Comprendre les facteurs jouant sur l’état nutritionnel du sujet âgé est un enjeu fort. Une première enquête pluridisciplinaire a permis d'interroger 559 seniors de plus de 65 ans de niveaux d'autonomie culinaire différents. Si un effet de l’âge et des facteurs associés à la dépendance est constaté sur les performances sensorielles, 42% de l’échantillon ont des capacitésolfactives et gustatives préservées. Trois outils de mesure des rejets et des préférences ont été développés afin de mieux prendre en compte les attentes des personnes âgées à l’entrée dans la dépendance : la mesure de la sélectivité alimentaire, le questionnaire des styles de mangeur et le choix du menu préféré. Les facteurs les plus associés à un risque de dénutrition sont une mauvaise santé orale ou un état dépressif. Garder du plaisir à manger et de l'intérêt pour son alimentation sont au contraire des facteurs favorables au maintien du statut nutritionnel. La stratégie sensorielle consistant à améliorer des produits en tenant compte des attentes des personnes âgées plutôt qu’en renforçant en saveurs ou en arômes s'est révélée la plus efficace. Les 166 personnes âgées qui ont testé les différentes variantes ont notamment apprécié, pour le produit le plus complexe, la variante améliorée dans toutes ses dimensions sensorielles – etce, quels que soient leurs niveaux de capacités gustatives et olfactives. Même si le vieillissement s’accompagne d’une baisse des perceptions du goût et des arômes, prendre en compte les attentes des personnes âgées et améliorer les produits qui leur sont destinés est une voie pertinente pour améliorer le statut nutritionnel tout en contribuant à une plus grande satisfaction. / Understanding which factors are linked to nutritional status of the elderly is a major challenge for our aging societies. A first multidisciplinary survey was performed with 559 elderly people, varying on their culinary dependency level, from free living people without help to people living in nursing home. Even if an age and dependency effect on sensory performances was shown, 42% of the sample had still good olfactory and gustatory capacities, compared to the young. Three measurement tools to evaluate food likes and dislikes have been developed: the selectivityevaluation, the eater style questionnaire and the menu choice. They will help to take account of the elderly’s expectations, when becoming culinary dependent. Associated factors to malnutrition risk were mainly poor oral health and depression. Having still eating pleasure and interest for food were on the contrary positive factors for a good nutritional status. Sensory strategy aiming at improving products, starting from the elderly expectations, is more efficient than reinforcing products in taste or flavor, trying to compensate sensory deficiencies. The 166 elderly who evaluated the different products, have liked the improved variant of the most complex product – and that, whatever their gustatory and olfactory abilities. Even if ageing comes with sensory perceptions loss, it is worth taking account the elderly’s expectations and improving products. This is a relevant way to improve the elderly’s nutritional status, while maintaining a gold satisfaction level.

The growth of the Greek-style yogurt market is causing many problems for dairy companies who are trying to handle the voluminous whey by-product. Acid whey, unlike sweet whey, has a low amount of protein and high amounts of lactic acid, calcium, and other minerals. Therefore, it has limited commercial value to the food industry and often requires additional processing for disposal. Lactic acid and calcium solutions have shown efficacy in increasing the tenderness of beef and other types of meat. The purpose of this project is to investigate the use of acid whey, with its high amounts of lactic acid and calcium, to tenderize beef (eye of round, IMP 171C) during marination. This study evaluated the effects of marination of utilizing acid whey in improving quality parameters of beef. 13 roasts (Top round steaks from USDA Select steers) were randomly assigned to one of six marination treatments: (1) calcium chloride, (2) lactic acid, (3) phosphate (4) acid whey (lot 1), (5) acid whey (lot 2), and (6) control. Steaks were marinated in vacuum pouches, aged for 48 hours, cooked to 70º C and evaluated by a consumer sensory panel and other quantitative tests (texture analyzer, colorimeter, collagen, cook loss, and pH). Marination with acid whey increased the tenderness and juiciness ratings without decreasing hedonic liking scores for the overall flavor or aftertaste of the beef samples.

