Feeding microalgae meal (All-G Rich™; Schizochytrium limacinum CCAP 4087/2) to beef heifers. I: Effects on longissimus lumborum steak color and palatibility12

Abstract

The objective of this study was to examine effects of 4 levels of microalgae meal (All-G Rich, CCAP 4087/2; Alltech Inc., Nicholasville, KY) supplementation to the diet of finishing heifers on longissimus lumborum (LL) steak PUFA content, beef palatability, and color stability. Crossbred heifers ( = 288; 452 ± 23 kg initial BW) were allocated to pens (36 pens and 8 heifers/pen), stratified by initial pen BW (3,612 ± 177 kg), and randomly assigned within strata to 1 of 4 treatments: 0, 50, 100, and 150 g·heifer·d of microalgae meal. After 89 d of feeding, cattle were harvested and LL were collected for determination of fatty acid composition and Warner-Bratzler shear force (WBSF), trained sensory panel evaluation, and 7-d retail color stability and lipid oxidation analyses. Feeding microalgae meal to heifers increased (quadratic, < 0.01) the content of 22:6-3 and increased (linear, < 0.01) the content of 20:5-3. Feeding increasing levels of microalgae meal did not impact total SFA or MUFA ( > 0.25) but tended ( = 0.10) to increase total PUFA in a quadratic manner ( = 0.03). Total omega-6 PUFA decreased (linear, = 0.01) and total omega-3 PUFA increased (quadratic, < 0.01) as microalgae meal level increased in the diet, which caused a decrease (quadratic, < 0.01) in the omega-6:omega-3 fatty acid ratio. Feeding microalgae meal did not affect WBSF values or sensory panel evaluation of tenderness, juiciness, or beef flavor scores ( > 0.16); however, off-flavor intensity increased with increasing concentration of microalgae meal in the diet (quadratic, < 0.01). From d 5 through 7 of retail display, steaks from heifers fed microalgae meal had a reduced a* value and oxymyoglobin surface percentage, with simultaneous increased surface metmyoglobin formation (quadratic, < 0.01). Lipid oxidation analysis indicated that at d 0 and 7 of display, as the concentration of microalgae meal increased in the diet, the level of oxidation increased (quadratic, < 0.01). Muscle fiber type percentage or size was not influenced by the inclusion of microalgae meal in diets ( > 0.19); therefore, the negative effects of microalgae on color stability were not due to fiber metabolism differences. Feeding microalgae meal to finishing heifers improves PUFA content of beef within the LL, but there are adverse effects on flavor and color stability.

Feeding microalgae meal (All-G Rich™; Schizochytrium limacinum CCAP 4067/2) to beef heifers. II: Effects on ground beef color and palatability12

“…Blackmon et al (2015) and Kerth et al (2015) both reported differences in the fatty acid profile of beef subprimals; however, these differences were not maintained after ground beef manufacturing. Although the magnitude of DHA increase is not similar to the LL value (Phelps et al, 2016), the increase in the ground beef product would provide more of that fatty acid when compared with a product from a nonsupplemented animal.…”

“…The authors identified microalgae as an alternative to fish oil/ meal. In the first portion of this study, feeding microalgae meal increased DHA and EPA content by a maximum of 850 and 340% in LL steaks, respectively (Phelps et al, 2016). In the current portion of the study, including microalgae at 150 g/d produced a similar maximum EPA content elevation (300%) but did not produce the same increase in DHA (416%).…”

“…After 48 h of refrigeration, the knuckle (rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius; Institutional Meat Purchase Specifications number 167; NAMP, 2010) was removed from the left side of each carcass, vacuum packaged, transported to the Kansas State University Meats Laboratory (Manhattan, KS), and stored at 2 ± 1°C until d 44 postmortem. Also, the left strip loin (Institutional Meat Purchase Specifications number 180; NAMP, 2010) was collected for the companion experiment (Phelps et al, 2016). Subcutaneous fat trimmed from the strip loins was properly identified with each individual number, vacuum packaged, and stored at 2 ± 1°C until d 44 postmortem.…”

“…A more detailed description of heifer management is described in Phelps et al (2016). Briefly, crossbred feedlot heifers (452 ± 23 kg initial BW) were assigned to pens (36 pens and 8 heifers/pen), blocked by initial pen BW (3,612 ± 177 kg), and assigned within strata to 1 of 4 treatments.…”

“…Increasing the omega-3 fatty acid content of beef can be achieved through supplementation of forages, oilseeds, and fish-derived products (Woods and Fearon, 2009). In the first part of this study, Phelps et al (2016) reported supplementation of microalgae meal up to 150 g/d increased EPA and DHA content of longissimus lumborum (ll) steaks; however, adverse fresh quality attributes such as decreased shelf life and increased off-flavors were reported. Recognizing the importance of ground beef for U.S. consumers and importance of color (Mancini and Hunt, 2005) and flavor (O'Quinn et al, 2016) on consumer acceptance of ground beef, the objective of this study was to evaluate the effect of feeding a microalgae meal on ground beef color stability and palatability characteristics.…”