively. Finally, populations of Salmonella spp. were 0.86 log CFU/g less than populations in the absence of LPP after three days of storage. LPP had a significant effect on the growth of L. monocytogenes and Salmonella spp. on alfalfa seeds (p < 0.05). After five days of sprouting, populations of L. monocytogenes at an initial concentration of 101 CFU/g and 103 CFU/g on seeds treated with LPP were approximately 4.5 log CFU/g and 1.0 log CFU/g less than the untreated seeds, respectively. Populations of Salmonella spp. at an initial concentration of 101 CFU/g and 103 CFU/g were 1.0 log CFU/g less than the control. Overall, on apple slices the combination of Lb. plantarum with P. acidophilum and P. pentosaceus demonstrated greater efficacy than Lb. plantarum alone and reduction of L. monocytogenes by Lb. plantarum and LPP was greater than Salmonella spp. and E. coli O157:H7 on apple slices and alfalfa seeds, alike. LAB had a minimal effect on the quality of the apple slices and alfalfa seeds. LAB could be an effective strategy in reducing pathogen populations at abusive temperatures and germination conditions without influencing the quality of minimally processed fruit and vegetables.

Neste trabalho é apresentado um sistema automatizado para armazenamento e conservação de alimentos vegetais frescos baseado em instrumentação eletroeletrônica e software de controle desenvolvido em LabView. Para a conservação, os produtos (já embalados) são armazenados imersos em uma solução aquosa preparada com água e um anticongelante como o etileno glicol (2%). Esta metodologia de armazenamento permite aumentar o tempo de prateleira através da redução da temperatura, sem o perigo de congelar os produtos armazenados. Os resultados mostram que a metodologia permite armazenar produtos frescos com segurança a apenas 0,4ºC acima do ponto de congelamento, enquanto que em câmaras convencionais esses devem ser armazenados a, pelo menos, 2,0ºC acima do ponto de congelamento. Essas condições proporcionam ao sistema de hidroconservação maior imunidade a perturbações de carga térmica e abertura de porta e velocidade adequada para um rápido resfriamento de produtos frescos. / This work presents an automated system for fresh vegetable food conservation based on electronic instrumentation, a storage chamber, and software for system control, whose procedures were developed in LabView. For conservation the fresh packaged products are stored into a controlled temperature liquid volume (55.3 liters), i.e., an aqueous solution prepared with water and ethylene glycol (2%). This conservation methodology allows to increase shelf time of fresh vegetables by means of reducing the storage temperature range to a safe operating condition without freezing the products. Results have shown the suitability of the developed system, which enables to store fresh products with safety and preserving quality as close as 0.4°C of the freezing point. In a conventional chamber fresh products must be stored considering at least a safety range of 2.0°C, which is much farther from the freezing point. Therefore, these conditions give to the hydro-conservation system large immunity regarding thermal load perturbation as well during door operation and adequate speed for fast cooling processes for fresh products.

UGARTE, Sheila Dayanna Milan. Atividade antimicrobiana da cobertura comestível de quitosana adicionada com trans-cinamaldeído sobre Escherichia coli E Listeria innocua em melão cantaloupe (Cucumus melo, L.) minimamente processado. 2012. 96 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Tecnologia de Alimentos, Fortaleza-CE, 2012 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-06-27T13:37:34Z No. of bitstreams: 1 2012_dis_sdmugarte.pdf: 3028823 bytes, checksum: 631442b469207df51398ae6e1ded8c92 (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-06-27T13:37:49Z (GMT) No. of bitstreams: 1 2012_dis_sdmugarte.pdf: 3028823 bytes, checksum: 631442b469207df51398ae6e1ded8c92 (MD5) / Made available in DSpace on 2016-06-27T13:37:49Z (GMT). No. of bitstreams: 1 2012_dis_sdmugarte.pdf: 3028823 bytes, checksum: 631442b469207df51398ae6e1ded8c92 (MD5) Previous issue date: 2012 / The consumption of fresh-cut fruits have grown considerably in recent years due to its nutritional advantages and because these are ready-to-eat products. However, the potential presence of pathogenic microorganisms in these products is a health risk for consumers, as they are eaten raw. The main purpose of this research was to evaluate in vivo the efficiency of a chitosan edible coating added with trans-cinnamaldehyde applied to fresh-cut melon (Cucumis melo L.), against fresh-cut melon’s own microflora and against Escherichia coli (ATCC 25922TM) and Listeria innocua (ATCC 33090). Firstly, in order to obtain the effective antimicrobial concentration, the Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) were obtained in vitro. Subsequently, the melons were minimally processed and divided into three parts, the first part without inoculation, the second part inoculated