Thesis (MNutr (Human Nutrition))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Background Patients with chronic renal failure must deal not only with the disease itself, but also have to follow a strict dietary regimen. In South Africa there is currently a great demand for new and updated recipes based on the South African Renal Exchange Lists. The focus of this research was the development and testing of recipes commonly used by renal patients following a westernised diet. Objectives The main objectives of the study were to develop and test recipes that meet the nutritional requirements of patients with chronic renal failure. The secondary objectives were to determine the gender and racial differences in participants’ responses during consumer sensory testing. Methodology The study population consisted of patients with chronic renal failure on hemodialysis and continuous ambulatory peritoneal dialysis from Tygerberg Academic Hospital (TAH). Data was collected in three phases, using census sampling: Phase 1 included the development and adaptation of recipes to suit the renal diet. Phase 2 included the consumer sensory testing of the recipes by the dialysis patients, using the 9-point hedonic scale. Phase 3 included the rating of the recipes, the final nutritional analysis and allocation of renal exchanges to one portion of each recipe, as well as the final formatting of the recipe to make it more user-friendly for the renal patient. Results In total, 45 patients took part in the sensory evaluation of 30 recipes. Eighty percent of the subjects were coloured, 4% were white while 16% were black. Fifty-one percent (n=23) were female and 49% (n=22) were male. Of the 30 recipes that were evaluated for overall acceptance, appearance, smell, texture and taste, only 7 were deemed unacceptable. Recipes were unacceptable when less than 80% of the study participants gave a mean overall score of more than 6. Significant differences in the overall acceptability scores were found between the male and female subgroups for the Fish and Vegetable Pie (p=0.031), Chicken Pilaf (p=0.008) and Date Fingers (p=0.002). The females showed a greater preference for these two main meals while the males showed a greater preference for the Date Fingers. Significant differences were found between the black and westernised subgroups for the Rice Salad (p=0.006), Wheat and Mushroom Casserole (p=0.022), Curried Wheat Salad (p=0.043) and the Coconut Ice (p=0.005), with the westernised subgroup showing a greater preference for the dishes than the black subgroup. Conclusion The 23 recipes that were acceptable to the study participants are recommended for inclusion in the RenalSmart Software programme. These recipes are suitable for patients following a westernised diet. It is proposed that recipes suitable for the black and Indian population must be developed in future research. / AFRIKAANSE OPSOMMING: Agtergrond Pasiënte met chroniese nierversaking moet nie net slegs die siektetoestand hanteer nie, maar moet ook ‘n streng dieet regime volg. Daar is huidiglik in Suid-Afrika ‘n groot behoefte vir nuwe en opgedateerde resepte gebasseer op die Suid-Afrikaanse Nier Ruillyste. Die fokus van hierdie navorsing was om resepte te ontwikkel en te toets wat algemeen ingeneem word deur nierversaking pasiënte wat ‘n westerse dieet volg. Doelwitte Die hoof doelwitte van die studie was om resepte te identifiseer en te toets wat voldoen aan die nutrisionele behoeftes van nierpasiënte met kroniese nierversaking. Die sekondêre doelwitte was om geslag en ras verskille in die deelnemers se reaksies tydens verbruiker sensoriese evaluering te bepaal. Metodologie Die studie populasie het bestaan uit pasiënte met chroniese nierversaking op hemodialise en aaneenlopende ambulatoriese peritoneale dialise van Tygerberg Akademiese Hospitaal (TAH). Data was versamel in drie fases deur gebruik te maak van sensus steekproeftrekking: Fase 1 het die ontwikkeling en aanpassings van die resepte, om dit toepaslik te maak vir die nier dieet, ingesluit. Fase 2 het die verbruiker sensoriese evaluering van die resepte deur die dialise pasiënte, met behulp van die 9-punt hedoniese skaal, ingesluit. Fase 3 het die klassifisering van die resepte, die finale nutrisionele analise en die toekenning van nier ruile per porsie