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Post mortem carcass interventions to improve beef quality

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010.

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Main Author: Du Toit, Francois Matthys
Other Authors: Hoffman, Louwrens C.
Format: Thesis
Language:English
Published: Stellenbosch : University of Stellenbosch 2010
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access_status_str Open Access
author Du Toit, Francois Matthys
author2 Hoffman, Louwrens C.
author_browse Du Toit, Francois Matthys
Hoffman, Louwrens C.
author_facet Hoffman, Louwrens C.
Du Toit, Francois Matthys
author_sort Du Toit, Francois Matthys
collection Thesis
dc_rights_str_mv University of Stellenbosch
description Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010.
format Thesis
id oai:scholar.sun.ac.za:10019.1/4359
institution Stellenbosch University (South Africa)
language English
last_indexed 2026-06-10T12:41:42.083Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2010
publishDateRange 2010
publishDateSort 2010
publisher Stellenbosch : University of Stellenbosch
publisherStr Stellenbosch : University of Stellenbosch
record_format dspace
source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/4359 Post mortem carcass interventions to improve beef quality Du Toit, Francois Matthys Hoffman, Louwrens C. McMillan, K. W. University of Stellenbosch. Faculty of Agrisciences. Dept. of Animal Sciences. Tenderstretch Tendercut Beef -- Quality Dissertations -- Animal sciences Theses -- Animal sciences Dissertations -- Agriculture Theses -- Agriculture Beef -- Carcasses Hock suspension Tenderness Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010. ENGLISH ABSTRACT: A total of 32 cattle were divided into four groups of eight each (A1-8, A9-16, A17-24, B1-B8) to be slaughtered on different days over a period of 45 days. All the cattle in Groups A were of Bonsmara type and those in Group B were of Charolais type. Three treatments, Tenderstretch (TS), Tendercut (TC) and Hock suspension (HS) were randomly allocated to each of the 48 sides from group A. Only two treatments (TC and HS) were implemented on the carcass sides in Group B alternating between the right and left sides. Two muscles from each side namely Gluteus medius and Longissimus dorsi were evaluated for purge, cooking loss, shear force and sarcomere length after 2, 4, 6, 10 and 14 days of aging. Paired t-Tests were performed for each pair of treatments and each day separately, on all variables accessed (Snedecor, 1980). The differences in purge and cooking loss between treatments were all found to be inconclusive for each day of aging. Although purge had significant differences between the treatments TC and TS for the GM and LD muscle after 14 days of aging (P = 0.0341 and P = 0.0348 respectively) these were found to be open to doubt as the treatment that delivers the most purge differs between muscles and that the two treatments delivered no differences compared to its HS values. Aging had a significant effect on purge as it doubles after 14 days of aging. Cooking loss values only differed significantly on day 2 for the LD muscle between treatments TC and HS. The differences in shear force were all smaller than 0.3205 kg/ 1.27cm and not consistent over all carcasses. A mean positive improvement in tenderness was calculated from high difference in mean values from some carcasses although some carcasses showed a decrease in tenderness when using TS and TC, which suggests that the treatments are of no relevance towards the industry. Although the differences in shear force become smaller as aging commences, it is not constant, a phenomenon most probably due to the variance between animals. Aging again had the most significant effect (P<.0001) on shear force. Correlations between sarcomere lengths and shear force were low for all the treatments