Showing papers in "Food Science and Technology International in 1999"
TL;DR: In this article, the quality of frozen fruit pulps of cashew apple, yellow mombin and acerola produced by enterprises from Paraiba and Pernambuco States (Brazilian northeastern region), in order to verify if they are according to Brazilian regulatory laws.
Abstract: This work was conducted to study the quality of frozen fruit pulps of cashew apple, yellow mombin and acerola produced by enterprises from Paraiba and Pernambuco States (Brazilian northeastern region), in order to verify if they are according to Brazilian regulatory laws. The mean values for pulps from both states were: a) cashew apple: pH 4.11; soluble solids = 9.8°Brix; acidity in citric acid = 0,39%; reducing sugars = 5.74%; ascorbic acid = 162.89mg/100g. b) yellow mombin: pH = 2.50; soluble solids = 7.5°Brix; acidity in citric acid = 1.09%; reducing sugars = 2.70%; ascorbic acid = 8.87mg/100g. c) acerola: pH = 3.05; soluble solids = 6.50°Brix; acidity in citric acid = 1.04%; reducing sugars = 3.20%; ascorbic acid = 989.51mg/100g. The result revealed that 68.2% of yellow mombin pulp samples and 59.1% of cashew apple pulp samples were found in disagreement with the QIS juice of these fruits. Concerning to acerola pulp, 40,7% of samples were also in disagreement with the required standard, according to Brazilian legislation. Such findings indicate the necessity to set up QIS for yellow mombin and cashew apple pulps in order to offer good quality products to consumers.
88 citations
TL;DR: In this article, the formation of anthocyanin-derived pigments in red wines was examined for nine months of storage in bottles at 15 °C at pH 3.2 with added acetaldehyde (800 mg/L).
Abstract: Red wines obtained by microvinification in the laboratory and adjusted to three pH values (3.2, 3.6 and 4.0) were examined for the formation of anthocyanin-derived pigments throughout nine months of storage in bottles at 15 °C. The formation of the pigments was also followed in aliquots of the wines at pH 3.2 with added acetaldehyde (800 mg/L). Pigment analyses were accomplished by HPLC using double on-line detection by diode array spectrophotometry and mass spectrometry. Two dif ferent types of pigments were observed. The first were products derived from the condensation be tween anthocyanins and flavanols by ethyl bridges. The second corresponded to products showing an additional heterocycle in the anthocyanin structure (vitisin-like pigments); of these, vitisin B, which derives from malvidin 3-monoglucoside, was the most important one. Products similar to vitisin B derived from other anthocyanins were also detected, as well as structurally related pigments con taining flavanol moieties. The formation o...
82 citations
TL;DR: Supercritical extraction (SFE) is a unit operation that exploits the dissolving power of supercritical fluids (SF) under conditions above their critical temperature and pressure as discussed by the authors, and it is possible to...
Abstract: Supercritical extraction (SFE) is a unit operation that exploits the dissolving power of supercritical fluids (SF) under conditions above their critical temperature and pressure. It is possible to ...
78 citations
TL;DR: Partial removal of water through air dehydration, dewatering-impregnation-soaking in concentrated solutions (DIS) or their combination, has been applied to strawberry slices before freezing in order to reduce structural cullapse after thawing as discussed by the authors.
Abstract: Partial removal of water through air dehydration, dewatering-impregnation-soaking in concentrated solutions (DIS) or their combination, has been applied to strawberry slices before freezing in order to reduce structural cullapse after thawing. The changes produced at the structural level have been studied through both texture and microscopic analysis, so defining the structure-texture relation ships in the freeze-thawed fruit. Tissues subjected to DIS in a 60% (w/w) glucose solution for 4 hours at room temperature showed structural damage to the cell walls and cell ruptures, which are in agree ment with the observed decrease of texture. After thawing, the pre-dehydrated strawberry slices showed a much better tissue organization than the strawberry frozen without pretreatment. Air dry ing and the combination DIS-air drying gave the highest texture improvement of the fruit after thaw ing. A good agreement was obtained between structural and textural changes observed after both pre-dehydration and freeze-tha...
52 citations
TL;DR: The objetive of this research was to check the utilization of fecula film to postharvest conservation of strawberry fruits stored in ambient temperature (21oC; 64,5% RH) and the result showed that no differences were noted.
