Effect of Spray Dryer Scale Size on the Properties of Dried Beetroot Juice

Pectin as the carrier for the spray drying of green tea extracts: Tailoring microencapsulation to obtain a prospective nutraceutical

In this study, microencapsulated green tea (GT) extracts, as prospective nutraceuticals, were obtained using spray drying with pectin in different pectin-to-extract (P:E) ratios. Pectin was selected as wall material based on its previously reported superiority to encapsulate phenols, low cost/sustainability of production and intrinsic hypoglycemic and antioxidant potential. A significant degradation (13.74 %) of epigallocatechin was observed in powder without pectin, in contrast to pectin-loaded samples, suggesting its role in chemical stability enhancement of stated compound. FTIR and DSC indicated GT extract bioactives to remain stable during drying. Addition of pectin significantly increased encapsulation efficiency (EE) of epigallocatechin-3-gallate (up to 8.94 %), epicatechin-3-gallate (up to 7.68 %) and caffeine (up to 12.39 %) compared to pectin-free sample. Significant EE enhancement for epigallocatechin-3-gallate was observed until the P:E ratio of 1:1 compared to pectin-free sample, while further increase of pectin share did not lead to a comparative increase in EE. Similar trend was observed for powder flowability, probably due to excess of pectin in the highest P:E ratio (2:1), preventing proper droplets formation, which was also confirmed by SEM. Sample with P:E ratio of 1:1 revealed the slowest release of bioactives, which may be important for facilitating potential GT therapeutic usage. Stated microencapsulate further revealed satisfactory antioxidant (IC50 of 23.70 μg/ml vs. 4.45 μg/ml for ascorbic acid) and hypoglycemic activities (IC50 of 39.48 μg/ml vs. 156.64 μg/ml for acarbose). These findings represent the basis for further experiments regarding usage of the developed GT microencapsulate as nutraceutical applicable in diabetes-related impairments.

Fermentation of American elderberry juice yields functional phytochemicals for spray dried protein-polyphenol ingredients

American elderberry juice (EBJ) and fermented elderberry juice (EBF) were spray dried using two different carriers: S. cerevisiae yeast (SC), used for juice fermentation and as encapsulating agent, and pea protein, to produce protein-polyphenol ingredients. The spray drying (SD) performance (solids recovery, SR; phenolic retention, PR) and quality attributes (physicochemical and functional properties, phytochemical content and bioaccessibility after in vitro digestion) of eight treatments of spray dried elderberry particles were determined. The total phenolic content (TPC) of EBJ (4476 ± 169 mg GAE/L) increased by 27 % after fermentation (EBF: 5706 ± 199 mg GAE/L). The SD performance of EBF (SR > 50 %; PR 55.7-63.9 %) was significantly higher (p < 0.05) compared to EBJ (SR < 50 %; PR 28.6-42.8 %). Stable (aw < 0.3) protein-polyphenol particles, with pH-dependent solubility that increased as pH went from 4 to 10, were produced. The TPC of EBF-derived particles (26.2-28.7 mg GAE/g) was 22-31 % higher than EBJ-derived particles (20.4-21.9 mg GAE/g) and anthocyanins were the major phenolic group detected. An increase in nearly all phenolic metabolite concentrations was observed after fermentation, and an additional increment was observed after spray drying. Phenolic bioaccessibility improved (17-25 % higher) after S. cerevisiae fermentation and when using SC as the drying carrier compared to phenolics source (EBJ or EBF). Overall, here we show a sensible strategy to produce protein-polyphenol particles with better SD performance and enhanced phytochemical content and profile. Our fermentation and spray drying strategy provides practical and efficient means to produce functional fruit ingredients for the emerging clean-label, health-oriented market.

Encapsulation of Phenolic Compounds Extracted from Beet By-Products: Analysis of Physical and Chemical Properties