on the GM muscle (HS = -0.453; TC = -0.401 and TS = -0.2) but in the LD muscle the TS method showed a higher correlation (TS = -0.665) than the other treatments (HS = 0.059 and TC = 0.059). AFRIKAANSE OPSOMMING: `n Totaal van 32 beeste was opgedeel in vier groepe van agt elk (A1-8, A9-16, A17-24, B1-B8) wat geslag is op verskillende dae oor n periode van 45 dae. Beeste van die A groep was almal Bonsmara tipe en die van die B groep charolais tipe. Drie behandelings naamlik Tenderstretch (TS), Tendercut (TC) en Hak suspensie (HS) was ewekansig tot die 48 sye van die karkasse van groep A toegedeel. Groep B se 16 sye is net met TC en HS ewekansig tot die linker en regter sy toegedeel. Twee spiere naamlik Gluteus medius en Longissimus dorsi was geevalueer vir drup verlies, kook verlies, sarkomeer lengte en taaihied na 2, 4, 6, 10 en 14 dae se veroudering. Gepaarde t – toetse is gedoen vir elke paar behandelings vir elke dag van veroudering op al die veranderlikes genoem. Die verskil in drup verlies en kook verlies tussen behandelings was as nie betekeinisvol bestempel. Behalwe vir die feit dat drup verlies betekenisvolle verskille getoon het tussen die behandelings TC en TS vir die GM (P = 0.0341) en die LD (P = 0.0348) spiere na 14 dae se veroudering was dit bevind as nie betekenisvol juis oor dat die twee behandelings teenoor hul HS waardes geen verskille getoon het nie. Veroudering van die vleis het wel die grootste betekenisvolle verskil in drupverlies gemaak waar dit amper verdubbel soos die vleis verouder vir 14 dae. Kookverlies het net op dag twee n betekenisvolle verskil getoon in die LD spier vir die HS – TC kombinasie. Die verskil in taaiheid was almal kleiner as 0.3205 kg/ 1.27cm en nie kostant vir alle karkasse nie. n’ Positiewe gemiddelde verbetering in sagtheid is verkry deur die kalkulasie van hoë positiewe waardes en lae negatiewe waardes vir sommmige karkasse wat n laer sagtheid getoon het wanneer TS en TC gebruik is. Hierdie onkonsekwente verbeterings in sagtheid maak dat hierdie behandelings van min praktiese nut vir die bedryf is. Alhoewel hierdie verskille tussen behandelings kleiner raak tydens veroudering, is dit nie konstant nie, wat as gevolg van die variasies tussen diere kan wees. Veroudering het weereens die mees betekenisvolle effek op die vleis getoon (P< 0.001). Die korrelasie tussen sarkomeer lengte en WBSF taaiheid was laag vir alle behandelings in die GM spier (HS = -0.453; TC = -0.401 en TS = -0.2) behalwe vir die LD spier waar die TS behandeling n hoer korrelasie van TS = -0.665 as die ander twee behandelings (HS = 0.059 en TC = 0.059) opgelewer het. Masters 2010-02-24T15:07:46Z 2010-08-13T15:02:00Z 2010-02-24T15:07:46Z 2010-08-13T15:02:00Z 2010-03 Thesis http://hdl.handle.net/10019.1/4359 en University of Stellenbosch 118 p. : ill. application/pdf Stellenbosch : University of Stellenbosch
spellingShingle Tenderstretch
Tendercut
Beef -- Quality
Dissertations -- Animal sciences
Theses -- Animal sciences
Dissertations -- Agriculture
Theses -- Agriculture
Beef -- Carcasses
Hock suspension
Tenderness
Du Toit, Francois Matthys
Post mortem carcass interventions to improve beef quality
title Post mortem carcass interventions to improve beef quality
title_full Post mortem carcass interventions to improve beef quality
title_fullStr Post mortem carcass interventions to improve beef quality
title_full_unstemmed Post mortem carcass interventions to improve beef quality
title_short Post mortem carcass interventions to improve beef quality
title_sort post mortem carcass interventions to improve beef quality
topic Tenderstretch
Tendercut
Beef -- Quality
Dissertations -- Animal sciences
Theses -- Animal sciences
Dissertations -- Agriculture
Theses -- Agriculture
Beef -- Carcasses
Hock suspension
Tenderness
url http://hdl.handle.net/10019.1/4359
work_keys_str_mv AT dutoitfrancoismatthys postmortemcarcassinterventionstoimprovebeefquality