Investigation of the effects of encapsulated raspberry (Rubus idaeus L.) powder on nugget quality and shelf life

In this study, the usability of encapsulated raspberry powder (ERP) in the production of phosphated and phosphate-free chicken nuggets and its effects on quality and shelf life were investigated. Raspberry powders encapsulated by spray drying using maltodextrin (12-16 DE; 40.0%, m/m) were used in nugget production, various quality characteristics (antioxidant activity, total anthocyanin, total phenolics, color, moisture and pH) of the produced ERP were determined. Then, six different groups of chicken nuggets were produced using different rates of phosphate (0.0%, 0.3%) and ERP (0.0%, 0.5%, 1.0%) and MAP (40% CO2 + 60% N2) and stored at 2.0±0.5 °C for 120 days. ERP and with phosphate affected the moisture (p<0.01), salt (p<0.01), and aw (p<0.01) values of the nugget samples. While the addition of phosphate increased the pH value of the samples, the addition of ERP decreased it (p<0.05). Both ERP (p<0.01) and phosphate (p<0.01) use prevented lipid oxidation, the lowest value was determined as 0.89±0.24 mg malondialdehyde/ kg nugget in samples with 1.0% ERP addition. While the lowest TBARS values during storage were determined in samples containing phosphate + 1.0% ERP (p<0.05), the values were found to be at an acceptable level in samples containing 0.5% and 1.0% ERP in addition to phosphate (<1 mg MDA/kg). Depending on the added ERP level, the external surface (p<0.01) and internal surface (p<0.01) a* values of the nuggets increased. The a* value was found to be higher in samples with phosphate added in addition to ERP (p<0.05). The use of ERP in nugget production affected the total aerobic mesophilic bacteria count (TAMB) (p<0.01) and yeast-mold counts (p<0.01). The counts of TAMB decreased depending on the ERP level and exceeded 6 log CFU/g only in control samples. During storage, Salmonella spp. and Listeria monocytogenes were not detected (negative), and the count of Enterobacteriaceae was found below the detectable limit (<2.0 log CFU/g). In the nuggets to which ERP was added due to its protective properties, the decrease in CO2 rate in MAP and increase in O2 rate during the storage period were less than the control samples. As a result, it has been determined that ERP can be used in nugget production, considering its natural colorant, antioxidant, and antimicrobial effects and its properties that increase storage stability/shelf life.