O envelhecimento de destilados ocorre com a estocagem do produto em barris de madeira durante um período de tempo suficiente para que ocorram reações específicas que agregam qualidade e melhoram o perfil sensorial da bebida. O objetivo deste estudo foi avaliar a influência de diferentes madeiras na composição química e atributos sensoriais de aguardentes de cana envelhecidas. A aguardente foi envelhecida em barris novos de carvalho francês (Quercus petraea) e carvalho americano (Quercus alba) com diferentes intensidades de queima da madeira. A composição em teor alcoólico, compostos fenólicos totais, intensidade de cor, glicerol, contaminantes, congêneres voláteis e de maturação permitiu a caracterização da evolução dos compostos ao longo de dois anos de envelhecimento. A espécie e origem da madeira de carvalho, assim como a intensidade do tratamento térmico influenciaram na modificação das concentrações de todos os congêneres de maturação. O grau de maturação da bebida pôde ser estimado por comparação da taxa de evolução dos compostos com destilados estudados em literatura. Sugere-se que a maior evolução dos compostos da aguardente foi obtida até um ano de envelhecimento, e que barris de carvalho francês com queima média permitiram a evolução ideal dos congêneres para a formação de novos compostos no destilado. O perfil sensorial descritivo diferenciou a aguardente envelhecida em barris de carvalho francês com intensidades de queima média e forte. Aguardentes envelhecidas em barris de queima forte receberam os descritores sensoriais mais intensos em \"cor amarela\", \"aroma de especiarias\", \"aroma doce\", \"aveludado\", apimentado\" e \"retrogosto amadeirado\". Foram testados a interação de lascas de madeira de carvalho com a aguardente com e sem aeração. O processo de aeração afetou negativamente a qualidade química e sensorial das aguardentes. No entanto, a interação com lascas promoveu efeito positivo nas aguardentes não aeradas. Aguardentes envelhecidas em barris de 9 diferentes madeiras brasileiras e carvalho apresentaram diferenças na composição química. Todas as madeiras exerceram influência na qualidade da bebida. Destaque positivo foi observado para aguardentes envelhecidas em barris de carvalho (Quercus sp), amburana (Amburana cearensis) e jequitibá rosa (Cariniana legalis). O presente estudo confirma a possibilidade e o sucesso para o envelhecimento de aguardente em barris de madeiras brasileiras. Desenvolveu-se uma roda sensorial para perfil descritivo rápido em cachaça e aguardente, com objetivo de ativar a memória sensorial e fornecer termos descritivos padronizados e organizados. A roda sensorial foi construída contendo 50 descritores finais para aspectos: visual, aromas, gostos e sensações. O uso da roda é destinado tanto para provadores experientes em análise sensorial, como para formar novos degustadores e avaliadores da qualidade da bebida. / The ageing process occurs with the storage of the product in wooden barrels for a period of time sufficient to happen specific reactions, which improves quality, and the sensory profile of the spirit. The objective of this study was to evaluate the influence of different woods in the chemical composition and sensory attributes of aged sugarcane spirits. The spirit was aged in new French oak barrels (Quercus petraea) and American oak (Quercus alba) with different wood toast intensity. The composition of alcohol, phenolic compounds, color intensity, glycerol, contaminants, volatile and maturation congeners afford to distinguish the two species of timber and characterization of the compounds development over two years of ageing.The type and origin of the oak wood, as well as the toast intensity influenced in of all congeners maturation. The degree of the spirit maturation could be estimate by comparing the evolution rate of the compounds studied in literature. It is suggested that the further evolution of the compounds was obtained within one year of aging, and French oak barrels with a medium toast allowed the better evolution of the counterparts to the formation of new compounds in the spirit. The descriptive sensory profile distinguished spirit aged in French oak barrels of medium and heavy toasted. Spirit aged in heavy toasted barrels received the most intense sensory descriptors in \"yellow\", \"spice aroma\", \"sweet scent\", \"velvety\" \"spicy\" and \"woody aftertaste\". It was tested the interaction of oak wood chips with spirit with and without aeration. The aeration process affected negatively the chemical and sensory quality of the spirits. However, interaction with chips promoted positive effect in the non-aerated spirits. It was tested the ageing process in 9 different Brazilian woods and oak barrels. Every wood promoted alterations in chemical composition and all the wood exerted influence on the quality of the beverage. Highlight positive was observed for spirit aged in oak barrels (Quercus sp), amburana (Amburana cearensis) and pink jequitibá (Cariniana legalis). This study points to the possibility and success for spirits aging in Brazilian wood barrels. A sensory wheel was developped for Flash Profile in sucarcane spirits and cachaça. The sensory wheel was constructed containing 50 final descriptors for aspects: visual, smells, tastes and sensations. The use of the wheel is intended for both experienced tasters in sensory analysis as to form new tasters and spirits quality evaluators in order to activate the sensory memory and provide standardized and organized descriptive terms.

