Dulce de Leche—Chemistry and Processing Technology

Originally hailing from Latin America, dulce de leche (DL) is one of the most widely manufactured dairy products in South America, where it is marketed as a paste or bar. Due to DL’s low moisture content, the product can be safely stored at room temperature, which facilitates storage and transportation logistics. The primary ingredients used to manufacture DL are milk, sucrose, and an acidity reducer. Needless to say, the raw materials must be of good quality from reliable suppliers in order for the final product to have the desired characteristics. The milk used to make DL must be microbiologically safe, remain stable during thermal processing, and preferably exhibit a high solid content. Dulce de leche is defined as a product made with or without the addition of other food substances that is obtained from milk or reconstituted milk and added sucrose (either partially substituted or not by monosaccharides and/or other disaccharides) via concentration and heat action at normal or reduced pressure. This chapter aims to explore the chemistry, processing technology, and most common industrial practices for manufacturing DL in South America

Influência do equipamento na cinética de cristalização do soro concentrado

O principal objetivo deste trabalho consistiu na determinação do efeito do tipo de cristalizador na eficiência da cristalização da lactose em soro de leite concentrado, utilizando dois equipamentos que dispõem de diferentes formas de agitação (tanque 1 – agitador central e tanque 2 – agitador periférico), mantendo as demais condições de cristalização constantes, como: taxa de resfriamento; temperatura; velocidade de agitação; tempo de cristalização e teor se sólidos solúveis por tratamento. A maior taxa de cristalização no soro concentrado foi obtida pelo emprego da agitação central [Tempo (min) = 0,1927 (% cristalização da lactose) + 21,681] e [Tempo (min) = -0,06 (oBrix) + 51,233] sob a taxa de resfriamento de -0,34 oC ± 0,05 oC por minuto, durante a primeira hora e alcançando a temperatura de 25,8o ± 1,2 oC após 4 horas. A agitação central promoveu as maiores taxas de cristalização em soro concentrado com 50 oBrix, 55 oBrix e 60 oBrix. Observou-se que mudanças nas condições de cristalização do soro concentrado (em diferentes tanques) e no teor de sólidos solú­veis implicam na obtenção de pós com diferentes propriedades de reidratação, de adesão e com teores distintos de lactose cristalizada, impactando na conservação durante o prazo de validade.The main objectives of this project were to determine the effect of the crystallizer design on lactose crystallization efficiency in concentrated whey. Two different crystallizers were used, one presenting a central agitation (tank 1) and the other presenting a peripheral agitation (tank 2). All others crystallization parameters were kept constant such as cooling rate; temperature; stirring speed; crystallization time and concentration of soluble solids by treatment.The best rate for lactose crystallization in concentrated whey was obtained applying central stirring and 55 oBrix [Time (min) = 0.1927 (% lactose crystallization) + 21.681] and [Time (min)= -0.06 (oBrix) + 51.233] under the cooling rate of -0.34 oC ± 0.05 oC per minute during the first hour and achieving the final temperature of 25.8o ± 1.2 oC after 4 hours, central stirring promoted highest rates of lactose crystallization in concentrated whey with 50, 55 and 60 oBrix.The type of Tank for crystallization and the dry matter content in concentrated whey affect whey powder rehydration, stickiness into the chamber, different levels of lactose crystallization and storage of the powder

Lactose-free dairy products: Challenges in the processing and quantification of lactose

Lactose is the main sugar in milk, being hydrolyzed in glucose and galactose through the action of the enzyme lactase. Some individuals are deficient of this enzyme, therefore, they are intolerant to lactose. In order to attend the special needs of these consumers, the free lactose product market has been growing over the years. However, there are still a number of industrial limitations on the manufacture of these products. The manufacture of lactose-free powdered milk is a challenge for industry, due to the occurrence of problems such as adhesion to the equipment, generating low industrial yield. The most sensitive and effective methods for quantifying lactose are high cost, making it unfeasible to the industrial reality. Other techniques are time consuming and cannot distinguish carbohydrates individually. The thermal processes applied to these foods cause sensorial and nutritional damages, because the monosaccharide units of lactose are more reactive to the reaction of non-enzymatic browning. Furthermore, these products are more prone to proteolytic activity. It is necessary to optimize the manufacturing processes, aiming at reducing time and operating costs, as well as obtaining quality and safe products to the consumer

