Leila Maria Spadoti

Development and shelf-life determination of pasteurized, microfiltered, lactose hydrolyzed skim milk

The segment of the world population showing permanent or temporary lactose intolerance is quite significant. Because milk is a widely consumed food with an high nutritional value, technological alternatives have been sought to overcome this dilemma. Microfiltration combined with pasteurization can not only extend the shelf life of milk but can also maintain the sensory, functional, and nutritional properties of the product. This studied developed a pasteurized, microfiltered, lactose hydrolyzed (delactosed) skim milk (PMLHSM). Hydrolysis was performed using β-galactosidase at a concentration of 0.4mL/L and incubation for approximately 21h at 10±1°C. During these procedures, the degree of hydrolysis obtained (>90%) was accompanied by evaluation of freezing point depression, and the remaining quantity of lactose was confirmed by HPLC. Milk was processed using a microfiltration pilot unit equipped with uniform transmembrane pressure (UTP) ceramic membranes with a mean pore size of 1.4 μm and UTP of 60 kPa. The product was submitted to physicochemical, microbiological, and sensory evaluations, and its shelf life was estimated. Microfiltration reduced the aerobic mesophilic count by more than 4 log cycles. We were able to produce high-quality PMLHSM with a shelf life of 21 to 27d when stored at 5±1°C in terms of sensory analysis and proteolysis index and a shelf life of 50d in regard to total aerobic mesophile count and titratable acidity.

Avaliação da proteólise e do derretimento do queijo prato obtido por ultrafiltração

Prato cheese is the second most consumed cheese in Brazil. Milk ultrafiltration (UF) is one of the processing alternatives for cheese manufacture which is receiving increased interest of the dairy sector, however, a lower rate of maturation in semi-hard cheeses made by UF has been reported. On this study were realized three processing experiments with three treatments each, respectively: with non concentrated milk (Trat. 1) and with milk concentrated by UF up to volumetric concentration ratios (RCV) of 2.5:1 and 3.7:1 (Trat. 2 and Trat. 3, respectively). The cheeses were manufactured by the traditional process with enzymatic coagulation (calf rennet Bela Vista® - 90% quimosin) forty minutes/35oC), cut size one, partial remotion of 20% of whey and direct cooking by addition of water at 80oC, molding, pressing and ripening at 7oC. The three treatmens were compared among them with respect to composition, melting and proteolysis. With respect to composition, cheeses made by UF presented larger acidity, moisture and total protein and lower fat content. It was observed on treatment 3 a larger melting capacity and more intense proteolysis, as also their increase with respect to time.

Avaliação sensorial de queijo prato obtido por modificações do processo tradicional de fabricação

Os efeitos de cinco diferentes metodologias para processamento de queijo prato foram avaliados sensorialmente. foram estudados os seguintes tratamentos (T) de elaboracao de queijos: T1 - (padrao) sem o uso de leite concentrado por ultrafiltracao (lCUf); T2 - com uso de lCUf sem pre-fermentacao; T3 - com uso de lCUf e pre-fermentacao de 10% do mesmo; T4 - com uso de lCUf e pre-fermentacao de 20% do mesmo e T5 - com uso de lCUf, pre-fermentacao de 20% do mesmo e o unico com aquecimento indireto da massa. Segundo o teste de Analise Descritiva Quantitativa, os tratamentos diferiram significativamente entre si com relacao a aparencia, sabor e textura. Os queijos T3, T4 e T5 apresentaram cor amarelada mais forte e maior uniformidade na aparencia e foram considerados os queijos mais duros. O queijo T1 foi considerado o mais acido e salgado. Os queijos T4 e T5 tiveram menor derretimento. no teste de aceitacao, os queijos apresentaram a seguinte ordem de preferencia: T3=T4=T5>T1>T2.

Efeito do fator de concentração do retentado na composição e proteólise de queijo minas frescal de baixo teor de gordura fabricado por ultrafiltração

The effect of milk concentration by ultrafiltration on the chemical composition and proteolysis of low fat Minas Frescal cheese during refrigerated storage was determined. Three batches of cheese were made in one day using milk concentrated by ultrafiltration at three different concentration factors (CF): 2:1, 3:1 and 4:1. Cheese making was replicated on a different day. Protein breakdown, as well as pH and titratable acidity changes, were monitored during cheese storage for 2, 10, 20 and 30 days. It was observed that pH decreased with time, while titratable acidity and protein breakdown increased. The different concentration factors tested did not significantly change cheese composition and proteolysis, which means that the inclusion of whey proteins did not inhibit rennet proteolytic activity as expected. This leads us to believe that potential advantages associated with the use of ultrafiltration retentates in cheesemaking were compensated by negative effects related to the high humidity level of low fat cheese made from ultrafiltration retentates. Consequently, the shelf-life of this typically Brazilian cheese was lower than that of cheese made by conventional procedures.

