Hybrid cultivars of pear in subtropics regions: processing ability in the form of jelly / Cultivares de peras híbridas em regiões subtropicais: aptidão para processamento na forma de geleia

The aim of this study was to characterize five different hybrid cultivars pears (‘Tenra, ‘Centenária, ‘Cascatence, ‘Primorosa and ‘Seleta) deployed in subtropical regions of Brazil regarding its physicochemical characteristics, bioactive compounds and antioxidant activity, as well as to evaluate the influence of these cultivars on the characteristics physicochemical, rheological properties and sensory acceptance of the obtained jelly, for identifying varieties with higher potential for industrial use. Regardingthe bioactive compounds and antioxidant activity it was observed that ‘Seleta cultivar was characterized by a higher phenolic content (57.68mg GAEs 100g-1), higher antioxidant activity (13.56% of DPPH sequestration and 1.25μM of trolox g -1) and higher content of vitamin C (3.59mg 100g-1). As the acidity, it ranged from 4.09 to 5.81 g of malic acid 100g-1 (‘Tenra and ‘Seleta, respectively). Regarding color, the color parameter L* varied from 32.14 to 36.83, a* ranged from 2.87 to 5.20, b* ranged from 16.57 to 20.42, Chroma ranged from 16.67 to 21.02 and °Hue ranged from 74.94 to 80.18. Regarding the texture, the jellies produced from ‘Centenária and ‘Tenra were characterized by having the highest values of hardness (1.21 and 1.23N, respectively), gumminess (0.42 and 0.45, respectively) and chewiness (0.40 and 0.45N, respectively). The jelly obtained from the ‘Centenária still showed the highest adhesiveness (2.27N s-1) and springiness (0.99). Already jellies prepared by ‘Cascatence showed the highest cohesiveness values (0.68). The jellies prepared with different pear cultivars showed good sensory acceptance for all measured properties, with average scores ranging between the hedonic terms “liked slightly” to “liked very much”. Cultivars of subtropical pear trees present different physicochemical characteristics, resulting in jellies with different physicochemical characteristics and rheological properties...(AU)

O objetivo deste estudo foi caracterizar cinco diferentes cultivares híbridas de peras (‘Tenra, ‘Centenária, ‘Cascatence, ‘Primorosa e ‘Seleta) implantadas em regiões subtropicais do Brasil quanto as caracteristicas físico-química, compostos bioativos e atividade antioxidante, bem como avaliar a influência destas cultivares sobre as características físico-químicas, propriedades reológicas e aceitação sensorial da geleia obtida, para identificação de cultivares com maior potencial para a utilização industrial. Com relação aos compostos bioativos e atividade antioxidante, pode-se observar que a cultivar ‘Seleta caracterizou-se pelo maior teor de fenólicos (57,68mg GAEs 100 g-1), maior atividade antioxidante (13,56% de sequestro de DPPH e 1,25μM de trolox g-1) e se destaca devido ao seu maior teor de vitamina C (3,59mg 100g-1). A acidez, variou de 4,09 a 5,81g de ácido málico 100 g-1 (‘Tenra e ‘Seleta, respectivamente). Em relação à cor, o parâmetro de cor L* variou de 32,14 a 36,83, a* variou de 2,87 a 5,20, b* variou de 16,67 a 20,42, Chroma variou de 16,57 a 21,02 e °Hue variou de 74,94 a 80,18. Em relação à textura, as geleias produzidas a partir de ‘Centenária e ‘Tenra caracterizam-se por apresentar os maiores valores de dureza (1,21 e 1,23N, respectivamente), gomosidade (0,42 e 0,45N, respectivamente) e mastigabilidade (0,40 e 0,45, respectivamente). A geleia obtida da ‘Centenária ainda apresentava a maior adesividade (2,27N s-1) e a elasticidade (0,99). Já as geleias preparadas com a ‘Cascatence apresentaram os maiores valores de coesividade (0,68). As geleias preparadas com diferentes cultivares de pera mostraram boa aceitação sensorial para todas as propriedades avaliadas, com notas médias variando entre os termos hedônicos “gostei ligeiramente” e “gostei muito”...(AU)

Hybrid cultivars of pear in subtropics regions: processing ability in the form of jelly / Cultivares de peras híbridas em regiões subtropicais: aptidão para processamento na forma de geleia

