Quantification and differentiation of egg quality as affected by hen age and storage time, with the aid of near infrared hyperspectral imaging
| dc.contributor.advisor | Pieterse, Elsje | en_ZA |
| dc.contributor.advisor | Colling, Janine | en_ZA |
| dc.contributor.author | Badenhorst, Ruben | en_ZA |
| dc.contributor.other | Stellenbosch University. Faculty of AgriSciences. Dept. of Animal Sciences. | en_ZA |
| dc.date.accessioned | 2021-03-01T11:11:37Z | |
| dc.date.accessioned | 2021-04-21T14:34:43Z | |
| dc.date.available | 2021-03-01T11:11:37Z | |
| dc.date.available | 2021-04-21T14:34:43Z | |
| dc.date.issued | 2021-04 | |
| dc.description | Thesis (MScAgric)--Stellenbosch University, 2021. | en_ZA |
| dc.description.abstract | ENGLISH ABSTRACT: The aim of the study was to investigate the effect of hen age and egg storage time on certain internal, external and proximate egg quality parameters. Additionally, near infrared (NIR) hyperspectral imaging was used, in combination with multivariate data analysis, for the differentiation and quantification of egg quality as influenced by hen age as well as storage time. Amberlink hen eggs (n = 480) were collected from eight different age groups, which included ages 21, 29, 37, 45, 53, 61, 69 and 77 weeks. Each age group consisted of 60 eggs, which was further divided into six groups with 10 eggs per group, representing six different storage intervals. Storage days included 0 (day eggs were laid and collected), 15, 30, 45, 60 and 90 days where temperature was kept at roughly 15˚C and humidity at 75%. Eggs were first subjected to hyperspectral imaging, followed by physical quality analysis as well as proximate analysis, on the given storage days, to assess several egg quality parameters. The objectives for this study included: (i) to establish the effect of hen age on egg quality parameters; (ii) to study the effect of hen age and increased storage time on egg quality parameters and (iii) to investigate the application of NIR hyperspectral imaging for differentiation as well as quantification of hen egg quality. Hen age had a significant impact on the majority of the internal, external and proximate quality parameters. The most pronounced differences in egg quality parameters were observed in eggs collected from hens between the ages of 21 and 29 weeks. A significant interaction (hen age × storage time) for a few quality parameters were observed, while the rest of the parameters were either influenced by the main effect (storage time) or not affected. Eminent changes already occurred within the first 15 days of storage for the majority of the parameters. Near infrared hyperspectralimages for all eggs were acquired with a HySpex SWIR-384 pushbroom imaging system in the 400 – 2500 nm spectral range. Principal component analysis (PCA) could accurately separate eggs laid by different aged hens and stored for different time periods, and the trends observed correspond to differences in the proximate content. Subsequently, partial least squares regression (PLSR) was applied to the full dataset to construct quantitative prediction models for the Haugh unit (HU), protein, lipid and moisture content. Several optimization steps were implemented to test if the prediction models improved. This included, comparing the use of whole egg spectra with a smaller region of interest and a reduction in the wavelength. All constructed models showed reasonable accuracies, however refinement of the models is still needed. Overall the results indicated that hen age and storage time are two highly influential factors, which need to be considered when assessing egg quality. Hyperspectral imaging could also be used as a rapid, non-destructive screening technique for the successful differentiation and quantification of egg quality. | en_ZA |