Abstract: The objetive of this research was to check the utilization of fecula film to postharvest conservation of strawberry fruits were stored in ambient temperature (21oC; 64,5% RH). It was set out in a system randomized complete test with 2 factors and submited to Tukey test. In following, the fruits were submited by six differents treatments: 1) control (without film); 2) 1% fecula film; 3) 2% fecula film; 4) 3% fecula film; 5) 4% fecula film; 5) 5% fecula film. The valuation were done by 0, 2, 4, 6, 8 and 10 days about weight loss, sensorial evaluation and quality visual (color and texture). At the end of 10 days the following was observed; smaller weight loss in the treatment with 1, 2 and 3% fecula film, and higher texture, increasing in until 5 times the postharvest life in the fruits. The result from the sensorial evaluation showed that no differences were noted.
49 citations
TL;DR: In this paper, the honey samples were divided in groups, stored in different conditions and analized according to the rules adopted by the Instituto Adolfo Lutz, Laboratorio Nacional de Referencia Animal e Official Analytical Chemists.
Abstract: In accordance with the colour, the honey samples were divided in groups, stored in different conditions and analized according to the rules adopted by the Instituto Adolfo Lutz, Laboratorio Nacional de Referencia Animal e Official Analytical Chemists. The samples were packed in recipients of glass and polypropilene and they were stored at room temperature . A group of samples were stored at room luminosity while the other group was stored at room without natural light. Chemical analyses for moisture, pH, acidity, colour, reducing sugars and non-reducing sugars, hydroxymethylfurfural (HMF) and the determinations for the index of Lugol, Lund, Fiehe and diastase were made for one year of storage. The results obtained show that the samples analyzed maintened their characteristics among the acceptable standards and that the producers have to be orientated how to use the techniques of packing and storing their honey samples for assuring the quality of their products.
49 citations
TL;DR: In this article, the effects of different cooking techniques on the lipids of pork meat were evaluated, and the assayed cooking techniques were deepfrying (DF), shallow-frying, roasting (RO), and boiling (BO).
Abstract: The effects of different cooking techniques on the lipids of pork meat were evaluated. The assayed cooking techniques were deep-frying (DF), shallow-frying (SF), roasting (RO) and boiling (BO). Modi fication of the roasting meat due to reheating in a microwave oven after 24 h at 4 °C (MW), was also studied. In DF and SF significant increases were found in the lipid content (13.7 and 16.7 g/100 g of dry basis, respectively) and in the nun-polar lipids (11.2 and 14.2 g/100 g of dry basis, respectively) due to the absorption of the oil used in these cooking treatments. The main variations in the fatty acid composition of phospholipids and non-polar lipids were observed in the polyunsaturated fatty acid fraction. There was an increase in the content of free fatty acids (SFA, MUFA, PUFA) after MW, BO and RO. By contrast, free fatty acid content in DF and SF was similar to the content of initial raw meat. MW showed the greatest degradation of the phospholipid fraction, with a significant decline in phosphatidyl...
43 citations
TL;DR: In this article, the fruit was submitted to vacuum osmotic dehydration (VOD) processes (60 mbar) in 60 °Brix sucrose syrups to depress a w from 0.99 to 0.98 (or less).
Abstract: The application of vacuum osmotic impregnation at constant temperature (25 °C) to obtain high moisture minimally processed papaya was evaluated. The fruit effective porosity was determined employing vacuum impregnation in isotonic sucrose solutions, obtaining values of around 3.4%. The fruit was submitted to vacuum osmotic dehydration (VOD) processes (60 mbar) in 60 °Brix sucrose syrups to depress a w from 0.99 to 0.98 (or less), always having a greater effectiveness than in the case of osmotic dehydration (OD) processes at atmospheric pressure. The use of a VOD initial process for different times, followed by the application of OD (called pulsed vacuum osmotic dehydration, PVOD, processes) had a greater effectiveness in depressing the aw than when only OD was applied in pro cesses up to 240 min. The pH reduction due to the addition of citric acid (2.5, 5.0 and 7.5%) to the sucrose syrup was more effective when applying VOD or PVOD processes. Minimally processed papaya (aw 0.98, pH 3.5) could be obtained ...
