Synthesis of dietary lipids from pumpkin (Cucurbita pepo. L) oil obtained by enzymatic extraction: a sustainable approach.

This study aimed to assess the nutritional properties of dietary lipids obtained through the modification of aqueous enzymatically extracted pumpkin seed (Cucurbita pepo. L) oil. The optimal growth conditions for producing pectinase using strain Aspergillus sp. 391 were determined, and partial characterization of pectinase and commercial cellulase was conducted. The enzymatic extraction was performed at pH 4.0, 50 °C, for 24 h, using a combination of pectinase and cellulase for optimum effectiveness. The crude oil obtained was analyzed for acid, peroxide, and fatty acid composition. The study found a high amount of unsaturated fatty acids, mainly linoleic acid (C18:2), and a 59% oil recovery rate. Subsequently, this oil was subjected to enzymatic acidolysis with capric acid in solvent-free media, catalyzed by lipase Lipozyme RM IM®, resulting in a product with a higher incorporation degree (48.39 ± 0.5 mol%), observed after 24 h at 60 °C using molar ratio oil:acid capric of 1:9 (run 4). The nutritional properties of this oil were improved.

Optimization and characterization of rhamnolipids produced by Pseudomonas aeruginosa ATCC 9027 using molasses as a substrate.

The present study aims to evaluate the growth potential of the P. aeruginosa ATCC9027 strain with molasses as the sole carbon source to produce rhamnolipids. The influence of the cultivation time and substrate concentration on biosurfactant production was investigated by using a complete 3-level factorial design, with the rhamnolipid concentration as the variable response. The strain was able to produce the biosurfactant in all design conditions tested, producing 758.04 mg/L rhamnolipids with 7% v/v substrate concentration in a cultivation time of 120 h. The substrate concentration used in the cultivation step directly influenced the biosurfactant production, and, even with the decrease in biomass growth, the biosurfactant production continued to increase. High Performance Liquid Chromatography (HPLC) revealed the presence of 62.3% mono- (RL1) and 37.6% di-rhamnolipids (RL3). The stability tests showed that the biosurfactant has good performance in extreme conditions of temperature, pH and saline concentration. The emulsification index was also evaluated for several oils and hydrocarbons, obtaining emulsification rates of up to 84.9% for the burnt motor oil. In addition, rhamnolipid showed a good ability to remove spilled oil from the sand, removing 58.51% of burnt motor oil and 70.09% of post-frying soybean oil. The results indicate that molasses, an agro-industrial residue abundant in Brazil, can be used as the only carbon source for quality rhamnolipid production when under optimized conditions, therefore presenting itself as a management option for this residue and, at the same time, providing the production product with high added value.

Improved synthesis of dietary triglycerides by using lipase supported on clay carriers.

BACKGROUND: In the search for healthier and more functional foods, dietary triglycerides (TAGs) have played a prominent role in the food industry. The objective of this work was to evaluate new clay supports to immobilize lipase from Rhizopus oryzae and use it in the synthesis of TAGs. MAIN METHODS AND MAJOR RESULTS: The immobilization of lipase by physical adsorption was carried out, determining the hydrolytic activity, esterification, immobilization yield, thermal stability, and kinetic and thermodynamic parameters. Afterwards, acidolysis was carried out and the product characterized as to composition, acidity index (AI), peroxide index (PI), and analysis of the sn-2 position. The mean hydrolytic activity of free lipase was 23,568.43 ± 559.20 U g-1 and for lipase immobilized in acidified kaolin and diatomite, 1409.04 ± 51.07 and 1235.67 ± 9.56 U g-1 ; immobilization yield of 23.78% and 20.21% and esterification activity of 1827.99 and 1722.66 U g-1 , respectively, maintaining more than 60% of the relative activity after 8 h of incubation at different temperatures. The reaction using the derivative immobilized in acidified diatomite resulted in the degree of incorporation (DI) 41.53% ± 3.99%. CONCLUSIONS AND IMPLICATIONS: From the results, the potential of diatomite and kaolin as support in the immobilization of lipase for the synthesis of dietary TAGs was verified.