Recobrimentos comestíveis associados a óleos essenciais no controle da antracnose e na qualidade de goiabas ‘Pedro Sato’
Carregando...
Data
2021-11-08
Autores
Rodrigues, Ellen Cristina Nabiça
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo deste estudo foi verificar o potencial dos recobrimentos comestíveis (REC) à base de hidroxipropilmetilcelulose e cera de abelha a 20% associados a óleos essenciais (OEs) na conservação e qualidade pós-colheita de goiabas ‘Pedro Sato’ e no controle do agente causal da antracnose (Colletotrichum gloeosporioides). No experimento I, avaliou-se o potencial antifúngico in vitro no controle do Colletotrichum gloeosporioides de OEs de canela (Cinnamomun cassia) nas concentrações 0,25; 0,5; 0,75 e 1,0 mL L-1, tomilho (Thymus vulgaris) nas concentrações 0,05; 0,1; 0,2; e 0,3 mL L-1, alecrim (Salvia rosmarinus) nas concentrações 0,05; 0,1; 0,2 e 0,3 mL L-1 e basilicão (Ocimum basilicum) nas concentrações 0,5; 1,0; 2,0 e 3,0 mL L-1. No experimento II avaliou-se o efeito de REC associados aos OEs com melhor desempenho no teste in vitro em goiabas inoculadas propositalmente com Colletotrichum gloeosporioides e armazenadas por dez dias a 21 ± 1 °C, os OEs selecionados foram de canela (0,10; 0,25 e 0,50 mL L-1) e tomilho (0,10; 0,20 e 0,30 mL L-1). Para o experimento III, selecionou-se o OE de canela e elevou-se suas concentrações para 1,0 e 1,5 mL L-1, foi avaliado o efeito do REC associados ao OE de canela quanto aos parâmetros de qualidade e conservação pós-colheita; atividade antioxidante e estresse oxidativo de goiabas ‘Pedro Sato’. Verificou-se no experimento I, que os melhores resultados de atividade antifúngica para os OEs no controle do Colletotrichum gloeosporioides foram os OE de canela e OE de tomilho, ambos inibindo 100% do crescimento micelial e da germinação conidial do micro-organismo, o OE de basilicão inibiu o crescimento do patógeno de maneira dependente da dose e o OE de alecrim não foi eficaz nas concentrações testadas. No experimento II as concentrações dos OEs de canela e tomilho associadas ao REC, reduziram significativamente a incidência da antracnose nos frutos tratados, no entanto não apresentando diferença significativa (P>0,05) entre as si, mas apresentando diferença (P < 0,01) entre os OEs e os tratamentos controles, diminuindo a severidade da antracnose nos frutos, com menor desenvolvimento da doença. Para o experimento III, o REC + OE de canela nas concentrações 1,0 e 1,5 mL L-1, foram eficientes no atraso do amadurecimento, na manutenção da cor da casca e polpa, firmeza, sólidos solúveis, acidez titulável, ácido ascórbico e atividade antioxidante, além de reduzir o estresse oxidativo e a perda de massa nos frutos. O tratamento com REC + OE 1,0 mL L-1 de canela é o mais indicado para possíveis aplicações industriais, exibindo, ao sexto dia de avaliação, características físico-químicas comparáveis aos frutos-controle no primeiro dia de armazenamento, contribuindo com ganho de 4 dias na vida útil de goiabas ‘Pedro Sato’.
