Orientador: Helena Maria Andre Bolini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T19:15:40Z (GMT). No. of bitstreams: 1 Moraes_PatriciaCarlaBarbosaTrevizam_M.pdf: 708314 bytes, checksum: 20a2b366e6fa92fd633e7c9f7eb1a47f (MD5) Previous issue date: 2004 / Resumo: O presente projeto teve a finalidade de traçar o perfil sensorial de marcas comerciais de iogurte tradicional e iogurtes adoçados com substitutos da sacarose, aplicando-se os seguintes Métodos Sensoriais: Análise de Aceitação, Análise Descritiva Quantitativa (ADQ) e Análise Tempo Intensidade (ATI). A análise de aceitação foi realizada por uma equipe de 97 consumidores de iogurte e os resultados foram avaliados por análise de variância univariada (ANOVA), teste de médias de Tukey e por Mapa de Preferência Interno. Quanto a Análise de Aceitação as amostras adoçadas com sacarose apresentaram as maiores médias quando comparadas com a versão¿light¿ na maior parte dos atributos avaliados, entretanto nem sempre essa diferença foi significativa (p£0.05). A ADQ foi realizada por uma equipe de dez provadores pré-selecionados, treinados e selecionados com base no poder de discriminação entre amostras, capacidade de repetir os resultados e concordância com a equipe. Os termos gerados pela ADQ foram: para aparência: cor rosa, viscosidade, presença de polpa e presença de bolhas; para o aroma: morango, doce, ácido e artificial; para sabor: doce, ácido, residual doce, residual amargo, morango, artificial e adstringência; textura: homogeneidade e consistência. As médias geradas pela ADQ, mostram que para a maior parte dos atributos avaliados existiu diferença significativa (p£0.05) entre as versões tradicional e ¿light. Foi realizada Análise Tempo-Intensidade do atributo doçura das amostras de iogurte. Para esta análise foi utilizada uma equipe de 8 provadores, que registraram os estímulos sensoriais utilizando o Programa Sistema de Coleta de Dados Tempo-Intensidade. Tanto para a ADQ como ATI, as amostras foram apresentadas aos provadores de forma monádica com três repetições, e os resultados avaliados por Análise de Variância - ANOVA, Teste de Médias de Tukey e Análise de Componentes Principais. Foram realizadas ainda determinações físico-químicas: pH, acidez total titulável, º Brix, açúcares redutores e não redutores e determinação de cor e viscosidade. Foram verificadas correlações entre as medidas sensoriais e instrumentais para: sabor morango e açúcares redutores, aroma ácido e acidez total titulável, doçura e açúcares redutores, consistência e viscosidade / Abstract: The present work had the purpose to determine the sensory profile of commercial marks of traditional yogurts and yogurts that had been sweetened with sucrose substitutes, using the following sensory methods: Acceptance Analysis, Quantitative Descriptive Analysis (QDA) and Time Intensity Analysis (TIA). The acceptance analysis was evaluated by 97 consumers of yogurt and the results were analyzed (evaluated) by Analysis of Variance (ANOVA), TUKEY¿s comparison of means test and by Internal Preference Mapping. About the acceptance analysis, the samples sweetened with sucrise showed greater average whem compared to the ¿light¿ version in most of the characteristics evaluated, however this difference was not always meaningful. The QDA was conduted by a panel of 10 pre-selected panelists, that had been trained and selected based on their power of discrimination between the samples, the capacity of repeating the results and the agreement with the rest of the staff. The terms that had been generated by QDA were; for appearance: pink color, viscosity, presence of pulp and presence of bubbles; for aroma: strawberry, sweet, acid and artificial; for flavor: sweet, acid, residual sweet, residual bitter, strawberry, artificial and astringency; for texture: homogeneity and consistency. The averages generated by QDA show that for the major part of the characteristics evaluated there was a meaningful difference between the traditional and ¿light¿ versions. The PCA the Spider grafic where done. It was done Time Intensity Analysis for the attribute sweetness of the yogurts samples. For this analysis it had been used a staff of 8 panelists which had registered the sensory stimulus by using the program Data Catch System for Time Intensity. For QDA like as for TIA, the samples had been presented to the panelists in a monadic way, using 3 repetitions, and the results had been evaluated by ANOVA, Tukey test and Principal Components Analysis. Chemical-physics determinations have also been done: pH, titratable acidity, oBrix, reducer and no-reducer sugar and determination of color and viscosity. Correlations between the sensorial and instrumental means where ascertained for: strawberry flavor and reducer sugar, acid aroma and titratable acidity, sweetness and reducer sugar, consistency and viscosity / Mestrado / Mestre em Alimentos e Nutrição

