Thesis (MAgricAdmin)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The objective of this study was to determine the sensory characteristics of Cheddar cheese that drive consumer acceptance. In addition, it investigated whether specific sensory profiles would satisfy specific consumer segments to ultimately facilitate greater acceptance and consumption of Cheddar cheese. A trained panel applied descriptive sensory analysis (DSA) to characterise the sensory attributes of six commercially produced cheeses ranging in maturity from 1 to 32 months. The cheese samples were differentiated by appearance, aroma, flavour and textural attributes. A consumer panel comprising of 115 target consumers rated preference for the cheeses on a 9-point hedonic scale. Moreover consumers completed a screener designed to collect socio-demographic information and opinions on cheese and cheese products. Instrumental colour analysis was performed on the cheese samples and in-depth consumer opinions and attitudes towards cheese were examined using the focus group technique. Analysis of variance (ANOVA) was conducted on the sensory and instrumental data, as well as the consumer liking and perception data. Additionally, a t-test was performed at a 5% significance level to determine the direction of the difference between the mean values. Multivariate analyses were performed on the sensory and consumer data to determine whether relationships existed between sample attributes and consumer liking. Consumer acceptability scores were segmented by agglomerative hierarchical clustering (AHC) using Ward’s test. ANOVA was performed on the consumer data per cluster for colour liking, texture liking, flavour liking and overall liking. Partial least squares regression (PLS) was performed in an attempt to relate consumer degree of liking data, the socialdemographic and attitudinal data, as well as the sensory and instrumental data. The younger cheeses; Gouda at one month, Edam at two months and Cheddar at 4 months were characterised as glossy, with a buttery and creamy aroma; creamy flavour, salty and slightly sour taste combined with lingering cheese flavour. Textures were described as creamy, springy and rubbery. Sensory attributes of visible white crystals, moisture seepage, brothy and Cheddar aromas; brothy, Cheddar and prickle flavours together with textural attributes of firm, hard, crumbly, grainy and teeth-coating characterised the aged Cheddar cheeses. Flavour development was not progressive as the cheeses aged and atypical flavour development was identified in the Cheddar cheese aged to 8 and 15 months, respectively. Flavour followed by price and convenience drive cheese purchase amongst this group of consumers. From a sensory perspective, glossy appearance, a red hue and yellow colour drive cheese colour liking. Texture liking is driven by springy and hard attributes. Flavour liking is driven by cooked milk, buttery and creamy aroma and creamy flavour. Finally overall cheese liking is driven by glossy appearance; cooked milk, buttery and creamy aroma; creamy flavour; springy and creamy texture; specific instrumental colour values, as well as fat, moisture and salt content. Three clusters per variable of colour, texture, flavour and overall liking of cheese were identified through segmentation performed on the preference data. Results indicate that consumers are not homogenous in their sensory requirements, attitudes and behaviour towards cheese. Based on the consumer preference for specific sensory characteristics of cheese, consumer segments can be identified and cheese can be optimised to satisfy these sensory requirements. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was eerstens om te bepaal watter spesifieke sensoriese eienskappe van Cheddarkaas verbruikersaanvaarbaarheid dryf, en tweedens om verbruikersdata te segmenteer ten einde vas te stel of verskillende verbruikersegmente verskillende voorkeure het wat betref Cheddarkaas. Kennis hiervan sal uiteindelik bydra tot verhoogde verbruikerstevredentheid, en dus verhoogde verkope van Cheddarkaas op die plaaslike mark. Beskrywende sensoriese analise en ’n opgeleide paneel is gebruik om die sensoriese eienskappe van ses kommersiële kaas variante te bepaal. Instrumentele kleuranalise is ook bepaal. Die monsters kaas het gewissel in ouderdom (van 1 tot 32 maande veroudering), asook in voorkoms, aroma, geur, smaak en teksturele eienskappe. ’n Verbruikerspaneel bestaande uit 115 individue het die voorkeur en aanvaarbaarheid van die ses variante kaas ge-evalueer deur gebruik te maak van die 9-punt hedoniese skaal. Sosio-demografiese inligting en verbruikeropinies betreffende kaas is ook versamel. Ten laaste is die fokusgroep tegniek gebruik om in-diepte inligting te verkry wat betref verbruikeropinies en –houdings ten opsigte van Cheddarkaas. Analise van variansie (ANOVA) is op sensoriese, instrumentele en verbruikersdata toegepas. T-toets is by ‘n betekenispeil van 5% uitgevoer om te bepaal of daar per eienskap betekenisvolle verskille tussen monstergemiddeldes was. Meerveranderlike analise is uitgevoer op die sensoriese en verbruikerdata ten einde te bepaal of spesifieke sensoriese produkeienskappe verbruikersvoorkeur dryf. Ward se statistiese groepering is gebruik om te bepaal of die verbruikers in verskillende voorkeursegmente gegroepeer kan word. Hierna is ANOVA op elke segment uitgevoer ten einde per segment verbruikersvoorkeur van die onderskeie produkte te bepaal wat betref voorkoms, geur en tekstuur. Meervoudige regressie analise is toegepas om die verwantskap tussen verbruikervoorkeur-, houding- en sosio-demografiese eienskappe van die verbruikers te bepaal, asook tussen die sensoriese en instrumentele produkeienskappe. Die kase wat vir ‘n kort tydperk verouder is, m.a.w. Gouda, Edam en Cheddar na 4 maande veroudering is beskryf as glansend, met ‘n ryk botter en romerige aroma, romerige geur, sout en effense suur smaak, asook ‘n standhoudende kaasgeur. Teksturele eienskappe van hierdie drie kaassoorte is beskryf as romerig, veerkragtig en effe rubberig. Die Cheddar kase wat langer verouder is, het tekens getoon van sigbare wit kristalle en sinerese op die kaasoppervlak, ‘n prikgevoel op die tong, asook sopagtige (“brothy”) en Cheddaragtige aromas en geure. Die teksturele eienskappe van die verouderde Cheddar kase is beskryf as ferm, hard, krummelagtig en greinerig, asook met’n geneigdheid van die kaas om aan die tande vas te kleef. Geurontwikkeling het nie progressief plaasgevind soos die kase verouder het nie. Die Cheddar kase wat onderskeidelik vir 8 en 15 maande verouder is, het atipiese geurontwikkeling getoon. Belangrike faktore wat tydens die aankoop van kaas’n rol speel, en dus voorkeur dryf is eerstens geur, tweedens prys en derdens produk-gemak. Sensoriese aspekte wat voorkeur dryf, is ‘’n glansende voorkoms en effe rooierige-gelerige kleur. Tekstuur voorkeure sluit in veerkragtiheid en hardheid, terwyl geur voorkeure die volgende insluit: romerige, botterige en melk aromas, asook ‘n romerige geur. In die geheel gesien, dryf die volgende eienskappe dus verbruikersvoorkeur: kaas met ‘n glansende voorkoms, geure soos botteragtig, roomagtig en melkerig en teksture soos veerkragtig en romerig. Voedinstofinhoud beȉnvloed ook verbruikersvoorkeur, nl. soutinhoud, vetinhoud en voginhoud. Segmentasie van verbruikersdata het getoon dat die onderskeie verbruikersegmente nie ooreenstem wat betref hul verbruikersvoorkeure, houdings en persepsies van kaassorte nie. Die resultate het egter spesifike sensoriese rigtingwysers geidentifiseer wat die bedryf kan gebruik om kaas te produseer vir elk van die onderskeie marksegmente.