Microencapsulation of Rambutan Peel Extract by Spray Drying

Characterization of Grape Pomace Extract Microcapsules: The Influence of Carbohydrate Co-Coating on the Stabilization of Goat Whey Protein as a Primary Coating

Both grape pomace and whey are waste products from the food industry that are rich in valuable ingredients. The utilization of these two by-products is becoming increasingly possible as consumer awareness of upcycling increases. The biological activities of grape pomace extract (GPE) are diverse and depend on its bioavailability, which is influenced by processes in the digestive system. In this work, goat whey protein (GW) was used as the primary coating to protect the phenolic compounds of GPE during the spray drying process. In addition, trehalose (T), sucrose (S), xylose (X), and maltodextrin (MD) were added to the goat whey proteins as co-coatings and protein stabilizers. All spray drying experiments resulted in microcapsules (MC) with a high encapsulation efficiency (77.6-95.5%) and yield (91.5-99.0%) and almost 100% recovery of phenolic compounds during the release test. For o-coumaric acid, the GW-coated microcapsules (MC) showed a bioavailability index of up to 731.23%. A semi-crystalline structure and hydrophilicity were characteristics of the MC coated with 10% T, S, X, or 5% MD. GW alone or in combination with T, S, MD, or X proved to be a promising carrier for polyphenols from grape pomace extract and ensured good bioavailability of these natural antioxidants.

The application of encapsulation technology in the food Industry: Classifications, recent Advances, and perspectives

Encapsulation technology has been extensively used to enhance the stability, specificity, and bioavailability of essential food ingredients. Additionally, it plays a vital role in improving product quality and reducing production costs. This study presents a comprehensive classification of encapsulation techniques based on the state of different cores (solid, liquid, and gaseous) and offers a detailed description and analysis of these encapsulation methods. Specifically, it introduces the diverse applications of encapsulation technology in food, encompassing areas such as antioxidant, protein activity, physical stability, controlled release, delivery, antibacterial, and probiotics. The potential impact of encapsulation technology is expected to make encapsulation technology a major process and research hotspot in the food industry. Future research directions include applications of encapsulation for enzymes, microencapsulation of biosensors, and novel technologies such as self-assembly. This study provides a valuable theoretical reference for the in-depth research and wide application of encapsulation technology in the food industry.

Wall Materials for Encapsulating Bioactive Compounds via Spray-Drying: A Review

Spray-drying is a continuous encapsulation method that effectively preserves, stabilizes, and retards the degradation of bioactive compounds by encapsulating them within a wall material. The resulting capsules exhibit diverse characteristics influenced by factors such as operating conditions (e.g., air temperature and feed rate) and the interactions between the bioactive compounds and the wall material. This review aims to compile recent research (within the past 5 years) on spray-drying for bioactive compound encapsulation, emphasizing the significance of wall materials in spray-drying and their impact on encapsulation yield, efficiency, and capsule morphology.

By-Products of Fruit and Vegetables: Antioxidant Properties of Extractable and Non-Extractable Phenolic Compounds

Non-extractable phenolic compounds (NEPs), or bound phenolic compounds, represent a crucial component of polyphenols. They are an essential fraction that remains in the residual matrix after the extraction of extractable phenolic compounds (EPs), making them a valuable resource for numerous applications. These compounds encompass a diverse range of phenolic compounds, ranging from low molecular weight phenolic to high polymeric polyphenols attached to other macro molecules, e.g., cell walls and proteins. Their status as natural, green antioxidants have been well established, with numerous studies showcasing their anti-inflammatory, anti-aging, anti-cancer, and hypoglycemic activities. These properties make them a highly desirable alternative to synthetic antioxidants. Fruit and vegetable (F&Veg) wastes, e.g., peels, pomace, and seeds, generated during the harvest, transport, and processing of F&Vegs, are abundant in NEPs and EPs. This review delves into the various types, contents, structures, and antioxidant activities of NEPs and EPs in F&Veg wastes. The relationship between the structure of these compounds and their antioxidant activity is explored in detail, highlighting the importance of structure-activity relationships in the field of natural antioxidants. Their potential applications ranging from functional food and beverage products to nutraceutical and cosmetic products. A glimpse into their bright future as a valuable resource for a greener, healthier, and more sustainable future, and calling for researchers, industrialists, and policymakers to explore their full potential, are elaborated.

