Uva BRS Núbia: influência da origem geográfica e safra nas características físico-químicas e viabilidade de uso para produção de polpa
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Data
2019-02-01
Autores
Dodorico, Patricia Pereira
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A uva tinta de mesa pirênica BRS Núbia (Michele Palieri x Arkansas 2095) é uma nova cultivar brasileira que apresenta suas características físicas e químicas, bem como suas propriedades bioativas pouco exploradas. Neste estudo, objetivou-se avaliar a influência da região (Jales-SP e Marialva-PR) de produção em diferentes safras (2016-2018) nos parâmetros físicos e químicos, concentração de compostos fenólicos totais (CFT) e antocianinas totais (AT), e atividade antioxidante (AAT) da cultivar BRS Núbia, além da viabilidade do seu uso como matéria-prima para a produção de polpa empregando diferentes tratamentos térmicos (congelamento seguido de descongelamento e branqueamento a vapor) e enzimáticos (complexos pectinolíticos comerciais). Os resultados de rendimento de polpa e de coprodutos, bem como de CFT, AT, antocianinas poliméricas (AP) e cor instrumental das polpas foram utilizados para definir o melhor processo. A polpa de uva BRS Núbia foi processada quatro vezes, usando o melhor processo, para verificar a repetibilidade do processo a partir dos rendimentos percentuais de polpa e coprodutos, além da caracterização (umidade, sólidos solúveis, sólidos totais, acidez total, açúcares totais e redutores e pH) da polpa. Investigou-se também a presença de enzimas oxidativas nas bagas das uvas, antes e após o branqueamento a vapor, visando minimizar reações enzimáticas indesejáveis durante o processamento da uva. A partir da caracterização física e química das uvas das diferentes safras e regiões foi possível observar que as uvas provenientes de Jales diferiram principalmente com relação a massa, largura e formato dos cachos, bem como com relação a umidade e acidez total em decorrência de emprego de técnicas de manejo (desbaste e desponte) realizadas por diferentes produtores e em virtude do uso de diferentes porta-enxertos (IAC 572 e Paulsen 1103) na produção das safras das uvas analisadas, enquanto as uvas provenientes de Marialva, diferiram em todas as características físicas e nas características químicas em relação a acidez total e pH em decorrência da alteração quanto ao período produtivo (safra de inverno (safrinha) e safra de verão (safra normal)) e, por conseguinte, nas condições edafoclimáticas do período de cultivo. As uvas das diferentes safras apresentaram importante concentração de CFT (457,67 a 2473,34 mg equivalentes de ácido gálico (EAG)/kg de uva) e AT (522,08 a 960,16 mg malvidina-3-glicosídeo/kg de uva), o que refletiu positivamente na AAT (3,10 a 13,85 mmol de Trolox/kg de uva). As safras de Marialva-PR foram as que mais se destacaram, de forma geral, com relação aos parâmetros de qualidade avaliados, sendo que a safrinha (maio/2017) apresentou maior concentração dos CFT e, por conseguinte, de AAT enquanto a safra normal de Marialva (dezembro/2017) apresentou melhores características físicas com cachos cônicos de massa elevada contendo bagas grandes de elevado percentual de polpa e baixo percentual de sementes. Com relação ao processamento da uva BRS Núbia na forma de polpa, o branqueamento a vapor seguido por tratamento enzimático contendo pectina liase e poligalacturonase em iguais proporções resultou em elevado rendimento em polpa, maiores concentrações de AT e menores concentrações de AP. O processo demonstrou ter repetibilidade (média ± margem de erro), obtendo-se alto rendimento em polpa (90,17% ± 2,14) e baixo de coproduto (7,01% ± 2,66), bem como características químicas dentro dos padrões de identidade e qualidade preconizados pela legislação brasileira para polpa de uva. O desenvolvimento de processos e novos produtos derivados da cultivar BRS Núbia permitirá minimizar perdas pós-colheita e evitar desperdícios, além de auxiliar na geração de renda e empregos.