ABSTRACT: The aim of this study was to characterize five different hybrid cultivars pears ('Tenra', 'Centenária', 'Cascatence', 'Primorosa' and 'Seleta') deployed in subtropical regions of Brazil regarding its physicochemical characteristics, bioactive compounds and antioxidant activity, as well as to evaluate the influence of these cultivars on the characteristics physicochemical, rheological properties and sensory acceptance of the obtained jelly, for identifying varieties with higher potential for industrial use. Regardingthe bioactive compounds and antioxidant activity it was observed that 'Seleta' cultivar was characterized by a higher phenolic content (57.68mg GAEs 100g-1), higher antioxidant activity (13.56% of DPPH sequestration and 1.25µM of trolox g -1) and higher content of vitamin C (3.59mg 100g-1). As the acidity, it ranged from 4.09 to 5.81 g of malic acid 100g-1 ('Tenra' and 'Seleta', respectively). Regarding color, the color parameter L* varied from 32.14 to 36.83, a* ranged from 2.87 to 5.20, b* ranged from 16.57 to 20.42, Chroma ranged from 16.67 to 21.02 and °Hue ranged from 74.94 to 80.18. Regarding the texture, the jellies produced from 'Centenária' and 'Tenra' were characterized by having the highest values of hardness (1.21 and 1.23N, respectively), gumminess (0.42 and 0.45, respectively) and chewiness (0.40 and 0.45N, respectively). The jelly obtained from the 'Centenária' still showed the highest adhesiveness (2.27N s-1) and springiness (0.99). Already jellies prepared by 'Cascatence' showed the highest cohesiveness values (0.68). The jellies prepared with different pear cultivars showed good sensory acceptance for all measured properties, with average scores ranging between the hedonic terms "liked slightly" to "liked very much". Cultivars of subtropical pear trees present different physicochemical characteristics, resulting in jellies with different physicochemical characteristics and rheological properties. Processing in the form of jelly is extremely viable due to the good acceptance by consumers of all formulations elaborated.

RESUMO: O objetivo deste estudo foi caracterizar cinco diferentes cultivares híbridas de peras ('Tenra', 'Centenária', 'Cascatence', 'Primorosa' e 'Seleta') implantadas em regiões subtropicais do Brasil quanto as caracteristicas físico-química, compostos bioativos e atividade antioxidante, bem como avaliar a influência destas cultivares sobre as características físico-químicas, propriedades reológicas e aceitação sensorial da geleia obtida, para identificação de cultivares com maior potentcial para a utilização industrial. Com relação aos compostos bioativos e atividade antioxidante, pode-se observar que a cultivar 'Seleta' caracterizou-se pelo maior teor de fenólicos (57,68mg GAEs 100 g-1), maior atividade antioxidante (13,56% de sequestro de DPPH e 1,25μM de trolox g-1) e se destaca devido ao seu maior teor de vitamina C (3,59mg 100g-1). A acidez, variou de 4,09 a 5,81g de ácido málico 100 g-1 ('Tenra' e 'Seleta', respectivamente). Em relação à cor, o parâmetro de cor L* variou de 32,14 a 36,83, a* variou de 2,87 a 5,20, b* variou de 16,67 a 20,42, Chroma variou de 16,57 a 21,02 e °Hue variou de 74,94 a 80,18. Em relação à textura, as geleias produzidas a partir de 'Centenária' e 'Tenra' caracterizam-se por apresentar os maiores valores de dureza (1,21 e 1,23N, respectivamente), gomosidade (0,42 e 0,45N, respectivamente) e mastigabilidade (0,40 e 0,45, respectivamente). A geleia obtida da 'Centenária' ainda apresentava a maior adesividade (2,27N s-1) e a elasticidade (0,99). Já as geleias preparadas com a 'Cascatence' apresentaram os maiores valores de coesividade (0,68). As geleias preparadas com diferentes cultivares de pera mostraram boa aceitação sensorial para todas as propriedades avaliadas, com notas médias variando entre os termos hedônicos "gostei ligeiramente" e "gostei muito". As cultivares de pereiras subtropicais apresentam características físico-químicas diferentes, resultando em geleias com características físico-químicas e propriedades reológicas distintas. O processamento sob a forma de geleia é extremamente viável devido à boa aceitação por parte dos consumidores de todas as formulações elaboradas.

Free amino acids in the xylem sap of pear trees during dormancy / Aminoácidos livres na seiva do xilema de pereiras durante a dormência

Storage and remobilization are considered key processes for the effective use of nitrogen in temperate fruit trees. As dormancy begins, storage proteins are synthesized, coinciding with a reduction in the levels of free amino acids. Consequently, as dormancy breaks, these storage proteins are degraded, and an increase in the concentrations of amino acids occurs, in order to support new growth. The objective of this study was to evaluate water content of different vegetative tissues (buds, bark, and bole wood), volume of xylem sap, and free amino acid concentrations of xylem sap, during winter dormancy of Hosui Japanese pear trees (VL). Plant material was obtained from the Embrapa Temperate Climate experimental orchard at Pelotas, in the state of Rio Grande do Sul, Brazil. Xylem sap was extracted from the branches with the aid of a vacuum pump, and the free amino acids were determined by gas chromatography, using the EZ kit: Faast GC/FID (Phenomenex). Water content of buds, as well as the volume of sap and concentrations of both aspartic acid and asparagine, substantially increased over time, reaching maximum values in the phase preceding sprouting.(AU)

