Proximate Composition, Phytochemicals and Heavy Metals in Natural Colourants Applied to Meat Processing and Their Effects on Storage and Sensory Properties of Spatchcock Chicken

Abstract

This study aimed to evaluate the proximate composition, phytochemical profile, and heavy metal content of natural colorants (hibiscus, turmeric, bell pepper, and beetroot) used in meat processing, compared to the synthetic colorant Ja’wa, and assess their effects on the storage stability and sensory quality of skewer spatchcock chicken (SSC). Broiler chickens were processed into SSC, cured with the colorants, and analyzed for proximate components (dry matter, crude protein, lipid, fiber, ash, nitrogen-free extract) and minerals using standard procedures, heavy metals (arsenic, chromium, cadmium, lead, manganese) via atomic absorption spectrophotometry, and phytochemicals (alkaloids, flavonoids, saponins, phenols, tannins, glycosides). Sensory evaluation involved 30 semi-trained panelists scoring colour, flavour, texture, juiciness, tenderness, and acceptability on a 9-point hedonic scale, with data analyzed using general linear model and Tukey’s HSD. Results revealed natural colorants exhibited superior proximate profiles, with beetroot highest in crude protein (14.23%), bell pepper in dry matter (96.11%), and turmeric in flavonoids (70.50 mg/g) and phenols (65.48 mg/g); heavy metal levels were minimal (0.00–0.31 ppm) and within permissible limits, while Ja’wa showed toxic concentrations (lead 7.85 ppm). Sensory scores improved with natural colourants, particularly turmeric (highest flavour 6.21, tenderness 6.46, acceptability 6.63), and short-term storage (0–4 days) enhanced attributes like juiciness and acceptability. In conclusion, natural colorants provide safer, nutrient-rich alternatives to synthetic dyes, improving SSC's nutritional value, safety, and consumer appeal during storage, supporting their adoption in meat processing for healthier products.