Available at: https://digitalcommons.calpoly.edu/theses/3107
Date of Award
6-2025
Degree Name
MS in Agriculture - Animal Science
College
College of Agriculture, Food, and Environmental Sciences
Advisor
Iksoon Kang
Advisor Department
Animal Science
Advisor College
College of Agriculture, Food, and Environmental Sciences
Abstract
Microalgae are a promising feed ingredient due to their high content of proteins, lipids, polysaccharides, vitamins, pigments, and enzymes. This study evaluated the effects of algae as a dietary supplementation on the appearance, quality, and sensory attributes of broiler carcasses. In each of experiment I and II, a total of 54 Ross-708 broilers were randomly obtained from the pool of 270 broilers in the 18 floor pens of soybean-mealbased diets at 0, 2.5%, and 5% Spirulina (Experiment I) and Nannochloropsis (Experiment II) supplements in the Poultry Unit at California Polytechnic State University (Cal Poly, San Luis Obispo, CA). Broiler carcasses were processed traditionally in the Meat Processing Center at Cal Poly. Both microalgae showed no significant effects on chilling yield, sarcomere length, pH, flavor, aroma, aftertaste, and overall sensory acceptability (P > 0.05). Spirulina supplementation led to a linear increase in the intensity of yellowness (b*) in both carcass skin and skinless fillets (P < 0.05) as the amount of supplement increased. In sensory evaluations, a higher appearance score was noted at the 2.5% Spirulina level compared to both the control and the 5% Spirulina group. Additionally, a lower juiciness score was recorded at the 5% Spirulina level compared to the control and the 2.5% group (P < 0.05). Nannochloropsis significantly improved cooking yield, shear force, and sensory tenderness score at 5% compared to the control (P < 0.05), with an intermediate value found at 2.5% except for tenderness. In color evaluation, no color v difference was observed regardless of supplementation level (P < 0.05), except for the lightness (L*) at 5%. These results suggest that the addition of Spirulina at 2.5 - 5 % showed no obvious benefits except for the intensity of yellowness on carcasses. However, Nannochloropsis at 5% enhanced both tenderness and the cooking yield of breast fillets, offering some benefits to the poultry industry and consumers.