Increased thermal stability of phycocyanin extracted from Spirulina platensis by cysteine addition during enzyme extraction

Abstract

Phycocyanin, a natural pigment extracted from spirulina (Spirulina platensis), is used in foods, but its use is limited due to its relatively heat labile nature. Thus, here, we aimed to investigate the effect of cysteine addition on increasing the thermal stability of phycocyanin extracted from spirulina using Collupulin. Our results showed that 0.5% cysteine was the most effective in extracting phycocyanin. Furthermore, 95 °C heat treatment increased the stability of phycocyanin extracted with Collupulin and cysteine. The thermal kinetic model of the phycocyanin extracted with Collupulin and cysteine was confirmed to follow the second order. The activation energy of phycocyanin extracted with Collupulin and cysteine, calculated using the reaction constant (k) obtained from the secondary thermal kinetic model, was 65.3 kJ. Collectively, the addition of 0.5% cysteine increased the thermal stability of phycocyanin extracted with Collupulin, and this phycocyanin could be used in foods that undergo a heating process.

Exploring the Benefits of Phycocyanin: From Spirulina Cultivation to Its Widespread Applications

“…Incubation of phycocyanin with 0.6% lysozyme for 16 h resulted in a purity of 1.19 with a yield of 82.07 mg/g and recoveries of 68.96%. Ultrasound with enzyme-assisted extraction resulted in the highest phycocyanin yield of 92.73 mg/g dry biomass, with 77.92% extraction efficiency and a purity of 1.09 [167]. In another study, an effective extraction of phycocyanin was achieved using Collupulin protease in combination with the application of a pulsed electric field [167].…”

“…Ultrasound with enzyme-assisted extraction resulted in the highest phycocyanin yield of 92.73 mg/g dry biomass, with 77.92% extraction efficiency and a purity of 1.09 [167]. In another study, an effective extraction of phycocyanin was achieved using Collupulin protease in combination with the application of a pulsed electric field [167]. The combination of a pulsed electric field with enzymes can be a promising technology for phycocyanin extraction.…”

Arthrospira platensis as future food: a review on functional ingredients, bioactivities and application in the food industry

“…This improvement is attributed to cysteine's ability to protect and stabilise the thiol groups forming covalent disulphide bonds, ultimately stabilising protein. Meanwhile, the thermodynamic model for extracting C‐phycocyanin and allophycocyanin from Collupulin and cysteine was in accordance with the secondary kinetic model (Lee et al ., 2022). The C‐phycocyanin and allophycocyanin extracted by this method have high thermal stability and could be used as a natural novel pigment or active substance.…”

Impact of Biomass Drying Process on the Extraction Efficiency of C-Phycoerythrin

“…Over the years, several pre-treatment methods have been designed and tested for the efficient extraction of phycobiliproteins. According to the scientific literature, the most frequently reported pre-treatment methods are freeze–thaw [ 5 , 6 , 7 , 8 ], enzymatic treatment [ 7 , 9 , 10 ], and drying of biomass [ 3 , 11 , 12 , 13 , 14 , 15 ]. In the case of freeze–thaw, the biomass is first dried with a mild method such as freeze drying or spray drying; then, the biomass is rehydrated using a known volume of cold phosphate buffer or a mixture of green solvents and mixed using a bead-miller, sonicator, or another equipment available.…”