Simplex-Centroid Mixture Design Applied to the Aqueous Enzymatic Extraction of Fatty Acid-Balanced Oil from Mixed Seeds

Blue honeysuckle seeds and seed oil: Composition, physicochemical properties, fatty acid profile, volatile components, and antioxidant capacity

Blue honeysuckle seeds are often overlooked by the processing industry, but they are a good source of healthy oil. The composition, volatiles, and antioxidant capacity of blue honeysuckle seeds and seed oil were investigated for the first time. The fatty acid profile of the seed oil was analysed using GC-MS. The seed oil was particularly rich in polyunsaturated fatty acid, especially linoleic acid (71.24 ± 1.64 %). HS-SPME-GC-MS analysis temporarily detected 34 and 37 volatiles in the seeds and seed oil, respectively. Notably, aldehydes were identified as the major contributors to the aroma. The phytosterols, tocopherols, and triglycerides were identified in the seed oil. Interestingly, the total phenolic content and antioxidant capacity of the seeds were found to be much higher than the seed oil. This study evaluates the nutritional profile and value of blue honeysuckle seed oil, and suggests that it can be used as new functional oil.

Effect of cavitation jets on the physicochemical properties and structural characteristics of the okara protein

The structural andphysicochemical properties of okara protein (OP) subjected to different cavitation jet (CJ) treatment times (0-15 min) were analyzed. In this study, the microstructure and apparent morphology of OP were analyzed by Raman spectrum, fluorescence spectrum, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and atomic force microscopy (AFM). Physicochemical properties, such as emulsion ability (EA), emulsion stability index (ESI), foaming characteristics (FC), foaming stability (FS), and solubility analysis of the OPs, were characterized. Raman spectrum analysis showed that CJ treatment caused increases in the ordered structure of OPs (α-helix, β-sheet, and β-turn), and the disulfide bond g-g-g and g-g-t modes, while it caused a decrease in the t-g-t mode. However, the tertiary structure of OP unfolded and mostly degraded into small subunits because of higher cavitation, shear and temperature effects. AFM observation indicated that CJ resulted in a more uniform distribution of OP. Moreover, changes in the structure of OP significantly affected its functional properties. The results showed that when CJ treatment time was 10 min, the solubility of OP was up to (28.72 ± 1.26)%, the soluble protein content of okara was up to (10.44 ± 0.03) g/100 g, and interface properties were better. In summary, OP has great potential for application in the food area, especially in emulsifying agent and foam system. PRACTICAL APPLICATION: The cavitation jet technology improves the structure and physical and chemical properties of the protein extracted from soybean residue (okara) and provides new ideas for the further development and utilization of soybean residue protein, which may lead to the production of high-value-added functional ingredients from the processing of soybean byproducts.

Background, Applications and Issues of the Experimental Designs for Mixture in the Food Sector

BACKGROUND

Mixtures play a key role in Food Science and Technology. For studying them, rational approaches should be used. In detail, the experimental designs for mixtures are useful tools for studying the effects of ingredients/components in formulations.

RESULTS

Food Science and Technology is the fourth category among the total records considered in this review. The applications span from food formulation to the composition of modified atmosphere, shelf-life improvement and bioactives extraction. However, the majority of the studies regards few products and ingredients. Simplex-lattice and simplex-centroid designs are the most common used, although some optimal designs, such as the D-optimal, have also interesting applications. Finally, some issues are highlighted, which basically regard the interpretation of the models coefficients and the lack of model validation.

CONCLUSION

In the last decade, mixture designs have been fairly used in the field of Food Science and Technology. Modeling the response(s) allows researchers to achieve a global knowledge of the system under study within the defined experimental domain. However, the majority of application has regarded limited classes of products, and thus an increase in the spectrum of applications is desired.