This study aimed to assess the potential of edible coatings (COA) based on hydroxypropylmethylcellulose and 20% beeswax combined with essential oils (EOs) in the quality, postharvest conservation, and control of the causative agent of anthracnose (Colletotrichum gloeosporioides) in 'Pedro Sato' guava. In the first experiment, the antifungal potential of EOs was evaluated in vitro for Colletotrichum gloeosporioides. We tested the following EOs: cinnamon (Cinnamomun cassia) at concentrations 0.25, 0.5, 0.75, and 1.0 mL L-1; Thyme (Thymus vulgaris) at concentrations 0.05, 0.1, 0.2, and 0.3 mL L-1; Rosemary (Sage rosmarinus) at concentrations 0.05, 0.1, 0.2, and 0.3 mL L-1; Sweet Basil (Ocimum basilicum) at concentrations 0.5, 1.0, 2.0, and 3.0 mL L-1. In the second experiment, we evaluated the effect of COA combined with the EOs that better performed in the in vitro test. The selected EOs were cinnamon (0.10, 0.25, and 0.50 mL L-1) and thyme (0.10, 0.20, and 0.30 mL L-1). The fruit were inoculated with Colletotrichum gloeosporioides and stored for ten days at 21 ± 1 °C. In the third experiment, the EO of cinnamon was selected, and its concentrations were raised to 1.0 and 1.5 mL L-1. We evaluated the effect of the COA combined with the EO of cinnamon for quality parameters, postharvest conservation, antioxidant activity, and oxidative stress of ‘Pedro Sato’ guava. The findings of the first experiment showed that the EOs of cinnamon and thyme inhibited 100% of mycelial growth and conidial germination of C. gloeosporioides. The EO of sweet basil inhibited the growth of the pathogen in a dose-dependent manner, and the EO of rosemary was not effective at the concentrations tested. In the second experiment, the tested concentrations of cinnamon and thyme combined with COA significantly reduced the incidence of anthracnose in the treated fruit. No significant difference was observed between the concentrations (P > 0,05). However, the EOs presented a difference (P < 0,01) compared to control. The EOs decreased the severity of anthracnose in fruit and less disease incidence. In the third experiment, the COA + EO of cinnamon at 1.0 and 1.5 mL L-1 delayed ripening, maintained peel and pulp color, firmness, soluble solids, titratable acidity, ascorbic acid, and antioxidant activity. Also, the oxidative stress and weght loss of fruit were reduced. The COA + cinnamon EO at 1.0 mL L-1 is the most suitable for potential industrial application. On the sixth day of evaluation, it exhibited physico-chemical characteristics comparable to the control fruit on the first day of storage, contributing to a 4-days gain in the shelf life of guava ‘Pedro Sato'.
This study aimed to assess the potential of edible coatings (COA) based on hydroxypropylmethylcellulose and 20% beeswax combined with essential oils (EOs) in the quality, postharvest conservation, and control of the causative agent of anthracnose (Colletotrichum gloeosporioides) in 'Pedro Sato' guava. In the first experiment, the antifungal potential of EOs was evaluated in vitro for Colletotrichum gloeosporioides. We tested the following EOs: cinnamon (Cinnamomun cassia) at concentrations 0.25, 0.5, 0.75, and 1.0 mL L-1; Thyme (Thymus vulgaris) at concentrations 0.05, 0.1, 0.2, and 0.3 mL L-1; Rosemary (Sage rosmarinus) at concentrations 0.05, 0.1, 0.2, and 0.3 mL L-1; Sweet Basil (Ocimum basilicum) at concentrations 0.5, 1.0, 2.0, and 3.0 mL L-1. In the second experiment, we evaluated the effect of COA combined with the EOs that better performed in the in vitro test. The selected EOs were cinnamon (0.10, 0.25, and 0.50 mL L-1) and thyme (0.10, 0.20, and 0.30 mL L-1). The fruit were inoculated with Colletotrichum gloeosporioides and stored for ten days at 21 ± 1 °C. In the third experiment, the EO of cinnamon was selected, and its concentrations were raised to 1.0 and 1.5 mL L-1. We evaluated the effect of the COA combined with the EO of cinnamon for quality parameters, postharvest conservation, antioxidant activity, and oxidative stress of ‘Pedro Sato’ guava. The findings of the first experiment showed that the EOs of cinnamon and thyme inhibited 100% of mycelial growth and conidial germination of C. gloeosporioides. The EO of sweet basil inhibited the growth of the pathogen in a dose-dependent manner, and the EO of rosemary was not effective at the concentrations tested. In the second experiment, the tested concentrations of cinnamon and thyme combined with COA significantly reduced the incidence of anthracnose in the treated fruit. No significant difference was observed between the concentrations (P > 0,05). However, the EOs presented a difference (P < 0,01) compared to control. The EOs decreased the severity of anthracnose in fruit and less disease incidence. In the third experiment, the COA + EO of cinnamon at 1.0 and 1.5 mL L-1 delayed ripening, maintained peel and pulp color, firmness, soluble solids, titratable acidity, ascorbic acid, and antioxidant activity. Also, the oxidative stress and weght loss of fruit were reduced. The COA + cinnamon EO at 1.0 mL L-1 is the most suitable for potential industrial application. On the sixth day of evaluation, it exhibited physico-chemical characteristics comparable to the control fruit on the first day of storage, contributing to a 4-days gain in the shelf life of guava ‘Pedro Sato'.
Descrição
Palavras-chave
Tecnologia pós-colheita, Biopolímeros, Óleos essenciais, Fitopatologia, Qualidade