Spray-Drying of Green or Gold Kiwifruit Juice–Milk Mixtures; Novel Formulations and Processes to Retain Natural Fruit Colour and Antioxidants

Effect of Maltodextrin, Arabic Gum, and Beetroot Juice Concentration on the Powder Properties of Spray-Dried Beetroot-Skim Milk Mixtures

Milk products are widely consumed as a beverage and used as the main ingredient in many food applications. Beetroot is suitable as an ingredient for the natural red color in food products. Color stability of natural colorants is mainly affected by mixtures of materials and temperatures. The effect of beetroot juice concentration and types of carrier agents on the physical properties of the red-colored skim-milk powder and rehydrated powder at different temperatures were studied. Beet juice concentration significantly affects the redness (a*) and lightness (L*) of skim milk in both powders and reconstituted forms. Powder with mixtures of maltodextrin and Arabic gum showed better retention of redness, high solubility, low moisture content, water activity, and less hygroscopic. The finding from this study may benefit food product development, beverage, and confectionery in the food industry.

Development of Functional Kiwifruit Jelly with chenpi (FKJ) by 3D Food Printing Technology and Its Anti-Obesity and Antioxidant Potentials

With the growing popularity of the concept of healthy diet, modern obesity treatment is gradually shifting from surgical or pharmacological treatment to nutritional intervention. As a safe and effective measure, natural product interventions are a potential strategy of obesity management. The present study aimed to develop a kind of functional food rich in bioactive compounds (chenpi, kiwifruit, and pectin as raw materials) and investigate their bioactive effects on a mouse model. For development of functional kiwifruit jelly with chenpi (FKJ), the results of single-factor and response surface experiments showed that the optimized formulation was composed of a 30.26% addition of chenpi, 35% addition of kiwifruit juice, and 2.88% addition of pectin. The FKJ obtained with the optimal formulation could be used as a 3D printing raw material to print the desired food shapes successfully. For bioactivity evaluation of FKJ, the results with a mouse model showed that the food intake, liver weight, and adipose tissue weight were significantly decreased after administration of FKJ with dose-dependent effect compared to the CON group (p < 0.05). Meanwhile, the serum levels of several inflammatory factors (TG, IL-6, and TNF-α) were decreased and the activities of several antioxidant-related enzymes (SOD, GSH-PX, and CAT) were increased. In short, a functional kiwifruit jelly with chenpi was developed in this study. It is a functional snack food rich in active phenolic compounds, low in calories, with antioxidant and anti-inflammatory activity, and prevents fat accumulation. FKJ could well meet the needs of modern people for nutrition and health and also promote the processing and utilization of natural products, and has good development prospects in the functional food industry.

Microencapsulation of Cymbopogon citratus D.C. Stapf Essential Oil with Spray Drying: Development, Characterization, and Antioxidant and Antibacterial Activities

This study aimed to microencapsulate Cymbopogon citratus essential oil (CCEO) with spray drying using maltodextrin and gelatin. The effects of the operational conditions (inlet temperature (130–160 °C), CCEO concentration (5–15%), maltodextrin concentration (10–20%)) on the physicochemical stability and antioxidant and antibacterial activities of the CCEO microcapsules were determined. The CCEO microencapsulation process had yield and encapsulation efficiency values varying from 31.02 to 77.53% and 15.86–61.95%, respectively. CCEO microcapsules had antibacterial effects against Staphylococcus aureus and Escherichia coli with minimum inhibitory concentration varying from 10 to 20%, and total phenolic contents and antioxidant activities varying from 1632 to 4171.08 μg TE/g and 28.55–45.12 µg/g, respectively. CCEO microcapsules had average diameters varying from 5.10 to 10.11 µm, with spherical external structures without cracks and apparent pores. The best desirable process conditions for CCEO microencapsulation were process inlet temperature of 148 °C, maltodextrin concentration of 15%, and CCEO concentration of 10%. The results showed that CCEO microcapsules with increased stability and low degradation of active components can be prepared by spray drying using maltodextrin and gelatin with the production of microcapsules, which could be exploited as potential food preservatives.

