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Whole ground white, high tannin and black sorghum with and without additional high tannin sorghum bran were used in different proportions to develop ready to eat breakfast cereals and snacks. The effect of extrusion on the phenolic compounds and on in vitro starch digestibility of sorghum based cereals and snacks were observed. Gluten free and gluten containing breakfast cereal and snacks were developed with different physical, chemical and sensory characteristic. By increasing the sorghum and bran level in the formulations, the bulk density of extrudates was increased while expansion ratio was decreased. Bowl life of extrudates was increased up to 18 min. when 60% whole ground white sorghum was used with additional 10% high tannin sorghum bran. Water soluble index was significantly higher for the extrudates without additional bran and decreased as bran was added. A positive correlation between water soluble index and expansion ratio (R^2=0.89) indicated that the more expansion ratio provided a large surface area for water to interact with starch and other soluble components. The retention of total phenols in these extrudates varied from 13-41% and it was found that extrudates with additional high tannin sorghum bran had more total phenols than extrudates without it. Sorghum extrudates showed a significant reduction in antioxidant activity varied from 21-83%. Similarly, the effect of extrusion on condensed tannins was detrimental, and their retention was ranged from 12-28%. The smaller particle size of ground sorghum increased the surface area of contact between composite flour components and extruder barrel which promoted interactions during extrusion, lowering condensed tannins and antioxidant activity. All sorghum based extrudates had significantly (P<0.05) lower starch digestibility than that of corn flour extrudates. All types of sorghum had non-significant difference in starch digestibility from 0.5-2hrs. After 16 hrs., high tannin sorghum extrudates had the lowest starch digestibility (79%), which was significantly different from other sorghum types. There was a negative correlation between the rapid digestible starch and tannin contents (R^2=0.62). Breakfast cereals made from different types of sorghum and bran levels were statistically equally rated in taste and overall acceptability.

The taste qualities of acidulants have not been studied in detail despite the fact that they are widely used by the food industry. Studies on characterizing the sensory properties of organic and inorganic acids are very limited. Reported studies are commonly on threshold, equi-sour and the time intensity values of sourness. A series of experiments were conducted to determine the sensory properties of selected acidulants by different sensory and multivariate methods. First, the technique of Free-Choice Profiling was applied in order to characterize the sensory profile of some selected acids (adipic, citric, fumaric, glucono-delta-lactone, hydrochloric, lactic, malic, phosphoric, quinic, succinic, tartaric, citric:fumaric, citric:malic and fumaric:malic) on a weight (0.08% w/v or v/v) basis. Results analyzed through Generalized Procrustes Analysis indicate that on a weight basis (w/v or v/v), acids differed in their flavor and taste dynamics. Likewise, acids were described differently by individual panelists. Second, the sourness power functions of the selected acidulants were generated from five molar concentrations by magnitude estimation involving 16 trained panelists. Equi-sour concentrations were determined by regressing the log of the rescaled response (sensory) on the log of the stimuli (physical). The calculated equi-sour levels ranged from 0.48 ml/L for HCl to 2.34 g/L for glucono-delta-lactone when citric add was set at 1.0 g/L. These theoretical equi-sourness were then tested by using an alternative sensory method, the directional difference from control test. Third, the sensory profile of the acidulants at their equi-sour levels was characterized using two sensory methods, free-choice profiling and the conventional descriptive analysis. The former was analyzed by Generalized Procrustes Analysis while the latter was analyzed by Principal Component Analysis. The two sensory methods gave similar patterns of information regarding the add samples. The similarities of several organic acids and their mixtures were very evident. Hydrochloric and phosphoric acids were astringent while succinic add was bitter and had a monosodium glutamate taste. It was concluded that adds had other sensory properties aside from sourness that must be considered in a given food application. / Graduation date: 1993

Thesis (Ph. D.)--University of Sydney, 2003. / Title from title screen (viewed Apr. 24, 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Dept. of Psychology, Faculty of Science. Includes bibliography. Also available in print form.

Thesis (Ph. D.)--Michigan State University. Dept. of Packaging, 2006. / Title from PDF t.p. (viewed on Nov. 20, 2008) Includes bibliographical references (p. 275-287). Also issued in print.

Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains vii, 115 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

Orientador: Helena Maria André Bolini / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-25T18:55:07Z (GMT). No. of bitstreams: 1 Morais_ElisaCarvalhode_D.pdf: 3160768 bytes, checksum: 0b8115f9591c2b2239a194de4b03743c (MD5) Previous issue date: 2014 / Resumo: As sobremesas lácteas são produtos amplamente consumidos em todo o mundo e estão atualmente instituídas como parte integrante de diversas dietas modernas. A crescente procura dos consumidores por produtos alimentícios com valor agregado estimula o estudo da adição de prebióticos e edulcorantes. Na primeira parte deste trabalho, que avaliou os efeitos da adição de prebióticos (inulina:frutooligossacarídeos; 50:50) e gomas, nas propriedades sensoriais de sobremesas lácteas cremosas sabor chocolate, a adição de 7,5% (p/p) de prebióticos e 0,2% (p/p) de gomas (guar:xantana; 2:1) foi considerada ótima pelos consumidores, de acordo com modelo avaliado por metodologia de superfície de resposta. No segundo estudo, a análise ideal de doçura determinou a concentração ideal de sacarose como 8% (p/p). A análise relativa de doçura mostrou que o neotame apresentou o maior poder adoçante, na sobremesa láctea cremosa prebiótica sabor chocolate, seguido pela sucralose, aspartame e estévia. No terceiro estudo, os atributos de aparência, aroma, sabor, textura e impressão global foram avaliados por 120 consumidores usando escala hedônica de 9 pontos. Um mapa de preferência interno de três dimensões foi obtido por meio da análise de fator paralelo (PARAFAC). Análise de componentes principais (ACP) também foi realizada e comparada ao PARAFAC. A caracterização física das amostras de sobremesa láctea cremosa sabor chocolate foi determinada por meio da análise do perfil de textura e medidas de cor. A amostra integral foi caracterizada por firmeza e gomosidade e por cor mais clara que as amostras com adição de prebióticos e edulcorantes. O quarto estudo avaliou a qualidade das sobremesas lácteas cremosas sabor chocolate por meio das análises de tempo-intensidade (TI) múltiplo e dominância temporal das sensações (TDS). A análise tempo-intensidade mostrou que a amostra com neotame apresentou a maior intensidade de doçura; as amostras com neotame e estévia a maior intensidade de amargor; e as amostras com sacarose, sucralose, aspartame, e a integral, apresentaram a maior intensidade de sabor de chocolate. No TDS a substituição de sacarose pelos edulcorantes sucralose e aspartame apresentou um perfil temporal similar. No quinto estudo as seis sobremesas lácteas cremosas sabor chocolate foram avaliadas por 14 provadores treinados utilizando a metodologia da Análise Descritiva Quantitativa. Os assessores identificaram 20 termos descritores para aparência, aroma, sabor e textura. As amostras apresentaram diferença significativa entre si (p?0,05) em 14 atributos avaliados. Análises de composição centesimal também foram realizadas com o intuito de avaliar as propriedades globais das sobremesas lácteas. As amostras com edulcorantes foram definidas como diet, por serem isentas de açúcar, e light, em calorias e lipídios. E, no sexto estudo, foi avaliada a influência da alegação de propriedade funcional e diet/light na aceitação das sobremesas lácteas cremosas sabor chocolate pelos consumidores. Os consumidores avaliaram as alegações de maneira diferente / Abstract: Dairy desserts are widely consumed products worldwide and are now established as an integral part of many modern diets. The growing consumer demand for food products with added value encourage the study of prebiotics and sweeteners addition. In the first part of this study, which evaluated the effects of prebiotics and gums incorporation on chocolate dairy desserts, the addition of 7.5% (wt/wt) prebiotics (inulin:fructooligosaccharides, 1:1) and 0.2% (wt/wt) gums (guar:xantham, 2:1) was considered as optimal by consumers, according to a model provided by response surface methodology (RSM). In the second study, the ideal sweetness analysis revealed that 8.0% (wt/wt) was the ideal concentration of sucrose. The relative sweetness analysis showed that neotame presented the highest sweetening power with respect to the prebiotic chocolate dairy dessert containing 8.0% of sucrose, followed by sucralose, aspartame and stevia. In the third part, the attributes of appearance, aroma, flavor, texture and overall liking were evaluated by 120 consumers using a 9-point hedonic scale. A three-way internal preference map was obtained by parallel factor analysis (PARAFAC). A principal component analysis (PCA) was also discussed and compared to PARAFAC. A physical characterization of chocolate dairy dessert samples was determined by texture profile analysis and color measurements. The integral sample was characterized by firmness and gumminess and was lighter colored than the others with prebiotic and sweetener agents. The fourth study analyzed the quality of chocolate dairy desserts by the multiple time-intensity (TI) analysis and temporal dominance of sensations (TDS). TI analysis showed that the sample developed with neotame had a higher intensity of sweetness; the samples with neotame and stevia had a higher intensity of bitterness; and the samples with sucrose, sucralose, aspartame, and the integral one had a higher intensity of chocolate flavor. In TDS analysis the replacement of sucrose by the sweeteners sucralose and aspartame presented a temporal profile similar to the one. In the fifth study the six creamy chocolate dairy desserts were evaluated by 14 trained panelists using the methodology of Quantitative Descriptive Analysis. Assessors identified 20 descriptor terms for appearance, aroma, flavor and texture. Samples differed significantly (p?0.05) in 14 attributes. Chemical composition analyses were also performed in order to evaluate the overall properties of dairy desserts. The samples with sweeteners were defined as diet, being no added sugar, and light in calories and fat content. And in the sixth study, the influence of the functional property and diet/light claims on acceptance of creamy dairy desserts of chocolate flavor was evaluated by consumers. Consumers rated the claims differently / Doutorado / Consumo e Qualidade de Alimentos / Doutora em Alimentos e Nutrição

