Evaluation of alternative preservation treatments (water heat treatment, ultrasounds, thermosonication and UV-C radiation) to improve safety and quality of whole tomato

Previously optimised postharvest treatments were compared to conventional chlorinated water treatment in terms of their effects on the overall quality of tomato (‘Zinac’) during storage at 10 °C. The treatments in question were water heat treatment (WHT = 40 °C, 30 min), ultrasounds (US = 45 kHz, 80 %, 30 min), thermosonication (TS =40 °C, 30 min, 45 kHz, 80 %) and ultraviolet irradiation (UV-C: 0.97 kJ m−2). The quality factors evaluated were colour, texture, sensorial analysis, mass loss, antioxidant capacity, total phenolic content, peroxidase and pectin methylesterase enzymatic activities, and microbial load reduction. The results demonstrate that all treatments tested preserve tomato quality to some extent during storage at 10 °C. WHT, TS and UV-C proved to be more efficient on minimising colour and texture changes with the additional advantage of microbial load reduction, leading to a shelf life extension when compared to control trials. However, at the end of storage, with exception of WHT samples, the antioxidant activity and phenolic content of treated samples was lower than for control samples. Moreover, sensorial results were well correlated with instrumental colour experimental data. This study presents alternative postharvest technologies that improve tomato (Zinac) quality during shelf life period and minimise the negative impact of conventional chlorinated water on human safety, health and environment.info:eu-repo/semantics/publishedVersio

Qualidade pós-colheita de frutos de tomate cv. Andréa tratados com etileno Postharvest quality of tomato fruits cv. Andréa treated with ethylene

O tomate é uma das principais hortaliças cultivadas no Brasil e tratamentos que propiciem o controle do amadurecimento são extremamente desejáveis. Avaliou-se a qualidade pós-colheita de tomates tipo italiano tratados com etileno. Tomates 'Andréa' foram colhidos em campos de produção comercial no estádio verde-maduro, selecionados para presença de danos externos e classificados quanto ao tamanho e cor e posteriormente foram tratados com 100 µL L-1 de etileno. Os ensaios foram planejados com delineamento inteiramente casualizado em esquema fatorial com quatro tratamentos e quinze repetições (n=10). Após a aplicação, os frutos foram divididos em dois lotes. Um lote permaneceu a 20º±1ºC e outro foi mantido a 12,5º±1ºC, ambos sob umidade relativa 90±5%. Tomates do tratamento controle foram mantidos nas mesmas condições de temperatura e umidade relativa. Os frutos foram avaliados após cada mudança de estádio de amadurecimento para as seguintes variáveis: coloração externa (L*a*b*), perda de massa, sólidos solúveis totais, acidez titulável e teor de ácido ascórbico. A aplicação de etileno não influenciou de maneira significativa as variáveis químicas e físicas estudadas. Frutos armazenados à temperatura de 20ºC demonstraram maior porcentagem de perda de massa ao longo do amadurecimento, com média de 2,60%. A relação brix/acidez apresentou pouca variação entre os tratamentos avaliados. Frutos do tratamento controle e mantidos à temperatura de 20ºC apresentaram mudança de coloração mais rápida no início dos experimentos, não sendo observada posteriormente diferença significativa no desenvolvimento da cor dos tratamentos avaliados. O tratamento com etileno não acelerou de forma significativa o amadurecimento de tomates 'Andréa' armazenado sob as duas temperaturas estudadas.<br>Tomatoes are one of the most important vegetable crops grown in Brazil and treatments that facilitate ripening control are extremely desirable. The present work was carried out aiming to evaluate postharvest quality of roma-type tomatoes treated with ethylene. 'Andréa' tomatoes were harvested in commercial fields at the mature-green stage, were graded for size and color, and treated with ethylene (100 µL L-1) for 48 hours at 20º±1ºC and relative humidity of 90±5%. The experiments were carried out using a completely randomized design with four treatments and fifteen replicates (n=10). After ethylene application, tomatoes were stored at two temperatures. One lot remained at 20º±1ºC and another one was kept at 12.5º±1ºC and relative humidity of 90±5%. Control fruits were kept in the same storage conditions of temperature and relative humidity. For each maturity color change, the following analyses were carried out: color indexes (L *, a* and the b * and its relations), water loss (%), soluble solids (ºBrix), titratable acidity (g 100g-1), and ascorbic acid (mg 100g-1). Ethylene application promoted color uniformity in treated fruits. However, there were no significant changes in the other postharvest variables evaluated. Fruits stored at 20ºC showed 2.6% of mass loss during storage. Brix/titratable ratio showed slight variation throughout the experiment. Control fruits stored at 20ºC changed external color earlier than other treatments in the beginning of the trial, showing no significant difference after that. Postharvest ethylene application was not an efficient technique to hasten ripening of 'Andréa' tomatoes