A capacidade de armazenamento e a remobilização de nitrogênio são consideradas processos-chave para o uso eficiente desse macronutriente em plantas frutíferas de clima temperado. Na fase de indução à dormência, ocorre a síntese de proteínas de reserva, coincidindo com a redução nos teores de aminoácidos livres. Entretanto, na fase de superação da dormência, ocorre a degradação dessas proteínas e o aumento nas concentrações de aminoácidos para suprir um novo ciclo de crescimento. O objetivo deste trabalho foi avaliar o conteúdo de água em diferentes tecidos vegetativos (gemas, casca e lenho), o volume de seiva xilemática e suas respectivas concentrações de aminoácidos livres durante o período de dormência de pereiras japonesas cv. 'Hosui'. O material vegetal pertence ao pomar experimental da Embrapa Clima Temperado de Pelotas/RS. A seiva do xilema foi extraída dos ramos com auxílio de bomba de vácuo e os aminoácidos livres foram determinados por cromatografia gasosa, utilizando-se o kit EZ: Faast GC/FID (Phenomenex). O conteúdo de água, bem como o volume e as concentrações de ácido aspártico (Asp) e asparagina (Asn) da seiva do xilema aumentaram substancialmente, atingindo valores máximos na fase que antecede a brotação.(AU)

Free amino acids in the xylem sap of pear trees during dormancy / Aminoácidos livres na seiva do xilema de pereiras durante a dormência

ABSTRACT: Storage and remobilization are considered key processes for the effective use of nitrogen in temperate fruit trees. As dormancy begins, storage proteins are synthesized, coinciding with a reduction in the levels of free amino acids. Consequently, as dormancy breaks, these storage proteins are degraded, and an increase in the concentrations of amino acids occurs, in order to support new growth. The objective of this study was to evaluate water content of different vegetative tissues (buds, bark, and bole wood), volume of xylem sap, and free amino acid concentrations of xylem sap, during winter dormancy of Hosui Japanese pear trees (VL). Plant material was obtained from the Embrapa Temperate Climate experimental orchard at Pelotas, in the state of Rio Grande do Sul, Brazil. Xylem sap was extracted from the branches with the aid of a vacuum pump, and the free amino acids were determined by gas chromatography, using the EZ kit: Faast GC/FID (Phenomenex). Water content of buds, as well as the volume of sap and concentrations of both aspartic acid and asparagine, substantially increased over time, reaching maximum values in the phase preceding sprouting.

RESUMO: A capacidade de armazenamento e a remobilização de nitrogênio são consideradas processos-chave para o uso eficiente desse macronutriente em plantas frutíferas de clima temperado. Na fase de indução à dormência, ocorre a síntese de proteínas de reserva, coincidindo com a redução nos teores de aminoácidos livres. Entretanto, na fase de superação da dormência, ocorre a degradação dessas proteínas e o aumento nas concentrações de aminoácidos para suprir um novo ciclo de crescimento. O objetivo deste trabalho foi avaliar o conteúdo de água em diferentes tecidos vegetativos (gemas, casca e lenho), o volume de seiva xilemática e suas respectivas concentrações de aminoácidos livres durante o período de dormência de pereiras japonesas cv. 'Hosui'. O material vegetal pertence ao pomar experimental da Embrapa Clima Temperado de Pelotas/RS. A seiva do xilema foi extraída dos ramos com auxílio de bomba de vácuo e os aminoácidos livres foram determinados por cromatografia gasosa, utilizando-se o kit EZ: Faast GC/FID (Phenomenex). O conteúdo de água, bem como o volume e as concentrações de ácido aspártico (Asp) e asparagina (Asn) da seiva do xilema aumentaram substancialmente, atingindo valores máximos na fase que antecede a brotação.

