Post-extraction algal residue in beef steer finishing diets: II. Beef flavor, fatty acid composition, and tenderness

Microalgae cultivation for biofuel will yield a high volume of post-extraction algal residue (PEAR), which could be a viable source of nutrients for ruminants so long as inclusion does not have negative effects on beef quality and flavor. Eighteen Angus×Hereford steers (BW=549±38.8kg) were randomly assigned to one of three treatments applied for the last 35days prior to harvest: PEAR hand-mixed into the diet at 1.0kg organic matter (OM)/day (PEAR), or 1.0kg OM/day glucose infused ruminally (GR), or abomasally (GA). In Part II of a two-part study, beef subprimals from each carcass from GR and PEAR steers were collected for evaluation by a consumer panel and for fatty acid analysis. Strip steaks were collected from each carcass from GA, GR, and PEAR treatments for analysis by an expert trained sensory panel and additional strip steaks were collected from each carcass from GR and PEAR treatments for tenderness evaluation. Data from the consumer panel and fatty acid analysis were analyzed as a 2×2 factorial treatment arrangement (diet: GR or PEAR; primal: chuck or round). Data from the trained sensory panel and tenderness evaluations were analyzed as a one-way treatment arrangement. No significant differences for overall (all attributes), overall flavor, beef flavor, or juiciness liking were observed in ground beef from PEAR or GR fed steers (P≥0.17), but various differences in fatty acid composition of ground beef did occur (P≤0.03). No off-flavors were detected by the trained sensory panel (P>0.05) and tenderness of strip steaks was not affected (P=0.25). Inclusion of PEAR in finishing rations did not negatively impact consumer likability of ground beef products, impact flavor or tenderness of steaks, but did result in changes in fatty acid composition of ground beef.