Food fermentation is a method widely used in the past to extend the storage life of food. Numerous studies on fermented food have revealed that they not only have biopreservative properties but also health benefits. Lactic acid bacteria are the major group of microorganisms involved in food fermentation and the properties that influence food are primarily due to the compounds released from microorganisms such as organic acids and bacteriocins. Their health benefits are exerted through several mechanisms including inhibiting the growth of pathogenic bacteria and modifying the host immune response. A number of strains that have been investigated show different properties even between the same species thus emphasizing the importance of strain identification. To determine if some traditional fermented Swedish foods contain lactic acid bacteria, bacteria from four fermented Swedish foods (two surströmming and two sausages) were isolated using MRS broth. Bacterial isolates were examined for their colony and cell morphology and Gram staining and were found to be predominantly Gram-positive cocci or rods. 16S rRNA PCR amplifications of selected isolates was performed using universal prokaryotic primers and sequenced. The sequencing results showed that the bacterial isolates from Oskars surströmming Filéer and Gognacs medvurst were Lactobacillus sakei and the isolate from Mannerströms surströmming was Enterococcus sp. This study showed that the traditional Swedish fermented food evaluated did contain lactic acid bacteria.

5 p. / Originally published: 2011 / Healthy bone growth and maintenance requires adequate calcium intake. You can meet your calcium needs from foods, beverages, and, if necessary, supplements.

4 pp. / Originally published 04/2011 / Finding foods to bring on a camping or hiking trip may seem challenging. Not only do they need to be nutritious, but they must also leave minimal waste so you can leave the environment just as you found it. Whole foods (such as fruits, nuts, and vegetables) tend to be better choices than processed foods (such as pre-packaged cereal bars, lunch meat) since they tend to be rich in nutrients and produce minimal waste. Finding reusable and recyclable ways to package your foods may also help cut down your impact on the environment. Revised 04/2016. Originally published 04/2011

The recent increase in the number of black working women has meant that time has become an even more precious commodity in the majority of households with working women than before. Growth in women’s participation in the labour market has tended to stimulate the demand for time-saving goods and services, especially convenience foods to cope with time pressure in the preparation of meals. South African working women are moving towards the consumption of convenience foods as they become busier, managing both work and household chores, and also having more disposable income. This study aimed at gathering ideas and insight on the acceptability and use of convenience foods by black women employed by government in Mpumalanga. It investigated the consumption frequency of convenience foods in four categories, the contributing sensory attributes and the influence of resources, the socio-cultural environment and the occasion or situation on the acceptability and use of convenience foods. Food outlets used by black working women for the purchase of convenience foods were also identified. To elicit relevant information, a quantitative research design and survey techniques using structured questionnaires, with open and closed-ended questions were used to gather information. With the literature review and the objectives of the study in mind, 200 working women employed by government at the government Boulevard complex in Nelspruit formed the sample group. The Statistical Package for the Social Sciences Version 9.0.1 (SPSS), a computer statistical data programme. Descriptive and inferential statistics facilitated data analysis. From the discussion and interpretation of the results of the sample survey it was clear that black working women tend to either use certain types of convenience foods in the four convenience food categories less frequent (not more than twice in a week) or to use certain types of convenience foods, frequently (3 -4 times in a week or 5 - 6 times and every day of the week). The results showed clearly that there were relatively high proportions of working women (more than 56, 5% of the respondents) who were low users of almost each type of the convenience foods in the four convenience food categories except for baked products, cereal dishes, fried/grilled/roasted meat, and fully prepared refrigerated salads in category A; meat stews and fully prepared vegetable dishes in category B; breakfast cereals, vegetable salad ingredients, instant soups and instant sauces in category C and cleaned/pealed ready to cook vegetable items, pre-cut frozen vegetables, crumbed frozen fish and crumbed frozen or refrigerated meat portions in category D. Moreover, the findings confirmed that the sensory attributes, appearance, texture, smell and taste and flavour were considered very important in the acceptability and use of convenience foods. Resources, the socio-cultural environment and occasion or situation were also seen to have had a positive influence on the acceptability and use of convenience foods by the black women employed by government in Mpumalanga who participated in the survey. The study has contributed to the limited literature on the use of convenience foods especially by black working women. Moreover, food product developers and retailers will gain insight into the provision of convenience foods relevant to the needs and desires of time pressed consumers. / Dissertation (MConsSci)--University of Pretoria, 2009. / Consumer Science / unrestricted

