Ivana Greice Sandri

Effect of freezing and processing technologies on the antioxidant capacity of fruit pulp and jelly

The effect of freezing and processing technology on the antioxidant capacity of grape (Vitis vinifera), apple (Malus domestica), strawberry (Fragaria x Anassa), pear (Pyrus communis L.), guava (Psidium guajava L.), and fig (Ficus carica L.) was evaluated for 90 days. Under a storage temperature of -15 o C, there was no significant difference in the antioxidant capacity of grape and fig pulp, and a higher antioxidant capacity was found for guava pulp (27 µmol/g). While the technological processing did not affect the antioxidant capacity of pear and apple jellies, all other jellies studied showed a reduced antioxidant capacity. The processing reduced the antioxidant capacity of grapes in 45%. Among the fruit products, the highest antioxidant activities were found for guava pulp and jelly (27 and 25 µmol/g, respectively), followed by grape pulp (22 µmol/g).

Application of enzymatic preparations to produce araçá pulp and juice

In the present study, the effect of pectinases on the production of pulp and juice of araca and the presence of bioactive compounds were evaluated. An enzyme extract (EE) produced by Aspergillus niger LB-02-SF in solid state fermentation and the commercial enzyme Ultrazym®AFP-L were used in this study. After enzyme treatment with the EE preparation, the extraction yield increased by 23.1% and viscosity decreased by 42.8%, during pulp maceration. During juice processing, there was an increase of 70.6% in clarification and a decrease of 72.87% in turbidity. Higher values of these parameters, 47.7, 69.0, 80.7, and 79.7%, respectively, were obtained using the Ultrazym®AFP-L, which also led to a significant increase in the polyphenol content, both in the pulp (24%) and in the juice (28%), with a less pronounced effect when the EE was applied (10 and 21%, respectively). The anthocyanins content in the araca pulp increased after treatment with the commercial preparation (23%), and there was no significant increase with the use of EE. The use of Ultrazym®AFP-L increased the β-carotene content by 29.4% in the fruit pulp, while the treatment with EE did not result in significant changes compared with those of the juice and pulp controls.

Study of the pre-treatments for the dehydration of cherry tomato (Lycopersicon esculentum var. cerasiforme).

Este trabalho teve como objetivo estudar o efeito de pre-tratamentos de sacarose 20%, NaCl 5%, sacarose 10% + NaCl 5%, CaCl 2 1% e polvilho doce 2,5% no tempo de secagem de tomate-cereja, bem como na capacidade de reidratacao e nas caracteristicas sensoriais do produto final. Metades de tomate-cereja oblongo foram imersas nas solucoes e desidratadas a 60 °C em um desidratador de bandejas com ventilacao forcada de ar, ate a umidade final de 25% (base umida). Por meio das curvas de secagem, observou-se que o pre-tratamento mais efetivo foi o de sacarose 10% + NaCl 5%, que reduziu o tempo de processo em 27%. Quanto a reidratacao, o tratamento com sacarose 20% aumentou significativamente a capacidade de absorcao de agua do tomate desidratado, quando comparado com o controle. Ja na avaliacao sensorial dos atributos, a amostra que foi mais bem conceituada foi aquela submetida ao pre-tratamento de sacarose 10% + NaCl 5%, enquanto que a amostra pre-tratada somente com NaCl 5% apresentou as notas mais baixas.