Optimization and Characterization of Interspecific Hybrid Crude Palm Oil Unaué HIE OxG Nanoparticles with Vegetable By-Products as Encapsulants.

Interspecific hybrid crude palm oil (HCPO) HIE OxG derived from crossbred African oil palm (Elaeis guineensis) and American Caiaué (Elaeis oleifera) is prominent for its fatty acid and antioxidant compositions (carotenoids, tocopherols, and tocotrienols), lower production cost, and high pest resistance properties compared to crude palm oil. Biodegradable and sustainable encapsulants derived from vegetable byproducts were used to formulate HCPO nanoparticles. Nanoparticles with hybrid crude palm oil and jackfruit seed flour as a wall material (N-JSF) and with hybrid crude palm oil and jackfruit axis flour as a wall material (N-JAF) were optimized using a 22 experimental design. They exhibited nanoscale diameters (<250 nm) and were characterized based on their zeta potential, apparent viscosity, pH, color, and total carotenoid content. The nanoparticles demonstrated a monodisperse distribution, good uniformity, and stability (polydispersity index < 0.25; zeta potentials: N-JSF -19.50 ± 1.47 mV and N-JAF -12.50 ± 0.17 mV), as well as high encapsulation efficiency (%) (N-JSF 86.44 ± 0.01 and N-JAF 90.43 ± 1.34) and an optimal carotenoid retention (>85%). These nanoparticles show potential for use as sustainable and clean-label HCPO alternatives in the food industry.

Insect residues as an alternative and promising source for the extraction of chitin and chitosan.

This work aimed to obtain and characterize chitin and chitosan extracted from the rearing residues of Tenebrio molitor, Zophobas morio, and Blaptica dubia insects in different growth stages in the same rearing cycles chitin and chitosan yielded 11.21 %-20.89 % and 6.26 %-7.07 %, respectively. The deacetylation degrees of chitosan ranged from 75.75 %-89.21 %, and the solubilities from 69.88 %-94.39 %. Infrared spectroscopy corroborated the acquisition of chitin and chitosan and can be used as a semi-quantitative technique for determining the degree of chitosan deacetylation. The X-ray diffraction profiles revealed the presence of α-chitin, and the relative crystalline indices ranged from 65.9 %-89.2 %. Typical TG profiles with two thermal events are observed for chitin and chitosan samples with different residue contents from the extraction procedure. The chitosan solutions exhibited pseudoplastic behavior, with apparent viscosities ranging from 195.96 to 249.86 mPa.s. The characterization results of the biopolymers extracted from insect residues were similar to those obtained from conventional sources. The growth stage influenced the chitin yield and crystallinity index. The results of this study reinforce the feasibility of using alternative sources of chitin and chitosan, providing the use of waste from insect farms and contributing to sustainability and a circular economy.

Optimization of enhanced oil recovery using ASP solution.

Many studies have been conducted to focused on developing an optimal alkali/surfactant/polymer (ASP) composition to increase the recovered fraction of oil in reservoirs that have already undergone water injection. To analyze the effect of alkali (Na2CO3), surfactant (lauryl sodium sulfate), and polymer (commercial xanthan gum) concentration on oil recovery, a complete factorial experimental design was performed with combinations of three variables (alkali, surfactant, and polymer) and three central point replications (2³ + 3). The experiments were carried out on a core holder using rock samples from the Botucatu formation. The simulated oil reservoirs have an average permeability of 348 mD and a temperature of 60 °C. The crude oil was acquired from the Carmópolis field, with 25.72 °API. Synthetic production water containing 40,000 mg L-1 of NaCl and 13,000 mg L-1 of Na2SO4 was injected through an HPLC pump to saturate the rock samples and to recover the oil in the secondary step. From the experimental results, it was verified that the surfactant and polymer concentrations are the most statistically significant independent variables and that first-order interactions are not statistically significant for the process. The oil recovery factors in the secondary stage ranged between 30 and 36 % of the OOIP, which are within the range reported in the literature. The optimal composition of the ASP fluid obtained a recovered fraction of oil of 62 % in the advanced step. Other combinations reported in the literature used higher concentrations of alkali, surfactant, and polymer with lower recoveries and higher cost in the injection design. Thus, the present study highlights the necessity to investigate the performance of each component of the ASP solution. In addition, the results obtained in this study are very attractive for possible full-scale applications.

Production and characterization of Spirulina sp. LEB 18 cultured in reused Zarrouk's medium in a raceway-type bioreactor.

