RESUMO: Objetivou-se com este estudo verificar a eficiência do 1,4-dimetilnaftaleno na supressão da brotação e a consequente manutenção da qualidade de tubérculos de batata das cultivares Asterix e Challenger, em diferentes temperaturas e tempos de armazenamento. Foram testados seis tratamentos, com e sem 1,4-DNM, nas temperaturas de 8 °C e 20 °C. As avaliações foram feitas aos 0, 45, 90, 135 e 180 dias após a aplicação. Os parâmetros avaliados foram: número de brotos, teores de açúcares solúveis totais, teores de açúcares redutores, e não redutores, e coloração dos palitos de batata após a fritura. Os efeitos do 1,4-DMN no controle da qualidade das batatas resultaram no controle da brotação e em menores teores de açúcares solúveis totais e de açúcares redutores, sobretudo na cultivar Challenger e à temperatura de 20 ºC.

ABSTRACT: The aim of this study was to verify the efficiency of 1,4-dimethylnapthalene in suppressing sprouting and the consequent maintenance of the quality of potato tubers of Asterix and Challenger cultivars, at different temperatures and storage regimes. Six treatments were tested, with and without 1.4-DNM, at temperatures of 8 ° C and 20 ° C. Assessments were made at 0, 45, 90, 135 and 180 days after application. The parameters evaluated were: number of sprouts, levels of total soluble sugars, levels of reducing and non-reducing sugars and coloration of potato strips after frying. The effects of 1.4-DMN on the quality control of potatoes resulted in sprout control and lower levels of total soluble sugars and reducing sugars, especially in the Challenger cultivar and at a temperature of 20 ºC.

Abstract The banana is one of the most consumed fruits in the world, but it has little shelf life due to its high water activity. Drying is able to increase shelf life and pre-treatments can optimize the process. The objective was to study the solar drying kinetics and evaluate the effect of pre-treatments on the drying kinetics and physico-chemical quality of 'Prata' bananas. The drying was carried out in a solar dryer and the pre-treatments consisted of immersing the samples in solutions of water, citric acid (1%) and lemon juice (10%). Water loss, drying kinetics, mathematical models and physical-chemical and colorimetric characteristics of fresh and dried bananas were evaluated. The drying rate was higher at the beginning and stabilized after 20 hours. The mathematical model of Midilli and Kucuk was the one that best fit the experimental data. The water content, ascorbic acid and the parameters L *, b *, C * and h ° reduced after drying. Reducing sugars and a * coordinate increased and the acidity was not changed with drying. The solar drying of 'Prata' bananas is a sustainable and economical way to make a product available with a longer shelf life.

Abstract Changes in the population's eating habits have expanded the French fries market. However, the need for refrigerated storage to supply sprouts and maintain a constant supply to the industry has led to a reduced number of cultivars suitable for processing due to the accumulation of sugars and browning after frying. Because of this, the objective of this study was to evaluate the suitability of the Donata and BRS F132 cultivars for use in the pre-fried potato processing industry. The tubers were stored at 6 and 8 °C for up to 180 days and the analysis of sprouting, total soluble sugar (TSS), reducing sugar (RS), non-reducing sugar (NRS), post-frying color by scale visual color used by the industry and L* and b* parameters. The sprouting was higher at 8 °C and in the BRS F 132 cultivar. The sugar content was high in both cultivars, however, the color remained adequate. It is concluded that the Donata and BRS F132 cultivars are suitable for the potato processing industry, and Donata presented better quality parameters. Conditioning at 8 °C is recommended in both cultivars that maintained the quality for 180 days.

Abstract This work aimed to analyze 1,4-DMN efficiency in the suppression of sprouting and the consequent maintenance of quality in potato tubers of Asterix and Challenger cultivars stored during different periods under varying temperatures: eight treatments with and without 1,4-DMN under temperatures of 8 °C and 20 °C. Treatments effect were evaluated after 0, 45, 90, 135 and 180 days after application. The evaluated parameters were the loss of fresh mass, length of the sprouts and activity of the enzymes polyphenoloxidase and peroxidase. The results indicate that the application of 1,4-DMN reduces the loss of fresh mass, this effect was more intense for the cultivar Challenger, at 8 °C. There were also significant effects in reducing the average length of the sprouts for both cultivars evaluated, after 180 days, at 20 °C. There was little or no difference in the level of oxidative stress caused in the tubers. Hence, the effects of 1,4-DMN on the quality control of potatoes included reduced loss of fresh mass and a shorter average length of sprouts for both cultivars evaluated compared to control, for both temperatures. These effects intensify in the cultivar Challenger and treatments with temperatures of 20 °C.