The objective of the study was to determine growth performance, physico-chemical attributes, oxidative stability and sensory quality of pork from pigs fed one of three dietary treatments, eac containing 0%, 2.5% or 5% (T1, T2 and T3, respectively) Moringa oleifera leaf meal (MOLM). Dietary treatments were formulated to be isonitrogenous and isoenergetic for weaner (6 – 8 weeks) and grower (9 – 13 weeks) phases. Twelve Large White (LW) and 12 Kolbroek (KB) male pigs at 6 weeks of age, initially weighing an average 10 kg, were randomly allocated to one of the dietary treatments, each with four replicates, in individual pens. Feed and water were offered ad libitum. The Longissimus thoracis et lumborum (LTL) muscle of each carcass (n = 24) was sampled for meat quality and fatty acid analyses. Breed differences in measured parameters were observed. In pigs receiving 5% MOLM, the LW had significantly the highest ADFI (P<0.05) than KB pigs. In pigs receiving 2.5% and 5% MOLM, backfat thickness was significantly highest (P<0.05) compared to those receiving 0% MOML. Dietary inclusion of MOLM had no significant effects (P>0.05) on the physico-chemical quality of pork from LW pigs; although it significantly (P<0.05) increased a* and reduced WBSF values in pork from KB pigs. Pork from LW pigs receiving 5% MOLM had significantly increased (P<0.05) n-3 content of the subcutaneous tissue of LW pigs compared to KB, and also when compread to other treatment groups. In both breeds, the composition of PUFA: SFA and n-6: n-3 in the subcutaneous adipose tissue was significantly (P<0.05) lower in T2 and T3 than in T1. The n-3 levels for pork muscle from LW pigs receiving 2.5% and 5% MOLM, and from KB pigs receiving 5% MOLM, were significantly (P<0.05) lower. Inclusions of MOLM significantly (P<0.05) reduced the n-6: n-3 fatty acids in pork from both LW pigs and KB pigs. Consumer scores on sensory attributes (aroma intensity, initial impression of juiciness, first bite, sustained impression of juiciness, muscle fibre and overall tenderness and overall flavor intensity) significantly (P<0.05) increased as the level of MOLM inclusion in the diet increased; and higher scores were observed in fried meat than in boiled for most sensory attributes. It may be concluded that inclusion of MOLM in pig diets up to 5% improved the ADFI, a*, tenderness of pork without adversely affecting the FCR and other physico-chemical quality attributes; and resulted in desired increase in levels of n-3 and reduced the n-6: n-3 fatty acid ratio.

Read the abstract in the section 00front of this document. / Dissertation (MSc (Agric) Food Science and Technology)--University of Pretoria, 2006. / Food Science / unrestricted