The consumption of fresh-cut fruits has been increasing in recent years due to their health benefits. Fresh-cut cantaloupe (Cucumis melo L.) represents a great snack alternative due to its low caloric content, freshness, and basic component of a healthy diet. One of the latest alternatives to reduce the decay of quality brought by minimal processing of fruits is the development of edible coatings. Acting as a barrier to moisture and gases, the coatings are expected to extend the shelf-life of fresh-cut products, thus the main objective of this research was to determine the effectiveness of an antimicrobial edible coating on the shelf-life of fresh cut cantaloupe (stored at 4 degrees C for 15 days) while maintaining its quality attributes. The effect of different coating compositions and their concentrations on a product's chemical properties and quality attributes was studied. A set of solutions containing chitosan, beta-cyclodextrin, trans-cinnamaldehyde, pectin and calcium chloride were used as coating systems for the fruit using the layer-by-layer method. Quality was measured in terms of texture, color, weight loss, moisture, acidity, and pH. In addition, a consumer sensory test was carried out to support the findings from the objective quality data. Microbiological tests were carried out to determine the effectiveness of trans-cinnamaldehyde as antimicrobial agent within the coating. Uncoated fresh-cut cantaloupe samples stored at 4 degrees C served as controls. In terms of microbiological and physicochemical quality attributes, the antimicrobial coating improved the shelf-life of fresh-cut cantaloupe (up to 12 days), compared to the controls (only 6 days). The coating composed of 2% antimicrobial, 2% chitosan and 1% pectin was the most effective in terms of consumer's acceptance (P<0.05) and shelf-life extension. The results indicated that different ratios between solutions present a variation for each specific quality attribute. The thicker the coating, the firmer the fruit and different thicknesses resulted in different amounts of antimicrobial compound in the coating, thus critically affecting the shelf-life of the product. This study demonstrates the feasibility of a new generation of edible coating for fresh-cut cantaloupe, the coating consists of using a system specially designed to allow the incorporation of natural antimicrobial agents by means of the application of microencapsulation and the layer-by-layer assembly.

