**5.2. Nanoparticles and innovation products**

Park and Ikegaki [122] studied propolis extracts obtained from water with 96% ethanol solution as solvents. The results demonstrated that propolis extract obtained with 80% ethanol grade showed higher absorption at 290 nm. Using ethanol solution at 60%, higher quantities of isosakuranetin, quercetin, and kaempferol were extracted, while pinocembrin and sakuranetin were better extracted with ethanol solution at 70% and kaempferide, acacetin, and isorham‐ netin were most extracted with ethanol solution 80%. More expressive antimicrobial activities were found in propolis extracts from 60 to 80% of ethanol solution extraction and higher

The most common extraction process for propolis to oral administration is the alcoholic (70%) extraction using maceration, percolation and/or turboextraction. The ratio of propolis raw material:extract used is completely variable and usually, in Brazil, 1:3–4, i.e., 1 part of propolis raw material may offer 3 or 4 parts of extract, considering the production of a liquid extract with at least 11%w/v of propolis dry matter. Of course, this ratio may vary and it is completely

Jorge et al. [46] studied green propolis extracts obtained from four different locations in São Paulo and Minas Gerais States, using the same extraction process, i.e., hydroalcoholic solution 70% with maceration for 30 days. Although all samples evaluated were Brazilian green propolis using the same extract, different results were found for drupanin, baccharin, and artepillin C during the same month, in spite of seasonal differences. Therefore, it is possible to conclude that, using the same floral source, solvent and process extraction, different regions, and seasonal variations also offer a different chemical composition. Interestingly, these

Besides maceration, percolation or turboextraction, Trusheva et al. [123] compared ultrasound extraction and microwave‐assisted extraction with the maceration process. The careful analysis of the results obtained with each process demonstrated that statistical differences were found for total phenolics and propolis total extractable matter for ultrasound process (30 min) and microwave (2 · 10 s) when compared to maceration extraction. For ultrasound, higher total phenolics were found (52 3%) in comparison to maceration (43 2%) while the reduced total extractable matter (53 3% versus 55%). In turn, microwave offered reduced values for total phenolics (40.4 0.6% versus 43 2%) and expressively higher amounts of the total extractable matter (75% versus 55%). Flavonoids analysis did not show important differences among the procedures evaluated. It is important to consider the time of extraction in each process, since maceration takes around 72 h, and ultrasound was effective with 30 minutes and microwave 2 · 10 s. Another important thing is to define the objective of the extraction: for analytical purposes, it is more practical and cheaper to use ultrasound or microwave, however, for

Propolis water extract was also obtained by some authors [12, 17, 98, 124] using completely different procedures, demonstrating some interesting biological activities that had been previously studied for propolis alcoholic extract, such as anti‐inflammatory [12], inhibition of inflammatory angiogenesis [98], and antiviral [17]. Although the demonstration of these interesting results, chemical characterization was poorly explored in the manuscripts, except by Urushisaki et al. [17] that presented the caffeoylquinic derivatives as the most important

antioxidant results came from propolis extract obtained with ethanol 70–80%.

dependent on the quality of propolis raw material used.

76 Superfood and Functional Food - An Overview of Their Processing and Utilization

differences did not affect the safe of propolis ingestion [111].

industrial scale, these latter may not be easily implemented.

Nowadays, finding natural additives has increased the efforts both to obtain bioactive compounds from natural raw materials and develop stable and functional derivative products. The former mentioned properties attributed to propolis are valuable and find applications in several industries, such as pharmaceutics, agrochemical, and food. The growing interest in propolis has also promoted technological development for the suitable application of propolis.

Propolis in the powder form, for example, exhibits several advantages as increased concen‐ tration of propolis dry matter, higher chemical stability of the compounds, and longer preservation of the biological properties. Additionally, the powder form also permits the production of presentations with higher compliance in therapeutics, i.e., sachets, tablets, and capsules. The drying process may also involve the encapsulation of the product resulting in micro/nanoencapsulation systems, which can minimize sensory flavor and odor and control the release of the active compounds.

