Enrichment of pasteurized skim milk with grape seed oil multilayer emulsions: Investigating the effect of emulsion layers on physicochemical, microbial, and sensory characteristics

Cow milk is a nutritionally valuable food, although it lacks essential UFA. Enriching milk with these fatty acids can reduce risks associated with cholesterol and saturated fats while meeting consumers' dietary needs. Grape seed oil (GSO), which is rich in n-6 and n-9 fatty acids, is one potential additive to replace milk fat and increase the unsaturated fat content. However, these essential UFA are hydrophobic, making them difficult to dissolve in water, and are prone to oxidation, which can negatively affect the aroma and flavor of the milk. The layer-by-layer emulsion method is a promising approach to mitigate these challenges. This study investigated the enrichment of pasteurized skim milk with optimized multilayer emulsions of GSO and evaluated the physicochemical, microbial, and sensory characteristics of the milk over a storage period of 7 d at 4°C. Results indicated that single- and triple-layer emulsions remained stable within the milk matrix, but the 2-layer emulsion became unstable by d 3 of storage. During storage, acidity increased in all samples (from 0.16 to 0.44, 0.24 to 0.48, and 0.2 to 0.36 for single-, double-, and triple-layer emulsions, respectively), as did viscosity (from 1.53 to 1.9, 1.55 to 2.2, and 1.46 to 1.78 mPa·s, respectively), total microorganism count, peroxide value (from 5.52 to 17.6, 4.7 to 19.38, and 3.09 to 10.3 mEq/kg oil, respectively), and thiobarbituric acid index (from 0.43 to 0.52, 0.44 to 0.63, and 0.39 to 0.47 mg malondialdehyde/kg of oil, respectively). The pH values decreased slightly across all samples (from 6.6 to 6.5). No mold, yeast, or coliforms were detected in any sample throughout the study. Overall, the use of bioactive compounds such as essential fatty acids through milk enrichment can greatly enhance the quality of widely consumed dairy products.

Ultrasound-assisted fabrication of chitosan-hydroxypropyl methylcellulose nanoemulsions loaded with thymol and cinnamaldehyde: Physicochemical properties, stability, and antifungal activity

This study investigated the influence of chitosan (CH) and hydroxypropyl methylcellulose (H), along with ultrasound power, on the physicochemical properties, antifungal activity, and stability of oil-in-water (O/W) nanoemulsions containing thymol and cinnamaldehyde in a 7:3 (v/v) ratio. Eight O/W formulations were prepared using CH, H, and a 1:1 (v/v) blend of CH and H, both with and without ultrasonication (U). Compared to untreated samples, U-treated nanoemulsions had lower droplet sizes (433-301 nm), polydispersity index (0.42-0.47), and zeta potential (-0.42-0.77 mV). The U treatment decreased L* and b* values, increased a* color attribute values, and increased apparent viscosity (0.26-2.17) at the same shear rate. After 28 days, microbiological testing of nanoemulsions treated with U showed counts below the detection limits (< 2 log CFU mL-1). The U-treated nanoemulsions exhibited stronger antifungal effects against R. stolonifer, with the NE/CH-U and NE/CH-H-U formulations demonstrating the lowest minimum inhibitory and fungicidal concentrations, measured at 0.12 and 0.24 μL/mL, respectively. On day 28, U-treated nanoemulsions demonstrated higher ionic, thermal, and physical stability than untreated samples. These findings suggest that the stability and antifungal efficacy of polysaccharide-based nanoemulsions may be improved by ultrasonic treatment. This study paves the way for innovative, highly stable nanoemulsions.

The prescription design and key properties of nasal gel for CNS drug delivery: A review

Central nervous system (CNS) diseases are among the major health problems. However, blood-brain barrier (BBB) makes traditional oral and intravenous delivery of CNS drugs inefficient. The unique direct connection between the nose and the brain makes nasal administration a great potential advantage in CNS drugs delivery. However, nasal mucociliary clearance (NMCC) limits the development of drug delivery systems. Appropriate nasal gel viscosity alleviates NMCC to a certain extent, gels based on gellan gum, chitosan, carbomer, cellulose and poloxamer have been widely reported. However, nasal gel formulation design and key properties for alleviating NMCC have not been clearly discussed. This article summarizes gel formulations of different polymers in existing nasal gel systems, and attempts to provide a basis for researchers to conduct in-depth research on the key characteristics of gel matrix against NMCC.

Microencapsulation of Essential Oils by Spray-Drying and Influencing Factors

Essential oils (EOs) are known as any aromatic oily organic substances which are naturally synthesized in plants. Exhibiting a broad range of biological activities, EOs have played a key role in numerous industries for ages, including pharmaceutical, textile, and food. However, the volatility and high sensitivity to environmental influences pose challenges to the application of EOs on industrial scale. Microencapsulation via the spray-drying method is one of the promising techniques to overcome these challenges, thanks to the presence of wall materials that properly protect the core EOs from oxidation and evaporation. By optimization of key factors related to the infeed emulsion properties and spray-drying process, the encapsulation efficiency and retention of encapsulated EOs could be significantly improved, thus allowing a wide range of EO applications. This review attempts to discuss on different determining factors of the spray-drying process to develop an effective encapsulation formula for EOs. Furthermore, recent applications of encapsulated EOs in the fields of foods, pharmaceuticals, and textile industries are also thoroughly addressed.