Uso de leite reconstituído na fabricação de queijo mussarela

Nowadays the Mozzarella cheese is the most produced in Brazil. However, due to the problem of the seasonal production of milk, in a certain period of the year, there is a shortage of the milk offer and than the cheese price rises. For this reason, the usage of reconstituted dry milk blended with fresh milk could be an alternative for the stabilization of the offer of the product in the market. In this experiment, Mozzarella cheeses were produced with fresh milk and with fresh milk added of 10% and 20% of reconstituted dry milk (obtained from medium-heat dry milk). The physico-chemical and slicing properties of the cheeses made with fresh milk and with fresh milk added of reconstituted milk (10% and 20%) were compared. The statistical analysis of data permited withdraw the following conclusions: the Mozzarella cheese may be produced by adding 10% of reconstituted milk to the fresh milk without affecting its physico-chemical characteristics nor the property of slicing; on the other hand, that one produced by addition of 20% of reconstituted milk to the fresh milk showed a poor property of slicing.

Ácido linoleico conjugado (CLA) - benefícios para saúde, sua presença e estabilidade em produtos lácteos

O Programa de Puericultura acompanha o crescimento e o desenvolvimento de criancas durante os primeiros anos de vida, estabelecendo condutas preventivas adequadas a idade da crianca, sendo fundamental na prevencao de doencas e no controle da mortalidade infantil. Este trabalho teve como objetivo avaliar o estado nutricional das criancas atendidas no Programa de Puericultura em uma Unidade de Saude do Municipio de Guarapuava-PR. Foram investigados 55 prontuarios de criancas inscritas no Programa para verificacao das variaveis de peso, altura, perimetro cefalico, numero de consultas realizadas, aleitamento materno exclusivo ate os seis meses de idade, alimentacao atual e uso de suplementacao. Os resultados mostraram que a maioria das criancas avaliadas estava eutroficas para os parâmetros nutricionais avaliados, sendo Peso/Idade (85,5%), Peso/Estatura (65,5%), Estatura/Idade (76,4%) e Indice de Massa Corporal/Idade (72,7%). A maioria das criancas fazia uso de suplementacao (67,3%), 38,2% de aleitamento materno complementar e 40% nao receberam leite materno de forma exclusiva ate os seis meses de idade. Destaca-se a importância do acompanhamento do crescimento e desenvolvimento como parte integral a saude da crianca em programas e acoes de promocao a saude e qualidade de vida.O comportamento alimentar dos adolescentes geralmente e vinculado ao consumo de alimentos com alto valor energetico e pobres em nutrientes, com omissao de refeicoes e tendencia as restricoes alimentares, contribuindo, dessa forma, para alteracoes no estado nutricional, o que pode desencadear futuras patologias como a anorexia e bulimia. O objetivo do presente trabalho foi avaliar o efeito da imagem corporal sobre o estado nutricional e comportamento alimentar de adolescentes do sexo feminino, com faixa etaria entre 14 e 17 anos (media de 15,41±1,11 anos), frequentadoras de um Centro Estadual de Educacao Profissional no municipio de Guarapuava-PR. Participaram do estudo 96 adolescentes, regularmente matriculados na Instituicao. Foram analisadas questoes relativas a percepcao da imagem corporal, comportamento alimentar e dados antropometricos. Apos a avaliacao dos resultados, observou-se uma media de altura de 1,62±0,06m, peso de 56,07±5,21kg e IMC de 21,41±2,24kg/m². A maioria das meninas apresentou IMC adequado (84,4%) e nao mostraram riscos para desenvolver transtornos alimentares (72,9%), sendo que a maioria demonstrou distorcao da imagem corporal (52,1%). Torna-se necessario maior atencao em relacao a alimentacao, pois a distorcao da imagem corporal pode levar a pratica de dietas restritivas e desenvolvimento de transtornos alimentares.O aumento da procura de produtos prontos para consumo e considerado uma tendencia atual, principalmente em grandes centros urbanos, refletindo na expansao de estabelecimentos como redes de “fast-food”, padarias, confeitarias e lanchonetes, e aumentado de forma direta a preocupacao pelos orgaos de vigilância na manutencao da qualidade higienico-sanitaria dos produtos comercializados. Este trabalho teve como objetivo avaliar a qualidade microbiologica de bolos cremosos comercializados no municipio de Curitiba-PR e analisar as condicoes higienico-sanitarias as quais os produtos foram expostos durante o processamento e armazenamento. Para a presente pesquisa foram coletadas 14 amostras diferentes de bolos cremosos. Avaliou-se a qualidade microbiologica de cada amostra seguindo recomendacoes contidas na RDC no12, de 02 de janeiro de 2001, ANVISA/MS. Neste estudo constatou-se o nao isolamento de Salmonella em nenhuma das amostras analisadas. Em 14,3% (n=2) das amostras o NMP de coliformes termotolerantes apresentou-se acima do padrao microbiologico vigente. Em 28,6% (n=4) das amostras, observou-se contagens de estafilococos coagulase-positiva acima do limite estabelecido, sendo que 02 amostras eram potencialmente capazes de causar intoxicacao alimentar. Observou-se a incidencia de 14,3% (n=2) de Listeria sp nas das amostras analisadas. O numero mais provavel de coliformes totais acima de 2,17 log/g foi quantificado em 05 amostras (35,7%). Os resultados mostram que ha necessidade de maior controle de qualidade desde a aquisicao da materia-prima ate ao produto acabado, atraves da adocao de Boas Praticas de Fabricacao e o Programa de Analise de Perigos e Pontos Criticos de Controle, de forma a garantir um produto saudavel e seguro para o consumidor.