In 2003 the Department of Health of South Africa embarked on a mandatory fortification programme of maize meal as part of the Integrated Nutrition Program (INP) to alleviate malnutrition. The aim of this study was two-fold: firstly, to determine the vitamin A content of South African fortified white maize meal as purchased and the maize porridge as traditionally prepared from it as consumed and secondly, to determine the relative efficacy of the daily consumption of maize meal in sustaining or improving vitamin A status. Maize meal samples for analysis were purchased from various supermarkets and small retail outlets. A High Performance Liquid Chromatograph-Diode Array Detector system with a Reverse Phase C-18 column and isocratic elution was used for separation and quantification of vitamin A. The highest mean vitamin A concentration measured in the maize meal was 261 μgRE/100g and the lowest mean vitamin A concentration was <19 μgRE/100g. Pertaining to the regulations the final minimum level of vitamin A in fortified maize meal must not be less than 187.7 μgRE/100g. The average retention of vitamin A in maize porridge as the difference in vitamin A concentration measured between raw maize meal and cooked porridge was calculated at 39.8%. One of the considerations in a fortification program is the availability of certain micronutrients in the fortified foods, with the focus in this project on vitamin A. An animal model, namely chickens, closely relating the metabolism of vitamin A in humans was used. Chickens are very susceptible to vitamin A deficiencies with similar symptoms. Growth and vitamin A status was evaluated by the weight, feed conversion and liver retinol stores of chickens on five different maize based diets over a six week period. No significant difference in vitamin A levels in the livers of birds on diets with fortified white maize meal, compared to the normal poultry diet consisting of yellow maize meal with added vitamin A was found. It can thus be concluded that the fortificant in the white maize meal is as bioavailable as the vitamin A in the premix used in poultry nutrition. The results of this study show that the vitamin A added as fortificant is absorbed and available to the body. Therefore, fortification of commonly eaten staple foods in the country can significantly improve the vitamin A intake of the population and will improve the overall micronutrient density of their diets. Fortification should be set at levels to include losses incurred through packaging and during transportation, shelf losses and preparation losses. It is also important that the vitamin A content of the product as purchased and consumed must be regularly monitored and regulated by government. Valid and reliable evaluation data are needed to evaluate a program’s success, and to make timeous adjustments for optimal efficiency. / Thesis (PhD)--University of Pretoria, 2011. / Animal and Wildlife Sciences / unrestricted

The total water uptake, rate of water uptake, extract release volume and maximum shear force were measured on a series of samples of irradiated freeze-dried beef. Forty seven pieces of round steak (2.5 cm x 2.5 cm x 10.4 cm or 1" x 1" x 4") were irradiated at one, three and five megarad. The control samples were not irradiated. Half of the samples were irradiated when fresh, and the other half were irradiated after freeze drying. This procedure has been defined as the "fresh-dry" irradiation sequence throughout the report. The samples were frozen in an air blast at two temperatures (-22.2°C and -56.1°C). Freeze-drying was carried out below 300 microns of Hg and a maximum shelf temperature of 15.6°C (60°F). There appears to be three phases of water uptake: 1) A very rapid, almost instantaneous, absorption. 2) A more gradual uptake (called Part.1 in the report). 3) A relatively slow asymptotic approach to an equilibrium condition (Part 2). These two last phases are shown to be straight lines when the logarithm of the water uptake is plotted against the logarithm of the immersion time. Irradiation level has no significant effect on the final water content or on the slow asymptotic absorption (Part 2) or the extract release volume, but has a significant effect on the gradual water uptake (Part 1) and on the shear press force. Fresh-dry irradiation sequence (and freezing rate) have a significant effect on the total water uptake and on the slow asymptotic water (Part 2) uptake, but not on the gradual water uptake (Part 1), or on the extract release volume or on the shear press forces. Freezing rates have a significant effect on the total water uptake, but not on the slow asymptotic water uptake (Part 2), on the gradual water uptake (Part 1), on the extract release volume or on the shear press forces. The highest total water uptake was found for the meat irradiated when fresh, and slow frozen at -2 2.2°C. The mechanism of the gradual absorption appears to follow a phenomena of water flow, as evidenced by the straight line relationship found in the plots of logarithm water uptake versus logarithm immersion time. / Land and Food Systems, Faculty of / Graduate