39 citations
TL;DR: The most commonly measured ultrasonic parameters are velocity, attenua tion and frequency spectrum composition as discussed by the authors, which is the parameter used most since it is the simplest and most common parameter.
Abstract: Ultrasonic applications can be classified into low intensity or high intensity applications. The latter are used to modify a process or product with ultrasonics, while in low intensity applications the process or product modifies the ultrasonic signal, thus providing information about the product. Low inten sity ultrasonics in food technology can be used to monitor a process (liquid level, flowmeters) or to determine the quality of food products. Since ultrasonic techniques are rapid, non-destructive, easy to automate and relatively inexpensive, the number of applications is rapidly growing in this field. Ultrasonics can also be considered for use in laboratory testing devices to determine physical and chemical properties of foods. Ultrasonics has been used to determine texture, composition and physical state in liquid and solid foods. The commonly measured ultrasonic parameters are velocity, attenua tion and frequency spectrum composition. Velocity is the parameter used most since it is the simplest and ...
36 citations
TL;DR: In this paper, a metodologia de extracao com acido cloridrico foi empregada for a determinacao dos teores de minerais em sucos processados de abacaxi, acerola, caju, goiaba, manga, maracuja e uva.
Abstract: Dois metodos de preparacao de amostra para determinacao de minerais em suco de uva foram comparados: extracao com acido cloridrico a frio com agitacao e digestao em sistema fechado, sob pressao, empregando-se energia de microondas. As concentracoes dos minerais foram obtidas empregando-se a tecnica de Espectrometria de Emissao Optica em Plasma Indutivamente Acoplado (ICP-OES). Os teores dos minerais Ca, P, Na, K, Mg, Zn, Fe, Mn e Cu nao diferiram significativamente ao nivel de 5% (Teste F) para as duas metodologias empregadas. A precisao e exatidao dos metodos foi avaliada usando o suco de uva. A metodologia de extracao com acido cloridrico foi empregada para a determinacao dos teores de minerais em sucos processados de abacaxi, acerola, caju, goiaba, manga, maracuja e uva. Para facilitar a interpretacao dos teores dos minerais encontrados, foram utilizadas as tecnicas de Analise por Componentes Principais (PCA) e Analise Hierarquica por Agrupamento (HCA).
35 citations
TL;DR: In this paper, the same authors investigated other fermented starch sources for manufacturing biscuits and found that the fermented starch showed characteristics similar to those of commercial fermented cassava starch, and the biscuits manufactured from the fermentation of arrowroot and of baroa-potato were approved by the consumers.
Abstract: The fermented cassava starch has been used as raw material for many products of the Brazilian culinary mainly in the biscuit manufacturing. Starch of arrowroot, english potato, baroa-potato and cassava were extracted and fermented in order to investigate other fermented starch sources for manufacturing biscuits. The fermented starch showed characteristics similar to those of commercial fermented cassava starch. The biscuits manufactured from the fermented starch of english potato didnt expand and was very hard and the biscuits manufactured from the fermented starch of arrowroot and of baroa-potato were approved by the consumers and can be used in the biscuit manufacturing the same way as the fermented cassava starch.
TL;DR: In this paper, the mechanical and optical properties of nile tilapia myofibrillar proteins-based biofilms, as a function of filmogenic solution (fs) [composition: ph (2 to 3), protein (cp = 0.5 to 2.0g/100g solution) and glycerol concentration (cg = 30 to 70g /100g protein)]. Force and percentage deformation at break were determined by a puncture test and the apparent opacity by spectrophotometry, at 22oc and ambient relative humidity.
