Orientador: Helena Maria André Bolini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-26T18:20:31Z (GMT). No. of bitstreams: 1 Buainain_AnaPaulaMunis_M.pdf: 1568372 bytes, checksum: 3467bc7ac896d0fd114d7b20322dfee3 (MD5) Previous issue date: 2014 / Resumo: De acordo com diversas pesquisas realizadas, há uma grande preocupação com relação às calorias, açúcares e gorduras ingeridos diariamente pela população, que passa de altos índices de desnutrição para elevados índices de obesidade, principalmente nos países desenvolvidos e em desenvolvimento. A cada dia, as pessoas têm menos tempo para o preparo dos seus alimentos e, buscando praticidade, alimentos como pães, bolos e biscoitos tornam-se muito presentes nas dietas dos consumidores. Visando encontrar alimentos alternativos com boa aceitabilidade e praticidade, este estudo tem por objetivo formular bolos de baunilha com diferentes ingredientes edulcorantes para a substituição da sacarose, considerada uma grande vilã que contribui para a obesidade. Os edulcorantes utilizados neste estudo foram: sucralose, acessulfame-K, estévia, neotame e taumatina, e o poder de adoçamento dos mesmos foi obtido através do método de estimação de magnitude. Para entendimento do perfil sensorial de cada amostra, aplicou-se a Análise Descritiva Quantitativa, a qual 12 avaliadores pré-selecionados determinaram 21 termos descritores. A análise de tempo-intensidade foi aplicada para avaliar a doçura, principal termo descritor da própria sacarose. A amostra com avaliação dinâmica de dulçor mais próxima à curva da sacarosefoi a que continha acessulfame-K. As amostras que apresentaram maior diferenciação de perfil sensorial foram a estévia e a taumatina e, de acordo com o teste de aceitação conduzido com 150 consumidores, as mesmas também foram as menos aceitas. Apresentaram-se como bons substitutos da sacarose em bolo sabor baunilha os edulcorantes sucralose e acessulfame-K, comprovados através da correlação dos dados de perfil sensorial determinados pela ADQ e avaliação dos consumidores, através da análise de regressão múltipla por quadrados mínimos parciais (PLS) / Abstract: According to some surveys conducted, there is a great concern with respect to calories, sugars and fats ingested daily by the population, moving from high rates of malnutrition to high rates of obesity, especially in developed and developing countries. Every day, people have less time to prepare their food and seeking practicality, foods such as breads, cakes and biscuits become very present in the diets of consumers. With the objective of finding alternative foods with good acceptability and practicality, this study aimed to formulate vanilla cakes with different sweeteners to replace sucrose, considered a great villain that contributes to obesity. Sweeteners used in this study were: sucralose, acesulfame - K, stevia, neotame and thaumatin, and the same sweetening power was obtained by the method of magnitude estimation. To understand the sensory profile of each sample, Quantitative Descriptive Analysis was applied in, that 12 pre-selected assessors determined 21 descriptors. Time-intensity analysis was applied to assess sweetness, the main term descriptor of sucrose. The sample with the curve nearest the sweetness of sucrose, in the dynamic evaluation, was the one containing acesulfame-K. Samples that showed greater differentiation of the sensory profile were stevia and thaumatin and, according to the acceptance test conducted with 150 consumers, they were also evaluated as worst. Good substitutes for sucrose in cake vanilla flavored sweeteners were sucralose and acesulfame-K, as evidenced by the correlation of data from the sensory profile determined by ADQ and consumer evaluation through multiple regression analysis by partial least squares (PLS) / Mestrado / Consumo e Qualidade de Alimentos / Mestra em Alimentos e Nutrição