Aumento da produção de pereira asiática pelo uso de fitorreguladores / Fruit production increase in Asian pear trees by use of plant growth regulators

A baixa frutificação de pereiras nas condições do Sul do Brasil é um dos limitantes à produção da cultura no país, podendo o problema ser minimizado pelo uso de fitorreguladores. Objetivou-se avaliar a efetividade de diferentes fitorreguladores e a combinação dessas substâncias no aumento da frutificação de pereira asiática 'Shinseiki. A aplicação dos fitorreguladores foi realizada quando as pereiras atingiram o estádio de plena floração. O delineamento experimental foi em blocos casualizados, com quatro repetições de uma planta, sendo avaliados os seguintes tratamentos: 1. testemunha (sem aplicação); 2. thidiazuron (TDZ) 20mg L-1; 3. ácido giberélico (AG) 20mg L-1; 4. proexadione cálcio (PCa) 600mg L-1; 5. PCa 600mg L-1 + TDZ 20mg L-1; 6. PCa 600mg L-1 + AG 20mg L-1; e 7. AG 20mg L-1 + TDZ 20mg L-1. Os fitorreguladores thidiazuron e ácido giberélico, e a combinação dessas substâncias, ambos na concentração de 20mg L-1, quando aplicados na floração, determinam aumento significativo da frutificação e da produção de peras 'Shinseiki'. A utilização do proexadione cálcio na floração, tanto isoladamente quanto associado ao thidiazuron e ao ácido giberélico, não repercutiu no aumento da frutificação.

The low fruit set in the Southern Brazil conditions is one of the limiting factors to pear production in the country. The use of plant growth regulators may minimize this problem. This study was carried out aiming to evaluate the effectiveness of different growth regulators and the combination of these substances on fruit set increase of 'Shinseiki Asian pears. The application of growth regulators was performed when the pears have reached the full bloom stage. The experimental design was randomized blocks with four replications of one tree, with the following treatments: 1. control (no application); 2. thidiazuron (TDZ) 20mg L-1; 3. gibberellic acid (GA) 20mg L-1; 4. prohexadione calcium (PCa) 600mg L-1; 5. PCa 600mg L-1 TDZ + 20mg L-1; 6. PCa 600mg L-1 + AG 20mg L-1; and 7. AG 20mg L-1 + TDZ 20mg L-1. When sprayed on full bloom stage, thidiazuron and gibberellic acid, and combinations of these substances, both at a concentration of 20mg L-1, increased significantly the fruit set and the fruit production of 'Shinseiki' pears. The use of prohexadione calcium, single or in combination with thidiazuron and gibberellic acid, did not increase the fruit production.

Chilling privation during dormancy period and carbohydrate mobilization in Japanese pear trees

The flower bud abortion is one of the main problems that limit commercial pear (Pyrus pyrifolia) production in the southern region of Brazil. Insufficient chilling during the dormancy period is known as the main factor of this problem. One of the hypotheses to explain this problem is that the starch mobilization and carbohydrate fluxes to the buds are impeded when mild temperatures occurred during winter. This study compared the total soluble sugars (TSS) and reducing sugars (RS) concentrations, the cell wall acid invertase (CWAI - EC 3.2.1.26) and sucrose-phosphate synthase (SPS - EC 2.4.1.14) activities in wood of branches and floral buds of Japanese pear trees cv. Housui, grafted on Pyrus calleryana and submitted to chilling conditions during the dormancy period. Treatments were: (i) natural conditions; (ii) continuous artificial chilling; (iii) alternating temperatures, and (iv) total chilling privation. TSS and RS contents, as well as CWAI and SPS activities in tissues of branches that received insufficient chilling were lower than those that received sufficient chilling during winter. The starch concentration was superior in wood tissues of branches kept under chilling privation. The chilling privation disturbs carbohydrate mobilization in pear trees, reducing the sucrose synthesis capacity in wood tissues (source) and sucrose importation by the floral buds (sink).

Chilling privation during dormancy period and carbohydrate mobilization in Japanese pear trees

The flower bud abortion is one of the main problems that limit commercial pear (Pyrus pyrifolia) production in the southern region of Brazil. Insufficient chilling during the dormancy period is known as the main factor of this problem. One of the hypotheses to explain this problem is that the starch mobilization and carbohydrate fluxes to the buds are impeded when mild temperatures occurred during winter. This study compared the total soluble sugars (TSS) and reducing sugars (RS) concentrations, the cell wall acid invertase (CWAI - EC 3.2.1.26) and sucrose-phosphate synthase (SPS - EC 2.4.1.14) activities in wood of branches and floral buds of Japanese pear trees cv. Housui, grafted on Pyrus calleryana and submitted to chilling conditions during the dormancy period. Treatments were: (i) natural conditions; (ii) continuous artificial chilling; (iii) alternating temperatures, and (iv) total chilling privation. TSS and RS contents, as well as CWAI and SPS activities in tissues of branches that received insufficient chilling were lower than those that received sufficient chilling during winter. The starch concentration was superior in wood tissues of branches kept under chilling privation. The chilling privation disturbs carbohydrate mobilization in pear trees, reducing the sucrose synthesis capacity in wood tissues (source) and sucrose importation by the floral buds (sink).