The Emulsifying Performance of Mildly Derived Extracts from Argan By-products: Towards a Sustainable Production of Natural Emulsifiers

この博士論文は内容の要約のみの公開（または一部非公開）になっています筑波大学 (University of Tsukuba)201

The Emulsifying Performance of Mildly Derived Extracts from Argan By-products: Towards a Sustainable Production of Natural Emulsifiers（アルガン副産物からの抽出物の乳化性の解析と応用 -天然乳化剤の持続的生産をめざして-）

筑波大学 (University of Tsukuba)201

Formulation and stabilization of oil-in-water nanoemulsions using a saponins-rich extract from argan oil press-cake

In this study, we formulated and stabilized oil-in-water nanoemulsions using a crude extract from argan press-cake as sole emulsifier. Various extracts from argan press-cake were prepared in order to select the most surface-active one(s) foreseeing emulsions preparation. Fifty percent (v/v) ethanolic extract reduced the interfacial tension to a minimum value at both MCT oil and soybean oil interfaces (12.7 and 10.5 mN m−1 respectively). This extract was also effective at producing fine emulsions with small droplet sizes (d3,2 < 115 nm) and good physical stability using different oils such as soybean oil, MCT oil and fish oil and at conventional homogenization conditions (100 MPa for 4 passes). On the other hand, the emulsions were very sensitive to NaCl addition (≥25 mM) and to acidic pH (<3) indicating that the main stabilization mechanism is electrostatic, likely due to the presence of surface-active compounds with ionizable groups such as saponins

Emulsion Formation and Stabilizing Properties of Olive Oil Cake Crude Extracts

The surface-active and emulsifying properties of crude aqueous ethanolic extracts from untreated olive oil cake (OOC) were investigated. OOC extracts contained important concentrations of surface-active components including proteins, saponins and polyphenols (1.2–2.8%, 7.8–9.5% and 0.7–4.5% (w/w), respectively) and reduced the interfacial tension by up to 46% (14.0 ± 0.2 mN m−1) at the oil–water interface. The emulsifying ability of OOC extracts was not correlated, however, with their interfacial activity or surface-active composition. Eighty percent aqueous ethanol extract produced the most stable oil-in-water (O/W) emulsions by high-pressure homogenization. The emulsions had average volume mean droplet diameters of approximately 0.4 µm and negative ζ-potentials of about −45 mV, and were stable for up to 1 month of storage at 5, 25 and 50 °C. They were sensitive, however, to acidic pH conditions (&lt;5) and NaCl addition (≥25 mM), indicating that the main stabilization mechanism is electrostatic due to the presence of surface-active compounds with ionizable groups, such as saponins

Plant-Based Food By-Products: Prospects for Valorisation in Functional Bread Development

The industrial and small-scale processing of plant-based food materials is associated with by-products that may have a negative impact on the environment but could add value to bread-based products. The bioactivity of plant-based food by-products, their impact on the properties of functional bread, and their bioavailability/bioaccessibility leading to potential health effects when consumed was reviewed. Plant-based food by-products which may be added to bread include rice bran, wheat bran, corn bran, grape pomace/seed extract, tomato seed/skin, and artichoke stems/leaves. These by-products contain high concentrations of bioactive compounds, including phenolics, bioactive peptides, and arabinoxylan. Pre-treatment procedures, including fermentation and thermal processing, impact the properties of plant-based by-products. In most cases, bread formulated with flour from plant-based by-products demonstrated increased fibre and bioactive compound contents. In terms of the sensory and nutritional acceptability of bread, formulations with an average of 5% flour from plant-based by-products produced bread with acceptable sensory properties. Bread enriched with plant-based by-products demonstrated enhanced bioavailability and bioaccessibility and favourable bioactive properties in human blood, although long-term studies are warranted. There is a need to investigate the bioactive properties of other underutilised plant-based by-products and their potential application in bread as a sustainable approach towards improving food and nutrition security

<i>Limnophila aromatica</i> Crude Extracts as Natural Emulsifiers for Formation and Stabilizing of Oil-in-Water (O/W) Emulsions

This study mainly focused on the emulsifying performance of Limnophila aromatica crude extracts obtained by using different ethanolic aqueous solutions (0, 25, 50, 75, and 99.5% (v/v)). All Limnophila aromatica extracts (LAEs) were able to produce emulsions with a volume mean droplet diameter (d4,3) ranging from 273 to 747 nm, except for LAE-99.5 (3269 nm). Only the emulsion prepared by LAE-75 was stable during seven days of storage, without significantly changing droplet size (479–495 nm). The result showed that all LAEs could reduce interfacial tension varied within 12.5 and 16.1 mN/m at the soybean oil/extracts (1% w/w) interface. Compared to other extracts, LAE-75 did not contain the highest protein, saponin, and phenol content (4.36%, 20.14%, and 11.68%, respectively), but it had the lowest ash content (14.74%). These results indicated that the emulsifying performance of LAEs did not rely only on interfacial tension and/or surface-active compounds. The residual demulsifiers, such as inorganic substances, were also significantly involved in the emulsions’ destabilization. Finally, the emulsion consisting of 0.5% (w/w) LAE-75 and 5% (w/w) soybean oil showed considerable stability during storage up to 30 days at different temperatures (5 or 25 °C). Therefore, Limnophila aromatica extract has a potential application as a new source of natural emulsifier

<i>Cupressus arizonica</i> Greene: Phytochemical Profile and Cosmeceutical and Dermatological Properties of Its Leaf Extracts

For many decades, natural resources have traditionally been employed in skin care. Here, we explored the phytochemical profile of the aqueous and ethanolic leaf extracts of Cupressus arizonica Greene and assessed their antioxidant, antiaging and antibacterial activities in vitro. Liquid chromatography–mass spectrometry (LC-MS/MS) analysis led to the tentative identification of 67 compounds consisting mainly of phenolic and fatty acids, diterpene acids, proanthocyanidins and flavonoid and biflavonoid glycosides. The aqueous extract demonstrated substantial in vitro antioxidant potential at FRAP and DPPH assays and inhibited the four target enzymes (collagenase, elastase, tyrosinase, and hyaluronidase) engaged in skin remodeling and aging with IC50 values close to those of the standard drugs. Moreover, the aqueous extract at 25 mg/mL suppressed biofilm formation by Pseudomonas aeruginosa, a bacterial pathogen causing common skin manifestations, and decreased its swarming and swimming motilities. In conclusion, C. arizonica leaves can be considered a promising candidate for potential application in skin aging