ABSTRACT. This study examined biochemical changes associated with chilling injury (CI) in sweet potato roots stored at low temperatures and reconditioned at ambient temperature. Sweet potato cultivars BRS Amélia and BRS Rubissol were stored at 6 or 13°C for 4 days at ambient temperature (“ambient reconditioning”: 21 ± 2°C). CI on the outer surface of the roots occurred earlier in BRS Amélia than in BRS Rubissol. The CI index on the inner surface of the BRS Amélia was higher when it was stored at 6°C for 40 + 4 days. BRS Amélia showed higher proline content and electrolyte leakage when stored at 6°C. Ascorbate peroxidase was induced by storage at 6°C for 30 + 4 days in BRS Amélia and from 40 + 4 days in BRS Rubissol. The malondialdehyde and phenolic compounds of BRS Rubissol increased during storage at 6°C. CI in both cultivars was associated with increased peroxidase and polyphenol oxidase activities. Storage of sweet potato cultivars at 6°C for 50 + 4 days caused severe damage to the roots. Cultivars BRS Amélia and BRS Rubissol showed similar symptoms of CI and can be characterized as being sensitive to low temperatures.

Abstract Sweet potato fried chips have great acceptance and high market value. Sprouting and fresh mass loss of tuberous roots during storage compromise the quality of the processed products. The objective of this work was to evaluate the effect of 1-Methylcyclopropene (1-MCP), amino-oxyacetic acid (AOA), and ethylene on the physico-chemical quality of fresh sweet potato and its relationship with fried color score in processed chips of cv. BRS Rubissol stored at room temperature. During storage, the weight loss, sprouts number, dry matter content, non-enzymatic browning, protein content, soluble phenols fraction, reducing sugars, total amino acids, pH, soluble solids (SS), titratable acidity (TA) and SS/TA ratio were evaluated. The sweet potato roots cv. BRS Rubissol present good potential for processing as fried chips. 1-MCP and AOA treatments reduced the root sprouting, physico-chemical quality was maintained in all treatments and the fried chips showed less browning in all treatments with storage. Since the sprouting process compromises the storage of roots, AOA and 1-MCP treatments may be applied to extend the shelf-life of roots and improve the processing potential.

Resumo A floricultura é uma atividade promissora e de grande importância econômica. Neste contexto, o cultivo de Lilium pumilum Redouté vem recebendo destaque. Contudo, uma das dificuldades enfrentadas pelos floricultores é que grande parte dos produtos se perde antes de chegar ao consumidor, devido às perdas pós-colheita. Tais empecilhos podem ser revertidos por meio de técnicas adequadas, como é o caso do uso de solução de condicionamento (pulsing), a qual tem sido eficaz no controle da senescência precoce. Diante disso, esse estudo teve como objetivo avaliar a influência da solução via pulsing de sacarose, ácido cítrico e tiossulfato de prata sobre a conservação pós-colheita de hastes florais de L. pumilum. Todos os tratamentos promoveram aumento de 1.8±0.3 dias na longevidade, uniformização da abertura floral e menor perda de massa fresca em relação ao controle. Não houve diferença significativa nos teores de clorofila e no teor relativo de água da folha. O tempo de exposição ao pulsing ocasionou diferenças significativas na redução dos teores de antocianina quando comparado ao controle, demonstrando que o uso de solução preservativa aplicada a partir de 6 h, em pulsing, proporciona aumento da vida de vaso para o L. pumilum.

Abstract Floriculture is a promising activity and has great economic importance. In this context, the cultivation of Lilium pumilum Redouté stands out. However, one of the main challenges flower farmers face is that a large part of the products is lost before reaching the final consumer, due to postharvest losses. Such losses can be minimized by adopting some techniques, such as the use of conditioning solution (pulsing), which has been effective in preventing early senescence. In this sense, this study aimed to evaluate the effect of pulsing with sucrose, citric acid and silver thiosulphate on postharvest conservation of L. pumilum cut flowers. All treatments promoted a 1.8±0.3 day increase in longevity, uniformity of floral opening, and reduced fresh weight loss compared to the control (flowers that were not pulse-treated). There was no significant difference in chlorophyll content and leaf relative water content. The time of exposure to pulsing caused significant differences in the reduction of anthocyanin contents when compared to the control, demonstrating that pulsing preservative solution for at least 6 h extends the vase life of L. pumilum cut flowers by two days.