The influence of nanodelivery systems on the antioxidant activity of natural bioactive compounds

Bioactive compounds may lose their antioxidant activity (e.g., phenolic compounds) at elevated temperatures, enhanced oxidative conditions and severe light exposures so they should be protected by various strategies such as nano/microencapsulation methods. Encapsulation technology has been employed as a proper method for using antioxidant ingredients and to provide easy dispersibility of antioxidants in all matrices including food and pharmaceutical products. It can improve the food fortification processes, release of antioxidant ingredients, and extending the shelf-life and bioavailability of them when ingested in the intestine. In this study, our main goal is to have an overview of the influence of nanoencapsulation on the bioactivity and bioavailability, and cellular activities of antioxidant ingredients in different delivery systems. Also, the effect of encapsulation process conditions, storage conditions, carrier wall materials, and release profile on the antioxidant activity of different natural bioactives are explained. Finally, analytical techniques for measuring antioxidant activity of nanoencapsulated ingredients will be covered.

Investigation of lamb fat quality attributes during deodorization

Edible lamb fat is an illustrious frying fat due to its good flavor and stability to oxidation. Fat deodorization is a vacuum–steam distillation process that is accomplished for removing the unwanted components such as free fatty acids and volatile compounds. The present work has studied the kinetics of lamb fat deodorization under different temperatures in a batch deodorization system. Variations of acid value (AV), peroxide value, p-Anisidine value, TOTOX value and total color difference were measured during the deodorization process. The Logarithmic, Wang and Singh, Hénon et al., and linear models were fitted with obtained data using nonlinear regression method. Results indicated that the Logarithmic and Henon et al. models gave the best fitness respectively with AV and p-Anisidine value, based on the statistical criteria of correlation coefficient (R2), reduced chi-square (χ2) and root mean square error (RMSE). Furthermore, the linear model was selected as the best model to describe the variations of TOTOX value and peroxide value during the deodorization process.

Evaluation of freeze-dried milk-blackberry pulp mixture: Influence of adjuvants over the physical properties of the powder, anthocyanin content and antioxidant activity

The blackberry fruit (Rubus spp.) presents an attractive color ranging from purple red to blue, due to the high content of bioactive compounds, such as anthocyanins. Bioactive compounds have antioxidant properties, acting as free radical scavengers and are also frequently linked to the prevention of cardiovascular and other chronic diseases. Due to native-form anthocyanins instability against environmental stress, bioactive compounds are not always as effective in improving human health as they could be. Therefore, the production of powders using adjuvants is a promising approach for encapsulating anthocyanins-rich pastes, in order to improve their stability and application. Thus, the aim of the present study was to evaluate the influence of adjuvants on the physical properties of the powder, and on anthocyanin content and antioxidant activity of the pastes and freeze-dried milk-blackberry pulp mixtures. The pastes formulated were of milk-blackberry pulp (25%:75%, (weight/weight (w/w)) and of milk-blackberry pulp-adjuvant (25%:70%:5%, (w/w/w)), and the adjuvants employed were maltodextrins 10DE and 20DE and Capsul®. The addition of maltodextrin 20DE and Capsul® resulted in pastes with high anthocyanins content (451.6 ± 80.0 μg/g and 453.1 ± 26.0 μg/g, respectively), similar to the paste without adjuvants (568.6 ± 3.4 μg/g). Also, maltodextrin 20DE and Capsul® showed a high protection capacity of the anthocyanins present on the powders (around 96% of anthocyanins retention). When no adjuvants were used, the anthocyanins retention was very low (40.1%). The freeze-drying process maintained the antioxidant capacity of the bioactive compounds and the powders obtained showed good quality with low moisture content and hygroscopicity.

Effect of Gum Arabic, β-Cyclodextrin, and Sodium Caseinate as Encapsulating Agent on the Oxidative Stability and Bioactive Compounds of Spray-Dried Kenaf Seed Oil

Kenaf seed oil is prone to undergo oxidation due to its high content of unsaturated fatty acids, thus microencapsulation stands as an alternative to protect kenaf seed oil from the adverse environment. This study primarily aimed to evaluate the oxidative stability of microencapsulated refined kenaf seed oil (MRKSO) by the use of gum arabic, β-cyclodextrin, and sodium caseinate as the wall materials by spray drying. Bulk refined kenaf seed oil (BRKSO) and MRKSO were kept at 65 °C for 24 days to evaluate its oxidative stability, changes of tocopherol and tocotrienol contents, phytosterol content, and fatty acid profile. The results showed that the peroxide value, p-Anisidine value, and total oxidation value of BRKSO were significantly higher than the MRKSO at day 24. The total tocopherol and tocotrienol contents were reduced 66.1% and 56.8% in BRKSO and MRKSO, respectively, upon the storage. There was a reduction of 71.7% and 23.5% of phytosterol content in BRKSO and MRKSO, respectively, upon the storage. The degradation rate of polyunsaturated fatty acids in BRKSO was higher than that of MRKSO. This study showed that the current microencapsulation technique is a feasible way to retard the oxidation of kenaf seed oil.

