Investigation of Porphyridium cruentum microalgae biomass as a natural coloring for soft candy

Microalgae are among the main potential sources of bioactive ingredients and natural colorants. These biological pigment sources, whose biochemical compositions are rich in various bioactive compounds, has attracted great attention in recent years and can be used in functional product development studies as well as a natural colorant. In this study, the usage possibilities of Porphyridium cruentum biomass which was grown by using a tubular photobioreactor and encapsulated by using spray dryer technique, as a natural pigment source, was investigated. Maltodextrin (1:1) was used for encapsulation of P. cruentum biomass. Encapsluated microalgae biomasses (0.10, 0.20, 0.30, 0.40 and 0.50 g/100 g ) were used as coloring agent in confectionery samples as gummy candy and marshmallow. In microalges including confectionery samples, the effect of the microlage usage level on the main quality characteristics as well as the color stability were investigated. Color properties [L*, a*, b*, C* (chroma), h° (hue angle) and ∆E (color difference)] of samples were determined periodically during storage at 20.0±2.0°C. Considering the microalgae usage levels in gummy candies, it was determined that ∆E values varied between 1.47-7.12 during storage period. In particular, samples containing 0.10, 0.40 and 0.50 g/100 g encapsulated microalgae biomass, the ∆E value was lower than 3.00 and other samples' ∆E values (P <0.05). Considering the microalgae usage levels in marshmallow, it was determined that ∆E values varied between 2.57-5.90 during storage period. For samples containing 0.50 g/100 g microalgae, ∆E values were lower than 3.00 and other samples' ∆E values (P <0.05). As a result of the study, it was determined that higher color stability may be achieved with the use of high microalgae level (0.50 g/100 g) in both sample groups (marshmallow and gummy candy). The main physico-chemical (moisture content, water activity, pH and soluble solid matter) and sensory properties of marshmallow and gummy samples including various levels of encapsulated P. cruentum biomass were investigated. Additionally, to determine effect of concentration effects on textural properties of marshmallow and gummy candy samples, texture profile analysis (TPA) was performed with weekly periods during 12 weeks of storage at 20.0± 2.0°C. As a result of the TPA analysis, it was determined that the storage of marshmallow samples did not have a negative effect on the textural properties. It was determined that the textural properties of the samples, such as springiness, cohesiveness, chewiness and resilience were not significantly affected by the use of microalgae colorant or the concentration of this natural pigment source (P <0.05). Also, It was determined that the sensory properties of samples were not adversely affected due to using encpsulated microalgae (P <0.05). It has been determined that encapsulated algal biomass and other ingredients have an important advantage for using them as natural colorants in confectionery technology. In addition, it may be stated that microalages originated ingredients have potential for using them to enrich functionality of confectionery products. This potential effects sgould be investigated with futher studies.