O envelhecimento de destilados ocorre com a estocagem do produto em barris de madeira durante um período de tempo suficiente para que ocorram reações específicas que agregam qualidade e melhoram o perfil sensorial da bebida. O objetivo deste estudo foi avaliar a influência de diferentes madeiras na composição química e atributos sensoriais de aguardentes de cana envelhecidas. A aguardente foi envelhecida em barris novos de carvalho francês (Quercus petraea) e carvalho americano (Quercus alba) com diferentes intensidades de queima da madeira. A composição em teor alcoólico, compostos fenólicos totais, intensidade de cor, glicerol, contaminantes, congêneres voláteis e de maturação permitiu a caracterização da evolução dos compostos ao longo de dois anos de envelhecimento. A espécie e origem da madeira de carvalho, assim como a intensidade do tratamento térmico influenciaram na modificação das concentrações de todos os congêneres de maturação. O grau de maturação da bebida pôde ser estimado por comparação da taxa de evolução dos compostos com destilados estudados em literatura. Sugere-se que a maior evolução dos compostos da aguardente foi obtida até um ano de envelhecimento, e que barris de carvalho francês com queima média permitiram a evolução ideal dos congêneres para a formação de novos compostos no destilado. O perfil sensorial descritivo diferenciou a aguardente envelhecida em barris de carvalho francês com intensidades de queima média e forte. Aguardentes envelhecidas em barris de queima forte receberam os descritores sensoriais mais intensos em \"cor amarela\", \"aroma de especiarias\", \"aroma doce\", \"aveludado\", apimentado\" e \"retrogosto amadeirado\". Foram testados a interação de lascas de madeira de carvalho com a aguardente com e sem aeração. O processo de aeração afetou negativamente a qualidade química e sensorial das aguardentes. No entanto, a interação com lascas promoveu efeito positivo nas aguardentes não aeradas. Aguardentes envelhecidas em barris de 9 diferentes madeiras brasileiras e carvalho apresentaram diferenças na composição química. Todas as madeiras exerceram influência na qualidade da bebida. Destaque positivo foi observado para aguardentes envelhecidas em barris de carvalho (Quercus sp), amburana (Amburana cearensis) e jequitibá rosa (Cariniana legalis). O presente estudo confirma a possibilidade e o sucesso para o envelhecimento de aguardente em barris de madeiras brasileiras. Desenvolveu-se uma roda sensorial para perfil descritivo rápido em cachaça e aguardente, com objetivo de ativar a memória sensorial e fornecer termos descritivos padronizados e organizados. A roda sensorial foi construída contendo 50 descritores finais para aspectos: visual, aromas, gostos e sensações. O uso da roda é destinado tanto para provadores experientes em análise sensorial, como para formar novos degustadores e avaliadores da qualidade da bebida. / The ageing process occurs with the storage of the product in wooden barrels for a period of time sufficient to happen specific reactions, which improves quality, and the sensory profile of the spirit. The objective of this study was to evaluate the influence of different woods in the chemical composition and sensory attributes of aged sugarcane spirits. The spirit was aged in new French oak barrels (Quercus petraea) and American oak (Quercus alba) with different wood toast intensity. The composition of alcohol, phenolic compounds, color intensity, glycerol, contaminants, volatile and maturation congeners afford to distinguish the two species of timber and characterization of the compounds development over two years of ageing.The type and origin of the oak wood, as well as the toast intensity influenced in of all congeners maturation. The degree of the spirit maturation could be estimate by comparing the evolution rate of the compounds studied in literature. It is suggested that the further evolution of the compounds was obtained within one year of aging, and French oak barrels with a medium toast allowed the better evolution of the counterparts to the formation of new compounds in the spirit. The descriptive sensory profile distinguished spirit aged in French oak barrels of medium and heavy toasted. Spirit aged in heavy toasted barrels received the most intense sensory descriptors in \"yellow\", \"spice aroma\", \"sweet scent\", \"velvety\" \"spicy\" and \"woody aftertaste\". It was tested the interaction of oak wood chips with spirit with and without aeration. The aeration process affected negatively the chemical and sensory quality of the spirits. However, interaction with chips promoted positive effect in the non-aerated spirits. It was tested the ageing process in 9 different Brazilian woods and oak barrels. Every wood promoted alterations in chemical composition and all the wood exerted influence on the quality of the beverage. Highlight positive was observed for spirit aged in oak barrels (Quercus sp), amburana (Amburana cearensis) and pink jequitibá (Cariniana legalis). This study points to the possibility and success for spirits aging in Brazilian wood barrels. A sensory wheel was developped for Flash Profile in sucarcane spirits and cachaça. The sensory wheel was constructed containing 50 final descriptors for aspects: visual, smells, tastes and sensations. The use of the wheel is intended for both experienced tasters in sensory analysis as to form new tasters and spirits quality evaluators in order to activate the sensory memory and provide standardized and organized descriptive terms.

Master of Science / Food Science / Delores H. Chambers / Tools are available, through various reference books, to develop a purposeful sensory quality program. Some companies already have a strong sensory program in place; others may require a cultural change to facilitate the implementation. This paper indicates some of the challenges to be overcome, covers some current quality control (QC) sensory practices and addresses advantages and disadvantages of expert tasters Some specific issues regarding sensory evaluations of alcohol beverages are discussed and critical factors in production are reviewed with discussion on the potential for off taint development.

Master of Science / Food Science Institute, Human Nutrition / Koushik Adhikari / Oxidative deterioration is a significant contributing factor to the limited shelf life of foods containing lipids. The lipids in meats and dairy products make them susceptible to oxidation, limiting the amount of time that such products can be stored before a change in the sensory properties is evident. The use of rosemary oleoresin in meat products and fried foods has been extensively researched and used in commercialized foods. Since dry cheese and dairy products also contain lipids that are highly susceptible to oxidation, the use of a natural rosemary oleoresin may be beneficial in increasing the shelf life and sensory acceptability of these products as well. The overall objective of this report was to review the uses of a natural antioxidant, rosemary oleoresin, to inhibit oxidation and sensory changes in dairy and meat products and determine which areas need further study.

No description available.

Quinoa (Chenopodium quinoa) is a very nutritionally valuable crop with versatility. The aim of this work was a practical experiment to test the possibility of pasta production with different proportions of quinoa flour and evaluate their selected qualitative properties. The thesis includes also photos of pasta production and the results of questionnaires summarizing the views of consumers on pasta containing quinoa flour. We can advise to use of quinoa flour up to 30% share for the production of quinoa-semolina pasta. Adding eggs or the pregelatinized quinoa starch inches the possible share of quinoa in the pasta up to 40% representation.

