Food Chemistry
Atfeh Ghorchi; Akram Arianfar; Vahid Hakimzadeh; Sara Naji-Tabasi
Abstract
IntroductionRed beet has nutritional and health-promoting properties due to containing bioactive compounds such as phenolic compounds and betanin. Co-encapsulation of more than one core material in a single encapsulation system may increase the bioactivity of individual components. Customer attitudes ...
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IntroductionRed beet has nutritional and health-promoting properties due to containing bioactive compounds such as phenolic compounds and betanin. Co-encapsulation of more than one core material in a single encapsulation system may increase the bioactivity of individual components. Customer attitudes and behaviors have moved towards health foods because they have more concerns on increasing environmental stresses such as pollution and toxic substances in the environment. Confectionery products are not exactly foods, but they are widely consumed by children and adults. Traditional gummy confection consists of high amounts of synthetic colorings or flavorings in a gelling agent, commonly known as gelatin, along with acids and sweeteners. Natural color in the form of pigments is synthesized and accumulated in living biological cells of algae, vertebrates, invertebrates, fungi, lichens, or bacteria. The red color in food industry comes mainly from two pigments: anthocyanin and betalains. Among the major groups of natural pigments, betalains can be considered as the least studied, due to its limited sources. The main commercially produced crop containing betalain is red beet root, however many researchers are exploring red dragon fruit or pitaya as a viable alternative. Betalains, derived from beetroot are water-soluble nitrogenous pigments that stop or delay the oxidation process and exhibit anti-tumor and antiatherosclerotic effects. The application of red color from beetroot (mainly betalains) is permitted widely in ice cream, sherbet, yogurt, powdered soft drink mix along with confectionaries, soups, and bacon products. The stability of betalains varies with different levels of water activity, temperatures, exposure to oxygen, and light. Complex coacervation is one of the oldest and simplest techniques of encapsulating bioactive compounds for delivery in controlled manner. The technique associates simple preparation conditions, such as non-toxic solvent and low agitation, the techniques has also been employed in the encapsulation of protein and human cells. Microcapsules prepared by complex coacervation are water-insoluble, possessing excellent controlled-release characteristics. Complex coacervation is a technique by which phase separation occurs when oppositely charged polyelectrolytes are electrically balanced in aqueous media. This depends on relatively a set of conditions such as pH, charge density on the polymers, colloid concentration, ionic strength of the medium, temperature, etc. However, all polyelectrolytes do not exhibit this phenomenon.Materials and MethodsThe features of water activity, moisture, acidity, Brix, antioxidant activity, texture characteristics, colorimetry and sensory evaluation of pastilles were investigated. All analyzes were performed with three replications in a completely randomized design. Means were compared using Duncan's multi-range test at a significant level of 5% with SPSS version 22 software.Results and DiscussionThe results showed that water activity of samples containing nanomicrocoating of red beet extract was significantly lower than the control sample (p<0.05), but the moisture, acidity and brix of the sample containing nanomicrocoating of red beet extract were significantly higher from the control (p<0.05). During the storage period of 28 days, it showed that the sample containing 1.5% red beetroot extract's nano-coating had a significantly higher stability of the antioxidant property than other samples (p<0.05). The results of the histological test showed that the sample containing the red beet extract nano-coating had a significant decrease in hardness, stickiness and chewability compared to the control (p<0.05), but the degree of cohesion showed a significant increase (p<0.05). Examining the color parameters of the samples containing red beetroot extract nano-coating compared to the control sample also showed that it caused a decrease in brightness (L*) and yellowness (b*) and an increase in (a*).ConclusionThe results of the sensory evaluation showed that the sample containing 1% red beetroot extract nano-coating was awarded the highest score compared to the control.
Mahsa Faridnia; Ali Mohamadi Sani; Masoud Najaf Najafi
Abstract
Introduction: Natural substances with plant sources are rich in bioactive and useful compounds that promote health and improve the physicochemical properties of food products. Compounds such as antioxidants, polyphenols, pigments, flavors and etc. are among the most important bioactive plant-based compounds. ...
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Introduction: Natural substances with plant sources are rich in bioactive and useful compounds that promote health and improve the physicochemical properties of food products. Compounds such as antioxidants, polyphenols, pigments, flavors and etc. are among the most important bioactive plant-based compounds. Red beetroot is one of the unique plants that are rich in antioxidants, anthocyanins, and red pigmentation. The red pigment of the red beetroot is known as betacyanin, and betanin is the major betacyanin compound in red beetroot. Therefore, due to the red beetroot rich in natural pigments, especially betalains, this plant product has a high potential for use as a natural colorant in food, pharmaceutical, and cosmetic products. However, the restrictions on the use of natural and edible pigments are unstable during processing and preservation. The encapsulation process is one of the effective strategies in the food industry to resolve this problem and to protect bioactive compounds during production and storage. Different methods have been used for encapsulation of bioactive compounds, among which the most prominent ones are freeze-drying, emulsion, spray drying, liposomal, niosome, coacervation, and so on. Freeze drying and spray drying are two of the most widely used and industrial methods for the encapsulation of bioactive compounds, pigments, extracts, pharmaceuticals, and microorganisms. So, the aim of this study was to produce red beetroot pulp powder as a source of bioactive and colorant compounds using spray and freeze-drying processes. Materials and methods: Whey protein isolate (WPI) and maltodextrin with a DE 18-20 in different ratios (100: 0, 75:25, 50:50, 25:70 and 0: 100) as wall materials were used to the beetroot extract encapsulation. The spray drying process of the extracts was carried out at an inlet air temperature of 140 °C and outlet air temperature of 65-70 °C with a pump power of 75%, a compressed air flow of 3.5 m3/h, and a feed flow rate of 5 mL/min. To dry the freeze-dried extracts, each sample was first kept at a temperature of -18°C for 3 h, and then the drying operation was performed in a freeze dryer for 24 h. In all treatments, the Brix feed solution was kept constant at 10%. The produced powders were evaluated in terms of encapsulation efficiency, moisture content, water solubility, and total phenol content. Results & discussion: The results showed that by increasing the amount of WPI to 50% (50:50 ratio), encapsulation efficiency significantly increased (p<0.05). In the spray and freeze-dried samples, the lowest moisture content was observed in the sample treated with 100% maltodextrin. Increasing the maltodextrin ratio significantly (p<0.05) increased the solubility of the powders in water. The evaluation of total phenol content showed that the red beetroot extract powders prepared with freeze dryer had the total phenol content. Also, the powder samples obtained from the ratio of 50:50 maltodextrin to WPI had the highest total phenolic content. Based on the results obtained in this study, it was found that the use of the 50:50 ratio for maltodextrin and WPI resulted in desirable physicochemical properties in the powders obtained by both drying methods. Therefore, due to the high costs of freeze-drying and the results of the present study, it can be concluded that the spray drying method with the conditions applied during this study can be used as an effective and promising method for the production of natural pigments based on red beetroot extract for use in food, pharmaceutical, and cosmetic industries. Hence, using a 50:50 ratio for maltodextrin and WPI as wall materials and drying aid is recommended for the production of red beetroot pulp powder.