| dc.description.abstract | AFRIKAANSE OPSOMMING: Die doel van die studie was om die effek van hen ouderdom en eier stoor tydperk op sekere interne, eksterne en chemiese eierkwaliteitparameters te ondersoek. Gevolglik was naby-infrarooi (NIR) hiperspektrale beelding gebruik, in kombinasie met meerveranderlike data-analise, vir die differensiasie en kwantifisering van eierkwaliteit, soos beïnvloed deur hen ouderdom sowel as stoor tydperk. Amberlink hen eiers (n = 480) is versamel uit agt verskillende ouderdomsgroepe wat ouderdomme 21, 29, 37, 45, 53, 61, 69 en 77 weke insluit. Elke ouderdomsgroep het 60 eiers bevat, wat verder in ses groepe verdeel is met 10 eiers per groep. Die ses groepe het ses verskillende stoor periodes verteenwoordig. Stoor periodes het 0 (dag wat die eier gelê en versamel is), 15, 30, 45, 60 en 90 stoor dae verteenwoordig, waar temperatuur by rofweg 15˚C and humiditeit by 75% gehou is. Eiers is eers geskandeer met hiperspektrale beelding, gevolg deur fisiese kwaliteitsanalise en chemiese analise, op die gegewe stoor periodes om verskeie eierskwaliteit parameters te beoordeel. Die doelstellings vir hierdie studie was: (i) om die effek van hen ouderdom op sekere eierskwaliteitparameters vas te stel; (ii) om die effek van hen ouderdom en stoor periode op sekere eierkwaliteitparameters te bestudeer en (iii) om die toepassing van NIR hiperspektrale beelding vir die differensiasie sowel as kwantifisering van eierkwaliteit te ondersoek. Hen ouderdom het 'n beduidende impak gehad op die meeste interne, eksterne en chemiese kwaliteit parameters. Die mees opvallende verskille, in die meerderheid eierkwaliteitparameters is waargeneem in eiers wat gelê was deur henne tussen die ouderdom van 21 en 29 weke. 'n Beduidende interaksie (hen ouderdom × stoor tydperk) vir enkele kwaliteitparameters is waargeneem, terwyl die res van die parameters beïnvloed is deur of die hoofeffek (stoor tydperk) of is glad nie beïnvloed nie. Noemingswaardige veranderinge het reeds binne die eerste 15 dae van stoor plaasgevind, vir die meerderheid parameters. Naby infrarooi hiperspektrale beelding is gebruik om te onderskei tussen eiers wat gelê was deur verskillende ouderdom henne en eiers wat vir verskillende periodes gestoor was. Beelde is verkry met 'n HySpex SWIR-384 stelsel in die 400 - 2500 nm spektrale reeks. Hoofkomponentanalise (HKA) kon eiers wat deur verskillende ouderdom henne gelê is en vir verskillende periodes gestoor akkuraat skei. Die resultate het ooreengestem met die chemiese inhoud. Gevolglik is gedeeltelike kleinste kwadraat regressie (GKKR) toegepas op die volledige datastel om kwantitatiewe voorspellingsmodelle vir die Haugh-eenheid (HU), proteïen, lipied en voginhoud te bou. Verskeie optimaliseringstappe is geïmplementeer om te toets of die voorspellingsmodelle sou verbeter. Heel-eierspektra is met 'n kleiner belangstellingsarea vergelyk en die golflengte is ook verminder. Alle modelle het aanvaarbare akkuraatheid getoon, maar verbetering aan die modelle is steeds nodig. Oor die algemeen het die resultate aangedui dat hen ouderdom en stoor tydperk twee invloedryke faktore is om in ag te neem wanneer eierkwaliteit beoordeel word. Hyperspektrale beelding kan ook gebruik word as 'n vinnige, nie-vernietigende tegniek vir suksesvolle differensiasie en kwantifisering van eierkwaliteit. | af_ZA |
| dc.description.version | Masters | en_ZA |
| dc.format.extent | xvii, 137 pages : illustrations | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/10019.1/109978 | |
| dc.language.iso | en_ZA | en_ZA |
| dc.publisher | Stellenbosch : Stellenbosch University | en_ZA |
| dc.rights.holder | Stellenbosch University | en_ZA |
| dc.subject | Hens -- Breeding -- South Africa | en_ZA |
| dc.subject | Hens -- Age | en_ZA |
| dc.subject | Eggs -- Quality -- Effect of climatic changes on | en_ZA |
| dc.subject | Eggs -- Storage | en_ZA |
| dc.subject | Hyperspectral imaging | en_ZA |
| dc.subject | Eggs -- Production | en_ZA |
| dc.subject | UCTD | en_ZA |
| dc.title | Quantification and differentiation of egg quality as affected by hen age and storage time, with the aid of near infrared hyperspectral imaging | en_ZA |
| dc.type | Thesis | en_ZA |