Proteolysis of prato type cheese produced using ultrafiltration

The application of milk ultrafiltration technology for cheese manufacture presents several advantages. However, it also influences proteolysis and, consequently, cheese ripening. The effects of five different processing methods for Prato cheese were evaluated with respect to the time evolution of the extent and depth of proteolysis indexes (EPI and DPI). The following treatments (T) for cheese production were studied: T1 - without ultrafiltration (standard); T2, T3, T4 and T5 - using milk concentrated by ultrafiltration (UFCM) and respectively: T2 - without pre-fermentation of the UFCM; T3 - pre-fermentation of 10% of the UFCM; T4 - pre-fermentation of 20% of the UFCM, and T5 - pre-fermentation of 20% of the UFCM plus indirect heating. Treatments affected the EPI and DPI of the cheeses (T1 lower values for EPI and DPI and T4 higher values for EPI and DPI). The time influenced the extent and depth of proteolysis indexes.

Avaliação do rendimento do queijo tipo prato obtido por modificações no processo tradicional de fabricação

The objective of this research was to study the effect of the following modifications on the traditional manufacturing process of Prato cheese: use of milk concentrated by ultrafiltration (LCUF) up to a VCF=4:1; partial LCUF pre-fermentation; indirect curd cooking; on yield-(R), adjusted yield (RAJ) and fat (RGq) and protein (RPq) recovery on cheese, and comparison of the results with a standard cheese. Three processings with five treatments each were realized, respectively: treatment 1-(T1), without ultrafiltration; Treatment 2-(T2), ultrafiltration without LCUF pre-fermentation; Treatment 3-(T3), 10% LCUF pre-fermentation; Treatment 4-(T4), 20% LCUF pre-fermentation and direct curd heating; Treatment 5-(T5), 20% LCUF pre-fermentation and the only one indirect curd heating. It was realized composition, yield, and component recovery for all five treatments, and the results statistically evaluated. Treatments T2, T3, T4, and T5 presented lower values for R, RAJ and RGq, however, the pre-fermentation with indirect curd cooking presented a tendency of better values for RGq and RAJ. Lower yields and RGs possibly resulted from the fibrous structure presented by these curds as well as due to the difficulty on cutting and handling them.

EFEITO DOS SAIS FUNDENTES NAS CARACTERÍSTICAS DO REQUEIJÃO CREMOSO SEM ADIÇÃO DE GORDURA E COM TEOR REDUZIDO DE SÓDIO

Requeijao cremoso , a type of processed cheese widely consumed by the Brazilian population, may be considered a food source of fat and sodium, two nutrients the consumption of which - when present at high concentrations - may lead to the development of cardiovascular diseases. Considering the high and frequent consumption of this product in Brazil, it is highly important to develop alternative and healthier food products, such as a requeijao made without the addition of fat and with a reduced sodium content (NFARSR). For that reason, the objective of this study was to develop an optimized NFARSR formulation, by replacing fat by whey protein concentrate (WPC 34%) and reducing the sodium level by replacing 40% sodium chloride (NaCl) by potassium chloride (KCl) and part of the traditional emulsifying salt (Joha S9) - which contains 30.5% sodium - by an emulsifying salt with a sodium level of 8.2% (Joha SK75). The formulation was optimized using a factorial experimental design of the 22 type with two factors (Joha S9 and Joha SK75) and two levels (+1, -1), resulting in a total of 11 treatments. The 11 formulations were evaluated microbiologically and also as to physical-chemical, sensory and instrumental texture parameters using the response surface method. The NFARSR formulation with the best performance was R5, made with a blend of 1.0% JohaS9 and 1.2% Joha SK75.

Composição, proteólise, capacidade de derretimento e formação de "blisters" do queijo mussarela obtido pelos métodos tradicional e de ultrafiltração: composition, proteolysis, melting capacity and blisters formation

The objective of this research was to compare the composition, proteolysis, melting capacity and blisters formation in Mozzarella cheese manufactured with milk retentate (MR) of a volumetric concentration factor (FCV) of 2.34:1, with a standard Mozzarella cheese (MP) manufactured with non ultrafiltrated milk. It was realized one production assay with 3 batches of MRs and one of MP. It was evaluated the milk, retentate, whey, stretching water and cheeses composition and the proteolysis, melting capacity and the blisters formation on cheeses with 7, 15, 30 and 60 days of refrigerates storage. MRs presented larger pH, ash and total protein contents and lower titratable acidity and fat, fat on dry matter and salt contents when compared to MP. Along the storage time the MRs presented lower proteolysis and melting capacity in all the analyzed dates. The pizza area percentage covered by blisters and their average diameters were larger for the MP during the first storage month and thereafter both kinds of cheese presented similar behavior for these two parameters.