Abstract: During the last couple of years, biopolymers such as polysaccharides and proteins have been arousing scientists interest as raw materials for biodegradable and/or edible packaging. Packaging materials to be developed should have good mechanical and visual properties, to protect and to offer the packed product a presentable look. This work was aimed at characterization of the mechanical and optical properties of nile tilapia myofibrillar proteins-based biofilms, as a function of filmogenic solution (fs) [composition: ph (2 to 3), protein (cp = 0.5 to 2.0g/100g solution) and glycerol concentration (cg = 30 to 70g/100g protein)]. Force and percentage deformation at break were determined by a puncture test and the apparent opacity by spectrophotometry, at 22oc and ambient relative humidity. Easy handling and transparent biofilms were obtained in these conditions. Force and percentage deformation at break presented opposite behaviors as a function of cg (ph = 2.5 and cp = 1.25g/100g solution): increasing it from 30 to 70% and causing a variation in force and percentage deformation at break between 6.67n and 2.94n and 2.71% and 7.5%, respectively. Glycerol concentration and ph had significant effect over force at break (p <0.05). None of the studied factors showed any significant influence on the percentage deformation of biofilms at break, neither on their apparent opacity.
TL;DR: In this paper, a cassava starch film was applied to red peppers (Capsicum annuum L), with the purpose to observe its efficiency as a barrier to water loss as well as its influence in physical and chemical properties.
Abstract: One idea under studies is the application of edible films, derived from cassava starch. Red peppers (Capsicum annuum L.), received a starch film, with the purpose to observe its efficiency as a barrier to water loss as well as its influence in physical and chemical properties. The fruits were dipped for one minute in 1, 3 to 5% starch suspensions, dried naturally in air and then stored in environmental condiditions, where the average temperature and relative humidity for the period varied respectively of 26,0-29,0°C e 59,5-71,5%. The experiment was carried out in a completely randomized statistical design and factorial outline with 16 treatments, 3 replications and 2 fruits per parcel. The observations (to evaluate weight loss, texture, pH and total soluble solids) were made every three days on a 12 day period. It was observed that the texture of the fruits immersed in the 3 to 5% starch suspension was significantly different when compared to the control and of the fruits immersed in the 1%. The treatments didnt influence significantly in the weight loss, pH and total soluble solids.
TL;DR: The farinha teste as mentioned in this paper has been used in the preparation of dietas semi-sinteticas for ratos, e has been shown to be useful in reducing the number of defecações.
Abstract: As industrias brasileiras de processamento de fecula produzem, como descarte, grandes quantidades de bagaco ou farelo de mandioca que e jogado fora, poluindo o meio ambiente, ou e utilizado na alimentacao de animais. A proposta desta pesquisa consiste na utilizacao do bagaco, descarte da fecularia, como produto para consumo na alimentacao humana. Foi preparado, a partir do bagaco coletado na fecularia um produto farinaceo identificado como "farinha de mandioca teste", a qual apresentou, em comparacao com as farinhas comerciais, alta quantidade (43,1%) de fibra alimentar e baixa quantidade (47,1%) de amido. Os teores de proteina, lipideo e cinzas foram semelhantes ao das farinhas comerciais. A "farinha teste" foi usada no preparo de dietas semi-sinteticas para ratos em crescimento nas concentracoes de 11,6 , 34,8 e 58,0%; farinhas adquiridas no comercio foram usadas como referencia. A frequencia de defecacoes, o peso das fezes umidas e secas e o volume das fezes secas foram maiores para os grupos supridos com dietas contendo a "farinha teste", em comparacao com os grupos que receberam a farinha do comercio, mas, com relacao aos valores dos quocientes de eficiencia alimentar (QEA) e proteica (PERop) nao houve diferenca significativa entre as duas farinhas. Uma reducao no ganho de peso corporeo dos animais, resultante de diminuicao da ingestao de alimento, foi observado para os tratamentos contendo a farinha teste. Tais resultados permitiram concluir que a "farinha de mandioca teste" apresentou propriedades fisiologicas, em nivel intestinal, caracteristicas da fibra alimentar insoluvel e, em vista disso, constitui-se numa fonte potencial de fibra para a alimentacao humana. O bagaco de mandioca produzido como descarte nas fecularias podera ser aproveitado como materia-prima para a producao de uma farinha de mandioca rica em fibra alimentar insoluvel, caracteristica distinta das farinhas de mandioca existentes no comercio.
TL;DR: In this article, the effect of feeding regime on volatile aldehyde evolution in Biceps femoris muscle during the ripening of Iberian ham was studied, and α-tocopheryl acetate supplementation and feeding on acorn and pasture significantly decreased the total and individual aldehydes.