PRACTICAL APPLICATION

There is increasing research on the functional properties of crude kenaf seed oil, but the crude kenaf seed oil is not edible. This study offered in developing of microencapsulated refined kenaf seed oil by spray drying, which is suitable for food application. The microencapsulation of refined kenaf seed oil with healthier wall materials is beneficial in developing a diversity of functional food products and supplements.

Spray-drying of grape skin-whey protein concentrate mixture

The aim of this work was to evaluate the effect of process conditions (inlet air temperature, paste flow rate, and whey protein concentration) on the physical and physicochemical characteristics of the powder obtained from spray dried grape skin-whey protein concentrate mixture. The experiments were performed according to the 2³ factorial design, with repetition of the central point. The highest values of anthocyanin retention (> 92%) were obtained with the highest inlet air temperature (190 °C) and the highest whey protein concentration (15% (w/w)). The powder also showed solubility above 78.3%, and low values of moisture content, hygroscopicity and bulk density. Spray drying of grape residues, using whey protein as carrier agent, resulted in a powder with a high level of anthocyanin retention and of good quality, showing a potential application in food products. Therefore, the method indicates a possible alternative to change post-harvesting waste in a natural source of bioactive compounds.

Spray-Drying of Milk-Blackberry Pulp Mixture: Effect of Carrier Agent on the Physical Properties of Powder, Water Sorption, and Glass Transition Temperature

Spray dryer was used to produce particles from a milk-blackberry pulp mixture (25%:75% (w/w)). Maltodextrin 10DE and 20DE and gum Arabic were used as adjuvants in order to improve powder quality. The particles were analyzed with emphasis on physical and physicochemical characteristics: moisture content, bulk density, particle size, morphology, water activity, anthocyanins retention, anthocyanins content, hygroscopicity, solubility, water sorption, and glass transition temperature. The best results were obtained for the paste composition of 25% concentrated milk-70% blackberry pulp-5% gum Arabic, yielding high anthocyanins retention (>87.5%), low powder moisture content of 0.0265 g H₂ O/g dry matter and a higher powder solubility (>71.8%) when compared with other formulations. The increase of water content led to a decrease of powder's glass transition temperature. Powder stability was evaluated and the critical values of relative humidity and moisture content were estimated based on state diagrams of glass transition combined with sorption isotherm data.

PRACTICAL APPLICATION

The growing interest in blackberries is due to the presence of anthocyanins which have shown possible application as a natural dye for food and pharmaceutical products. Drying a mixture of blackberry pulp and milk may produce particles with a broad range of intrinsic nutrients. Milk components could act as a wall material and emulsifying agent, protecting the flavonoids from blackberry. Therefore, a milk-blackberry powder becomes an alternative, which may reduce postharvesting waste and increase the shelf life of the product without significantly altering its nutritional characteristics.

Thermodynamic and kinetics study of phenolics degradation and color of yacon (Smallanthus sonchifolius) microparticles under accelerated storage conditions

This study aimed to investigate the kinetics and thermodynamic of the phenolics degradation and the kinetics of degradation of the total color difference of yacon juice microcapsules produced by spray drying using Gum Arabic and polydextrose as wall materials. The degradation of the microcapsule was evaluated by accelerated tests under controlled conditions at 35 and 45 °C, and relative humidity of 75 and 90%, for 35 days. Degradation of phenolics followed the first order model and the degradation constant was in the range of 0.0124-0.0209 days^-1. The microparticles with gum Arabic were more stable than those with polydextrose for all conditions studied, with longer half-lives. Both wall materials showed similar thermodynamic characteristics, indicating similar mechanism of degradation of phenolics. With respect to the color parameters, the first order model adjusted to data of the total color difference, and no significant differences were observed for the conditions studied.