The BRS Nubia (Michele Palieri x Arkansas 2095) table grape is a Brazilian cultivar whose physical and chemical characteristics and bioactive properties are largely unexplored. This study aimed to evaluate the influence of the growing region (Jales-SP and Marialva-PR) on different harvests (2016-2018) of the BRS Núbia cultivar through the physical and chemical parameters, total phenolic content (TPC), total anthocyanins (TA) and antioxidant activity (TAA), as well as the viability of its use as a raw material for pulp production using different heat treatments (freezing followed by thawing and steam bleaching) and enzymatic treatment (using commercial pectinolytic complexes). The yields of pulp and coproducts, as well as of TPC, TA, polymeric anthocyanins (PA) and also the instrumental color of the pulps were used to define the best process. The BRS Núbia grape pulp was then processed four times, using the best process, to test the repeatability of the process in terms of the percentage yields of pulp and coproducts, in addition to the characterization (moisture content, soluble solids, total solids, total acidity, total and reducing sugars and pH) of the pulp. The presence of oxidative enzymes in the grape berries, before and after steam bleaching, was also investigated in order to minimize undesirable enzymatic reactions during the grape processing. The physical and chemical characterization of the grapes of the different harvests and regions showed that grapes from Jales differed mainly in relation to the mass, width and shape of the bunch, as well as in relation to moisture content and total acidity, resulting from the use of management techniques (roughing and blunting) performed by different producers and the use of different rootstocks (IAC 572 and Paulsen 1103) in the production of the grape harvests analyzed. Those grapes from Marialva, on the other hand, differed in all the physical characteristics, as well as in the chemical characteristics related to total acidity and pH due to changes in the productive period (winter harvest) and summer harvest (normal harvest)) and, therefore, changes in the edaphoclimatic conditions of the growing period. The grapes of the different harvests presented an important concentration of TPC (457.67 to 2473.34 mg equivalent of gallic acid (EGA/kg of grape) and TA (522.08 to 960.16 mg malvidin3-glucoside/kg of grape), which positively reflected in the TAA (3.10 to 13.85 mmol of Trolox/kg of grape). However, the Marialva-PR harvest was the ones that stood out, in general, regarding the quality parameters evaluated. The Marialva May 2017 harvest had the highest concentration of TPC and, consequently, TAA, while the normal Marialva harvest (December 2017) presented better physical characteristics with conical bunch of high mass containing large berries with a high percentage of pulp and a low percentage of seeds. Regarding the processing of the BRS Nubian grape in its pulp form, steam bleaching followed by enzymatic treatment with pectin lyase and polygalacturonase in equal proportions resulted in a high pulp yield, higher concentrations of TA and lower PA. The process was repeatable (average ± margin of error) obtaining high pulp yields (90.17% ± 2.14) and low co-product yields (7.00% ± 2.66), as well as chemical characteristics within the standards of identity and quality recommended by Brazilian legislation for grape pulp. The development of processes and new products derived from the BRS Núbia cultivar will help minimize post-harvest losses and avoid waste, as well as helping to generate income and jobs.
The BRS Nubia (Michele Palieri x Arkansas 2095) table grape is a Brazilian cultivar whose physical and chemical characteristics and bioactive properties are largely unexplored. This study aimed to evaluate the influence of the growing region (Jales-SP and Marialva-PR) on different harvests (2016-2018) of the BRS Núbia cultivar through the physical and chemical parameters, total phenolic content (TPC), total anthocyanins (TA) and antioxidant activity (TAA), as well as the viability of its use as a raw material for pulp production using different heat treatments (freezing followed by thawing and steam bleaching) and enzymatic treatment (using commercial pectinolytic complexes). The yields of pulp and coproducts, as well as of TPC, TA, polymeric anthocyanins (PA) and also the instrumental color of the pulps were used to define the best process. The BRS Núbia grape pulp was then processed four times, using the best process, to test the repeatability of the process in terms of the percentage yields of pulp and coproducts, in addition to the characterization (moisture content, soluble solids, total solids, total acidity, total and reducing sugars and pH) of the pulp. The presence of oxidative enzymes in the grape berries, before and after steam bleaching, was also investigated in order to minimize undesirable enzymatic reactions during the grape processing. The physical and chemical characterization of the grapes of the different harvests and regions showed that grapes from Jales differed mainly in relation to the mass, width and shape of the bunch, as well as in relation to moisture content and total acidity, resulting from the use of management techniques (roughing and blunting) performed by different producers and the use of different rootstocks (IAC 572 and Paulsen 1103) in the production of the grape harvests analyzed. Those grapes from Marialva, on the other hand, differed in all the physical characteristics, as well as in the chemical characteristics related to total acidity and pH due to changes in the productive period (winter harvest) and summer harvest (normal harvest)) and, therefore, changes in the edaphoclimatic conditions of the growing period. The grapes of the different harvests presented an important concentration of TPC (457.67 to 2473.34 mg equivalent of gallic acid (EGA/kg of grape) and TA (522.08 to 960.16 mg malvidin3-glucoside/kg of grape), which positively reflected in the TAA (3.10 to 13.85 mmol of Trolox/kg of grape). However, the Marialva-PR harvest was the ones that stood out, in general, regarding the quality parameters evaluated. The Marialva May 2017 harvest had the highest concentration of TPC and, consequently, TAA, while the normal Marialva harvest (December 2017) presented better physical characteristics with conical bunch of high mass containing large berries with a high percentage of pulp and a low percentage of seeds. Regarding the processing of the BRS Nubian grape in its pulp form, steam bleaching followed by enzymatic treatment with pectin lyase and polygalacturonase in equal proportions resulted in a high pulp yield, higher concentrations of TA and lower PA. The process was repeatable (average ± margin of error) obtaining high pulp yields (90.17% ± 2.14) and low co-product yields (7.00% ± 2.66), as well as chemical characteristics within the standards of identity and quality recommended by Brazilian legislation for grape pulp. The development of processes and new products derived from the BRS Núbia cultivar will help minimize post-harvest losses and avoid waste, as well as helping to generate income and jobs.
Descrição
Palavras-chave
Uva de mesa, Safra, Polpa, Compostos fenólicos, Antocianinas, Table grape, Harvest, Pulp, Phenolic compounds, Anthocyanins