Marama bean (Tylosema esculentum (Burch) A. Schreib) is an underutilised, drought- tolerant legume native to the semi-arid areas of Botswana, Namibia and South Africa. The edible seeds of marama beans are good sources of protein and fat, and its flours can potentially enhance the nutritional quality of sorghum porridge, a staple in many African countries. Sorghum has a low protein content and is deficient in lysine. Compositing sorghum with lysine-rich marama flour when preparing porridges would address this problem. Utilisation of marama flour in composite porridge depends on sensory acceptance. In this study nutritional and sensory quality of marama-sorghum composite flours and porridges are investigated. Full fat and defatted flours from unheated and dry heated (150 °C /20 min) marama beans were composited with condensed tannin-free sorghum meal (30:70). Marama flours, sorghum meal, marama-sorghum composite flours and porridges were analysed for proximate composition, amino acid composition, energy value, fatty acid composition, total phenolic content and antioxidant activity. Porridges (10% solids) were subjected to descriptive sensory analysis, consumer acceptance test (n=52), texture analysis, pasting profiles and colour measurements. Sorghum porridge and porridge composite with full fat marama flour from heated beans were more acceptable than other composite porridges. Compositing sorghum meal with marama flour reduced the cooked sorghum aroma/flavour intensities prominent in sorghum porridge. Dry heating marama beans prior to milling resulted in a roasted nutty flavour in the final product. Porridges from heated marama beans were darker in colour than porridges from unheated beans. This could be attributed to flavour and colour development due to Maillard reaction during dry heating. Composite porridges from full fat marama flours were described as buttery/creamy. A bitter taste and aftertaste was perceived in porridges from defatted flours. Presence of fat seems to mask bitterness in porridges. Marama-sorghum composites and Tsabotlhe porridges were less viscous than sorghum porridge. This was confirmed by pasting profiles (low final viscosities) and texture analysis indicating reduced firmness. Starch contributes greatly to the textural properties of sorghum porridge. Marama flour has no starch. Compositing the flour with sorghum reduced starch levels in the composite porridges. This explains the reduction in viscosity and firmness of the porridges. Compositing sorghum meal with marama flours significantly increased protein and fat contents in flours and porridges. The fat content in marama-sorghum flours was in the range of 5.6 to 14.6%. Protein increase ranged from 61% to 96% in marama-sorghum composite porridges compared with sorghum porridge. There was 11-24% energy value increase in marama-sorghum composite porridges compared with sorghum porridge. Porridges composited with full fat flours contributed to higher energy values than those composited with defatted flours. This is because of fat energy contribution. Lysine content in marama flour was significantly higher than sorghum meal. Lysine content was 3 to 4 times higher in marama-sorghum porridges than in sorghum porridge. Unsaturated fatty acids were the most present in both marama-sorghum composite porridges and sorghum porridge. There was an increase in oleic acid as marama flour was composited with sorghum. Marama flours had higher levels of total phenolics than sorghum flour. Marama flour has high levels of tyrosine which could react with the Folin Ciocalteu reagent thus leading to an increase in measurable phenols. Marama flours from dry heated beans had higher total phenolic content and antioxidant activity than flours from unheated beans. Heating may have increased phenolic compound extractability due to release of bound phenolics. There was a positive correlation between the total phenolic content and antioxidant activity (r = 0.80, p < 0.05) in all samples. Findings from this study indicate that marama flour can potentially be used to improve the nutritional quality of sorghum porridges. Furthermore this study shows that use of full fat flour in marama-sorghum composite porridges give more acceptable sensory properties. / Dissertation (MScAgric)--University of Pretoria, 2011. / Food Science / unrestricted