Abstract: The effect of feeding regime—free—range reared on acorn and pasture, or in confinement with and without the incorporation of 100 mg/kg α-tocopheryl acetate to pig mixed feeds—on volatile alde hyde content in Biceps femoris muscle throughout the ripening of Iberian ham was studied. Saturated aldehydes from 4 to 10 carbon chain and two diunsaturated aldehydes, 2,4-nonadienal and 2,4- decadienal, were found in ham samples. Volatile aldehyde evolution was not affected by feeding regime throughout ripening of hams. Volatile aldehyde content and individual aldehydes rose mark edly from Day 0 to Day 210 (p < 0.05), and afterwards decreased to Day 700 (p < 0.05). Both α- tocopheryl acetate supplementation and feeding on acorn and pasture significantly decreased the total and individual aldehydes in Biceps femoris samples at Days 0, 210 and 700 (p < 0.05) in compari son with muscle samples from pigs fed the non-supplemented diet.
TL;DR: In this paper, a trabalho tem como objetivo avaliar os teores de fibra alimentar soluvel, insoluvel e total e of beta-glicanas of cultivares de aveia recomendados pela Comissão Brasileira de Pesquisa de Aveia.
Abstract: A fibra alimentar e composta por celulose, hemiceluloses, gomas, pectinas e mucilagens sendo classificada em soluvel e insoluvel, quanto a sua solubilidade em agua. As beta-glicanas sao componentes da fibra alimentar soluvel presentes na aveia e sua importância e devido as propriedades funcionais e aos efeitos hipocolesterolemicos e hipoglicemicos apresentados. O presente trabalho tem como objetivo avaliar os teores de fibra alimentar soluvel, insoluvel e total e de beta-glicanas de cultivares de aveia recomendados pela Comissao Brasileira de Pesquisa de Aveia. Graos de aveia (Avena sativa, L) foram descascados, as cariopses moidas e as amostras acondicionadas e armazenadas a temperatura de -20° C. Para a analise de fibra alimentar foi adotada a metodologia da AOAC (1997). Entre os cultivares analisados, UPF 7, UPF 13, UPF 14 e UPF 16 apresentaram os maiores teores de fibra alimentar insoluvel. Os maiores teores de fibra alimentar soluvel foram verificados nos cultivares UFRGS 7, CTC 13, UPF 16 e CTC 2. O cultivar UPF 16 apresentou o maior teor de fibra alimentar total, seguido de UFRGS 7, CTC 13 e UFRGS 18. Para a determinacao de beta-glicanas foi adotada a metodologia da AOAC (1997). Os maiores teores de beta-glicanas foram verificados nos cultivares UFRGS 7, UPF 14 e UFRGS 18.
TL;DR: In this article, a trabalho on quantitativos sobre as classes of lipidios presentes no file de curimata, Prochilodus cearensis, is presented.
Abstract: O presente trabalho teve como objetivo obter dados quantitativos sobre as classes de lipidios presentes no file de curimata, Prochilodus cearensis. Os lipidios totais (LT) foram fracionados em classes de lipidios neutros (LN), gliceroglicolipidios (GL) e glicerofosfolipidios (PL) atraves de cromatografia em coluna aberta de silica gel 60 (70-230 mesh). As analises foram realizadas em quatro lotes de amostras contendo cada uma tres exemplares, adquiridos em feiras livres de Fortaleza-CE, nos meses de marco, maio, junho e julho de 1998. Os LT representaram em media 3,8% em relacao ao peso fresco da amostra. A classe lipidica dominante foi de LN com media de 75,1% dos LT ou 2,9g/100g de file. Os GL e PL contribuiram em media com 1,6% (61mg/100g de file) e 23,3% (885mg/100g de file), respectivamente. A composicao quimica centesimal apresentou media de 76,3% de umidade, 18,6% de proteina total e 1,3% de cinza.
TL;DR: In this article, the performance of mesquite gum and maltodextrin mixtures in the preparation of encapsulated orange peel oil was evaluated using an emulsifier for mulate.
Abstract: The performance of mesquite gum and maltodextrin mixtures in the preparation of encapsulated orange peel oil was evaluated. Emulsions of orange peel oil were prepared using an emulsifier for mulate...
