Optimization of the extrusion parameters for the production of lentil-quinoa extrudates enriched with pumpkin

This study aimed to develop a protein-fiber-rich extruded product based on yellow lentil, quinoa, and pumpkin flours. The final product quality is affected by formulation and extrusion parameters. Therefore, the effect of the pumpkin-flour ratio (A: 25-75%) and feed moisture content (C: 14-22%) besides barrel screw speed (B: 120-180 rpm) on the physical attributes of extrudates was investigated. Box-Behnken experimental design and stepwise-response surface method were used to analyze the effects of various process variables and ingredients on extrudates. The pumpkin-flour ratio had a significant positive correlation with bulk density (BD), water solubility index (WSI), and oil absorption index. Whereas the correlation between pumpkin-flour ratio with hardness, porosity, expansion ratio (ER), and water absorption index (WAI) was negative (P < 0.05). The feed moisture content positively affected the water activity (aw) and WAI and negatively affected the harness of samples (P < 0.05). The screw speed had a positive effect on ER, porosity, and WSI, whereas it negatively influenced the hardness, BD, and aw. By increasing the pumpkin-flour ratio, air cell size and wall thickness of samples had been decreased. The results showed that 44.2% pumpkin flour, 22% feed moisture, and 172.1 rpm screw speed gave an optimized product. There was no significant difference between predicted and experimental values (except for ER). The optimized snack was a good source of fiber (around 15%), protein (17.3%), and antioxidants (TPC = 15.28 mg GAE.g-1 and antiradical scavenging activity (DPPH) = 33.66%). The caloric value of the optimized snack was 362.6 cal.100g-1. The current formulation can be considered as the base of snack food or plant-based meat alternatives.

Fabrication of Dragee Containing Spirulina platensis Microalgae to Enrich Corn Snack and Evaluate Its Sensorial, Physicochemical and Nutritional Properties

In this work, the possibility of enriching snacks with Spirulina palatensis (SP) powder as a dragee was studied. In dragee formulation, the effects of various levels of SP, sunflower oil, NaCl and sour whey powder on sensory, physicochemical and nutritional properties were investigated. The dragee formulation was optimized and the characteristics of the optimal sample were compared with the control sample (containing dragee without SP). The results showed that adding SP increased the flavonoids, total anthocyanin content, vitamins, protein, minerals, essential and non-essential amino acids and fatty acids, including ω3 and ω6, while decreasing the energy intake. Based on the results, the optimal dragee sample was formulated and prepared with a desirability of 0.955. The correlation coefficient indicated that the effective optimization process and the performance of the model were carried out properly. The addition of SP had a significant impact on all color parameters considered by the panelists, and the enriched sample was given a very good taste score (75.10 ± 2.923) and an outstanding overall acceptance rate (91.20 ± 1.549) by the panelists. Although morphological data from scanning electron microscopy showed the distribution of non-uniform SP particles relative to the addition of SP in the extruded product formulation, the preservation of more nutritional properties and the good acceptance of sensory evaluators indicated the success of the application in dragee formulation. Therefore, instead of being utilized in an extruder, we discovered that SP may be used as a dragee for snack fortification.

Optimization of culture conditions for enhanced Dunaliella salina productions in mixotrophic culture

Dunaliella salina (D. salina) is a green microalga known for its tendency to produce lipid and β-carotene. Fatty acid profile, lipid and β-carotene productions of the microalga D. salina cultivated under different mixotrophic conditions were assayed. Notably, in spite of a broad spectrum of substrates served, mixotrophic cultivations slightly affected the fatty acid composition, and as a result C16:0 and C18:0, C18:1, C18:2 and C18:3 were identified as main fatty acids. Lipid in dry weight biomass (DWB) hit a high of 24.3% at 5% of NaCL and linolenic acid in lipid reached a peak of 9.15% at 15% of NaCL in medium containing glucose and equal amounts of yeast extract and soy bean powder. One-factor-at-a-time was applied to elucidate the substrates which had noticeable impacts on β-carotene production. Glucose, meat peptone, titanium dioxide nanoparticles (TiO₂ NPs), pH 7.5 and 5% NaCL were identified as key process parameters impacting β-carotene production. Following, the concentration of glucose, meat peptone and TiO₂ NPs were optimized by using response surface method. The highest content of β-carotene, 25.23 mg/g DWB, was obtained in medium composed of (g/L); 22.92 glucose, 5 meat peptone and 0.002 TiO₂ NPs.

Rheological and structural properties of oleogel base on soluble complex of egg white protein and xanthan gum

Oleogels can be used to provide solid-like properties without using high levels of saturated fatty acids. In this study, the edible oleogels structure developed based on egg white protein (EWP) (5%) and xanthan gum (XG) (0%, 1%, 0.5%, and 0.75% wt/wt) complex by using aerogels system as a template for oleogel preparation. The effect of pH on the EWP-XG mixture indicated the creation of a soluble complex of EWP-XG in pH 5.5. The Fourier-transform infrared spectroscopy confirmed the interaction between EWP and XG. The amount of absorbed oil was considerably higher in EWP-XG aerogels. SEM showed a soft surface in EWP 5% aerogel, which can be the reason for its less oil absorption. The aerogel and oleogel including more XG concentration had a stronger network structure and created more elastic oleogels. The light microscopy images revealed by increasing of XG concentration, the structure of protein gel mesh became more compact and regular. The XRD patterns of the aerogels did not show any clear differences between crystallinity of the samples. Therefore, it can be concluded that the aerogels based on the structuring of EWP-XG complexes have a high potential as a three-dimensional network for the oil absorption and creating oleogel.