Insect meal has excellent potential as food or feed. There is a need to provide enough food for the growing population, which is linked to the increasing demand for livestock production. Meat and fish have always been the staple of the human diet as a rich source of proteins and fats for human nutrition. Fish is a good source of animal protein and fat for humans, which forms the basis of the diet of a large number of people who generally live in coastal areas. The increasing demand for fish is associated with a growing interest in high-quality and affordable fish feed. Nowadays, the main ingredient in fish feed is fishmeal, and the price is constantly increasing. The sustainability of the aquaculture industry depends on finding a substitute for fishmeal with the same nutritional value and availability. Recently, there has been a growing interest in animal protein from insects for fish fattening. This thesis focused on analysing insect meal from mealworm larvae (Tenebrio molitor) and its use for food and feed purposes. The theoretical part describes the mealworm, the use of insect meal for human nutrition, and fish fattening. It also describes the requirements of fish for individual nutrients and the characterisation of insects for feeding purposes, focusing on the mealworm used as an alternative feed ingredient in fish. The individual major nutrients, namely protein, lipids, fatty acids, amino acids, fibre, chitin, and selected minerals, were determined in the experimental part. The experimental part was divided into two parts, and the first part was divided into two phases. The first phase was used to determine the nutritional components in two fractions of insect meal from Tenebrio molitor larvae. The first fraction contained the fine fraction, and the second fraction the coarse fraction of insect meal. In the second phase, the content of nutritionally significant components was only determined in the insect meal from dried larvae without fractionation. A fish feed was designed from the analyses results. In the second part, the effect of the addition of insect meal from Tenebrio molitor for food purposes was investigated; specifically, the sensory properties of muffins were monitored. From the results, it can be observed that the nutritional composition of the insect meal suggests the possibility of using the mealworm larvae as an ingredient in the fish diet. The insect meal contains a high proportion of valuable proteins and lipids necessary for fish farming and a low proportion of carbohydrates, which unlike humans, fish do not need in their diet. The sensory analysis results indicate that consumers are not prepared to eat foods with added insects.

This diploma thesis deals with sensory evaluation of herbal non-alcoholic beverages, being a part of a new product development. The theoretical part provides information concerning chemical composition, health effects, food applications and aroma compounds of the herbs of interest (peppermint (Mentha piperita), sage (Salvia officinalis), St. John’s wort (Hypericum perforatum) and lemon balm (Melissa officinalis). Another topic is a description of sensory methods, requirements and arrangement of the analysis, statistical methods, and also technological processes leading to herbal syrups and beverages production. The practical part comprises sensory analysis of a few, newly designed, formulas of one-component and two-component alcohol free herbal beverages. The sensory panel consisted of 40 students of master's and also doctoral study programme at Faculty of chemistry, University of Technology Brno. Four subsequent experiments are introduced, each of them consisting of a few sensory tests and including corresponding sensory forms attached. The sensory tests arrangement was based on currently valid Czech Technical Standards, using a ranking, descriptive, paired comparison, sensory profile testing and scaling methods. For the purpose of statistical evaluation, Friedman, Kruskal-Wallis, PCA and Faktor analysis were used. Level of abilities and sensory experience of panelists were found comparable to consumer testing. The results include sensory characteristics of all of the beverages tested. In general, the one-component beverages were preferred to the two-component beverages and the additive colouring with aronia concentrate wasn´t found any benefitial, from the sensory point of view. The consumer questionnaire proved all of the samples to be very promising, but based on the sensory results, we would consider the mint and the sage-mint beverages being the most potentialy applicable samples.

This master’s theses deals with a production and characterization of hard candies, a type of non-chocolate sweets. Methods of candies production were optimised with focus mainly on boiling temerature which significantly affects product consistency and stability. Production process optimisation was based on methods of sensoric analysis and Karl-Fishcher titration used to determine the water content in the product. Plant extracts Plectranthus amboinicus and Aronia melanocarpa which were applied to hard candies are rich source of bioactive compounds upon which prepared candies were characterised. Optimal conditions for candies production were – boiling temperature 155 °C, volume of citric acid 0,4 %, volume of Plectranthus extract 2 % and volume of Aronia extract 3 %. There were 42 volatile compounds identified in a sample containing 2 % of Plectranthus extract. Based on their content , the most significant compounds were carvacrol (8,44 %), carotol (1,47 %) and levomenthol (0,99 %). Total content of polyfenols was measured to be 7,10 ± 0,55 mgg-1 per 1 g of hard candy sample, antioxidant activity of a sample was 66,19 ± 1,80 gml-1. It was identified that 42 of volatile compounds were present inside the sample with 3 % of Aronia extract. The most significant being carotol (30,67 %), menthol (1,52 %) and thymol (1,39 %). The overall presence of polyphenols was measured to be 13,87 ± 1,12 mgg-1 per 1 g of the candy sample, the antioxidant activity of the sample was 115,00 ± 2,86 gml-1.

