Characterization of sausages added with a functional carrot powder ingredient rich in pro-vitamin a carotenoids and fortified with chlorogenic acid

Abstract

Metabolic syndrome has become a worldwide health issue that results in the increased risk of chronic degenerative diseases such as diabetes, cancer, and cardiovascular diseases. These metabolic conditions could be prevented if the intake of nutraceuticals is increased. The main source of these compounds in the diet are fruits and vegetables, however the consumption of such foods in the Mexican population is low, and thus it is relevant to design strategies that allow the incorporation of nutraceutical compounds in high-consumed foods in the population. The transformation of fruits and vegetables into powders, for later incorporation in food formulations as ingredients could be a strategy to increase the consumption of nutraceuticals. However, the heat treatments to which vegetables are subjected during drying to obtain powders induce a significant loss of these compounds. Also, there are additional losses during processing when the powder is added to a food formulation. In the past years, postharvest abiotic stresses such as wounding, modified atmospheres, and UV-radiation, have been studied as an effective tool to improve the accumulation of bioactive compounds in horticultural crops. In this context, it has been reported that wounding stress induces the accumulation of phenolic compounds, specially, chlorogenic acid (CHA) in carrots. Thus, the transformation of stressed carrots into a powder (carrot powder, CP) and its further incorporation into highly consumed foods, would be an effective strategy to overcome thermal losses of nutraceuticals observed during processing and to increase the consumption of antioxidants in the Mexican population. In the present study, a carrot powder with high concentration of phenolic compounds (functional carrot powder, FCP) was produced and added as an ingredient to sausage formulations. To obtain FCP, carrots were shredded, stored for 48 h at 15 °C, dried at 60 °C and grounded by milling. The nutraceutical content of phenolic compounds, carotenoids, water absorption index (WAI), and oil absorption index (OAI) were evaluated and compared to regular carrot powder (control carrot powder, CCP), which was obtained by drying carrots immediately after shredding (without storing the samples). Both CPs showed similar levels of α-carotene, β-carotene, and retinol equivalents (RE); whereas FCP showed 612.4% and 798.4% higher levels of total phenolics and CHA, respectively, as compared with CCP. Likewise, FCP showed higher values of WAI and OAI. Preliminary studies were performed to determine the optimum FCP concentration in sausages. Based on the results, formulation with 4% w/w FCP was chosen as the optimum concentration for a complete characterization of the product. A proximate analysis and dietary fiber content was determined in sausages added with 4% FCP and 4% CCP. Moreover, pH and purge values were evaluated as well as color, texture properties, and nutraceutical content (carotenoids and phenolic compounds) for 42 d of storage at 4 °C. Finally, a sensory acceptability test was performed. It was observed an increment of 72% in total dietary fiber by the addition of 4% CP, and a significant decrease of moisture in CCP formulation. Likewise, FCP addition decreased the pH of sausage, while CCP showed higher purge loss than the control and FCP formulation during storage. Color as well as texture parameters were also affected by CP addition. In general, phytochemical content showed stability during storage of sausages added with CP. Compared to CCP sausages, FCP formulation showed 377.7% higher concentration of total phenolic compounds. No significate differences in carotenoids were observed between CP formulations, while a portion of 62.5 g of 4% CP sausage contributes to 32.5% of daily retinol equivalent intake in Mexican population. Finally, a consumer’s acceptability test showed adequate acceptability of CCP and FCP formulations by consumers. Results demonstrated that FCP addition in a sausage formulation resulted on a product accepted by consumers, while providing nutraceutical compounds such as fiber, phenolic compounds and carotenoids, which could greatly aid on the prevention of chronic and degenerative diseases.