ABSTRACT. Excoriation damage is among the major causes of postharvest potato losses. Curing is known to increase the resistance of tubers to excoriation injury, with the temperature influencing the traumatic phellogen and periderm regeneration, as well as tuber processing quality. This study aimed to evaluate the effects of excoriation procedure and curing temperature on the industrial quality, histological characteristics, carbohydrate metabolism, and oxidative enzyme activity of potato tuber. Tubers with or without excoriation were cured at 8, 14, and 20°C for 15 days. Excoriation did not influence the levels of reducing sugars (RS), as well as polyphenoloxidase (PPO) and peroxidase (POD) activities. The concentrations of total soluble sugars (TSS) and non-reducing sugars (NRS) were higher in injured tubers, while reduction in curing temperature increased the concentrations of TSS, NRS, and RS. However, the sugar content was adequate as per the criteria of the pre-fried potato industry and potatoes classified in category 2 (USDA/fast-food industry color grading). The reduction in curing temperature also increased the activity of POD, despite the activity of PPO remaining unchanged. Formation of a closure layer from the outer parenchyma cells of the tuber that prevents desiccation and death of superficial cells, was observed. This protection was completed with the formation of the damage periderm. Periderm regeneration is faster at higher temperatures, 15 and 20°C, leading to a lower fresh mass loss and no enzymatic or non-enzymatic browning. The excoriation carried out at 14/20oC for 15 days was sufficient for curing, and for maintaining suitable post-fry quality of potatoes.

Abstract The objective of this study was to determine the storage efficiency and reconditioning of potato cv. Innovator for processing. Tubers were stored at 6, 7 and 8 °C in the dark for 30, 60, 90, 120 and 150 days and reconditioned at 15 °C for 15 days. TRS and RS were reduced as storage temperature increased from 6 + 15 °C to 8 + 15 °C. Regardless of temperature and storage time, sugar contents were suitable for industry; however non-enzymatic browning remained in category 2 for up to 60, 90 and 150 days in tubers stored at 6 + 15 °C, 7 + 15 °C and 8 + 15 °C, respectively. Starch was influenced by storage time, despite the absence of temperature effect. Regardless of the temperature, sprouting started at 90 days, but the growth of shoots was directly proportional to the increase in temperature. The PPO and POD increased at the beginning of storage but did not cause darkening before the frying. Reduction in storage temperature followed by reconditioning did not delay the onset of sprouting, but reduced the size of sprouts, maintained adequate sugar levels, however it promoted non-enzymatic browning.

Abstract Thus, the objective of the research was to evaluate the initial growth and development of seedlings under Platymiscium floribundum at different levels of luminosity. The experimental design was completely randomized in a 4 x 10 factorial scheme (four levels of shade: full sun, 50%, 65% and 80% with ten replications per treatment. The height, number of leaves was evaluated monthly. At the end of the experiment at 180 days, leaf dry matter, stems, roots, and dry matter. In addition, measurements were made of the variables related to gas exchange and plant anatomy of leaves. The results obtained were observed higher growth and developed satisfactorily at full sun), without presenting morphological changes. For the gas exchange did not differ statistically. It is concluded that the initial growth of P. floribundum seedlings was superior in the light level in full sun, providing favorable conditions for their development.

RESUMO: As batatas destinadas ao processamento industrial devem ter alto teor de matéria seca, baixo teor de açúcar e estar livre de danos ou doenças. O objetivo foi determinar a temperatura e o período de armazenamento ideais para cultivares comerciais para fritura. Os tubérculos das cultivares Asterix e Cronos foram armazenados em caixas de plástico a 6 e 8 °C com umidade de 85 a 95% por 180 dias. As perdas de massa acumulada (PMA), sólidos insolúveis em álcool (SIA), açúcares solúveis totais (AST), açúcares não redutores (ANR), açúcares redutores (AR), atividade de polifenoloxidase (PPO) e escurecimento enzimático e não enzimático foram analisadas. A PMA de tubérculos da cultivar Asterix a 6 e 8 ºC e a da cultivar Cronos, armazenadas a 6 °C foram maiores. Os teores de SIA foram menores e os de AST, AR e ANR maiores nos tubérculos de ambas as cultivares armazenadas a 6 ºC. A temperatura e o período de armazenamento não afetaram as cultivares Cronos e Asterix. O escurecimento foi maior nos palitos fritos das cultivares Asterix e Cronos armazenados a 6 ºC (4 a 5) por 60 e 90 dias e a 8 °C (2 a 3) por 180 dias, respectivamente. O período ideal de temperatura e armazenamento para as cultivares Asterix e Cronos é de 8 ºC por, no máximo, 120 dias devido ao escurecimento não enzimático.