In this study, a number of experiments were undertaken to investigate possible methods for effective improvement of the texture and flavour of canned late-run chum salmon. These included removal of the skin and bones from the fish, processing of the boneless-skinless steaks in retort pouches, brine treatment using two washes with an 8% salt solution for one hour each time, and a precanning treatment in which the boneless-skinless steaks were soaked in a solution of 10% tripolyphosphate and 2% brine for two minutes. Only fish of advanced sexual maturity were used. The canned salmon was steam processed at 120°C for 65 minutes in an FMC laboratory retort. This was based on a known commercial process for 307 x 115 cans. Heat penetration studies were carried out to design the process schedules for the pouched samples. It was found that the pouched product required 48% less thermal processing time than the canned product to achieve similar lethality. Sensory results showed that the removal of the skin and bones did not produce any significant improvement in the flavour and acceptability of the fish. There was no significant difference between the polyphosphate/brine samples and the untreated (control) samples for all attributes tested. The brine treatment also did not improve the texture of the samples. However, there was less detection of late-run flavour in the brine treated samples when compared to the control. Comments offered by panelists described these samples as having a salty/briny flavour. Pouched samples had a firmer, drier and more fibrous texture than the canned product. They also scored better in terms of late-run flavour. Acceptance of the fish however was only moderate. As a consequence, although this study demonstrated an improvement in the texture and flavour of the pouched late-run chum in comparison to the canned product, it was concluded that a more acceptable pouched product could probably be obtained by using late-run salmon of less advanced sexual maturity. Results of linear regression analysis showed that significant relationships were obtained between sensory firmness, fibrousness and chewiness and instrumental hardness, maximum slope and chewiness. However, none of the sensory parameters were well predicted by the instrumental results. / Land and Food Systems, Faculty of / Graduate

Ph.D. (Chemistry) / Please refer to full text to view abstract

Most of the traditional foods in Africa are fermented before consumption. Fermentation is an old technology; however, during this process, especially in traditional fermented cereal based products with special emphasis on Ting, there is very little control involved during the processes. Fermentation is thus left to chance inoculation from the environment. Ting is a sorghum based product that is a result of LAB fermentation and has 0.6-0.7% lactic acid with a final pH of 3.5-4.0. However, there is presently no adequate information on the employment of starter cultures for most South African traditional fermented foods. The aims of this research were therefore to evaluate the use of different isolates of LAB that had been previously isolated from Ting as potential starter cultures for Ting production, to evaluate whether these would result in a product with sensory characteristics similar to those of the naturally fermented Ting and also to determine the nutritional composition of Ting. Six isolates LAB isolates (Lactobacillus collinoides 1.42, Lactobacillus cellobiosus 3.42, Leuconostoc mesenteroides 2.35, Lactobacillus cellobiosus 4.35, Lactobacillus cellobiosus 3.30 and Lactobacillus curvatus 5.30) previously isolated from Ting were used in this study. When inoculated into sorghum mash to initiate Ting fermentation, the LAB starter cultures reduced the pH from 6.5-6.8 to levels below 4.5 within a reduced fermentation time of 12 h instead of 48-72 h as is the case with the naturally fermented Ting. The same starters increased the amount of lactic acid present in the samples from 0.02 to 0.3% within 12 h, reaching up to 0.5% after 72 h of fermentation. The nutritional composition of all the products was similar. The minerals calcium, phosphorous, magnesium and iron were analysed and phosphorous was the highest followed by magnesium; with calcium and iron being the lowest. Among all the amino acids analysed, glutamic acid was the highest in all the samples, followed by proline and leucine with cystine and lysine being the least. Generally, Ting was found to be high in protein and energy although with a low fat content. Based on the results of the consumer acceptability study, of all of the six LAB isolates; the LAB isolate L. cellobiosus 4.35 could be the best option when considering a starter culture for Ting production since the sample had the highest consumer acceptability results similar to the naturally fermented Ting sample. / Dissertation (MSc)--University of Pretoria, 2008. / Microbiology and Plant Pathology / unrestricted