Resumo O crisântemo faz parte do conjunto de plantas mais antigas a serem cultivadas pelo homem, possuindo grande área de produção de flores no Brasil. Diante de sua importância econômica e uso em melhoramento genético, o presente trabalho tem como objetivo caracterizar variedades de minicrisântemos, com ênfase em parâmetros morfológicos e fisiológicos. Para tanto, foram adquiridas no comércio local, quatro variedades de minicrisântemos em vaso: V1 - ‘Swifty Light Pink’ (lilás), V2 - ‘Diablo Time’ (vermelho), V3 - ‘White Cherie’ (branco); V4 - ‘Giovanni’ (amarelo), das quais foram retiradas amostras de folhas e inflorescências para a mensuração de altura; diâmetro; massa fresca, bem como quantificação do teor de açúcares solúveis totais (AST%), açúcares redutores (AR%) e açúcares não redutores (ANR%); teor de antocianina e clorofila. Quanto à caracterização das inflorescências, constatou-se que a ‘Diablo Time’ apresentou o maior diâmetro, altura e massa fresca, nestes dois últimos casos não diferindo de ‘Giovanni’, que apresentaram menor teor de antocianina; enquanto que os maiores valores de teor de carboidrato foram verificados em ‘White Cherie’. No que se refere à caracterização das folhas, ‘Giovanni’ apresentou as maiores dimensões, massa fresca e teor de clorofila. Enquanto ‘Swifty Light Pink’ se destacou quanto aos teores de açúcares. Assim, percebe-se que há diferenças morfofisiológicas entre as variedades de minicrisântemo, o que pode contribuir em programas de melhoramento genético.

Abstract Chrysanthemum is among the oldest plants cultivated by man, being widely cultivated in Brazil. In view of its economic importance and use in breeding, the present study aims to characterize mini chrysanthemum varieties, focusing on morphological and physiological parameters. Therefore, four varieties of mini chrysanthemums, in pots, were acquired in the local market: V1 - ‘Swifty Light Pink’ (purple), V2 - ‘Diablo Time’ (red), V3 - ‘White Cherie’ (white); V4 - ‘Giovanni’ (yellow), from which they were taken leaves and inflorescences samples for measurement of height, diameter and fresh mass, as well as to quantify the total soluble sugar (TSS, %), reducing sugar (RS, %), non-reducing sugar (NRS, %), anthocyanin and chlorophyll contents. Regarding the characterization of inflorescences, it was found that ‘Diablo Time’ had the largest diameter, height and fresh weight, in these last two cases not differing from ‘Giovanni’, which had lower anthocyanin content; while the highest values of carbohydrate content were found in ‘White Cherie’. In relation to the characterization of the leaves, ‘Giovanni’ had the largest dimensions, fresh mass and chlorophyll content. Already ‘Swifty Light Pink’ stood as to the sugar contents. Thus, it is clear that there are morphophysiological differences between the chrysanthemum mini varieties, which can contribute to breeding programs.

Abstract One of the major problems affecting potatoes quality on stored is the susceptibility to enzymatic browning, which occurs mainly after wounds during the harvest, at postharvest handling and by aging, leading to the development of dark color compounds. Enzymatic browning is associated with the action of polyphenoloxidases (PPO) and peroxidases (POD), which use phenolic compounds and oxygen as substrates. The products of these enzymes cause undesirable changes of color and flavor of processed potato products. The present study aimed to evaluate some kinetic properties based to optimum pH and reaction temperature, and to determine changes on activity of potato tubers PPO and POD treated with sprouting suppressors compounds menthol and eugenol. For each treatment, samples were collected in six different periods, before application (day 0) and 10, 20, 30, 40, and 50 days after the treatments to determine the influence of sprout inhibitors on the activity of PPO and POD. Changes in pH and temperature affected drastically the activity of both enzymes. The use of eugenol and menthol as sprouting suppressors decreased enzymatic activity on the treated tubers compared to control with an inverse relationship between enzymes activity and content of phenolic compounds.

RESUMEN En condiciones de cultivo que favorezca el crecimiento de la parte aérea de la planta, la adopción de prácticas de manejo que reduzca el tamaño de las plantas puede ser una alternativa para aumentar el rendimiento de los tubérculos. El objetivo de este trabajo fue evaluar el efecto del paclobutrazol sobre el crecimiento vegetativo y la partición de la materia seca de la planta de papa cv. Markies cultivado en verano en el estado de Minas Gerais, Brasil. Los tratamientos fueron 0,1; 1,0; 10 y 100 mg L-1 de paclobutrazol (PBZ) aplicado a las semillas germinadas antes de plantar y um control tratado con agua. PBZ fue eficiente em la reducción de la altura de la planta. Los tratamientos con dosis de 10 y 100 mg L-1 de PBZ retrasaron la aparición de la parte aérea y el comienzo de la tuberización de la planta. PBZ a 0,1 mg L-1 redujo la longitud del tallo en un 18%, pero no difirió con el control en relación al contenido de masa fresca y seca, la producción total, la gravedad específica y el contenido de almidón de los tubérculos. El tratamiento de tubérculos de papa con PBZ a 0,1 mg L-1 presentan plantas más pequeñas y compactas, que podrían ser adecuadas para una plantación más densa para maximizar la población de plantas y aumentar el rendimiento económico por unidad de área.

