Enzymatic interesterification effect on the physicochemical and technological properties of cupuassu seed fat and inaja pulp oil blends.

The objective of this work was to evaluate the effect of enzymatic interesterification process in blends with different proportions (w:w) of cupuassu fat and inaja oil (80:20, 70:30, 60:40, 50:50 and 40:60). The interesterification reaction was carried out at 65 °C, agitation at 150 rpm, and enzyme concentration of 5% (w/w), for 6 h. Acidity index, melting point, consistency and solid fat content of the blends were characterized before and after the interesterification process. Fatty acid content was characterized in cupuassu fat and inaja oil and, nutritional quality indexes of atherogenicity (AI) and thrombogenicity (TI) were calculated. Enzymatic interesterification promoted a decrease in acidity (<0.6%) and changes in the blends' properties, making them suitable for food product preparation. All esterified blends (cupuassu seed fat:inaja pulp oil) presented suitable consistency properties, plasticity and spreadability to be used for the preparation of functional, table and soft table types of margarine and used in food preparation such as special fats.

The combined use of ultrasound and molecular sieves improves the synthesis of ethyl butyrate catalyzed by immobilized Thermomyces lanuginosus lipase.

In this work, the combined use of ultrasound energy and molecular sieves was investigated for the synthesis of ethyl butyrate, ester with mango and banana notes, catalyzed by the immobilized lipase from Thermomyces lanuginosus (Lipozyme TL-IM). Initially, the best concentrations of biocatalysts (35%) and butyric acid (0.7M) were tested using ultrasound as an alternative to mechanical agitation. The amount of acid in the reaction could be increased by 2-fold when compared to previous works where mechanical agitation was used. In the next step, substrate molar ratio and reaction temperature were optimized and the best conditions were at their lowest levels: 1:1 (acid:alcohol), and 30°C, reaching 61% of conversion in 6h. Molecular sieves (3Å) were added to optimized reaction medium in order to remove the formed water and improve the maximum yield. The reaction yield increased 1.5 times, reaching 90% of conversion in 6h, when 60mg of molecular sieves per mmol of butyric acid was used. Finally, the reuse of Lipozyme TL-IM for the ultrasound-assisted synthesis of ethyl butyrate was verified for 10 batches, without any appreciable loss of activity, whereas in systems using mechanical agitation, the biocatalyst was completely inactivated after 5 batches. These results suggest that the combined use of ultrasound and molecular sieves greatly improve esterification reactions by stabilizing the enzyme and increasing yields.