with E. coli and the third part inoculated with L. inocua; immediately, the fresh-cut melon was immersed in two types of edible coating: a medium molecular weight chitosan edible coating (2%) and a chitosan edible coating added with trans-cinnamaldehyde (0.05%). Fresh-cut melon inoculated with water, inoculated with E. coli and inoculated with L. inocua, was used as controls. The determination of mesophilic bacteria, psychrophilic, coliform, yeasts and moulds was realized in non inoculated fresh-cut melon. In the other hand, the counting of E. coli and L. innocua was realized in inoculated fresh-cut melon; these microbiological analysis were done, in times: 0, 3, 7, 14 and 21 days of storage at 4 °C. Both edible coatings showed antimicrobial action against E. coli and L. innocua, mesophilic, psychrophilic, coliform bacterias, yeasts and moulds, no statistically significant difference was found between them (P>0,001). The chitosan edible coating added with trans-cinnamaldehyde (0.05%) do not show improved efficiency in its antimicrobial action, regarding the microorganisms used in this research. / O consumo de frutas minimamente processadas tem crescido consideravelmente nos últimos anos devido suas vantagens nutricionais e por estarem prontos para o consumo. Porém, a presença de microrganismos patogênicos nestes produtos é um risco para a saúde dos consumidores, pois são consumidos crus. O foco principal desta pesquisa foi avaliar in vivo a eficiência de uma cobertura de quitosana adicionada de trans-cinamaldeído em melão (Cucumis melo L.) minimamente processado, sobre a microbiota própria do melão e do melão inoculado com Escherichia coli (ATCC 25922TM) e Listeria innocua (ATCC 33090). Inicialmente determinou-se a concentração inibitória mínima (CIM) e bactericida (CBM) do trans-cinamaldeído a nível in vitro para obter-se a concentração efetiva como antimicrobiano. Posteriormente, os melões foram minimamente processados e divididos em três partes, sendo uma sem inoculação, outra inoculada com E. coli e outra com L. innocua, sendo em seguida imersos em dois tipos de cobertura: cobertura de quitosana de médio peso molecular (2%) e em cobertura de quitosana de médio peso molecular (2%) com 0,05% de trans-cinamaldeído. Como controles foram utilizados o melão inoculado com água; inoculado com E. coli e inoculado com L. innocua. Foram realizadas determinação de bactérias mesófilas, psicrófilas, coliformes, bolores e leveduras nos melões não inoculados e contagem de E. coli e L. innocua nos melões inoculados, nos tempos: 0, 3, 7, 14 e 21 dias de armazenamento a 4 ºC. Ambas coberturas apresentaram atividade antimicrobiana sobre E. coli, L. innocua, bactérias mesófilas, psicrófilas, coliformes, bolores e leveduras, não ocorrendo entre elas uma diferença estatística significativa (P>0,001). A cobertura com trans-cinamaldeído não apresentou maior eficiência na ação antimicrobiana com relação aos microrganismos pesquisados.

Neste trabalho é apresentado um sistema automatizado para armazenamento e conservação de alimentos vegetais frescos baseado em instrumentação eletroeletrônica e software de controle desenvolvido em LabView. Para a conservação, os produtos (já embalados) são armazenados imersos em uma solução aquosa preparada com água e um anticongelante como o etileno glicol (2%). Esta metodologia de armazenamento permite aumentar o tempo de prateleira através da redução da temperatura, sem o perigo de congelar os produtos armazenados. Os resultados mostram que a metodologia permite armazenar produtos frescos com segurança a apenas 0,4ºC acima do ponto de congelamento, enquanto que em câmaras convencionais esses devem ser armazenados a, pelo menos, 2,0ºC acima do ponto de congelamento. Essas condições proporcionam ao sistema de hidroconservação maior imunidade a perturbações de carga térmica e abertura de porta e velocidade adequada para um rápido resfriamento de produtos frescos. / This work presents an automated system for fresh vegetable food conservation based on electronic instrumentation, a storage chamber, and software for system control, whose procedures were developed in LabView. For conservation the fresh packaged products are stored into a controlled temperature liquid volume (55.3 liters), i.e., an aqueous solution prepared with water and ethylene glycol (2%). This conservation methodology allows to increase shelf time of fresh vegetables by means of reducing the storage temperature range to a safe operating condition without freezing the products. Results have shown the suitability of the developed system, which enables to store fresh products with safety and preserving quality as close as 0.4°C of the freezing point. In a conventional chamber fresh products must be stored considering at least a safety range of 2.0°C, which is much farther from the freezing point. Therefore, these conditions give to the hydro-conservation system large immunity regarding thermal load perturbation as well during door operation and adequate speed for fast cooling processes for fresh products.

