Production and Application of Pectinases from Aspergillus niger Obtained in Solid State Cultivation

In this study, different concentrations of the inducer (pectin) and the carbon source (glucose) were evaluated as components of the culture medium for the production of pectinases by Aspergillusniger. Furthermore, it evaluated the stability of the enzymes produced with respect to the temperature and the enzyme extract produced was tested for the clarification of strawberry juice. The highest pectinolytic activity (68 U/g) was obtained at a concentration of 6% (w/w) of pectin in the absence of glucose in the medium. Pectinases activity has shown high stability at 20 °C and 30 °C while a gradual decrease of activity was observed when the temperature rose. A reduction of about 50% of the total pectinases activity was measured at 50 °C after 60 min of exposure. The experimental enzymatic extract was compared with a high-quality commercial product for the clarification of strawberry juice. Similar data were obtained for turbidity and viscosity reduction. The enzymatic treatment led to a reduction of about 60% in the turbidity and 40% in the viscosity of the juice. After the enzymatic treatment, the total phenolic compounds, total anthocyanins, and antioxidant activity were preserved. The results obtained in the present work indicate the potential of the enzymes produced for using in fruit processing

ELABORAÇÃO DE PRÉ-MISTURA PARA BOLO SEM GLÚTEN

Para os portadores da doença celíaca a ingestão de produtos que contém glúten danifica a superfície da mucosa do intestino, dificultando a absorção de nutrientes pelo organismo. Neste contexto, este trabalho teve como objetivo desenvolver pré-misturas para bolos livres de glú- ten. Foram estudadas duas variáveis independentes - farinha de linhaça e farinha de arroz em substituição a farinha de trigo. A qualidade dos bolos foi avaliada, através das análises físico-químicas (umidade, volume e cor) e análise sensorial. Através da aplicação de um planejamento central 2², foi possível observar que grandes quantidades de farinha de linhaça apresentaram uma interação negativa com a farinha de arroz. Os bolos formulados com a adição de farinha de linhaça e farinha de arroz nas proporções testadas obtiveram aceitação entre os degustadores, representando uma alternativa de consumo para pessoas portadoras da doença celíacas ou para os adeptos de uma dieta isenta de glúten

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 araçá 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 araçá 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

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)