Effect of the nanoencapsulated sour tea (Hibiscus sabdariffa L.) extract with carboxymethylcellulose on quality and shelf life of chicken nugget

In this study, the antioxidant properties of sour tea extract (Hibiscus sabdariffa L.) were investigated in both free and nanoencapsulated forms to increase the quality and shelf life of chicken nugget during a 9‐day refrigerated storage period. For this purpose, the extract was prepared using ultrasound and quantities of phenolic and anthocyanin compounds, and antioxidant properties (DPPH free radical scavenging, FRAP) of extract was examined. The results showed that the value of phenolic compounds and anthocyanin compounds were 626.57 mg/g gallic acid and 379.11 µg/ml, respectively, and the extract had high antioxidant activity. Maltodextrin‐whey protein concentrate was used for nanoencapsulation of the extract. Then, to investigate the effect of sour tea extract (free and nanoencapsulated forms) with carboxymethylcellulose (CMC) on quality and shelf life of chicken nugget, five treatments, including T1: control, T2: CMC, T3: CMC +1,000 ppm extract, T4: CMC +1,000 ppm nano extract; and T5: CMC +TBHQ, were prepared. First, physicochemical properties of nugget were measured. The results showed that CMC and sour tea extract reduced oil uptake, moisture content, frying percentage, frying efficiency, and soft texture of fried chicken nugget, and overall the best results were observed in CMC treatment with both extract and nano‐extract (p < .05). Then, peroxide value (PV), total volatile nitrogen base (TVB‐N), thiobarbituric acid (TBA), and sensory indexes were evaluated in treatments stored at refrigerator for 9 days. The results showed that sour tea extract has antioxidant properties and coating of extract increased its antioxidant properties as nugget containing 1,000 ppm the nanoencapsulated sour tea extract with CMC delayed oxidative spoilage and organoleptic changes of chicken nugget (p < .05). Therefore, it seems that the nanoencapsulated sour tea extract with CMC can be used as a natural preservative in meat and meat products.