An advanced aqueous method of extracting rapeseed oil with high quality

A novel micro-aqueous cold extraction of salmon head oil to reduce lipid oxidation and fishy odor: Comparison with common methods

Traditional heat extraction (HE) has a low efficiency (75.2 wt%) and induces lipid oxidation of PUFAs. The novel micro-aqueous cold (<25 °C) extraction (MAE) was applied to extract salmon head oil. The recovery rate was 93.4 wt% at oil volume fraction Φ = 74 %. The extraction mechanism was agitation-induced droplet coalescence at an unstable and close-packing state (Φ = 74 %), increasing the portions of the large-sized droplets (>50 μm) from 2.8 vol% to 91.7 vol%. The MAE reduced the oil oxidation level and odor intensity compared to HE, although the lipid profile differed slightly. The HE head oil had more key fishy odor compounds, including hexanal (0.98 mg/kg), 3-methyl-butanal (0.25 mg/kg), 1-penten-3-ol (0.49 mg/kg), and 2-ethylfuran (0.19 mg/kg). The MAE oil had only 2-methyl-butanal (0.10 mg/kg) and 1-penten-3-ol (0.47 mg/kg). Overall, micro-aqueous extraction has great potential to replace industrial heat extraction with a better product quality.

New discovery of the coalescence kinetics of sesame oil droplets under a high internal phase: A highly efficient oil extraction technique

Traditional pressing is of low efficiency (< 80 %). A highly efficient sesame oil extraction technique was discovered via micro-hydration of sesame paste (φ = ∼ 75 %) and then agitation with a yield of ∼ 95 %. However, the extraction mechanism is still unknown. To uncover this, microscopic imaging was used, and it found that agitation progressively increased the droplet size of micro-hydrated paste (φ = 74.5 %) from an initial size of < 4 μm. As agitated for 20 min, almost 85 % (v/v) of oil was over 20 μm, which was linearly and positively correlated (R2 > 0.96) with oil yield. Increase in droplet size was due to droplet compression, film rupture, and droplet coalescence. The coalescence frequency based on agitation time followed an exponent curve (R2 > 0.97). This coalescence might be related to the decreased water relaxation time and increased paste viscosity. This study, for the first time, found the oil droplet coalescence in hydrated sesame paste (φ = 74.5 %) during agitation, thereby successfully extracting oil at room temperature. The findings of this work can be a starting point for research on micro-hydration extraction for oil-containing materials from a packing density of oil droplets point view.

High-oleic rapeseed oil quality indicators and endogenous antioxidant substances under different processing methods

This study exposed high-oleic rapeseed oil (HORO) to different pretreatment (microwave or roasting) and processing methods to investigate (cold pressing, hexane extraction, subcritical butane extraction, and aqueous enzymatic extraction) the effects of processing technologies on HORO parameters associated with its physicochemical properties, endogenous antioxidant substances, and antioxidant capacity. The oil yield of various processing technologies was between 35.4% and 59.7%, and the fatty acid composition did not significantly differ. Hierarchical clustering and principal component analyses were used for evaluation. The results revealed that the microwave pretreatment-hexane extraction (M-HE) method resulted in significantly higher levels of tocopherols (688.4 mg/kg), polyphenols (1007.76 mg/kg), and phytosterols (1810.6 mg/kg) in HORO, implying strong free radical scavenging capacity (DPPH-oil: 79.63, DPPH-nonpolar: 71.42, DPPH-polar: 6.65, FRAP: 55.4, ABTS: 3043.7 μmol TE/kg). Hence, M-HE is a promising method for producing HORO with a higher stability and nutritional value.

Polyphenolic compounds from rapeseeds (Brassica napus L.): The major types, biofunctional roles, bioavailability, and the influences of rapeseed oil processing technologies on the content

The rapeseed (Brassica napus L.) are the important oil bearing material worldwide, which contain wide variety of bioactive components with polyphenolic compounds considered the most typical. The rapeseed polyphenols encompass different structural variants, and have been considered to have many bioactive functions, which are beneficial for the human health. Whereas, the rapeseed oil processing technologies affect their content and the biofunctional activities. The present review of the literature highlighted the major types of the rapeseed polyphenols, and summarized their biofunctional roles. The influences of rapeseed oil processing technologies on these polyphenols were also elucidated. Furthermore, the directions of the future studies for producing nutritional rapeseed oils preserved higher level of polyphenols were prospected. The rapeseed polyphenols are divided into the phenolic acids and polyphenolic tannins, both of which contained different subtypes. They are reported to have multiple biofunctional roles, thus showing outstanding health improvement effects. The rapeseed oil processing technologies have significant effects on both of the polyphenol content and activity. Some novel processing technologies, such as aqueous enzymatic extraction (AEE), subcritical or supercritical extraction showed advantages for producing rapeseed oil with higher level of polyphenols. The oil refining process involved heat or strong acid and alkali conditions affected their stability and activity, leading to the loss of polyphenols of the final products. Future efforts are encouraged to provide more clinic evidence for the practical applications of the rapeseed polyphenols, as well as optimizing the processing technologies for the green manufacturing of rapeseed oils.

An advanced aqueous method of recovering pumpkin seed kernel oils and de-oiled meal: Optimization and comparison with other methods

The optimal process conditions of the advanced aqueous method for recovering oil and de-oiled meal from pumpkin seed kernels were: baking the kernels at 110 °C for 1 min, grinding them to pass through a sieve of 150 μm pore size, adding 1.60 ml brine to 10.00 g ground kernels, stirring for 30 min at 30 °C, centrifuging at 4000 r/min for 30 min and cold-pressing the residue from centrifugation. This method recovered > 94% oil. Its oil recovery rate was comparable to that of solvent extraction and higher than that of enzyme-assisted aqueous method or hot-pressing. It recovered edible oil with higher quality and level of coenzyme Q10, tocopherols, carotenoids, total phytosterols and squalene as compared to solvent extraction or hot-pressing and requirements of China’s national standard. It is superior to enzyme-assisted aqueous method or hot-pressing for recovering de-oiled meal which is suitable for making texturized protein.

Optimization and Evaluation of Hydration Method for Cold Recovery of Oils and Defatted Meal from Pinus armandi Seed Kernels

Large quantities of oils and proteins are demanded per year while their production needs environmentally friendly (green), safe, low cost, efficient and sustainable methods. Hydration method for producing Pinus armandi seed kernel oil and defatted meal rich in proteins was therefore developed, which had the following optimal conditions: baking kernels at 130 ℃ for 10 min, grinding them to pass through a 80-mesh sieve, mixing the ground kernel (10.00 g) with 1.00 mL of 8% brine or water and agitating at room temperature for 30 min. This method recovered 96.71% edible oil with vitamin E and K, phytosterols, carotenoids and squalene concentrated and de-oiled meal containing 57.98% proteins and 4.17% oils with ascorbic acid, thiamine, riboflavin, niacin, pantothenic acid, pyridoxine, folate, total phenolic and flavonoids concentrated. It had higher recovery rate and other physicochemical indices of edible oil and was found to be more sustainable as compared with cold pressing, enzyme-assisted aqueous extraction and solvent extraction.