Effects of different proteins and maltodextrin combinations as wall material on the characteristics of Cornus officinalis flavonoids microcapsules

The flavonoids in Cornus officinalis (CO) have various pharmacological activities, however, the flavonoid instability limits its application in food and pharmaceutical industries. In this study, Cornus officinalis flavonoid (COF) microcapsules were prepared by using a combination of whey isolate protein (WPI), soy isolate protein (SPI), gelatin (GE), and maltodextrin (MD) as wall materials, respectively. Meanwhile, the encapsulation efficiency, solubility, color, particle size, thermal stability and microstructure as well as the antioxidant capacity of microcapsules were assessed. When the protein/MD ratio was 3:7, three kinds of combined wall materials realized high encapsulation efficiency (96.32–98.24%) and water solubility index (89.20–90.10%). Compared with other wall material combinations, the microcapsules with WPI-MD wall ratio at 3:7 had lower particle size (7.17 μm), lower moisture content (6.13%), higher encapsulation efficiency (98.24%), better water solubility index (90.1%), higher thermal stability (86.00°C), brightness L* (67.84) and higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging capacity (6.98 mgVc/g), and better flowability. Results suggested that WPI and MD could be better wall materials applied in encapsulating COF.

Microencapsulation of Red Banana Peel Extract and Bioaccessibility Assessment by In Vitro Digestion

The use of food agricultural wastes as a source of bioactive compounds is an alternative to reduce their environmental impact and generate the possibility of producing value-added products as functional foods. This study aimed to extract and microencapsulate the bioactive compounds from the red banana peel (Musa acuminata Colla AAA “Red”) by spray drying and to evaluate the bioaccessibility of the bioactive compounds by in vitro digestion. The microencapsulation of bioactive compounds was carried out using two wall materials gum arabic (GA) and soy protein isolate (SPI). Microencapsulation using GA and SPI proved to be an effective technique to protect the phenolic compounds, flavonoids and antioxidant capacity of banana peel extract under in vitro digestion conditions. The extract without the encapsulation process suffered a significant (p ≤ 0.05) decrease in bioactive compounds and antioxidant capacity after in vitro digestion. Although microcapsules with SPI held the bioactive compounds for longer in the matrix, no significant difference (p ≤ 0.05) in bioactive compounds retention after in vitro digestion was observed between the microcapsules with GA or SPI. These results indicate that the microcapsules obtained may be used in the food industry as potential ingredients for developing functional foods to promote health benefits.

Spray Drying and Spout-Fluid Bed Drying Microencapsulation of Mexican Plum Fruit (Spondias purpurea L.) Extract and Its Effect on In Vitro Gastrointestinal Bioaccessibility

The Mexican plum (Spondias purpurea L.) is a source of phenolic compounds; however, these compounds are susceptible to various factors (humidity, temperature, light, oxygen), as well as the digestion process, which can modify their bioaccessibility. This study aimed to extract and microencapsulate the phenolic compounds (PC), total anthocyanins (TA), ascorbic acid (AA), dehydroascorbic acid (DHA) and total vitamin C (AA+DHA) from Mexican plum ecotype “Cuernavaqueña” by spray drying (SD) and spout-fluid bed drying (SFB) and evaluate the bioaccessibility of these compounds by in vitro digestion. Optimal extraction conditions for bioactive compounds (BC) and antioxidant capacity (AC) were: three consecutive extractions at 40 °C, for 90 min each, with 1/5 solid-solvent ratio (4 g/20 mL), and 40% v/v aqueous ethanol. The extract without the encapsulation process suffered a significant (p ≤ 0.05) decrease in bioactive compounds and antioxidant capacity after in vitro digestion. Microcapsules obtained by SFB showed better retention and encapsulation efficiencies coupled with better protection against the digestion process. Microencapsulation by SFB protects the BC of Mexican plum, and it could be used in the food industry as ingredient to develop functional foods.

Microencapsulation of Horseradish (Armoracia rusticana L.) Juice Using Spray-Drying

Horseradish contains many bioactive compounds with antioxidant activity. The current study aimed to evaluate the effect of various wall materials and their ratios on the physical properties and bioactive-compound retention and stability in microencapsulated horseradish leaf and root juices. Horseradish juice was microencapsulated using maltodextrin, maltodextrin/gum Arabic, soy protein isolate, and starch with three different core-to-wall ratios. The total phenolic, total flavonoid, total flavan-3-ol, and total phenolic-acid contents, as well as antioxidant activity, were determined using spectrophotometric methods, whereas individual phenol profiles were determined by high-performance liquid chromatography (HPLC). Multivariate analysis of variance showed that plant material, wall material, and core-to-wall ratio had a significant effect on the bioactive-compound retention and antioxidant-activity preservation. Microcapsules produced from horseradish leaf juice had a significantly higher content of phenolic compounds and antioxidant activity compared to root-juice microcapsules. However, better retention was observed for microencapsulated horseradish root juice. Maltodextrin and maltodextrin/gum Arabic were the most effective wall materials for the retention of bioactive compounds, while they also had a smaller particle size and better solubility. The horseradish-juice microcapsules possess a high content of rutin. The highest stability of bioactive compounds after storage was found at a core-to-wall ratio of 20:80.