The objective was to evaluate the effect of reusing Zarrouk's medium on a Spirulina sp. LEB 18 culture by determining kinetic parameters, chemical composition, biofuels, and thermal characterization. Cultivation was performed in a raceway bioreactor for 7 days, the supernatant was reused for four cycles. Culturing the microalga in the reused medium resulted in a cellular yield of 2.30 g L-1 (control) and 2.04, 1.89, 1.73, and 1.15 g L-1 for four cycles with no influence on cell growth and productivity. Biomass with high contents of carbohydrates (58.00%, 3rd cycle), phycocyanin (2.47 mg mL-1, 1st cycle), and saturated fatty acids (60.13%, 4th cycle) were obtained with an increase in the profiles of C16:0 (45.85%) and C18:2n6 (47.40%) in the 1st cycle. The reuse of Zarrouk's medium allowed obtaining biomass with reduced cost and differentiated characteristics, allowing the exploration of commercially important biomolecules by the completion of up to four cycles.

Influence of nitrogen on growth, biomass composition, production, and properties of polyhydroxyalkanoates (PHAs) by microalgae.

This study sought to evaluate influence of nitrogen availability on cell growth, biomass composition, production, and the properties of polyhydroxyalkanoates during cultivation of microalgae Chlorella minutissima, Synechococcus subsalsus, and Spirulina sp. LEB-18. The cellular growth of microalgae reduced with the use of limited nitrogen medium, demonstrating that nitrogen deficiency interferes with the metabolism of microorganisms and the production of biomass. The biochemical composition of microalgae was also altered, which was most notable in the degradation of proteins and chlorophylls and the accumulation of carbonaceous storage molecules such as lipids and polyhydroxyalkanoates. Chlorella minutissima did not produce these polymers even in a nitrogen deficient environment. The largest accumulations of the polyhydroxyalkanoates occurred after a 15 days culture, with a concentration of 16% (dry cell weight) produced by the Synechococcus subsalsus strain and 12% by Spirulina sp. LEB-18. Polyhydroxyalkanoates produced by Synechococcus subsalsus and Spirulina sp. LEB-18 presented different thermal and physical properties, indicating the influence of producing strain on polyhydroxyalkanoates properties. The polymers obtained consisted of long chain monomers with 14 to 18 carbon atoms. This composition is novel, as it has not previously been found in PHAs obtained from Synechococcus subsalsus and Spirulina sp. LEB-18.

Investigation of cellular fatty acid composition of Xanthomonas spp. as chemical markers of productivity and quality of xanthan gum.

In this study, we investigated the cellular fatty acid profiles of different Xanthomonas pathovars producing xanthan gum and explored the fatty acid composition to identify chemical markers of xanthan gum productivity and quality. Three Xanthomonas pathovars were studied. The fermentation was conducted for 168 h. Samples from the fermented medium were collected for extraction, quantification, and characterization of xanthan. The unsaturated/saturated (U/S) fatty acid ratio in Xanthomonas cells during fermentation was correlated with production, viscosity, and molecular weight of the gum obtained at each 24 h. The Xanthomonas axonopodis pv manihotis 290 strain showed a higher U/S ratio for major cell fatty acids (C16:1ω7/C16:0) as compared with the other two strains; this high ratio was directly associated with xanthan production. No correlation was observed between cellular fatty acid composition and characteristics of xanthan synthesized. Thus, it was possible to determine a production chemical marker for xanthan gum in Xanthomonas strains.

Properties and antioxidant action of actives cassava starch films incorporated with green tea and palm oil extracts.

There is an interest in the development of an antioxidant packaging fully biodegradable to increase the shelf life of food products. An active film from cassava starch bio-based, incorporated with aqueous green tea extract and oil palm colorant was developed packaging. The effects of additives on the film properties were determined by measuring mechanical, barrier and thermal properties using a response surface methodology design experiment. The bio-based films were used to pack butter (maintained for 45 days) under accelerated oxidation conditions. The antioxidant action of the active films was evaluated by analyzing the peroxide index, total carotenoids, and total polyphenol. The same analysis also evaluated unpacked butter, packed in films without additives and butter packed in LDPE films, as controls. The results suggested that incorporation of the antioxidants extracts tensile strength and water vapor barrier properties (15 times lower) compared to control without additives. A lower peroxide index (231.57%), which was significantly different from that of the control (p<0.05), was detected in products packed in film formulations containing average concentration of green tea extracts and high concentration of colorant. However, it was found that the high content of polyphenols in green tea extract can be acted as a pro-oxidant agent, which suggests that the use of high concentration should be avoided as additives for films. These results support the applicability of a green tea extract and oil palm carotenoics colorant in starch films totally biodegradable and the use of these materials in active packaging of the fatty products.