The effect of dietary conjugated linoleic acid supplementation on the physicochemical, nutritional and sensory qualities of pork
| dc.contributor.advisor | Hugo, A. | |
| dc.contributor.advisor | De Kock, H. L. | |
| dc.contributor.author | Bothma, Carina | |
| dc.date.accessioned | 2015-10-19T10:09:31Z | |
| dc.date.available | 2015-10-19T10:09:31Z | |
| dc.date.copyright | 2012-02-28 | |
| dc.date.issued | 2014-05-27 | |
| dc.date.submitted | 2012-02-28 | |
| dc.description.abstract | English: Forty eight gilts were fed one of four dietary treatments containing 0, 0.25, 0.5 and 1% CLA, until their weight reached 95 kg and were then slaughtered. There were a lack of significant differences in pig performance and growth traits (weight increase, ADG, ADFI, FCR), and slaughter characteristics (SLW, hot carcass weight, cold carcass weight, dressing percentage, BFT, MT and LMC). There were no change in M.longissimus thoracis area, drip loss, WHC, pH45 and pH 24, while L*-and b* values decreased with increased dietary CLA. Colour a*-values and SI also did not differ between the four treatments. For the BF, IVs decreased with increased dietary CLA, while RI, colour a* and SI values remained unchanged, and colour b* values and hardness increased. Conjugated linoleic acid supplementation resulted in improved technological quality of subcutaneous fat, demonstrated by reduced IVs, unchanged RI and extractable fat content, and increased FFDM. With increase in CLA supplementation, C18:0, cis 9, trans 11, trans 10, cis 12, UFA, SFA, n-6/n-3, PUFA/SFA, dienoic acid, C16:0+C18:0, C16:0/C18:2, C16:1+C18:1c9/C16:0+C18:0 and C18:0/C:18:2 increased, C18:1c9/C18:0, MUFA, PUFA, MUFA/SFA, n-3, PI, trienoic, tetraenoic, penta + hexaenoic acid and DBI decreased, while n-6 remained unchanged. There was a tendency for sampling positions on the dorsal (neck, BF, chuck) and lateral (rib area) sides of the carcass to have higher CLA content. Differential scanning calorimetry of subcutaneous fat showed the presence of β’-crystals in fat from 0.25 and 0.5% CLA- fed pigs and β-crystals in fat from 1% CLA-fed pigs. For IMF samples, increased dietary CLA led to no change in IV, C18:0, C18:1t9, C18:1c7, C18:3n-3, PUFA/SFA, tetraenoic acid, C16:0/C18:2 and C18:0/C18:2 contents, while C16:1c9, cis- 9, trans-11, trans-10, cis-12, C22:5, C22:6, SFA, AI, PI, n-3, n-6/n-3, PUFA, n-6, dienoic acid, trienoic acid, penta- + hexaenoic acid, C16:0+C18:0 and C16:1+C18:1c9/C16:0+C18:0 contents increased and C18:1c9, C20:1c11, C18:1c9/C18:0, C18:2, C18:3n-6, C20:3n-3, C20:2, C20:4, C20:5, MUFA, UFA, MUFA/SFA and AI contents decreased. Most CLA was deposited on the lateral sides of the carcass, namely the M.triceps brachi. M.supra spinatus showed an atypical FA composition. Descriptive sensory analysis was performed on oven-broiled pork chops and fat samples by a trained panel. The control was rated most tender, confirming the results from the physical texture analysis. The control also had least resistance for first bite, with the 0.5% CLA treatment having most resistance. The 0.5% CLA treatment had a chemical aroma for the fat. The accelerated oxidation test indicated that BF from the control did not become rancid faster than BF from the three CLA treatments. Refrigerated display of pork chops for 8 days resulted in increased L*and b* values for the CLA