RESUMO
Arthrospira maxima is a microalga that has been collected in Lake Texcoco in the Valley of Mexico since pre-Hispanic times and has been a traditional food source due to its high biomass production and protein content (50-60 %), making it promising for protein extraction. In this context, a protein isolate was obtained from powdered biomass of Arthrospira maxima (PbAm) by alkaline solubilization (pH 11) and isoelectric precipitation (pH 4.2). Arthrospira maxima protein isolate (AmPI) presented higher protein content (82.58 %) and total amino acids compared to PbAm. Functional properties of AmPI were evaluated in comparison with PbAm and soy protein isolate (SPI). Protein extraction resulted in a significant increase in protein solubility (PS) and foaming capacity (FC) of up to 87.78 % and 238.10 %, respectively. Emulsifying capacity (EC) of AmPI was superior to that of PbAm and SPI in pH range 5-7. Inclusion of AmPI as a partial substitute for SPI in the formulation of meat sausages was evaluated by implementing four treatments: T1 (15 % AmPI, 85 % SPI), T2 (10 % AmPI, 90 % SPI), T3 (5 % AmPI, 95 % SPI) and T4 (0 % AmPI, 100 % SPI). Although the texture attributes remained unchanged, a significant reduction in color parameters was observed as the concentration of AmPI increased. An inclusion of 15 % AmPI significantly enhanced the nutritional quality of meat sausages. Results highlight the excellent properties of AmPI, confirming Arthrospira maxima as a promising protein source in the food industry.
RESUMO
The effect of different process variables, such as solid/liquid ratio (1: 1, 1: 3, or 1: 5 g/ml) and stirring speeds (0, 200, or 400 rpm), was studied on the extraction mechanisms of eucalyptus essential oil obtained by hydrodistillation (HD). Different performance parameters such as obtained yield, energy requirements, and environmental impact were compared to those obtained by steam distillation (SD). Two different mathematical models were used to describe the process behavior. The obtained results indicate that the system with a solid/liquid ratio of 1:5 g/ml using a stirring speed of 400 rpm yielded maximum for HD (1.19% ± 0.01%). The environmental impact expressed as Ecopoints (EI99) ranged between 50.87 ± 13.18 and 78.17 ± 13.82 mPT/g essential oil (EO) for systems with steam injection, whereas for HD took values between 16.9 ± 0.3 and 19.24 ± 1.4 mPT/g EO at optimal operating conditions. The model parameters allowed us to identify that large amounts of steam at lower heating velocities induce a high accumulation of EO in the aqueous layer (vapor-liquid equilibrium at the interface), favoring the extraction process.
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Chia seeds provide a suitable environment for microorganisms. However, it is difficult to disinfect these seeds with water and/or chemical disinfectant solutions because the mucilage in the seeds can absorb water and consequently form gels. High-intensity light pulses (HILP) is one of the most promising emerging technologies for inactivating microorganisms on surfaces, in clear liquids and beverages, and on solid foods. The aim of this work was to evaluate the effect of HILP on Salmonella Typhimurium in culture medium (in vitro tests) and inoculated onto chia seeds (in vivo tests). HILP was effective against Salmonella Typhimurium under both conditions: 8 s of treatment (10.32 J/cm2) resulted in a 9-log reduction during in vitro tests, and 15 s of treatment (19.35 J/cm2) resulted in a 4-log reduction on the inoculated chia seeds. Salmonella Typhimurium inactivation kinetics were accurately described using the Weibull model (R2 > 0.939). These results indicate that the use of HILP for microbial inactivation on seeds could generate products suitable for human consumption.
Assuntos
Manipulação de Alimentos , Microbiologia de Alimentos , Viabilidade Microbiana , Salmonella typhimurium , Salvia , Sementes , Manipulação de Alimentos/métodos , Microbiologia de Alimentos/métodos , Salmonella typhimurium/efeitos da radiação , Salvia/microbiologia , Sementes/microbiologia , ÁguaRESUMO
Complex coacervation between gelatin type B (GE) and chia mucilage (ChM) was studied. GE-ChM were mixed at mass ratios of 1:1, 2:1, 3:1, 4:1, and 1:2 in a pH range of 1.50 to 5.00, maintaining a total solid concentration of 0.2% (w/w), using turbidity and viscosity tests to obtain the highest yield of complex coacervates. To characterize the complex coacervates, morphology and Fourier-transform infrared spectroscopy (FTIR) were determined. The optimum yield for complex coacervation was achieved with a GE-ChM mass ratio of 2:1 and pH value of 3.6. The critical pH values associated with the formation of soluble (pHc ) and insoluble (pHɸ1 ) complexes, and complete dissociation (pHɸ2 ) at the optimum GE-ChM ratio were found to be 4.50, 4.10, and 2.00, respectively. It was observed that increasing the mass ratio of GE or ChM, the yield of complex coacervates decreased; the higher yields were obtained with the proportions of 2:1 and 1:1 with values of 68.25 ± 0.05% and 61.04 ± 0.05%, respectively. Capsules formed at mass ratios of 1:1, 2:1, and 3:1, had the characteristic grape agglomerate shape for complex coacervates. Further characterization with scanning electron microscopy (SEM) showed a spherical shape for capsules. FTIR spectrum of complex coacervates at optimum conditions had a combination of bands corresponding to GE and ChM, suggesting an interaction between GE-ChM during the formation of complex coacervates. Therefore, complex coacervates between GE-ChM can be formed, and could be used as an alternative as encapsulating agents to be applied in the food industry. PRACTICAL APPLICATION: Complex coacervation is a technique that is being studied in several applications in the food industry. However, studies are still being made to explore different possibilities of natural sources to be used in complex coacervation. This study showed that the combination of gelatin and chia mucilage may be an alternative as encapsulating agents for complex coacervation to be applied in the food industry.
Assuntos
Gelatina/química , Mucilagem Vegetal/química , Salvia/química , Cápsulas/química , Concentração de Íons de Hidrogênio , Sementes/química , Espectroscopia de Infravermelho com Transformada de Fourier , ViscosidadeRESUMO
Edible films can incorporate antimicrobial agents to provide microbiological stability, since they can be used as carriers of a wide number of additives that can extend product shelf life and reduce the risk of pathogenic bacteria growth on food surfaces. Addition of antimicrobial agents to edible films offers advantages such as the use of low antimicrobial concentrations and low diffusion rates. The aim of this study was to evaluate inhibition of Aspergillus niger and Penicillium spp. by selected concentrations of Mexican oregano (Lippia berlandieri Schauer) essential oil added to amaranth, chitosan, or starch edible films. Oregano essential oil was characterized by gas chromatography-mass spectrometry (GC/MS) analysis. Amaranth, chitosan, and starch edible films were formulated with essential oil concentrations of 0%, 0.25%, 0.50%, 0.75%, 1%, 2%, and 4%. Mold radial growth was evaluated inoculating spores in 2 ways: edible films were placed over inoculated agar, Film/Inoculum mode (F/I), or the edible films were first placed in the agar and then films were inoculated, Inoculum/Film mode (I/F). The modified Gompertz model adequately described growth curves. There was no significant difference (P > 0.05) in growth parameters between the 2 modes of inoculation. Antifungal effectiveness of edible films was starch > chitosan > amaranth. In starch edible films, both studied molds were inhibited with 0.50% of essential oil. Edible films added with Mexican oregano essential oil could improve the quality of foods by controlling surface growth of molds.