In Deutschland nimmt der Anbau von Bleichspargel (Asparagus officinalis L.) sechzehn Prozent der Gesamtgemüseanbaufläche ein. Die Qualitätssicherung von Spargel, insbesondere aber von geschältem (Convenience-) Spargel stellt wegen der hohen Stoffwechselaktivität nach der Ernte eine Herausforderung dar. Insbesondere gilt es, die Textur und die Inhaltsstoffe vor qualitätsmindernden Veränderungen und verderbsförderndem Pilzbefall zu bewahren. Als Verpackung dienen in der Regel Folienverpackungen, die aber oft für das empfindliche Gemüseprodukt nicht geeignet sind. Daher wurde der Einfluss von unterschiedlichen Folienverpackungen (vier Polypropylenfolien, zwei biologisch abbaubare Folien und ein Oberflächencoating) mit unterschiedlicher Permeabilität für Sauerstoff und Kohlendioxid auf die Veränderungen der Qualitätsparameter ( Farbe, Textur, Frischmasse, Trockensubstanz, Gerüstkohlenhydrate ( Pectine, Lignin, Hemicellulose, Cellulose, Saccharose, Fructose, Glucose) von nicht geschälten und geschälten Spargel unmittelbar nach der Ernte und nochmals nach drei (bzw. vier) Lagertagen (2°C, 10°C, 20°C Lagertemperatur) ermittelt. Direkt nach der Ernte und nach drei Lagertagen wurde bei 10°C und 20°C Lagertemperatur die Kontamination mit Pilzen und der eventuell damit verbundene Gehalt an Fumonisin B1 geprüft. Die Lagertemperatur von 10°C (2 d Lagerdauer) erwies sich als geeignet zur Qualitätserhaltung von Convenience – Spargel. Bei 2°C und 20°C geschältem Spargel waren die Pectinfraktionen, bei nicht geschältem Spargel war der Hemicellulosegehalt Veränderungen unterworfen. Die Veränderungen dieser Qualitätsparameter waren mit den Veränderungen der Textur korreliert. Die Spargelspitze ist bei der Lagerung (2°C und 20°C) stoffwechselaktiver, als die restliche Spargelstange. Es zeigte sich, dass das Verhältnis von O2 zu CO2 (RQ) in der Verpackungsfolie signifikanten Einfluss auf die Qualitätsparameter von geschältem Spargel ausübte. Die geringsten stoffwechselphysiologischen Veränderungen wurden bei einem RQ von 0,65 festgestellt. Folienverpackungen mit RQ von 0,03-0,65 hatten sich für das endophytische Pilzwachstum als hemmend erwiesen. Das Mykotoxin Fumonisin B1 wurden in gesundheitlich unbedenklichen Mengen (< 1,67 mg * kg TS-1) in nicht gelagerten und in gelagerten Spargelstangen nachgewiesen. / The production area of white asparagus comprises 16 % of all vegetable crops in Germany. The economic important asparagus (Asparagus officinalis L.) is known for its high quality loss in postharvest. In order to protect convenience asparagus, i.e. fresh-cut peeled white asparagus from rapid deterioration in respect to phytopathological fungi, nutritive and sensory compounds the commercial use of film packaging might be an important tool. However, the film packaging materials used commercially do often not fulfil product physiological concerns. Therefore, the influence of different film packaging materials (four polypropylene-films, two biological degradable films and one coating) with different permeabilities for CO2 and O2 was investigated for unpeeled and peeled white asparagus during storage (2, 3, and 4 days) at temperatures of 2°C, 10°C, 20°C. Changes in the following quality attributes were studied: colour, texture, fresh weight, dry weight, structural carbohydrates (pectic substances, lignin, hemicellulose, cellulose), mono- and disaccharides (fructose, glucose, sucrose). Moreover, at harvest and after three days of storage the contamination with fungi and the content of the mycotoxin Fumonisin B1 was observed. The tests for contamination of fungi were conducted with slight nutrient agar (SNA) for seven days at 20°C under 14 h UV light and 10 h darkness (Nirenberg, 1976) Quality changes were most inhibited at a storage temperature of 10°C for two days. The ratio of O2 to CO2 (RQ) within the film packaging had a pronounced effect on the quality attributes of peeled asparagus. Changes in dry weight, fresh weight, lignin content were low at a RQ of 0,65 (P-Plus 2 film), whereas the water-soluble/insoluble pectin ratio (1 : 0,8) remained constant during the entire storage period. A low correlation was found between texture and hemicellulose, glucose, sucrose and the ratio of water-soluble to insoluble pectin. The meristematic zone of the asparagus tip revealed a higher metabolic activity than other morphological parts of the spear. Endophytic fungi, e.g. Fusarium spp., a precursor of mycotoxin, was found in control asparagus spears. During storage, the development of Fusarium spp. could be inhibited by all film packaging revealing a RQ of 0,003 - 0,65. The mycotoxin Fumonisin B1 occurred in all asparagus spears (control and stored spears), however the content (< 1,67 mg * kg TS -1) did not reach health risk threshold values.