Beet is a nutritious and health-promoting food with important bioactive compounds in its industrial by-products. The encapsulation of antioxidants from beet by-products has been proposed for valorization. For this, an ethanol-water extract was mixed with polyvinylpyrrolidone (PVP) (used as a carrier agent) and then encapsulated. The encapsulation was performed by spray drying, where the effects of temperature (140-160 °C), extract input flow rate (10-30%), and extraction solvent (ethanol-water 50/50 v/v and ethanol) were evaluated for the total phenol content and the spray-drying yield. The yields obtained were between 60 and 89%, and total phenols were between 136 and 1026 mg gallic acid equivalents/g of encapsulated product. Both responses were affected (p < 0.05) by the extraction solvent. The optimal spray-drying conditions were determined by response surface methodology (RSM). The encapsulated product obtained at optimal conditions was characterized by infrared spectrometry, X-ray fluorescence, Ultra-High Performance Liquid Chromatography, and scanning electron microscopy analysis. The results show that the encapsulated product has a high content of total phenols and compounds such as betanin, isobetanin, and neobetanin. Considering the results of physicochemical properties and the bioactive compounds, the optimized encapsulated product could be applied in the food industry as a bioactive ingredient or natural colorant. However, the further investigation of alternative carrier agents needs to be performed to reduce caking.

Encapsulation of enzymes in food industry using spray drying: recent advances and process scale-ups

Enzymes are widely used in the food industry due to their ability in improving the functional, sensory, and nutritional properties of food products. However, their poor stability under harsh industrial conditions and their compromised shelf-lives during long-term storage limit their applications. This review introduces typical enzymes and their functionality in the food industry and demonstrates spray drying as a promising approach for enzyme encapsulation. Recent studies on encapsulation of enzymes in the food industry using spray drying and the key achievements are summarized. The latest developments including the novel design of spray drying chambers, nozzle atomizers and advanced spray drying techniques are also analyzed and discussed in depth. In addition, the scale-up pathways connecting laboratory scale trials and industrial scale productions are illustrated, as most of the current studies have been limited to lab-scales. Enzyme encapsulation using spray drying is a versatile strategy to improve enzyme stability in an economical and industrial viable way. Various nozzle atomizers and drying chambers have recently been developed to increase process efficiency and product quality. A comprehensive understanding of the complex droplet-to-particle transformations during the drying process would be beneficial for both process optimization and scale-up design.

Spray Drying of Chokeberry Juice-Antioxidant Phytochemicals Retention in the Obtained Powders versus Energy Consumption of the Process

The production of chokeberry powder, an important functional additive in food, should exhibit both maximization of bioactive properties retention and minimization of energy consumption. The process of spray drying chokeberry juice on a maltodextrin carrier was tested on a semi-technical scale. The research scope included the variability of the inlet air temperature in the range of T = 150–185 °C and concentration of the feed solution in the range of U_d.m = 15–45% d.m. The powder yield, energy consumption and bioactive properties of the obtained powders were determined. The highest levels of bioactive properties retention were expressed in total polyphenol content (TPC) and anthocyanin content (AC) and obtained at T = 150 °C and U_d.m = 25–30% d.m. However, the most advantageous process parameters in terms of specific energy consumption (SEC) minimization were T = 160–170 °C and U_d.m = 30–35% d.m. Analysis of the dependence on SEC versus TPC and SEC versus AC showed that the most favorable drying parameters for chokeberry juice were as follows: inlet air temperature T = 170 °C and feed solution concentration U_d.m = 35%. Hence, under such process conditions, chokeberry powders were produced with approx. 3% lower bioactive properties retention (in relation to the maximum values), but with 20.5% lower SEC.

Effects of spray-drying parameters on physicochemical properties of powdered fruits

This review features different powdered fruits with optimal storage stability and physiochemical parameters. Spray-drying parameters, such as temperatures and flow rate, can affect the physical properties of powders. Carrier agents provide powders with various favorable qualities, e.g. good flow rate. Commercial spray-drying of fruit juice knows different carrier agents. The review involved scientific and methodological publications, conference papers, patents, regulatory papers, and Internet resources. They were subjected to grouping, categorization, comparative analysis, and consolidation. Inlet temperature, maltodextrin concentration, and air flow rate of spray-drying increased the powder yield but decreased the moisture content. Inlet temperature, maltodextrin concentration, and feed flow rate affected the solubility. Effects of atomization rate, air flow rate and free flow rate were assessed in terms of yield, moisture content, hygroscopicity, and solubility. The article introduces the fundamentals of spray-drying and describes the effect of each spray-drying parameter on the powder quality. The list of parameters included inlet air temperature, atomization rate, air flow, and feed flow rate. We also evaluated the impacts of various carrier agents on the powder quality. The article contributed to a better understanding of how variable parameters affect the quality of food powders. The results provide the food industry with better choice options to adopt certain parameters for specific production needs.