Heinz Johann Holschuh

Variation in physical and chemical composition during maturation of umbu (Spondias tuberosa) fruits

Abstract The fruits of the umbu ( Spondias tuberosa Arruda Camara), also known as ‘imbu’ in English, were analysed for some physical and chemical changes during various stages of maturity. The fruit was found to be round to ovoidal in shape, being, on average, 3.21 cm long and 2.86 cm in width. Half-ripe fruits contained the maximum (64.62%) pulp content. The pH of the fruits increased with the advance in maturity and ripe fruits were significantly less acidic than green mature and half-ripe fruits. Ripe and half-ripe fruits contained significantly higher reducing sugars (5.34 and 4.14%, respectively) than green mature (2.79%) fruits.

Changes in physical and chemical composition during maturation of yellow mombin (Spondias mombin) fruits

Abstract Yellow mombin (Spondias mombin L.) fruits were analyzed for some physical and chemical changes during various stages of maturity. The fruit was found to be ellipsoidal to ovoidal in shape, being, on average, 3·47 cm long and 2·65 cm in width. The weight of the pulp increased during ripening from green mature (40·67%) to the ripe stage (59·67%). The weight of the seeds and skin did not show any significant difference in green mature and half-ripe fruits. ° Brix acidity ratio increased with the advance in maturity. Half-ripe fruits had significantly higher (6·02%) reducing sugars than green mature (4·81%) and ripe (5·21%) fruits.

Postharvest respiratory activity and changes in some chemical constituents during maturation of yellow mombin (Spondias mombin) fruit

Mature fruit from the yellow mombin (Spondias mombin) was monitored for its respiration activity. Mature green fruit from the yellow mombin was stored in closed glass chambers and the concentration of oxygen and carbon dioxide at the end of a six hour respiration period was determined. At the same interval of time, the lid of the chamber was opened for air renewal. The increase in carbon dioxide and decrease in oxygen concentration demonstrated that the fruit was climacteric. The maximum liberation of CO2 54.2 mL Kg -1 h-1 and maximum absorption of O2 49.0 mL Kg -1 h-1 occurred 186 hours after the harvest which, obviously, represented the optimum fruit quality after the senescence process started. The respiratory quotient of fruit at a climacteric maximum was 1.11 representing the oxidation of carbohydrates. Total soluble solids increased from 9.1 °Brix (initial) to 13.7 °Brix (climacteric maximum) during maturation, while the total number of acids in the fruit decreased during maturation i.e. from 1.55% initially to 1.40% at pre-climacteric, 1.0% at climacteric maximum and 0.8% in the post-climacteric stage. A similar behaviour was observed in the case of ascorbic acid. There was a continuous decrease in chlorophyll and a continuous increase in the carotenoid content of fruit during maturation.

Extração, atividade da bromelina e análise de alguns parâmetros químicos em cultivares de abacaxi

Due to the risks and limitations which has come from exclusive cultivation of Perola and Smooth Cayenne - pineapple plant - and aiming genetic variability, the state of Paraiba provides diversified genetic material cultivating the hybrids Emepa - 01, Imperial and MD-2 pineapple varieties. Aiming the biochemical characterization of those new hybrids, some biochemical parameters were determined: pulp and rind of those cultivars including bromelain activity. Smooth Cayenne pineapple had introduced the smallest pH (3,44 for pulp and 3,91 for rind) and the biggest titled acidity (0,56g of citric acid for 100g of pulp and 0,52g of citric acid for 100g of rind), being the most acid cultivar. Among the pulps the Perola and the Smooth Cayenne varieties presented levels of reduced, non-reduced and total sugar significantly higher (p<0,05) than the hybrids, in spite of having more elevated values (bigger than 30,00) of the ratio of soluble solids to titled acidity, consequently resulted on a better acceptation by consumers. The crude extract of the Imperial cultivar had the biggest proteolytic activity and protein content in the pulp (56,41 U/ml and 7,50 mg of protein/mL) as well as in the rind (68,56 U/mL and 10,40 mg of protein/mL). For the specific activity, the rind of Perola pineapple (10,01 U/mg of protein) provided more significantly elevated value (p<0,05) than those ones observed in the other samples. However, the pulp from Imperial cultivar (7,49 U/ mg of protein) presented considerably superior activity if compared to the rest.