ABSTRACT Under cultivation conditions that favor the growth of plant shoots, the adoption of management practices that reduce the size of potato plants can be an alternative for increasing tuber yield. The objective of this study was to evaluate the effect of paclobutrazol on vegetative growth and dry matter partitioning in the potato plant cv. Markies, cultivated under summer conditions in the state of Minas Gerais. The treatments were 0.1, 1.0, 10 and 100 mg L-1 of paclobutrazol (PBZ), applied to sprouted seeds before planting and control with water. PBZ was efficient in reducing plant height. The PBZ treatments with doses of 10 and 100 mg L-1 delayed the emergence of shoots and the beginning of plant tuberization. PBZ at 0.1 mg L-1 reduced the lengh of the stem by 18% but did not differ from the control for the fresh and dry mass content, total production, specific gravity and starch content of tubers. The treatment with seed potatoes and PBZ at 0.1 mg L-1 resulted in smaller, more compact plants, which could be suitable for more densely planted cultivations in order to maximize plant populations and increase economic return per unit of area.

ABSTRACT. The increased demand for potato by the Brazilian processing industry requires long term refrigerated storage, but after a few months, natural dormancy ends, and sprouts start to grow. Thus, sprout inhibitors are necessary to reduce the rate of growth and allow further storage. The purpose of research described here was to determine the effects clove and menthol essential oils have on the inhibition of sprout growth in non-dormant ‘Asterix’ tubers. Both eugenol and menthol treatments reduced the rate of sprout growth during storage at 8oC for up to 50 days. Eugenol and menthol essential oils diminished the rate of accumulation of reducing sugar, which are responsible for browning of French fries. Color after frying was within acceptable levels when the tubers were treated with eugenol or menthol essential oils.

RESUMO A demanda por flores e plantas ornamentais tem apresentado aumento significativo nos últimos anos, entretanto, a produção de tais espécies, na maioria das vezes, vem acompanhada do manuseio pós-colheita inadequado, que é responsável por perdas significativas das flores que são comercializadas. Dentre as espécies ornamentais com potencial econômico como flor de vaso ou corte, destaca-se Lilium pumilum, pertencente à família Liliaceae, que se caracteriza por apresentar hastes longas contendo inflorescências alaranjadas com diversos botões florais, folhas numerosas, lisas e lineares. Devido à alta perecibilidade desse produto, a utilização de técnicas adequadas que possibilitem prolongar a longevidade das flores é necessária. Este trabalho teve como objetivo avaliar a influência do ácido salicílico sobre a conservação pós-colheita de hastes florais de L. pumilum. Para avaliar tal efeito, as hastes foram mantidas em diferentes concentrações de ácido salicílico (0, 1, 5 e 10mM) em solução de manutenção, durante 0, 6, 12, 18 e 24 horas. As flores de L. pumilum apresentaram redução na longevidade de 57,8 e 63,1% quando mantidas em 5 e 10mM de ácido salicílico, respectivamente, comparadas ao controle. Este efeito pode estar associado ao decréscimo observado na porcentagem de abertura floral e teor de clorofila, bem como ao tombamento das hastes, demonstrando fitotoxidade. Portanto, o uso das concentrações 5 e 10 mM de ácido salicílico é ineficiente para prolongar a longevidade de L. pumilum nas condições do experimento.

ABSTRACT The demand for flowers and ornamental plants has significantly increased in recent years. However, in most cases, the production of such species is accompanied by inappropriate postharvest handling, which is responsible for significant losses of marketed flowers. Lilium pumilum, a member of the family Liliaceae, is one of the ornamental species with economic potential as potted or cut flower, which features long stalks containing orange inflorescences with several flower buds and numerous smooth as well as linear leaves. Due the high perishability of this product, appropriate techniques that extend flower longevity should be employed. The present study was developed to evaluate the effect of salicylic acid (SA) on the postharvest preservation of L. pumilum inflorescences. Stalks were kept in maintenance solution with different concentrations of SA (0, 1, 5 and 10 mM) for 0, 6, 12, 18 and 24 h. The L. pumilum flowers had longevity decreased by 57.8 and 63.1% when kept in 5 and 10 mM SA, respectively, compared with control. This effect may be associated with the observed decrease in the percentages of flower opening and chlorophyll content as well as the damping-off of stalks, indicating phytotoxicity. Therefore, the use of 5 and 10 mM SA is inefficient to extend the longevity of L. pumilum.