Propolis dry extract was obtained by Da Silva et al. [125] by employing arabic gum and octenyl succinic anhydride (OSA) starch as carriers by spraydrier. The process allowed obtaining propolis in the powder form with preserved antioxidant activity, stability, and low hygrosco‐ picity. Microencapsulated propolis extract obtained by complex coacervation was reached and presented inhibitory activity against *S. aureus* [126]. Bruschi et al. [127] obtained gelatin microparticles containing propolis extractive solution by spray‐drying technique. The microencapsulation by spray‐drying technique maintained the activity of propolis against *S. aureus*. In another study, the effect of spray drying parameters on the chemical and biological properties of alcoholic extract of green propolis was investigated [128]. Several parameters of the process demonstrated to influence the polyphenol and flavonoid content, as well as the antioxidant activity, but under an optimized condition, the dried propolis extract showed significant antioxidant activity, with 50% lipid peroxidation inhibition at concentrations ranging from 2.5 to 5.0 mg/ml.

More recently, Marquiafável et al. [129] aimed to develop a propolis dry extract with high propolis (~40%w/w of propolis dry matter) and artepillin C contents by employing a combi‐ nation of silicon dioxide with arabic or modified starch and silicon dioxide by spray‐drier. They have successfully obtained a standardized propolis extract with high amount of propolis, flavonoid content, expected amounts of artepillin C, and with maintained antibacterial activity, and obtained microparticles with both excipients used. Recently, results of the same group obtained dry extracts of propolis with 70–80% of dry matter; however, the microparticles were not obtained (data not published yet), and then, the odor, color, and taste are not similarly reduced as it is possible to observe when microparticles are obtained (**Figure 10**). Although microparticles were not obtained with 70–80% of propolis dry matter, this extract is the most concentrated one found in the market until now and can be used in several products with very good results, for example soft or hard capsules or tablets.

**Figure 10.** Propolis standardized water extracts of green propolis; C: propolis standardized extract (EPP‐AF®).

In general, the propolis powder extracts obtained by spray‐drying technique investigated in the literature demonstrated the formation of particles at the micrometer scale, from 1 to 10–20 μm. On the other hand, as nanotechnology can offer new opportunities for propolis applica‐ tion, in another line of research, nanosized particles have been developed. Patil et al. [130] have obtained and characterized silver nanoparticles containing propolis [130]. Propolis nanopar‐ ticles have also been obtained employing lipid carriers. Our research group has focused on developing solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) encapsu‐ lating propolis. **Figure 11** shows atomic force microscopy (AFM) images of propolis‐loaded NLC. Additional studies were also conducted covering NLC surface with chitosan. The chitosan‐covered particles presented positive residual surface charge [≈ +40 mV], while the uncoated ones presented negative charges [≈ −30 mV]. Particles were anisometric in shape and approximately 150–200 nm in size. The images demonstrate the particle surface and confirm the nanometric size of the particle. Additionally, no roughness was observed on the particle surfaces.

**Figure 11.** Atomic force microscopy (AFM) images of propolis‐NLC (A) and chitosan coated propolis‐NLC.

Several important applications can be carried out with innovative propolis extracts. Different presentations of propolis were previously showed as in a liquid presentation without alcohol, usually using propylene glycol or polyethylene glycol, propolis powders in different systems or concentrations, micro or nanoparticles, and others, as soft or hard capsules, with immediate or sustained release systems. Considering the applications, it is possible to formulate capsules, tablets, pills, or others with a specific amount of propolis dry matter, or with a focus on some groups of compounds (total flavonoid or polyphenols) and finally, on a biomarker or a group of these substances such as artepillin C, drupanin, or baccharin, all presentations completely applicable to functional or supplement food, or medicines. Besides oral administration, it is possible to use all of these propolis presentations in topical products, as previously published by Berretta et al. [8] who presented a propolis thermoreversible gel to treat cutaneous lesions or burns, Barud et al. [131] with a propolis biomembrane for the same application, or Berretta et al. [50] that demonstrated the benefits of the application of a propolis mucoadhesive gel in vulvovaginal candidiasis. Several other products can be found in the market and in the literature, such as mouthwashes, toothpastes dental creams, among others.
