Silvia Regina de Toledo Valentini

Quality plums cv. Reubennel after treatment with alternative products, cold storage and climatization.

The purpose of this research was to evaluate the application of alternative products and refrigeration, with subsequent exposure to exogenous ethylene on quality of plums ‘Reubennel’, in order to prolong the marketing period. Products applied soon after harvest were: citric biomass (Ecolife ®) - 150 ml (pc) 100 L-1 for 30 s; ethanol vapor - 2 ml kg-1, per 2 h (20°C/80% RH) and , calcium chloride (CaCl2) - 1% (w / v) for 10 min. Then, the fruits were stored at 0°C/95% RH. After 17 to 33 days, three boxes per treatment with 40 fruits each were removed from the cooling chamber, one of the boxes segregated for analysis, while the other two were transferred to 20oC/85% RH for 4 more days. Of these boxes, one for each treatment was subjected to climatization through the application of ethylene (100 uL-1,72 h) in a mini-camera (200 L). We proceeded to evaluate the quality of the fruit at zero, 17, 17+4, 33, and 33+4 days, through physical-chemical, microbiological and sensory analysis. The results were analyzed statistically in a completely randomized design for alternative products and factorial (4x2) for the combination with the climatization. It was concluded that post-harvest treatment of plums with ethanol vapor reduces the microbial population as well as providing increased soluble solids. The ‘Reubennel’ plums can be stored for up to 33 days under refrigeration (0oC/95% RH), followed by climatization with ethylene and immediately commercialized.

Postharvest technologies for mangosteen (Garcinia mangostana L.) conservation

The application of technologies to extend the postharvest life of mangosteen fruit was studied and compared to storage at 25 °C/70-75%R.H (25 °C control treatment). The fruits were packed in expanded polystyrene (EPS) trays (5 fruits/tray). Five treatments were carried out at 13 °C/ 90-95% RH: application of carnauba wax coating, lecithin + CMC (carboxymethyl cellulose) coating, 50 µm LDPE (low density polyethylene) film coating, 13 µm PVC (Polyvinyl chloride), and non-coated sample (13 °C control treatment). Physicochemical analyses were performed twice a week. A statistical design was completely randomized with 8 repetitions for each treatment plus the control treatment. The results were submitted to variance analysis, and the averages compared by the Tukey test at 5% probability. Among the quality parameters analyzed, more significant differences were observed for weight loss, texture, and peel moisture content. The results showed that the maximum storage period for mangosteen at 25 °C is two weeks; while storage at13 °C can guarantee the conservation of this fruit for 25 days. Therefore, the treatment at 13 °C/90-95% RH without the use of coatings and films was more effective and economical.

Influência de tratamento térmico e sistemas de embalagens na qualidade de lichia 'Bengal

Litchi fruits cv. Bengal were submitted to hydrothermal treatments and packed in PET trays with lid (BT) and covered with PVC film 15µm (BF). The treatments were : T1-BT- and T2-BF without hydrothermal treatment; T3-BT-water at 55 o C for 20s, T4-BF-water at 55oC for 20s, T5-BT-water at 55o C for 10s plus citric acid 60% for 10s, T6-BF-water at 55oC for 10s plus citric acid 60% for 10s, T7-BT- citric acid 60% for 20s and T8-BF- citric acid 60% for 20s. Changes in the main physical, chemical and sensory characteristics and the presence of disease in litchi stored at 4oC and 25oC were evaluated. At the end of the study, litchi fruits were slightly less acid, with a slight increase in pH and a slight reduction of the soluble solids content. After two days at 25oC all fruits were infected by molds. The treatments T5, T6, T7, T8 were considered unacceptable (score > 4) from the 15th day, T1, T2, T3 and T4 were acceptable up to 21 days by visual assessment. The treatments T1 and T4 resulted in the best red color. Treatment T2 had the highest values of firmness of the pericarp, showing that the PVC film protected against loss of firmness, moisture and wilting. The weight loss was lower for the treatments T6 and T8 (0.4%) both with PVC film, and more than T5 (5.6%) with PET tray with lid.

Ripening of ‘Kumagai’ guavas and anthracnose control as affected by methyl jasmonate

O metil jasmonato (MJ) e um regulador endogeno que pode influenciar o processo de amadurecimento de frutos e o sistema de defesa contra patogenos. O objetivo do trabalho foi verificar a influencia desse regulador na fisiologia pos-colheita, no controle da antracnose e nas caracteristicas fisico-quimicas de goiabas (Psidium guajava L.) ‘Kumagai’. As goiabas foram colhidas nos estadios verde e amarelo e tratadas com 0, 1 e 10 µmol∙L−1 de MJ por volatilizacao em tambores hermeticos (200 L) com circulacao de ar por 24 h. Os frutos foram inoculados com Colletotrichum gloeosporioides (105 conidios∙mL−1) 24 e 48 h apos o tratamento. Durante o amadurecimento, a 25 °C e 80 – 90% de UR, foram realizadas analises de respiracao, producao de etileno, incidencia e severidade da antracnose e analises fisicoquimicas. Os dados foram submetidos a analise de variância e as medias, comparadas pelo teste de Tukey (p ≤ 0,05 e 0,10). A aplicacao de 1 e 10 µmol∙L−1 de MJ provocou discreto aumento na respiracao, producao de etileno e amarelecimento da casca em frutos colhidos no estadio amarelo. O tratamento com 1 e 10 µmol∙L−1 de MJ nao teve efeito na reducao da severidade e na incidencia de C. gloeosporioides quando aplicado em frutos nos 2 estadios de amadurecimento e inoculados apos 24 ou 48 h do tratamento. Conclui-se que a aplicacao de 1 e 10 µmol∙L−1 de MJ teve pouca influencia no amadurecimento e nao controlou a antracnose em goiabas ‘Kumagai’.