Development of walnut oil and almond oil blends for improvements in nutritional and oxidative stability

For the increase in oxidative stability and phytonutrient contents of walnut oil (WO), 5, 10, 20 and 30% blends with almond oil (AO) were prepared. The fatty acid compositions and the micronutrients of the oil samples such as tocopherol, phytosterol and squalene were measured by GC-MS and HPLC. It was found that the proportions of PUFAs/SFAs in blended oils with high AO contents were lowered, and the blends contained higher levels of tocopherols, phytosterols and squalene than those of pure WO. The 60 °C oven accelerated oxidation test was used to determine the oxidative stability of the blended oil. The fatty acid composition, micronutrients and oxidation products were determined. The results showed that the oxidation stability of the blended oil increased with an increasing proportion of AO. In addition, a significant negative correlation between micronutrient and oxidation products was observed as the number of days of oxidation increased.

NiO, Fe2O3, and MoO3 Supported over SiO2 Nanocatalysts for Asphaltene Adsorption and Catalytic Decomposition: Optimization through a Simplex–Centroid Mixture Design of Experiments

The main objective of this study was to evaluate the effect of functionalized silica nanoparticles with Fe2O3, NiO, and MoO3 metal oxides on the decomposition of asphaltenes, through an experimental simplex–centroid mixture design for surface area, asphaltene adsorption, and activation energy. The experimental nanoparticle surface area was measured by adsorption of N2. Adsorption isotherms, and the subsequent oxidation process of asphaltenes, were performed through batch adsorption experiments and thermogravimetric analysis, respectively. Among the monometallic systems, the presence of iron increased the affinity between the nanoparticle and the asphaltenes, and a higher metal oxide load increased the adsorptive capacity of the system. For the pairings evaluated, there was better synergy between iron and nickel, with the participation of the former being slightly superior. In the mixture design that included three transition elements, the participation of molybdenum was not significant, and the adsorption of asphaltenes was dominated by the active sites formed by the other two transition element oxides. The mixture design created to minimize the activation energy showed that the interaction of the three transition elements is important and can be evidenced in the interaction coefficients.

Effects of natural herbal extracts on hemp (Cannabis Sativa L.) oil quality indicators

The present research features such natural herbal extracts as rosemary (Rosmarinus officinalis L.), pome- granate (Punica granatum L.), and green tea (Camellia sinensis L.). Together with vitamin E, they were chosen to investigate hemp oil stability. The experiments revealed the effect of various fatty acids compositions on hemp oil properties. The effect of herbal extracts on the oxidative stability of oils was measured using the Rancimat method. The chemical tests included peroxide value (PV), free fatty acid (FFA) value, and acidity value (AV). Each herbal extract was applied in amounts of 30 mg/l and 50 mg/l. Vitamin E was mixed with the oil in the amount of 2 g/l. The changes in PV, FFA, AV, and fatty acid composition were measured on day 6, 12, 18, and 24. Hemp oil, pure or mixed with the extracts, was analyzed using the Rancimat method at 120°C with an airflow rate of 20 l/h to identify the in- duction periods (IP). IP values of oils with additional herbal extracts were found to be significantly higher (p < 0.05) than those of the control samples. The oil sample with vitamin E demonstrated the longest IP (4.12 hours at 120°C) during the Rancimat test. The herbal extracts and vitamin E had a positive effect on hemp oil PV compared with the control sample. Gas chromatography (GC) showed that hemp oil included a high amount of polyunsaturated Ome- ga-3 fatty acids, and the oil was not resistant to oxidation. In general, the natural herbal extracts and vitamin E in the recommended quantities had a positive effect on the oxidative stability of hemp oil.

Molecular Distillation-Induced Deacidification of Soybean Oil Isolated by Enzyme-Assisted Aqueous Extraction: Effect of Distillation Parameters

Soybean oil isolated by enzyme-assisted aqueous extraction (EAE) was subjected to molecular distillation-induced deacidification, and the effects of evaporator temperature, scraper speed, and feed flow rate on oil quality (acid value, color, peroxide value, p-anisidine value, tocopherol content, and fatty acid content) were evaluated to determine the suitable deacidification conditions. Fatty acid content was largely unaffected by evaporator temperature and scraper speed, while an increase of these parameters decreased tocopherol content as well as acid, peroxide, and p-anisidine values and resulted in Lovibond color deepening. The increase of feed flow rate had an opposite effect on the above quality indices. As a result, molecular distillation of EAE-produced soybean oil under suitable conditions (evaporator temperature = 180 °C, scraper speed = 220 rpm, feed flow rate = 4 mL/min) was found to afford a high-quality deacidified product in an environmentally friendly way.