ABSTRACT: Potatoes for industrial processing must have high dry matter, low sugar and free from damage or disease. The objective was to determine the ideal temperature and storage period of commercial cultivars for frying. Tubers of Asterix and Cronos cultivars were stored in a cold chamber (Gallant CMC4 Premium) inside plastic boxes at 6 and 8 °C with 85 to 95% humidity for 180 days. Accumulated mass loss (PMA), alcohol insoluble solids (SIA), total soluble sugars (AST), non-reducing sugars (ANR), reducing sugars (AR), polyphenoloxidase activity (PPO) and enzymatic and non-enzymatic browning were analyzed. The PMA of Asterix at 6 and 8 ºC and Cronos at 6 °C was higher. The SIA of both cultivars stored at 6 ºC were lower and AST, AR and ANR higher. Those parameters of Cronos and Asterix did not differ between temperature or storage period. The browning was greater in the fried sticks of Asterix and Cronos stored at 6 ºC (4 to 5) for 60 and 90 days and at 8 °C (2 to 3) for 180 days, respectively. The ideal temperature and storage period for Asterix and Cronos cultivars is 8 ºC for a maximum of 120 days due to non-enzymatic browning.

RESUMO: O milho-pipoca (Zea mays var. everta) tem um valor comercial mais elevado do que o milho comum e é um alimento popular entre os consumidores. Hoje, existe uma constante busca por cultivares com desempenho superior para os diversos caracteres de interesse, no caso da pipoca, produtividade e capacidade de expansão. O trabalho propõe caracterizar progênies de milho-pipoca com diferentes valores de capacidade de expansão quanto à composição química e micromorfologia. Foram estudados grãos do quinto ciclo (C5) de seleção recorrente intrapopulacional. As progênies foram selecionadas com base nos valores de capacidade de expansão de seus grãos. Os grãos foram quantificados para amilose e analisados quanto ao arranjo dos grânulos de amido e espessura do pericarpo por microscopia eletrônica de varredura. Progênies com baixa capacidade de expansão (0 e 7 mL g-1) apresentaram teor de amilose de 21,24 e 20,18% respectivamente; endosperma menos compacto, com grânulos de amido individualizados e intercalados com espaços vazios; e espessura do pericarpo medindo entre 40,94 e 38,99 µm, respectivamente. Por outro lado, progênies com alta capacidade de expansão (30 e 35 mL g-1) apresentaram teor de amilose de 23,92 e 26,10%, endosperma vítreo, sendo os grânulos de amido mais compactos e sem espaços vazios entre eles; e espessura do pericarpo medindo entre 107,66 e 107,84 µm. Progênies com altos valores de capacidade de expansão apresentam maior espessura de pericarpo, alta porcentagem de amilose e endosperma mais compactado, enquanto as com menores valores de expansão, apresentam menor espessura do pericarpo, menor porcentagem de amilose e grânulos de amido individualizados.

ABSTRACT: Popcorn (Zea mays var. everta) has a higher commercial value than common maize, in addition to being a popular food among consumers. Today, there is a constant search for cultivars with superior performance for several traits of interest in the case of popcorn, yield and popping expansion. On this basis, this project proposes to characterize progenies of popcorn with different values of expansion capacity regarding chemical composition and micromorphology. Kernels from the fifth cycle (C5) of intrapopulation recurrent selection were evaluated. The progenies were selected based on the popping expansion volume of their kernels. The kernels were quantified for amylose and analyzed for starch granule arrangement and pericarp thickness by scanning electron microscopy. Progenies with low popping expansion volume (0 and 7 mL g-1) showed amylose contents of 21.24 and 20.18%, respectively; a less compact endosperm, with individual starch granules interspaced with empty spaces; and pericarp thickness between 40.94 and 38.99 µm, respectively. By contrast, progenies with high popping expansion volume (30 and 35 mL g-1) showed amylose contents of 23.92 and 26.10%; a vitreous endosperm; more-compact starch granules without empty spaces in between; and pericarp thickness between 107.66 and 107.84 µm. Progenies with higher popping expansion volume exhibited a thicker pericarp, a high amylose percentage and a more-compact endosperm, whereas those with the lower expansion volumes showed a thinner pericarp, a lower amylose percentage and individual starch granules.