Document Type

Thesis - University Access Only

Award Date

1997

Degree Name

Doctor of Philosophy (PhD)

Department / School

Animal Science

Abstract

To determine consumer and trained sensory panel reactions to boar (BO), barrow (BA), and gilt (G) meat from pigs grown and finished on high (HI) or low (LO) protein diets, two separate trials were conducted, with bodyweight endpoints of I 00 kg (Trial 1) or 110 kg (Trial 2). Within each trial, 54 BO, BA, and G were allotted within sexes to HI or LO protein sequence diets for growing and finishing: 19 and 17% (BOHI), 18 and 16% (BOLO), 17 and 15% (GHI), 16 and 14% (GLO), 15 and 13% (BAHI), and 14 and 12% (BALO). Backfat skatole and salivary gland 16-androstene concentrations were measured from samples taken at slaughter. Longissimus (LM) and semitendinosus (ST) chops from 24 pigs ( with equal representation across diet and sex groups) were evaluated by trained panelists for tenderness, juiciness, and off-flavor. Consumer panelists evaluated acceptability of LM chops. In Trial 1, HI diets improved carcass leanness in BO and BA, but not G. In both trials, BO were leaner (P < .05) than G, and both were leaner (P < .05) than BA. Skatole and 16-androstene concentrations were similar (P > .05) among sexes in both trials. In Trial 1, trained panelists found BOLO chops had more (P < .05) off-flavor. In Trial 2, all BO had more (P < .05) off-flavor than BAHI, BALO, and GHI, but were similar (P > .05) to GLO. In both trials, BA chops were more tender (P < .05) than G and BO chops and LM chops had less off-flavor (P < .05) than ST chops. In Trial 2, skatole was correlated (r = .28, P < .001) with off-flavor. A relationship may exist between diet, skatole deposition, and off-flavor. Untrained consumers reported LM chops in both trials were equally acceptable (P > .05). In addition to the sensory properties discussed above, numerous other factors affect the appearance and palatability of meat products. All of these factors are directly or indirectly associated with basic muscle characteristics. To determine these characteristics, 12 muscles, including the biceps femoris (BF), gluteus medius (GM), quadriceps complex (QDI and QDRF), semimembranosus (SM), ST, LM, psoas (PS), infraspinatus (IF), pectoralis profundus, supraspinatus (SS), serratus ventralis (SV), and triceps brachii were removed from the same 24 carcasses used for taste panel evaluations in each trial. In both trials, differences (P < .05) were observed among muscles for color measurements of L *, a*, and b*, water holding capacity (WHC), percentages of moisture and ether extract (EE), collagen content, and shear force. For most characteristics, differences among muscles followed similar trends in Trial 1 and Trial 2. In Trial 1, sex by diet interactions (P < .10) were observed for EE, moisture, a*, b*, WHC, and shear force, and a sex by muscle interaction (P < .05) was observed for L *. In Trial 2, sex by Across all 12 muscles, BA had higher EE than BO and G. The highest EE were found in SV (5.4 and 5.3%, Trials 1 and 2, respectively) and ST (3.7 and 4.7%, Trials 1 and 2, respectively). The lowest EE were found in QDRF, GM, BF, and SM (1.4 to 2.4%, both trials). Correlations for EE between the LM and other muscles indicate EE of the LM should provide an estimate of the EE of the lean portion of the ham. Water holding capacity was lower in BO at 100 kg, but all sexes had similar WHC at 110 kg. The QDRF, GM, and LM had some of the higher relative WHC's. The BF and ST had some of the lower relative WHC's. Minimal differences existed among sexes for shear force. All shear force means were below means typical of "tough" meat. The highest shear forces were in the BF (3.25 kg, both trials). The highest L* values were observed in the ST (51.5 and 52.2, Trials 1 and 2, respectively). The highest a* values were observed for QDI, IF, SS, and SV (24.7 to 22.0, both trials). The lowest a* values were observed for LM, SM, and GM (11.8 to 16.0, both rials). Correlations for a* values between the LM and most ham muscles indicated a* values of the LM would give an estimate of the a* values of the ham.

Library of Congress Subject Headings

Pork -- Quality
Muscles
Swine -- Feeding and feeds

Format

application/pdf

Number of Pages

196

Publisher

South Dakota State University

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