Use of coconut sugar as an alternative agent in osmotic dehydration of strawberries.

This study aimed to evaluate coconut sugar (CS) as an alternative osmotic agent to sucrose for the osmotic dehydration (OD) of strawberries. OD was performed by immersing strawberries cut into 13.6 ± 0.4 mm edge cubes in osmotic solutions of CS or sucrose, at two different concentrations (40% and 60%, w/w), with and without application of vacuum (AV) in the first 20 min of the process. The total OD time was 300 min. Evaluations of the kinetics of solid gain (SG), water loss (WL), and weight reduction (WR) were performed at 30, 60, 120, 180, 240, and 300 min. SG, WL, and WR increased over the OD time and showed values of up to 7.94%, 63.40%, and 55.94%, respectively. AV increased WL, WR, shrinkage, pH, and total color difference and decreased anthocyanin, ascorbic acid (AA), phenolic, and antioxidant contents. The higher concentration led to higher SG, WL, WR, shrinkage, hardness, and lower moisture content, water activity, anthocyanin, AA, phenolic, and antioxidant contents. The use of CS instead of sucrose had little influence on strawberry properties, except pH and color responses. The optimal treatment was using a 60% CS solution without AV, showing a very distinct color change, hardness increased by approximately 4.5 times and maintenance of acidity, anthocyanins, AA, total phenolics, and antioxidants of 38.0%, 39.6%, 11.8%, 30.0%, 31.1%, and 30.3%, respectively, compared to fresh strawberries. PRACTICAL APPLICATION: Osmotic dehydration of fruit is a process traditionally carried out using sucrose. However, increasing health concerns have made consumers seek alternative sugars to sucrose. The use of coconut sugar made it possible to produce osmo-dehydrated strawberries different from the traditional one, maintaining product quality and process efficiency.

Encapsulation of coffee silverskin extracts by foam mat drying and comparison with powders obtained by spray drying and freeze-drying.

Coffee silverskin is a coproduct that has a rich composition in bioactive compounds. However, most of these compounds are susceptible to the conditions used during food processing and storage. Encapsulation is a process of great interest to increase the stability of these bioactive compounds, and different methods can influence the final characteristics of the product. Therefore, this study aimed to evaluate the encapsulation methods by foam mat drying, spray drying and freeze-drying for producing powder from coffee silverskin extracts. Density, porosity, overrun, and stability foam were evaluated and the physicochemical properties of powders, such as water activity, moisture, wettability, hygroscopicity, solubility, color, antioxidant activity, and total phenolic were determined. The optimal condition required for the feed mixture for foam formation was 7.6% gum arabic, 2% maltodextrin, and 10.4% egg albumin. All methods presented powders with desirable values of water activity, moisture content, and hygroscopicity, being considered stable for storage, and high content of bioactive compounds. Higher temperatures for foam mat drying produced powders with higher encapsulation efficiency (>77%) and longer wettability than lower temperatures (50 and 60°C). Therefore, this study verified that foam mat drying can be considered an efficient and promising method for encapsulating bioactive compounds from coffee silverskin extract. PRACTICAL APPLICATION: Foam mat drying can be considered an alternative method to conventional encapsulation by spray drying and freeze-drying. This method is simple, inexpensive, and generates high-quality products. Optimization of foam properties is necessary to ensure successful drying.