Food Science and Technology

Permanent URI for this collection

https://escholar.umt.edu.pk/handle/123456789/3176

Browse

Now showing 1 - 6 of 6

Formulation and characterization of astaxanthin-enriched nanoemulsions stabilized using ginseng saponins as natural emulsifiers
(Food Chemistry, 2018) Shu, Gaofeng; Nauman Khalid; Chen, Zhang; A. Neves, Marcos; J. Barrow, Colin; Nakajima, Mitsutoshi
In this study ginseng saponins (GS) were used as natural emulsifiers to formulate and stabilize O/W nanoemulsions loaded with astaxanthin (AST). GS were found to be highly effective at reducing the interfacial tension at the soybean oil–water interfaces, and were capable of producing nano-scaled droplets (d4,3 ≈ 125 nm) using a high-pressure homogenizer. The droplet size of the nanoemulsions decreased with increasing emulsifier concentration and homogenization pressure. The nanoemulsions were stable without droplet coalescence against thermal treatment (30–90 °C, 30 min), and over a narrow range of pH values (7–9). GS-coated droplets were unstable in acidic conditions (pH 3–6) and in the presence of salt (>25 mM NaCl). The formulated nanoemulsions showed slight change in d4,3 during 15 days of storage at 5, 25 and 40 °C. However, the chemical stability strongly depended on the storage temperature, with the lowest level of AST retained in nanoemulsions stored at higher temperature.
Formulation and characterization of water-in-oil nanoemulsions loaded with acai� berry anthocyanins: insights of degradation kinetics and stability evaluation of anthocyanins and nanoemulsions
(Food Research International, 2018) A.S. Rabelo, Cezar; Taarji, Noamane; Nauman Khalid; Kobayashi, Isao; Nakajima, Mitsutoshi; A. Neves, Marcos
Açaí berry is the fruit of an Amazonian palm tree and rich in anthocyanins (ACNs). Scientific studies have proven the health benefits of açaí berry and declared this fruit as “super fruit”. ACNs have high antioxidant activities, but they are unstable and can easily deteriorate during food processing. In order to protect ACNs and increase their applicability, food-grade water-in-oil (W/O) emulsions were successfully formulated with different concentrations of açaí berry extracts (AEs). The formulated W/O nanoemulsions were relatively stable, with no phase separation after 30 days of storage. The average droplet size varied between 146.8 to 814.8 nm, with higher values corresponding to samples without AEs. All W/O nanoemulsion samples exhibited antioxidant activity and high retention rates of polyphenols after 30 days of storage. ACN retention followed firstorder kinetics, with high protection of ACNs observed in emulsified samples. 2% AE encapsulated in a 30 wt% W/O nanoemulsion had an estimated half-life of 385 days. The results indicate that stable nanoemulsion systems with high ACN protection can be produced with possible applications in the food and pharmaceutical industries.
Formulation and stabilization of oil-in-water nanoemulsions using a saponinsrich extract from argan oil press-cake
(Food Chemistry, 2010) Taarji, Noamane; A. Rabelo da Silva, Cezar; Nauman Khalid; Gadhi, Chemseddoha; Hafidi, Abdellatif; Kobayashi, Isao; A. Neves, Marcos; Isoda, Hiroko; Nakajima, Mitsutoshi
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.
Gypenosides as natural emulsifiers for oil-in-water nanoemulsions loaded with astaxanthin: insights of formulation, stability and release properties
(Food Chemistry, 2018) Chen, Zhang; Shu, Gaofeng; Taarji, Noamane; J. Barrow, Colin; Nakajima, Mitsutoshi; Nauman Khalid; A. Neves, Marcos
The formulation, physicochemical stability and bioaccessibility of astaxanthin (AST) loaded oil-in-water nanoemulsions fabricated using gypenosides (GPs) as natural emulsifiers was investigated and compared with a synthetic emulsifier (Tween 20) that is commonly applied in food industry. GPs were capable of producing nanoemulsions with a small volume mean diameter (d4,3 = 125 ± 2 nm), which was similar to those prepared using Tween 20 (d4,3 = 145 ± 6 nm) under the same high-pressure homogenization conditions. GPs-stabilized nanoemulsions were stable against droplet growth over a range of pH (6–8) and thermal treatments (60–120 °C). Conversely, instability occurred under acidic (pH 3–5) and high ionic strength (25–100 mM CaCl2) conditions. In comparison with Tween 20, GPs were more effective at inhibiting AST from degradation during 30 days of storage at both 5 and 25 °C. However, GPs led to lower lipid digestion and AST bioaccessibility from nanoemulsions than did Tween 20.
In vitro bio accessibility of ergocalciferol in nanoemulsion-based delivery system: the influence of food-grade emulsifiers with different stabilising mechanisms
(International Journal of Food Science and Technology, 2018) Shu, Gaofeng; Nauman Khalid; Boon Tan, Tai; Zhao, Yiguo; A. Neves, Marcos; Kobayashi, Isao; Nakajima, Mitsutoshi
The effect of emulsifier type on thein vitrobioaccessibility of ergocalciferol-loaded nanoemulsions wasexamined (mouth, stomach and small intestinal phases). Oil-in-water nanoemulsions were prepared usingemulsifiers with different stabilising mechanisms: decaglycerol monooleate (MO7S; steric), modifiedlecithin (ML; electrostatic), sodium caseinate (SC; electrosteric) and ML-MO7S (combined electrostaticand steric). The droplet size, size distribution,f-potential and microstructure of nanoemulsions duringdigestion depended on the emulsifier type. The fate of lipid in the small intestinal phase also relied on theemulsifier type, with the free fatty acids release rate decreasing in the following order: MO7S>ML-MO7S>ML>SC. The ergocalciferol bioaccessibilities in nanoemulsions prepared using MO7S (62%),ML (64%) and ML-MO7S (65%) were similar and significantly higher than that stabilised by SC (12%).No significant loss of ergocalciferol was observed in all nanoemulsions after full digestion; they werechemically stable against digestion conditions, regardless of the emulsifier type.
Microchannel emulsification: a promising technique towards encapsulation of functional compounds
(Critical Reviews in Food Science and Nutrition, 2018) Nauman Khalid; Kobayashi, Isao; A. Neves, Marcos; Uemura, Kunihiko; Nakajima, Mitsutoshi
This review provides an overview of microchannel emulsification (MCE) for production of functional monodispersed emulsion droplets. The main emphasis has been put on functional bioactives encapsulation using grooved-type and straight-through microchannel array plates. MCE successfully encapsulates the bioactives like β-carotene, oleuropein, γ-oryzanol, β-sitosterol, L-ascorbic acid and ascorbic acid derivatives, vitamin D and quercetin. These bioactives were encapsulated in a variety of delivery systems like simple and multiple emulsions, polymeric particles, microgels, solid lipid particles and functional vesicles. The droplet generation process in MCE is based upon spontaneous transformation of interfaces rather than high energy shear stress systems. The scale-up of MCE can increase the productivity of monodispersed droplets >100 L h−1 and makes it a promising tool at industrial level.

Browse

Browsing Food Science and Technology by Author "A. Neves, Marcos"

Results Per Page

Sort Options