treatments, unchanged TBARS values, while SI decreased. After frozen storage for 3 months, TBARS values remained unchanged for pork chops from the different dietary treatments. After 6 months of frozen storage, TBARS values decreased for pork chops from CLA supplemented pigs. After eight and 16 weeks of frozen storage, PVs for frozen patties decreased for the 0.5 and 1% CLA treatments. Differences in TBARS values became evident after eight weeks for the frozen patties, compared to sixth months for frozen pork chops. The TBARS values for the frozen chops were lower than the frozen patties. At the end of the ripening period, PVs for salamis from the 0.5 and 1% CLA treatments decreased, along with TBARS values. Belly fat from the CLA treatments was firmer than the control. No significant differences were observed between the four bacon treatments for either PV or TBARS values over the course of the six week refrigerated storage. According to the consumer panel, the control bacon was preferred to the 0.25% CLA bacon. | en_ZA |
| dc.description.abstract | Afrikaans: Agt en veertig jong sôe is een van vier diëte wat 0, 0.25, 0.5 en 1% gekonjugeerde linoleïensuur (CLA) bevat het, gevoer, tot ‘n gemiddelde gewig van 95 kg bereik is en toe geslag. Daar was nie betekenisvolle verskille ten opsigte van varkprestasie en groei-eienskappe (massatoename, gemiddelde daaglikse massatoename, gemiddelde daaglikse voerinname, voer- omskakelingsverhouding), en slagkenmerke (slagmassa, warm karkasmassa, koue karkasmassa, dresseerpersentasie, rugvetdikte, spierdikte en maervleisinhoud) nie. Daar was ook nie verskille in M.longissimus thoracis- oppervlakte, drupverlies, waterhouvermoë, pH45 en pH 24 nie, terwyl kleur L*- en b*-waardes verminder het met toename in CLA in die dieet. Kleur a* -waardes en “chroma” en “hue angle” het ook nie verskil tussen die vier behandelings nie. Jodium- en kleur b*-waardes vir die rugvet het verminder, met gepaardgaande toename in CLA in die dieet, terwyl kleur a*- waarde, “chroma” en “hue angle” nie verander het nie, en vethardheid toegeneem het. Supplementering met CLA het die tegnologiese kwaliteit van die onderhuidse vet verbeter, soos aangedui deur verminderde jodiumwaardes, onveranderde ekstraheerbare vetinhoud en toename in vetvrye droë materiaal. Met toename in CLA, het 14:0, C16:0, C18:0, C18:1t9, cis-9, trans-11 CLA, trans-10, cis-12 CLA, SFA, arterogenetiese indeks, n-6/n-3, trienoïese suur, C16:0+C18:0, C16:0/C18:2, C18:0/C:18:2 en DBI verhoog, terwyl C18:1c9, C18:1c7, C20:1c11, C18:1c9/C18:0, C18:2, C18:3, C20:2, C20:3, C20:4, C22;5, C22:6, MUFA, UFA, MUFA/SFA, PI, n- 3, dienoïese suur, trienoïese suur, tetraenoïese suur, pentaenoïiese suur, heksaenoïese suur, penta+hexaenoïese suur en C16+C18:1/C16:0+C18:0 verlaag het, en C16:1c9 en n-6 nie verander het nie. Differensiële skanderingskalometrie van die onderhuidse vet het die teenwoordigheid van β’-kristalle getoon in die vet van varke wat 0.25 en 0.5% CLA gevoer is, en β-kristalle in die vet van varke wat 1% CLA gevoer is. Vir die spiervetmonsters het die verhoging van CLA in die dieet gelei tot geen verandering in ekstraheerbare vetinhoud, vetvrye droë material, voginhoud, jodiumwaarde, C18:0, C20:0, C22:0, C18:1t9, C18:1c7, C18:3, C16:0/C18:2, C18:0/C18:2 en DBI, terwyl C14:0, C16:0, C16:1c9, cis-9, trans-11 CLA, trans-10, cis-12 