Microencapsulation of winter squash ( Cucurbita moschata Duchesne) seed oil by spray drying

Enhancing the Physicochemical, Thermal, and Technological Properties of Freeze-Dried Welsh Onion Leaf Juice: Influence of Maltodextrin and Gum Arabic as Carrier Agents

Fresh Welsh onions are widely used in food formulations due to their distinctive flavor and biological properties, but their high perishability limits their industrial applications. In this study, powdered Welsh onion leaf juices were obtained through freeze-drying, with and without maltodextrin (MD) and gum arabic (GA) as carrier agents. MD was chosen for its high solubility and neutral taste, while GA was selected for its ability to improve powder stability and dispersibility. Powders were obtained using a completely randomized design to evaluate the effects of five MD:GA ratios (0:100, 25:75, 50:50, 75:25, and 100:0) on their physicochemical and technological properties. The addition of carriers enabled the formation of fine, homogeneous powders with higher water solubility. All formulations exhibited low water activity (<0.4) and moisture content (<7%). Polyphenol content ranged from 2.60 to 3.53 mg GAE/g of dry matter, with a high recovery percentage (94-96%). DPPH• scavenging activity was about 0.55 mg GAE/g of dry matter for all powders with carrier agents. Fourier-transform infrared (FTIR) analysis confirmed the presence of characteristic bands from both the carrier agents and the onion leaf juice, while thermogravimetric analysis (TGA) revealed enhanced thermal stability with carrier agents. Flowability tests showed that MD and MD:GA blends significantly improved powder handling.

Use of Natural Polymers for the Encapsulation of Eugenol by Spray Drying

Background: Eugenol is a colourless or yellowish compound whose presence in clove essential oil surpasses the 75% of its composition. This phenylpropanoid, widely used as an antiseptic, anaesthetic and antioxidant, can be extracted by steam distillation from the dried flower buds of Syzygium aromaticum (L.). Due to its chemical instability in presence of light and air, it should be protected when developing a formulation to avoid or minimise its degradation. Methods: A promising approach would be encapsulation by spray drying, using natural coating products such as maltodextrin, gum arabic, and soy lecithin. To do so, a factorial design was carried out to evaluate the effect of five variables at two levels (inlet temperature, aspirator and flow rate, method of homogenisation of the emulsion and its eugenol:polymers ratio). Studied outcomes were yield and outlet temperature of the spray drying process, eugenol encapsulation efficiency, and particle size expressed as d(0.9). Results: The best three formulations were prepared by using a lower amount of eugenol than polymers (1:2 ratio), homogenised by Ultra-Turrax®, and pumped to the spray dryer at 35 m3/h. Inlet temperature and flow rate varied in the top three formulations, but their values in the best formulation (DF22) were 130 °C and 4.5 mL/min. These microcapsules encapsulated between 47.37% and 65.69% of eugenol and were spray-dried achieving more than a 57.20% of product recovery. Their size, ranged from 22.40 μm to 55.60 μm. Conclusions: Overall, the whole spray drying process was optimised, and biodegradable stable polymeric microcapsules containing eugenol were successfully prepared.

Advances and trends in encapsulation of essential oils

There is a huge concern regarding the potential carcinogenic and mutagenic risks associated with the usage of synthetic chemicals as preservatives in various consumer products such as food and pharmaceutical formulations. In this aspect, there is a need for the development of alternative natural preservatives to replace these synthetic chemicals. More recently, naturally occurring essential oils have emerged as popular ingredients owing to their unique characteristics like antioxidant and antimicrobial activity, to enrich and enhance the functional properties of consumer products. However, due to their high volatility and hydrophobicity, their functionality is lost and their incorporation in aqueous products is challenging. One of the promising strategies to overcome this challenge is encapsulation which involves the entrapment of the essential oil inside a biocompatible material for its controlled release and increased bioavailability. Also, the choice of encapsulation method depends on the component to be encapsulated and the shell material. In this review, encapsulation in various colloidal systems that facilitate the potential delivery of essential oils is discussed. The focus is on encapsulation techniques along with their advantages and disadvantages, encapsulation efficiency, and in vitro release studies.

Optimization of spray drying process parameters for the food bioactive ingredients

Spray drying (SD) is one of the most important thermal processes used to produce different powders and encapsulated materials. During this process, quality degradation might happen. The main objective of applying optimization methods in SD processes is maximizing the final nutritional quality of the product besides sensory attributes. Optimization regarding economic issues might be also performed. Applying optimization approaches in line with mathematical models to predict product changes during thermal processes such as SD can be a promising method to enhance the quality of final products. In this review, the application of the response surface methodology (RSM), as the most widely used approach, is introduced along with other optimization techniques such as factorial, Taguchi, and some artificial intelligence-based methods like artificial neural networks (ANN), genetic algorithms (GA), Fuzzy logic, and adaptive neuro-fuzzy inference system (ANFIS). Also, probabilistic methods such as Monte Carlo are briefly introduced. Some recent case studies regarding the implementation of these methods in SD processes are also exemplified and discussed.

Spray Drying for the Encapsulation of Oils-A Review

The application of the spray drying technique in the food industry for the production of a broad range of ingredients has become highly desirable compared to other drying techniques. Recently, the spray drying technique has been applied extensively for the production of functional foods, pharmaceuticals and nutraceuticals. Encapsulation using spray drying is highly preferred due to economic advantages compared to other encapsulation methods. Encapsulation of oils using the spray drying technique is carried out in order to enhance the handling properties of the products and to improve oxidation stability by protecting the bioactive compounds. Encapsulation of oils involves several parameters-including inlet and outlet temperatures, total solids, and the type of wall materials-that significantly affect the quality of final product. Therefore, this review highlights the application and optimization of the spray drying process for the encapsulation of oils used as food ingredients.