TL;DR: In this paper, a high performance liquid chromatography (HPLC) analysis of commercial sour cassava starch collected in South and Southeast Brazil was conducted for high performance analytical analysis with a Biorad Aminex HPX-87H column.
Abstract: Organic acids are present in sour cassava starch ("polvilho azedo") and contribute with organoleptic and physical characteristics like aroma, flavor and the exclusive baking property, that differentiate this product from the native cassava starch. Samples of commercial sour cassava starch collected in South and Southeast Brazil were prepared for high performance liquid chromatography (HPLC) analysis. The HPLC equipment had a Biorad Aminex HPX-87H column for organic acid analysis and a refractometric detector. Analysis was carried out with 0.005M sulfuric acid as mobile phase, 0.6ml/min flow rate and column temperature of 60° C. The acids quantified were lactic (0.036 to 0.813 g/100g), acetic (0 to 0.068 g/100g), propionic (0 to 0.013 g/100g) and butyric (0 to 0.057 g/100g), that are produced during the natural fermentation of cassava starch. Results showed large variation among samples, even within the same region. Some samples exhibited high acid levels, mainly lactic acid, but in these neither propionic nor butyric acids were detected. Absence of butyric acid was not expected because this is an important component of the sour cassava starch aroma, and the lack of this acid may suggest that such samples were produced without the natural fermentation step.
TL;DR: The present knowledge on the nature of the taste stimuli, on the mechanisms of their perception and on the interactions among them is reviewed, and the effects of interactions with other sensory attributes (aroma, color, texture) are reviewed.
Abstract: Flavor is perceived through two human senses simultaneously: the sense of taste, operating in the mouth, mainly in the tongue, and the sense of smell in the nostrils, where aromas are detected. The stimuli responsible for aroma perception are volatile compounds; their nature and properties as well as the mechanisms of perception have been widely studied. This is not the case for the taste stimuli, consisting of non-volatile compounds responsible for the accepted four basic taste sensations: sweet, sour, salty and bitter. The available information on taste perception is almost exclusively dedicated to sweet taste for obvious economic and nutritional reasons. In this paper, the present knowledge on the nature of the taste stimuli, on the mechanisms of their perception and on the interactions among them is reviewed. The effects of interactions with other sensory attributes (aroma, color, texture) are also reviewed. Interactions may be due to different causes: physical and chemical interactions among food com...
TL;DR: In this article, the development of deterioration in fat and oils used in frying process in restaurants, bars and snack bars of Sao Jose do Rio Preto-SP, Brazil was investigated.
Abstract: Deep-frying is chosen for being a rapid food preparation process and for attributing to the fried products unique characteristics of flavor. At the frying temperature oil interacts with air, water and components of the food which is being fried, producing compounds that are responsible for off-flavor development and deterioration in abused oils. The objective of this work was to determine the development of deterioration in fat and oils used in frying process in restaurants, bars and snack bars of Sao Jose do Rio Preto-SP. The analytical methods used to evaluate the alterations in 60 oil samples included determining the total polar compounds in frying oils (%), free fatty acids (%, expressed in terms of oleic acid) and value peroxide (meq/kg). The established limits for alteration in frying fats were 25% for polar compounds, 1% for free fatty acids and 15 meq/kg for value peroxide. According to the results obtained, it could be observed that, from the 60 analyzed samples, 30% showed higher values of polar compounds than the established limit for discarding frying oil and fat. For the free fatty acids and value peroxide, 18.3% and 8.3% of the samples respectively, showed higher values than the established limit for discarding. The high levels of total polar compounds found (57.4%) in a significant number of samples proved the necessity of making the quality of frying fat and oil better in this field of food.
TL;DR: In this article, the factors responsible for the orange juice stability and their changes in quality are discussed, and a review of the factors that contribute to the stability of orange juice can be found.
Abstract: Fruit juices are complex foods so that their shelflife is limited by factors like microbiological spoilage, enzymatic action and chemical reactions, that compromise their characteristics of color, taste, odor and also loss of nutritional value. In this review the factors responsible for the orange juice stability and their changes in quality are discussed.
TL;DR: Avaliaram-se algumas propriedades funcionais de concentrados proteicos de feijao comum, variedade Carioca, envelhecido.