Conformational and Functional Properties of Soybean Proteins Produced by Extrusion-Hydrolysis Approach

The conformational and functional changes of soybean protein after a hybrid extrusion-hydrolysis method were evaluated. Three extrusion temperatures (60, 80, and 100°C) were used prior to enzymatic hydrolysis. The hydrolysis degrees, molecular weight profiles, solubilities, surface hydrophobicities, sulphydryl contents, disulfide bound, water holding capacity, emulsion, and foam properties of the protein isolated from the enzyme-hydrolyzed extruded soybeans were analyzed. It shows that extrusion caused significant changes in the hydrophobicity, molecular weight distribution, solubility, surface hydrophobicity, emulsification activity, and stability of the protein. The increase of molecular weights could be attributed to the formation of protein aggregates during extrusion. Extrusion and enzymatic hydrolysis led to a sharp increase in the number of disulfide bonds with a decrease of the sulphydryl group. The water holding capacity and the solubility of protein increased with the increase of extrusion temperature and hydrolysis time. Extrusion improved the emulsifying activity but reduced the emulsifying stability of the recovered proteins. Extrusion improved the foam capacity but reduced the foam stability of the proteins. The data demonstrated that the extrusion-hydrolysis treatment significantly altered the conformational and functional properties of soybean protein, which may be further optimized for the development of new soy protein ingredient with desired functional properties.

3D confocal Raman imaging of oil-rich emulsion from enzyme-assisted aqueous extraction of extruded soybean powder

The understanding of the structure morphology of oil-rich emulsion from enzyme-assisted extraction processing (EAEP) was a critical step to break the oil-rich emulsion structure in order to recover oil. Albeit EAEP method has been applied as an alternative way to conventional solvent extraction method, the structure morphology of oil-rich emulsion was still unclear. The current study aimed to investigate the structure morphology of oil-rich emulsion from EAEP using 3D confocal Raman imaging technique. With increasing the enzymatic hydrolysis duration from 1 to 3 h, the stability of oil-rich emulsion was decreased as visualized in the 3D confocal Raman images that the protein and oil were mixed together. The subsequent Raman spectrum analysis further revealed that the decreased stability of oil-rich emulsion was due to the protein aggregations via SS bonds or protein-lipid interactions. The conformational transfer in protein indicated the formation of a compact structure.

High-performance size-exclusion chromatography studies on the formation and distribution of polar compounds in camellia seed oil during heating

Camellia seed oil (CSO) is rich in oleic acid and has a high number of active components, which give the oil high nutritional value and a variety of biological activity. The aim of the present study was to determine the changes in the content and distribution of total polar compounds (TPC) in CSO during heating. TPC were isolated by means of preparative flash chromatography and further analyzed by high-performance size-exclusion chromatography (HPSEC). The TPC content of CSO increased from 4.74% to 25.29%, showing a significantly lower formation rate as compared to that of extra virgin olive oil (EVOO) and soybean oil (SBO) during heating. Furthermore, heating also resulted in significant differences (P<0.05) in the distribution of TPC among these oils. Though the content of oxidized triacylglycerol dimers, oxidized triacylglycerol oligomers, and oxidized triacylglycerol monomers significantly increased in all these oils, their increased percentages were much less in CSO than those in EVOO, indicating that CSO has a greater ability to resist oxidation. This work may be useful for the food oil industry and consumers in helping to choose the correct oil and to decide on the useful lifetime of the oil.