This work deals with influence of heat processing on longevity of two selected products of the packing company Seliko trading a.s. For the research there were selected products Sterilised sauerkraut in sweet-sour pickle and Fatback spread. Evaluation has been done in laboratory premises of the packing company. There has been monitored mikrobiological stability after heat processing and sensory properties of the mentioned products always with an interval of one month. During the monitored seven months there appeared changes in taste and consistence of the products that are not defective in these products. The microbiological test taken after seven months was negative, just like at the beginning of the experiment. The result of the given findings is that the heat sterilisation was efficient and that during the storage there did not rise number of micro-organisms in the products.

This diploma thesis deals with the determination of aroma compounds in fruit yoghurts. These compounds are crucial for flavour of these dairy products. Two types of fruit yoghurts were analyzed, creamy (8 % of fat) and light (less than 0,1 % of fat), with various fruit ingredients, produced in dairy Mlékárna Valašské Meziříčí, spol. s r.o. Analysis was carried out by gas chromatography with extraction of analytes by SPME - solid phase microextraction. Six groups of different aromatic compounds such as ketones, aldehydes, organic acids and their salts, alcohols and sulfides in different amounts were determined. These compounds have mostly microbiological origin (Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus are dairy yoghurt cultures usually used for yoghurt production), less amounts are present in cow's milk or in dairy additives. Yoghurts were simultaneously sensory evaluated using ranking test, scale test and pair test for determination of acceptability and flavour. The assessors were students and staffs faculty of chemistry VUT.

This diploma thesis was focused on visual and olfactory senses and their role in the sensory evaluation. The requirements for assessors working in sensory analysis, for testing place and requirements of the Czech Institute for Accreditation for the accreditation of laboratories working in the field of sensory testing are summarized here. An overview of methods and legislation in the field of sensory analysis is also presented. Methods for studying of smell and vision sensitivity of assessors were selected in the experimental part of this thesis. The methods were verified in the sensory laboratory, validated and standard operating procedures have been developed to the individual methods.

The aim of this diploma thesis is to study the sensitivity of one of the five human senses - taste. It deals with anatomy of taste sense, taste perception and it also describes which kinds of taste we are able to identify. Sensory analysis is focused on human senses and their practical use. Consequently, the requirements for sensory assessors, requirements for sensory laboratory, methods used in sensory analysis and summary of legislation in this area are described in this thesis. In order to perform qualified sensory assessment, the laboratory needs accreditation. On this account the requirements of Czech accreditation institute are mentioned here. Methods suitable for studying of taste sensitivity of sensory assessors are chosen and validated in experimental part. Standard operating procedures are elaborated for these chosen methods.

This diploma thesis deals with the questions of determination of aroma active compounds present in yoghurts. These compounds are crucial for flavour of these fermented dairy products. Four types of yoghurts were analyzed, creamy (10 % of fat), medium-fat and medium-fat Bio (3 % of fat) and light (0,1 % of fat), produced by Mlékárna Valašské Meziříčí, spol. s r.o. Analysis was carried out by gas chromatography with extraction of analytes by SPME - solid phase microextraction. Five groups of different aroma active compounds such as ketones, aldehydes, organic acids and their esters and alcohols in different amounts were determined. These compounds are mostly metabolic products of Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, dairy yoghurt cultures usually used for yoghurt production. Less amounts are present in cow's milk or in dairy additives. Yoghurts were simultaneously sensorially evaluated using ranking test and scale test for determination of acceptability and flavour. The assessors were students and staffs of faculty of chemistry BUT.

This diploma thesis was focused on the use of profile tests for sensory analysis of foods. The development of profile methods, advantages and disadvantages of the techniques, specific training of panelists, the organization and the requirements for testing place and testing is described in theoretical part. There is a brief overview of other methods and legislation used in sensory analysis. In the experimental part of this work several types of foods such as bread, ham, yogurt, apple and chocolate have been selected. For each of these foods the forms for profile evaluation of flavor and texture have been developed. Consequently, the selected samples were sensorially evaluated by panel composed from students of FCH BUT.