Chemical composition of selected seaweeds and their utilization in chicken sausages.

Abstract

Seaweeds have the potential of being a source of nutrients and additives in the food industry. The aim of this work was to identify a seaweed from the five harvested species with the best potential of being utilized in formulation of chicken sausages. The chemical composition and functional properties of five seaweed species namely; Hypnea musciformis, Eucheuma denticulatum, Laurencia intermedia, Sargassum oligocustum, and Ulva fasciata from the Kenya coast were studied The standard association of official analytical chemists (AOAC) methods were used for proximate analysis of seaweeds and chicken sausages while mineral composition was determined using atomic absorption spectrophotometry. The fatty acid profile was determined through gas chromatography (GC) and cholesterol by High Performance Liquid Chromatography (HPLC). Chicken sausages containing 0, 1, 3 and 4% seaweed powder with the best functional properties were formulated and analyzed. The physical properties (colour) and chemical properties (pH, water holding capacity, and cooking loss and emulsion capacity) of the formulated chicken sausage were determined. The shelf life and sensory properties were also determined. The analyzed seaweeds showed considerable amounts of saturated fatty acids with a range of 53.03 to 71.05% with Eucheuma recording the least and low amounts of polyunsaturated fatty acids (PUFA) with a range of 2.75 to 10.13%. Sodium and calcium were the dominant minerals in the seaweeds with a range of (9.88 ± 1.25 to 21.88 ± 0.71mg/100g) and (7.03 ± 1.97 to 56.38 ± 4.55mg/100g), respectively. The seaweeds had considerably high emulsion capacity with a range of 59.19 ± 0.97 to75.69 ± 3.62% with Eucheuma and Ulva recording the highest while the water holding capacity of the seaweeds was within 8.42 ± 0.84 to 13.75 ± 0.87ml/g. Based on proximate analysis, fatty acid profile and emulsion activity of the five seaweed species, Eucheuma with the optimum emulsifying activity, ash and crude fat content was selected for sausage formulation. The chicken sausage with 0% seaweed powder (control) recorded the highest amount of cholesterol (10.73 %) while the 4% recorded the least (2.95 %) (P< 0.05).The pH of the chicken sausages (5.52 to 5.75) was within the normal range of sausage products. Sodium was the dominant mineral followed by potassium while zinc was the least in the seaweed based sausage. In the chicken sausages with varying amounts of seaweeds, saturated fatty acids (SFA) were the highest (27.74 to 37.45%), while monounsaturated fatty acids were the least (22.06 to 23.77%). The lightness (L*) of the chicken sausages with varying amounts of seaweeds was 68.50 to 73.37, redness (a*) was 5.43 to 8.80, yellowness (b*) was 14.63 to 15.53 and the firmness was 11.67 to 13.33 N. The chicken sausage with 0% seaweed recorded the highest emulsion stability while those with 3% seaweed the least. The chicken sausages showed significance difference in water holding capacity (P= 0.007) with 4% seaweed recording the lowest water holding capacity (55.10%). There was an increase in total plate count of Staphylococcus aureus, yeast and molds in the chicken sausages containing varying amounts of seaweeds with increase in storage time (0,7, 30 days). Based on taste, firmness, aftertaste and overall acceptability, the chicken sausage with 0% and 1% seaweed were more liked by consumers compared to 3% and 4% seaweed chicken sausage. The findings of this study indicate the potential of seaweeds in improving the chemical and functional characteristics of processed meat products with reduced cholesterol levels.