van elke resep, sowel as die finale formatering om die resep meer gebruikersvriendelik te maak vir die nierpasiënt, ingesluit. Resultate In totaal het 45 pasiënte aan die sensoriese evaluering van die 30 resepte deelgeneem. Tagtig persent van die deelnemers was kleurling, 4% was wit en 16% was swart. Een en vyftig persent (n=23) was vroulik en 49% (n=22) was manlik. Van die 30 resepte wat geevalueer is vir algehele aanvaarding, voorkoms, reuk, tekstuur en smaak, was slegs 7 onaanvaarbaar gevind. Resepte is as onaanvaarbaar beskou indien minder as 80% van die deelnemers ‘n gemiddelde algehele telling van meer as 6 gegee het. Beduidende verskille in die algehele aanvaarbaarheid tellings is gevind tussen die mans en vroue vir die Vis en Groente Pastei (p=0.031), Hoender Pilaf (p=0.008) en Dadelvingers (p=0.002). Die vrouens het ‘n groter voorkeur vir die twee hoofgeregte getoon terwyl die mans ‘n groter voorkeur vir die Dadelvingers getoon het. Beduidende verskille is gevind tussen die swart en westerse sub-groepe vir die Rysslaai (p=0.006), Koring en Sampioen Kasserol (o=0.022), Kerrie Koringslaai (p=0.043) en die Klapperys (p=0.005), met die westerse sub-groep wat ‘n groter voorkeur vir dié geregte toon as die swartes. Gevolgtrekking Die 23 resepte wat aanvaarbaar gevind is sal voorgestel word om ingesluit te word in die RenalSmart Sagteware program. Die resepte is toepaslik vir pasiënte wat ‘n westerse dieet volg. Daar word voorgestel dat resepte toepaslik vir die swart en Indiër populasie ontwikkel word in toekomstige navorsing.

Two studies were conducted to determine the effect of panelist participation frequency and specific aspects of questionnaire design on overall acceptance scoring in consumer central location tests. Regarding participation frequency, research subjects who participate frequently in some survey types are known to provide responses that differ from subjects who participate less frequently, known as panel conditioning. With respect to questionnaire design, overall acceptance (OA) question placement and usage of pre-evaluation instructions (PEI) in questionnaires for food sensory analysis may bias consumers' scores via carry-over effects. To investigate these concerns, data from consumer sensory panels previously conducted at a central location, spanning 11 years and covering a broad range of food product categories, was extracted, compiled, and analyzed. For the first study, data was analyzed to determine evidence of panel conditioning by measuring the effect of participation frequency on mean consumer OA scoring among frequent, moderate, and infrequent participants. Practical significance and occurrence of panel conditioning, defined as mean scoring differences of ≥ 0.50 on a discrete 9-point scale hedonic point, were examined. Results indicate that for overall acceptance, in general, mean scoring differences were not practically significant and did not signify occurrence of panel conditioning. For the second study, OA question placement was studied with categories designated as first (the first evaluation question following demographic questions), after non-gustation questions (immediately following questions that do not require panelists to taste the product), and later (following all other hedonic and just-about-right questions, but occasionally before ranking, open-ended comments, and/or intent to purchase questions). Additionally, each panel was categorized as having or not having PEI in the questionnaire; PEI are instructions that appear immediately before the first evaluation question and show panelists all attributes they will evaluate prior to receiving test samples. Post-panel surveys were administered regarding the self-reported effect of PEI on panelists' evaluation experience. OA scores were analyzed and compared (1) between OA question placement categories and (2) between panels with and without PEI. For most product categories, OA scores tended to be lower when asked later in the questionnaire, suggesting evidence of a carry-over effect. Usage of PEI increased OA scores by 0.10 of a 9-point hedonic scale point, which is not practically significant. Post-panel survey data showed that presence of PEI typically improved the panelists' experience. Using PEI does not appear to introduce a meaningful carry-over effect.