RESUMO: Normalmente, não é recomendado o condicionamento de hastes de gladíolo em água durante o armazenamento ou transporte. A hidratação das pétalas acelera a abertura das flores, mesmo em baixa temperatura, o que compromete a qualidade no momento da comercialização. No entanto, para essa espécie, ainda não foi estudado o efeito do armazenamento refrigerado prolongado a seco e nem o seu comportamento quando transferida para a água em temperatura ambiente. O presente estudo teve como objetivo avaliar a vida de vaso e a capacidade de reidratação de hastes florais de gladíolo após armazenamento a seco em baixa temperatura ( Gladiolus grandiflora Hort.). As hastes das cultivares Blue Frost, Gold Field, Traderhorn e Jester foram armazenadas a seco em temperatura de 5 ± 1 ºC e umidade relativa de 85% por 12, 24, 36 e 48 horas. As hastes controle permaneceram sempre em água deionizada. Após armazenamento, retornaram a água sob condição de temperatura ambiente (22 ± 1 ºC) e foram avaliadas quanto à vida de vaso (adotando o critério de descarte quando 50% das flores basais apresentaram perda de coloração e murcha), variação da massa de matéria fresca (%), taxa de absorção de água e taxa transpiratória, bem como o teor relativo de água das pétalas (%). Em condições de armazenamento a seco em baixa temperatura, por até 36 horas, a vida de vaso não foi afetada, embora tenha ocorrido reidratação incompleta das flores. A capacidade de reidratação da haste está relacionada com a abertura escalonada das flores ao longo da inflorescência.

ABSTRACT: Normally, it is not recommended the conditioning of gladiolus stems in water during storage or transport. Hydration of petals may accelerate flower opening, even at a low temperature, which compromises quality at marketing moment. However, for this species, neither the effect of prolonged dry cold storage nor its behavior when transferred to water at room temperature has been evaluated. The present study aimed to evaluate the vase life and the rehydration capacity of gladiolus flowers ( Gladiolus grandiflora Hort.) after dry storage at low temperature. Flower stems of cultivars Blue Frost, Gold Field, Traderhorn, and Jester were dry-stored at a temperature of 5 ± 1 ºC and relative humidity of 85% for 12, 24, 36, and 48h. Control stems remained always in deionized water. After storage, they were returned to the water at room temperature and evaluated for vase life (adopting the discard criterion when 50% of the basal flowers displayed loss of color and wilting), fresh weight change (%), water uptake rate and transpiration rate, as well as relative water content of the petals (%). In dry cold storage conditions, for up to 36h, the vase life was not affected although incomplete rehydration of the flowers. Rehydration capacity of the stem is linked to the staggered opening of flowers along the inflorescence.

RESUMO: Lilium pumilum é uma espécie que se destaca na floricultura, por apresentar inflorescências alaranjadas que atraem o consumidor. Assim, este trabalho teve como objetivo caracterizar o metabolismo de carboidrato de estruturas florais de L. pumilum em diferentes estádios de desenvolvimento. Para isso, os níveis de carboidratos (açúcares solúveis totais, açúcares redutores, açúcares não redutores e amido), em diferentes estádios florais (E0 - botão sem coloração; E1 - botão em início de coloração; E2 - botão alaranjado; E3 - flor aberta; E4 - flor senescente), foram quantificados a partir da extração com etanol. As flores de L. pumilum apresentaram um alto potencial energético durante a abertura floral e senescência, sendo os açúcares solúveis totais os principais carboidratos presentes na espécie, mas com redução de acordo com o desenvolvimento floral, o mesmo ocorrendo com os teores de açúcar não redutor e amido. O conteúdo de açúcar redutor foi crescente entre os estádios florais. Portanto, a espécie apresenta grande mobilização de compostos, os quais são utilizados na produção de energia, que é empregada na abertura floral.

ABSTRACT: Lilium pumilum is a species that stands out in floriculture for presenting orange inflorescences that attract the consumer. This study thus aimed at characterizing the carbohydrate metabolism of floral structures of L. pumilum in different development stages. For this purpose, carbohydrate levels (total soluble sugars, reducing sugars, non-reducing sugars, and starch), at different floral stages (E0 - bud with no color; E1 - bud at early coloring; E2 - orange bud; E3 - open flower; E4 - senescent flower) were quantified after extraction with ethanol. Lilium pumilum flowers showed high energy potential during floral opening and senescence; total soluble sugars were the main carbohydrates present in the species, reducing with the floral development, and the same occurred with the non-reducing sugar and starch contents. The reducing-sugar content increased with the floral stages. Therefore, this species presents great mobilization of compounds, which are utilized in the production of energy that is employed in floral opening.