Properties of encapsulated raspberry powder and its efficacy for improving the pH, colour quality and shelf life of modified atmosphere packaged chicken nuggets

1. Recent research has shown that encapsulated raspberry powder (RP) is a natural colourant for foodstuffs. However, no research has been conducted on its use in chicken nuggets. In addition, the effect of RP on products with and without phosphate addition is unknown. This study assessed the effects of RP (control, 0.5%, 1.0%) and phosphate (0.0%, 0.3%) on the pH and colour quality properties of nuggets. 2. In the production of RP, red raspberry (Rubus ideaus L.) juices were encapsulated using maltodextrin in a spray-dryer. Antioxidant activity, total anthocyanin, total phenolics, colour, moisture and pH analyses of the RP were performed. 3. Nuggets were packaged in modified atmosphere packaging (MAP; 40%CO2 + 60%N2) and were stored at 2.0 ± 0.5°C for 120 d. The pH and external and internal surface colour (L*, a*, b*, C* and h) values were measured on d 0, 15, 30, 45, 60, 75, 90, 105 and 120 of storage. 4. The addition of phosphate increased the pH in the samples, while these decreased with the addition of RP (p < 0.05). During storage, the highest pH were seen in the phosphate samples and the lowest in the nuggets with 1.0% RP addition (p < 0.05). 5. With the addition of phosphate, the external surface a* value of nuggets increased (p < 0.05). Depending on the level of RP added to the nuggets, the external surface L* value decreased and a* and b* values increased (p < 0.05). After d 30 of storage, the a* value increased in the samples with RP addition and this increase was higher in the with phosphate nuggets (p < 0.05). 6. The internal surface a* value increased with the addition of RP during nugget production (p < 0.05). The increase in a* value was greater in samples with added phosphate (p < 0.05). During storage, the highest a* values were seen in nuggets treated with phosphate + 0.1% RP (p < 0.05). The addition of RP to chicken nugget emulsion improved redness, colour stability and shelf life.