Abstract: Avaliaram-se algumas propriedades funcionais de concentrados proteicos de feijao comum, variedade Carioca, envelhecido. Para acelerar o envelhecimento do feijao, armazenaram-se os graos em estufa a 41oC por 20, 30 e 40 dias, tomando-se o tempo zero (feijao novo) como controle. Medidas do tempo de cozimento demonstraram que o armazenamento provocou o endurecimento dos graos. Com o aumento do tempo de armazenamento dos graos houve uma diminuicao no conteudo de proteinas nos concentrados proteicos obtidos por extracao alcalina e posterior precipitacao isoeletrica. As propriedades emulsificantes, espumantes, de absorcao de agua, de absorcao de oleo e solubilidade das proteinas em funcao do pH foram avaliadas nos concentrados proteicos obtidos de graos de feijao envelhecidos nos diferentes tempos de armazenamento e na amostra controle. O envelhecimento do feijao provocou uma melhora nessas propriedades. A solubilidade das proteinas dos concentrados em funcao do pH foi menor no intervalo de 4 a 5.
TL;DR: In this article, the stable carbon isotope composition of honey was used to detect addition of commercial sugar cane and corn sugars to detect adulteration of honey, and the results showed that approximately 8% (5 samples) of the 61 samples analyzed had d13C values that clearly indicated the added commercial sugars.
Abstract: Honey is a known product for its nutritional value. Considering that offer is smaller than the market demand, honey is relatively expensive. This fact contribute to the incentive of its adulteration by commercial sugars derived from sugar cane and corn. As these plants have a distinct stable carbon isotope composition than plants commonly used by bees as sources of nectar, it is possible to use the stable carbon isotope composition of honey to detect addition of commercial sugar cane and corn sugars. In this study we analyzed samples of C3 plants commonly used by bees, subproducts of C4 plants, and 61 samples of honey. The d13C of C3 plants values had on average of -28.9±1.1 (n=8), while the commercial sugars had an average value of -11.1±0.7 (n=3). Approximately 8% (5 samples) of the 61 samples analyzed had d13C values that clearly indicated the addition of commercial sugars (adulteration). The sample number 5 had a d13C valor equal to -12.9, indicating that it was all made of commercial sugars. The samples numbers 13, 14, 33, and 54 had values equal to -21.0, -19.9, -21.9 and -17.6, respectively. These values also indicated the addition of commercial sugars. The methodology used in this study proved to be a valuable and simple complement to the conventional chemical and physical methods normally used to detect honey adulteration.
TL;DR: The microbial and color changes during storage at different temperatures (15, 25 and 35 °C) of ba nana puree preserved by the combination of a blanching, reduced pH (3.4) and water activity (aw, 0.
Abstract: The microbial and color changes during storage at different temperatures (15, 25 and 35 °C) of ba nana puree preserved by the combination of a blanching, reduced pH (3.4) and water activity (aw, 0....
TL;DR: In this paper, the quality of processed milk is reviewed in three sections: indices of heat treatment, detection of adulterations and assessment of shelf life, which can be achieved by measuring either the formation of new compounds (lactulose, furosine) or degradation of thermolabile constituents (enzymes, whey proteins).
Abstract: Selected indicators of the quality of processed milk are reviewed in three sections: indices of heat treatment, detection of adulterations and assessment of shelf life. The characterization of the thermal process to which milk was submitted can be achieved by measuring either the formation of new compounds (lactulose, furosine) or the degradation of thermolabile constituents (enzymes, whey proteins). The presence of certain compounds may indicate fraudulent additions committed for eco nomic reasons. Finally, residual or reactivated heat stable enzymes may cause serious storage defects in UHT milk and, therefore, the proteolytic and lipolytic activities and the degree of protein and lipid degradation are useful predictors of the shelf life. Different analytical methods for the determination of the selected quality indicators are also summarized.
TL;DR: A review of the literature on the markers used to evaluate the modi fications that milk undergoes during thermal treatment and subsequent storage was carried out, focusing mainly on... as discussed by the authors.