Differential scanning calorimetry study--assessing the influence of composition of vegetable oils on oxidation

The thermal oxidation of eight different vegetable oils was studied using differential scanning calorimetry (DSC) under non-isothermal conditions at five different heating rates (5, 7.5, 10, 12.5, and 15°C/min), in a temperature range of 100-400°C. For all oils, the activation energy (Ea) values at Tp were smaller than that at Ts and Ton. Among all the oils, refined palm oil (RPO) exhibited the highest Ea values, 126.06kJ/mol at Ts, 134.7kJ/mol at Ton, and 91.88kJ/mol at Tp. The Ea and reaction rate constant (k) values at Ts, Ton, and Tp were further correlated with oil compositions (fatty acids and triacylglycerols) using Pearson correlation analysis. The rate constant (k) and Ea of all oils exhibited varying correlations with FAs and TAGs, indicating that the thermal oxidation behaviors were affected by oil compositions.

Effect of co-products of enzyme-assisted aqueous extraction of soybeans on ethanol production in dry-grind corn fermentation

Enzyme-assisted aqueous extraction processing (EAEP) is an environmentally-friendly alternative to solvent and mechanical oil extraction methods, and can achieve ∼ 97% oil recovery from soybeans. The present study utilized soy skim (protein rich) and insoluble fiber (IF; carbohydrate rich), both co-products of EAEP, in dry-grind corn fermentation. The effects of adding soy skim and untreated IF (UIF), either separately or together, and adding pretreated IF (TIF), on ethanol production were investigated. Maximum ethanol production was achieved when UIF and skim were slurried together (corn-to-UIF ratio 1:0.16; skim-to-UIF ratio 6.5:1) and when fiber-hydrolyzing enzymes were added to corn fermentation. This modification to corn fermentation increased ethanol yield by 20%, ethanol production rate by 3%, and decreased fermentation time by 38 h compared to corn-only fermentation. An attempt was also made to utilize pentoses (from soy skim and IF) in integrated corn-soy fermentation slurry by an additional Escherichia coli KO11 fermentation step.

Effect of extruding full-fat soy flakes on trans fat content

To evaluate the effects of extrusion process on the trans fatty acids (TFAs) formation in soybean crude oils, three different extrusion parameters, namely, extrusion temperature (80-160 °C), feed moisture (10-26%), and screw speed (100-500 rpm), were carried out. It was found that only five different types of TFAs were detected out using gas chromatography-mass spectrometry. Before the extrusion started, the initial amount of total TFAs was 3.04 g/100 g. However, after extruding under every level of any variable, the total amounts of TFAs were significantly higher than those in the control sample (P < 0.05). For example, taking the effect of extrusion temperature into account, we can find that the highest amount of total of trans fatty acid (TTFA) was 1.62 times the amount of that in the control sample, whereas the lowest amount of TTFA was 1.54 times the amount of that in the control sample. Importantly, it was observed that the amounts of every type of trans fatty acid were not continuously increasing with the increase of the level of any extrusion variable. This phenomenon demonstrated that the formation and diversification were intricate during extruding process and need to be further studied.

Heating Quality and Stability of Aqueous Enzymatic Extraction of Fatty Acid-Balanced Oil in Comparison with Other Blended Oils

The heating performance of enzyme-assisted aqueous processing-extracted blended oil (EAEPO), hexane-extracted blended oil (HEBO), and three kinds of blended oils was investigated by varying the heating times. Oil degradation was monitored by analysis of the acid value (AV), peroxide value (PV),p-anisidine value (p-AV), color, and trans-fatty acid composition. The fatty acid ratios of EAEPO, HEBO, and the three kinds of blended oils were very similar (0.27 : 1.03 : 0.96, 0.27 : 1.08 : 1.16, 0.27 : 0.65 : 0.8, 0.27 : 0.6 : 0.84, and 0.27 : 0.61 : 0.79, resp.). The AV and color increased in proportion to the heating time for all the oils. There was a rapid increase in the PV andp-AV of EAEPO and HEBO after heating for only 1 h, whereas the other three blended oils showed a rapid increase after heating for 2 h or 6 h. Despite the highest trans-fatty acid content found for HEBO, this content was relatively low and remained low up to a heating time of 8 h. It was found that after heating, a fatty acid ratio relatively close to its ideal value (0.27 : 0.48 : 0.49) was maintained by EAEPO, which indicates that EAEPO is tolerant to heat treatment and is suitable for maintaining a healthy diet.