CLA, C22:5, C22:6, SFA, arterogenetiese indeks, peroksidasieindeks, n-3, n-6/n-3, PUFA, n-6, dienoïese suur, pentaenoïese suur, heksaenoïese suur, penta+ heksaenoïese suur en C16:0+C18:0 inhoud verhoog het en C18:1c9, C20:1c11, C18:1c9/C18:0, C18:2, C18:3, C20:3, C20:2, C20:4, C20:5, MUFA, UFA, MUFA/SFA, MUFA/UFA, trienoïese suur, tetraenoïese suur en C16:1+C18:1c9/C16:0+C18:0 inhoud verlaag het. Die meeste CLA is neergelê aan die sye van die karkas, naamlik die M.triceps brachi. Die M.supraspinatus het ‘n a-tipiese vetsuursamestelling getoon. ‘n Opgeleide paneel het oondgeroosterde varkkotelette and vetmonsters geëvalueer met behulp van beskrywende analise. Die kontrole was die sagste, wat die resultate van die fisiese tekstuuranalise bevestig het. Die kontrole het ook die minste weerstand gebied teen byt, terwyl die 0.5% CLA behandeling die meeste weerstand gebied het. Die 0.5% CLA behandeling het ook ‘n chemiese vet aroma gehad. Die versnelde oksiedasietoets het getoon dat die rugvet van die kontrole nie vinniger galsterig geword het, as rugvet van die drie CLA-behandelings nie. Verkoelde uitstalling van varkkotelette vir agt dae het gelei tot verhoogde L*- en b*-waardes vir die CLA-behandelings, terwyl tiobarbituriensuur reaktiewe bestandeelwaardes (TBARS) onveranderd gebly en versadigingsindeks verlaag het. Na bevrore opberging vir drie maande, het die TBARS-waardes steeds nie verander vir varkkotelette van die verskillende dieetbehandelings nie. Na ses maande van bevrore opberging, het die TBARS-waardes van die CLA-gevoerde varke verlaag. Na agt en 16 weke van bevrore opberging het die peroksiedwaardes van die bevrore vleiskoekies van die 0.5 en 1% CLA-behandelings gedaal. Vir die bevrore vleiskoekies het veranderinge in die TBARS- waardes duidelik geword na agt weke, teenoor die ses maande vir die bevrore varkkotelette. Die TBARS-waardes van die bevrore kotelette was laer as díe van die bevrore vleiskoekies. Aan die einde van die rypwordingsperiode het die peroksiedwaardes van die salamis van die 0.5 en 1% CLA-behandelings gedaal, saam met die TBARS-waardes. Rugvet van die CLA-behandelings was fermer as die kontrole. Geen betekenisvolle verskille in peroksied- of TBARS-waardes, tussen die spek van die vier behandelings, het voorgekom tydens die ses week verkoelde opberging nie. Volgens die verbruikerspaneel is die spek van die kontrole verkies bo die spek van die 0.25% CLA- behandeling. | af |
| dc.identifier.uri | http://hdl.handle.net/11660/1393 | |
| dc.language.iso | en | en_ZA |
| dc.publisher | University of the Free State | en_ZA |
| dc.rights.holder | University of the Free State | en_ZA |
| dc.subject | Thesis (Ph.D. (Microbial, Biochemical and Food Biotechnology))--University of the Free State, 2012 | en_ZA |
| dc.subject | Swine -- Feeding and feeds | en_ZA |
| dc.subject | Swine -- Carcasses | en_ZA |
| dc.subject | Linoleic acid | en_ZA |
| dc.subject | Quality of animals | en_ZA |
| dc.subject | Sensory evaluation | en_ZA |
| dc.subject | Conjugated linoleic acid | en_ZA |
| dc.subject | Subcutaneous | en_ZA |
| dc.subject | Intramuscular | en_ZA |
| dc.subject | Fatty acids | en_ZA |
| dc.subject | Pig | en_ZA |
| dc.title | The effect of dietary conjugated linoleic acid supplementation on the physicochemical, nutritional and sensory qualities of pork | en_ZA |
| dc.type | Thesis | en_ZA |