Abstract: The nutritional value of milk can be negatively affected by thermal treatments. The quality of the proteins can be modified as a consequence of a set of reactions, the most important of which are the interactions between protein and carbohydrates, also known as Maillard reactions. These reactions can also occur when the storage conditions of moisture and temperature are unfavorable. The differ ent thermal treatments involved in processing milk (pasteurization, sterilization, drying, etc.) lead to different steps of the Maillard reaction and therefore to the formation of different compounds that can be useful as chemical markers of milk alteration, or more exactly of protein alteration. Estimating these markers is useful in monitoring the changes, especially those related to proteins, that happen during processing and storage. A review of the literature on the markers used to evaluate the modi fications that milk undergoes during thermal treatment and subsequent storage was carried out, focusing mainly on ...
TL;DR: The substantial enzymic inhibition at acidic pH by the inhibitor trans-epoxysuccinyl-L-leucylamine-4-guanidine butane (E-64) revealed the pre dominance of lysosomal cysteine proteases (cathepsins) which showed higher activity at 65 °C than at 40 °C.
Abstract: La actividad proteolitica del musculo de pota (Todaropsis eblanae) fue maxima a 40 y 65o C. En todo el intervalo de pH (1,5-9,5) estudiado se observaron diversos picos de actividad proteolitica segun la presencia de proteasas activas a pH acido, neutro y alcalino, y de la temperatura. La gran inhibicion ejercida a pH acido del inhibidor trans-epoxisuccinil-L leucin, amino-4-guanidin, butano (E-64) revelo la predominancia de cistein proteasas lisosomales (catepsinas) cuyo maximo de actividad se dio a 65o C. A 65oC y a pH 5.5 se detecto tambien la actividad de metaloproteasas mediante la inhibicion ejercida por la fenantrolina. A pH neutro predomino la actividad de serin proteasas que ademas fue mayor a 40o C que a 65o C. A pH alcalino se detecto actividad de cistein proteasas. Se observo actividad de las catepsinas B y L a 65o C y en menor grado a 40o C.
TL;DR: This work aimed at determining the occurrence of heat resistant molds during the aseptic processing of tomato pulp (8° BRIX) and identified the most heat resistant isolated strain, Neosartorya fischeri.
Abstract: This work aimed at determining the occurrence of heat resistant molds during the aseptic processing of tomato pulp (8° BRIX). During tomato harvest, 9 lots were sampled (3 at the beginning, 3 at the apex and 3 at the end of harvest) and other 5 lots were sampled between harvest. For each lot, the enumeration of heat resistant molds was carried out in samples collected during the aseptic process. The mean count of heat resistant molds was relatively low, ranging from <1 to 8CFU/100mL of sample. The higher counts were observed in the raw material and the pre-wash and transportation water. Fifty strains of heat resistant molds detected in the enumeration procedure were isolated, codified and stocked. One-month-old spores of each isolate were submitted to different heat shocks to select the most heat resistant mold. The most heat resistant isolated strain (survived 100° C/25 minutes) was identified as Neosartorya fischeri.
TL;DR: Food irradiation is one of the most promising treatments that can be utilized for fruits desinfestation and extension of shelf life and the results demonstred that ethylene production, total soluble sugars, sucrose content, and sucrose-phosphate synthase and invertases activities were affected by irradiation, but not respiration, glucose and fructosecontent, and SS activity.
Abstract: A irradiacao de alimentos e um tratamento pos-colheita bastante promissor, capaz de atuar tanto na desinfestacao como no aumento da vida util de frutos. O mamao e um fruto com curta vida pos-colheita, levando de 6 a 12 dias para atingir a senescencia. Alem disto, a infestacao por larvas de mosca diminui sensivelmente o seu potencial de exportacao. O objetivo deste trabalho foi verificar a acao de uma dose de 0,5 kGy de irradiacao gama, normalmente utilizada para desinfestacao e aumento de vida util dos frutos, sobre o comportamento dos carboidratos soluveis durante o amadurecimento do mamao (Carica papaya L. cv. Solo), e sobre as enzimas relacionadas ao metabolismo da sacarose: sacarose sintase (SS), sacarose-fosfato sintase (SPS) e invertases acida e neutra. Os resultados demonstraram que a irradiacao nao exerce efeito sobre o teor de glicose e frutose, ou sobre a respiracao e atividade da SS. Entretanto, a composicao dos acucares soluveis totais e da sacarose, e a atividade da SPS e das invertases foram afetados.