Optimization for encapsulation of green tea (Camellia sinensis L.) extract by spray drying technology

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.

Influence of Encapsulation Parameters on the Retention of Polyphenols in Blackthorn Flower Extract

In order to utilize the benefits of blackthorn flower polyphenols and provide their stabilization during processing and storage, and to facilitate their application in functional food products, this study aimed to evaluate the encapsulation parameters during the spray-drying process of blackthorn flower extract. The effect of the type of wall material (maltodextrin (MD) and its mixtures with gum arabic (GA) and inulin (IN)), its ratio to extract dry matter (0.5, 1, and 2) and drying temperature (120, 150, and 180 °C) on the concentration of different polyphenolic groups was studied. While the lowest applied amount of wall material at the lowest drying temperature enabled efficient encapsulation of all polyphenolic groups, the type of wall material applied caused significant differences in retention. The highest concentrations of both phenolic acids and flavonoids were achieved with the addition of 25% of GA in MD. Unlike the addition of GA, mixtures of MD with IN did not show a positive effect on the retention of polyphenols. Selected encapsulation parameters ensured the high retention of total phenolics, namely 87.87% of the content determined in the liquid extract prior to spray drying, thereby providing a polyphenol-rich product with great potential for application in functional food and the nutraceutical industry.

Spray-drying microencapsulation of tea extracts using green starch, alginate or carrageenan as carrier materials

Tea industry generates many by-products which could be used to produce and incorporate bioactive tea extracts (TE) into nutraceuticals, cosmetics and/or clinical applications. However, sensibility to external factors is a major disadvantage hindering its utilization. This study deals with the implementation and characterization of suitable biopolymer delivery systems based on starch, carrageenan or alginate, as microencapsulation, to stabilize and protect TE through innovative thin-carbohydrate-coated formulations. TE were spray-dried and microencapsulated in recycled carrier materials (alginate, carrageenan or starch). Product yields varied from 55 to 58%. High microencapsulation and loading efficiencies were achieved (60-93% and 65-84%, respectively). Antioxidant capacity varied from 32 to 46 g Trolox/100 g extract, within different carrier-systems; which also showed promising rheological and UV-protective properties when transformed into gels. Total phenolic content, particle-size distribution, HPSEC-analysis, SEM-analysis and FTIR-analysis were also performed. In sum, this paper characterizes and discusses the high potential of these recycled carbohydrate-coated microparticles for future applications.

Oxidative stability of spray dried matcha-tuna oil powders

Matcha-tuna oil and matcha-maltodextrin-tuna oil emulsions (25% oil, dry basis), formulated to have protein: carbohydrate ratios of 1:1.1, 1:2, 1:3 and 1:4, were spray dried. Confocal laser scanning microscopy showed effective emulsification of oil in all emulsions. All powders had low surface fat (2.9-4.2%). The addition of maltodextrin enhanced the bulk density and flowability of powders. Water sorption isotherms indicated that addition of maltodextrin increased water uptake of powders. The oxidative stability of the powders under accelerated conditions in an Oxipres® was highest for the matcha-tuna oil powder. Increasing amounts of added maltodextrin decreased oxidative stability. A comparison of levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in neat oil and tuna oil powders over 12 weeks at 40 °C, demonstrated that % remaining EPA and DHA were higher for all spray dried powders compared to neat oil. There was a significant correlation (p < 0.01) between the amount of the loss of tea catechins and % remaining EPA and DHA after 12 weeks at 40 °C, suggesting that the catechins had a major role in protecting the tuna oil against oxidation. This study has demonstrated the potential of using a whole biomass (matcha) as the single encapsulant for protection and delivery of omega-3 oils.

Microencapsulation of green tea polyphenols by ionic gelation and spray chilling methods

The consumption of teas has been increasing with the dissemination of information regarding the health benefits of its constituents. Obtaining food products with healthier profiles is already a reality for industry with the increasing development of new functional ingredients, including the use of tea and its derivatives (extracts). This work aimed to evaluate the encapsulation of green tea extract powder in lipid microparticles (LMP) by the spray chilling method and in ionic gelation microparticles (IGMP) by the ionic gelation method to obtain polyphenol-rich water insoluble components. Microparticles were adequately obtained in both methods, with typical physical characteristics consistent with the results in literature results, 83.5 ± 2.8% encapsulation efficiency for LMP and 72.6 ± 0.4% for IGMP, and antioxidant activity (IC50 μg/mL) of 33,169.4 ± 123.8 (IGMP) and 2099.7 ± 35.3 (LMP). The microparticles samples were considered suitable as ingredients for add polyphenols in foods.

Application of microencapsulation for the safe delivery of green tea polyphenols in food systems: Review and recent advances

Green tea has been associated with the prevention and reduction of a wide range of severe health conditions such as cancer, immune, and cardiovascular diseases. The health benefits associated with green tea consumption have been predominantly attributed to green tea polyphenols. The functional properties of green tea polyphenols are mainly anti-oxidative, antimutagenic, anticarcinogenic, anti-microbial, etc. These excellent properties have recently gained considerable attention in the food industry. However, their application is limited by their sensitivity to factors like temperature, light, pH, oxygen, etc. More, studies have reported the occurrence of unpleasant taste and color transfer during food processing. Lastly, the production of functional food requires to maintain the stability, bioactivity, and bioavailability of the active compounds. To tackle these obstacles, technological approaches like microencapsulation have been developed and applied for the formulation of green tea-enriched food products. The present review discusses the novelty in microencapsulation techniques for the safe delivery of green tea polyphenols in food matrices. After a literature on the green tea polyphenols composition, and their health attributes, the encapsulation methods and the coating materials are presented. The application of green tea encapsulates in food matrices as well as their effect on food functional and sensory properties are also discussed.