Kinetic study of controlled release of flavor compounds from spray-dried encapsulated yeast powder using dynamic vapor sorption–gas chromatography

An optimized chitosan/alginate-based microencapsulation of lime peel essential oil and its application as an antibacterial textile

A functional textile immobilized by microcapsules of the lime peel essential oils of C. aurantifolia (LPEO) was prepared and characterized. A varied amount of Chitosan/Alginate (CH/AG) ratios, followed by a mass of LPEO and concentration of sodium tripolyphosphate (STPP) crosslinker, was optimized sequentially to coacervate LPEO using a Tween 80 emulsifier. An antibacterial assay against both Gram-positive and Gram-negative bacteria was further evaluated for the embedded microcapsules. The LPEO (0.2 g) was effectively coacervated by CH/AG (5:3) crosslinked by 2% of STTP to give a yield, oil content (OC), and encapsulation efficiency (EE) of 53.45 ± 2.16%, 65.08 ± 2.60% and 85.04 ± 0.70% respectively. A rough spherical shape of LPEO microcapsules was homogeneously observed with an average particle size of 0.757 mm. An Avrami's kinetic model revealed the release mechanism of the core following zero-order kinetics (k = 1.11 ± 0.13 × 10-9 s-1, Ea = 70.21 kJ/mol). The LPEO microcapsules demonstrated good thermal stability up to 122 °C and maintained 38% OC at ambient temperature for four weeks. A 70.34 ± 4.16% of the LPEO microcapsules were successfully overlaid onto the gauze with citric acid binder and sodium phosphate catalyst. Overall, the immobilized microcapsules exhibited strong inhibition against S. aureus and moderate against S. epidermidis, E. coli, and K. pneumonia.

Application of encapsulated flavors in food products; opportunities and challenges

Flavors are considered among the most important components of food formulations since they can predominantly affect the consumer acceptance and satisfaction. However, most flavors are highly volatile and inherently sensitive to pH, light, thermal processes, and chemical reactions such as oxidation and hydrolysis. Encapsulation is used as an effective strategy for protecting flavors from environmental conditions and extending their shelf life. Moreover, release characteristics of flavors can be modified via application of appropriate carriers and wall materials. This review focuses on the use of encapsulated flavors in various food products. Various factors affecting flavor retention during encapsulation, flavor release mechanisms, profiles and kinetics are discussed. Finally, the challenges associated with the use of encapsulated flavors in food products (in situ) and to model systems (in vitro), their storage stability, product requirements and problems related to the market are presented.

Microencapsulation of Citrus aurantifolia essential oil with the optimized CaCl2 crosslinker and its antibacterial study for cosmetic textiles

A functional fabric immobilized by the microcapsules of C. aurantifolia lime essential oil (LO) was prepared and characterized. A varied amount of CaCl2 crosslinker was optimized to coacervate LO using alginate-gelatin biopolymers and Tween 80 emulsifier. A further evaluation of the immobilized LO microcapsules for the antibacterial effect against both Gram-positive and Gram-negative bacteria was conducted. The optimized alginate/gelatin-based microcapsules were effectively crosslinked by 15% CaCl2 with an yield, oil content (OC), and encapsulation efficiency (EE) of 39.91 ± 3.10%, 78.33 ± 7.53%, and 90.27 ± 5.84%, respectively. A spherical shape of LO microcapsules was homogeneously found with an average particle size of 1.394 μm. A first-order kinetics mechanism for the release of LO out of the microcapsules was modeled by Avrami's kinetic equation (k = 1.60 ± 3.68 × 10-5 s-1). The LO microcapsules demonstrated good thermal stability up to 100 °C and maintained 51.07% OC and 43.56% EE at ambient temperature for three weeks. Using a pad dry method and citric acid binder, LO microcapsules were successfully immobilized on a cloth with a % add on 30.60 ± 1.80%. The LO microcapsules and the immobilized one exhibited a moderate ZoI of bacterial growth for Gram-positive S. aureus and S. epidermidis as well as Gram-negative E. coli and K. pneumonia. Further washing test toward the functional fabric showed that the LO microcapsules incorporated into the fabric were resistant to five cycles of normal washing with a mass reduction of 22.01 ± 1.69%.

Current trends in flavor encapsulation: A comprehensive review of emerging encapsulation techniques, flavour release, and mathematical modelling

Food flavors are volatile compounds that impact the human sensory perception profoundly and find extensive applications in various food products. Because of their volatility and high sensitivity to pH, temperature, oxidation, and external conditions, they require adequate protection to last for a longer duration. Encapsulation plays a critical role in preserving food flavors by enhancing their thermal and oxidative stability, overcoming volatility limitations, and regulating their rapid release with improved bioavailability in food products. The current review focuses on the recent developments in food flavor encapsulation techniques, such as electrospinning/spraying, cyclodextrin inclusion complexes, coacervation, and yeast cell micro-carriers. The review also comprehensively discusses the role of encapsulants in achieving controlled flavor release, the mechanisms involved, and the mathematical modelling for flavor release. Specific well-established nanoencapsulation techniques render better encapsulation efficiency and controlled release of flavor compounds. The review examined specific emerging methods for flavor encapsulation, such as yeast cell encapsulation, which require further exploration and development. This article provides readers with up-to-date information on different encapsulation processes and coating methods used for flavor encapsulation.

Yeast cells for encapsulation of bioactive compounds in food products: A review

Nowadays bioactive compounds have gained great attention in food and drug industries owing to their health aspects as well as antimicrobial and antioxidant attributes. Nevertheless, their bioavailability, bioactivity, and stability can be affected in different conditions and during storage. In addition, some bioactive compounds have undesirable flavor that restrict their application especially at high dosage in food products. Therefore, food industry needs to find novel techniques to overcome these problems. Microencapsulation is a technique, which can fulfill the mentioned requirements. Also, there are many wall materials for use in encapsulation procedure such as proteins, carbohydrates, lipids, and various kinds of polymers. The utilization of food-grade and safe carriers have attracted great interest for encapsulation of food ingredients. Yeast cells are known as a novel carrier for microencapsulation of bioactive compounds with benefits such as controlled release, protection of core substances without a significant effect on sensory properties of food products. Saccharomyces cerevisiae was abundantly used as a suitable carrier for food ingredients. Whole cells as well as cell particles like cell wall and plasma membrane can act as a wall material in encapsulation process. Compared to other wall materials, yeast cells are biodegradable, have better protection for bioactive compounds and the process of microencapsulation by them is relatively simple. The encapsulation efficiency can be improved by applying some pretreatments of yeast cells. In this article, the potential application of yeast cells as an encapsulating material for encapsulation of bioactive compounds is reviewed.