Green garden peas (Pisum sativum L.) are a popular vegetable used in meal preparation worldwide. Green peas are commonly available in their frozen form due to their short growing season. Green peas are easily susceptible to changes in the field, immediately after harvest, during processing and storage, and thereforerequire careful handling to maintain good quality. The acceptability of frozen green peas is greatly dependent on the sensory quality. Descriptive sensory profiles and physico-chemical properties of frozen green peas can be investigated and used to assess and explain product quality. Six brands of frozen green peas representing product sold for retail and caterer's markets were purchased and subjected to descriptive sensory evaluation, physico-chemical analyses and quality grading. Four batches with different best before dates were purchased for each brand. Quality grading was done using statutory standards and a selected company protocol. Dry matter content, alcohol insoluble solids content, starch content, °Brix, residual peroxidase activity, size sorting, hardness using texture analysis and colour measurements were carried out for physico-chemical analyses. Generally, retail class peas were of superior sensory quality to caterer's peas although one caterer's brand had quality traits that were more comparable with the retail brands than the other caterer's brands. Quality grading revealed that frozen green peas can be downgraded due to poor colour, presence of extraneous vegetable matter, presence of sandy grits and soil stains, poor flavour and poor texture. Downgrading of peas can be due to one reason or due to a combination of two or more poor quality characteristics. Good quality peas were described as sweeter, smaller, greener, more moist and more tender than the poorer quality peas usingdescriptive sensory evaluation. Good peas also had high °Brix content, more intense green colour, low starch, alcohol insoluble solids, dry matter contents and texture hardness measured. Quality grading revealed that flavour problems were the major cause for low graded samples. Sensory evaluation and the methods used for instrumental analyses however, showed more easily the variations in texture attributes than flavour attributes of peas. Poor flavour was probably caused by ineffective blanching, low soluble solids content which enhanced the perception of bitterness and the presence of acetone notes. Poorly coloured peas were also either underblanched or had low moisture contents. Mealiness and hardness in peas were explained by high starch, alcohol insoluble solids and dry matter contents. Instrumental texture analysis showed indications that the harder peas also had tougher skins in addition to harder cotyledons. Lower peas also displayed characteristics typical of delayed harvesting and post-processing temperature abuse such as dehydration and pale green/white colouration. The sensory quality of frozen green peas can be predicted from the physico-chemical methods of analysis used in this study. Some of the frozen peas on sale are below the acceptable standards of quality. To achieve good frozen pea quality it is important to put emphasis on maturity at harvest and post processing storage conditions (store at -18 °C or lower and avoidfluctuatingtemperatures). The use of a strict quality grading scheme has been shownto result in good quality frozen peas. Copyright / Dissertation (MSc)--University of Pretoria, 2012. / Food Science / unrestricted

Studies generally agree on the critical influence of physico-chemical characteristics of raw potatoes on the physico-chemical and sensory characteristics of potato chips. However, the actual magnitude of differences in sensory quality and consumer acceptance of potato chips as a result of differences in the physico-chemical characteristics of raw potatoes are scarcely reported in most studies. This research was conducted to determine the effect of different physico-chemical characteristics of potato samples on the sensory quality and acceptance of potato chips. The potato samples which represented typical variations in physico-chemical characteristics that a potato chip manufacturer experiences were sourced over a six month period. The samples comprised of four potato varieties (A, B, C, D) sourced from five regions (V, W, X, Y, Z). The samples were coded AV, BW1, BW2, CW, CX, DY, DW and DZ. BW1 and BW2 were of the same variety and grown in the same region but harvested at different time periods. The sourcing of potatoes and potato chips were done at the manufacturer’s processing line during regular production. The potatoes were analyzed for physico-chemical characteristics generally reported to influence potato chip sensory quality, i.e. specific gravity (solids contents), starch content and reducing sugars content. After processing, the physico-chemical characteristics i.e. moisture content, colour and oil content of the respective unflavoured potato chip samples were analysed. The sensory qualities of both unflavoured and flavoured (sour cream and onion) potato chips of the respective potato samples were also determined. There were significant differences (p<0.05) in the specific gravity/solids content of the potato samples. The specific gravity and solids content ranged from 1.073 to 1.098g/cm3 and 19.2 to 24.9% respectively. Reducing sugars were not detected in any of the potato samples at a minimum detection level of 0.05 %. The potato chip samples differed significantly (p<0.05) in moisture content, oil content and colour (a * and b* values, chroma, hue angle) with ranges of 1.2 to 1.9 % (moisture), 33.1 to 40.8 % d.b (oil content), 0.39 to 3.69 (a *), 15.88 to 21.26 (b*), 15.93 to 21.37 (chroma) and 79.92 to 88.96 o (hue angle). Descriptive sensory evaluation showed that 6 and 8 of the attributes identified in the unflavoured and flavoured potato chip samples, respectively, differed significantly (p<0.05). Consumer sensory evaluation indicated that there was no clear preference of one chip sample over the others despite of differences observed through descriptive sensory analysis and physico-chemical characteristics. All the chip samples were generally liked. To the manufacturer this research could be regarded as of a quality control nature since the potato chip samples used in this study were of chipping varieties actually used by the manufacturer. The value of this research to the chip manufacturer was the fact that despite of slight differences in the physico-chemical characteristics (specific gravity/solids content and starch content) of potato samples, potato chips of acceptable sensory quality to the consumers were produced. / Dissertation (MSc)--University of Pretoria, 2011. / Food Science / unrestricted