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Obtaining Petit Suisse with low amount of lactose and reduced addition of sugars

Considering the actual marketing tendencies and the Brazilian’s governmental guidelines on reduction of sugar levels in industrial products, it is necessary to adapt the traditional technologies for others which allow products modification according to the new reality without, however, losing quality. The development of this work aimed to comply with the consumers who are looking for products with low levels of lactose, as consequence of the increase of intolerant people. Together with the reduction of lactose, it was also expected to reduce the amount of added sugar. The results showed that the proposed reduction of 20% in added sugar was not supplanted by lactose hydrolysis and the products were considered different. The products also showed statistically different values for total solids, reducing sugars, non reducing sugars and acidity. Despite the differences, the results indicate that this is a product with potential and that it is possible to achieve a product closer to the original with small changes on the obtaining technology

Evaluation of Maillard reaction intensity, physical-chemistry attributes and texture analysis in "dulce de leche"

The Dulce de Leche, a product which is marketed and produced in Latin America, is much appreciated by consumers, with great importance for the Brazilian market. The standardization of the characteristics of this product as well as the suitability for recommendations of the Technical Identity and Quality Regulation becomes difficult due to the large cultural diversity and technological changes. In this context, the study of physical-chemical and rheological characteristics the Dulce de Leche becomes of great importance to achieve such uniformity, mainly by the lack of technical and scientific literature about this product. This work aimed to evaluate and relate the physical-chemical and texture attributes. Twelve Dulce de Leche brands were analyzed to moisture, water activity and texture analysis with statistical analysis of the data. Descriptive statistical analysis for texture attributes showed high variability between samples. As for the moisture content, 51.11% of the samples were outside the statutory standards. The analysis had results of free HMF and elevated totals. Through the Principal Component Analysis (PCA) it was found that the main source of variation and contribution to group of the appraised brands is related to the elements that make up the rheological characteristics of the product. The results showed high correlation between water activity, moisture and rheological attributes. The combination of physical, chemical and rheological attributes were shown to be useful for characterization and evaluation of Dulce de Leche quality. These results expand scientific knowledge about Dulce de leche favoring the dairy industry and the scientific community.Produzido e comercializado na América Latina, o doce de leite é muito apreciado por seus consumidores, com grande importância para o mercado brasileiro. A padronização das características desse produto, assim como sua adequação ao que é preconizado pelo Regulamento Técnico de Identidade e Qualidade, é dificultada pela grande diversidade cultural e variações tecnológicas da sua produção. Por essa razão, o estudo das características físico-químicas e reológicas do doce de leite torna-se de grande importância para se alcançar uniformidade, principalmente pela escassez de literatura técnica e científica sobre este produto. Neste trabalho, objetivou-se avaliar e relacionar os atributos físico-químicos e de textura. Foram analisadas doze marcas de doce de leite quanto aos teores de umidade, atividade de água e análise de textura, com posterior análise estatística dos dados. A análise estatística descritiva para os atributos de textura mostrou elevada variação entre as amostras. Quanto ao teor de umidade, 51,11% das amostras tiveram resultados em desacordo com os padrões legais vigentes. As análises realizadas apresentaram resultados de HMF livre e total elevados. Pela Análise de Componentes Principais (PCA), verificou-se que a principal fonte de variação e de contribuição para agrupamento das marcas avaliadas está relacionada com os elementos que compõem as características reológicas do produto. Os resultados mostraram elevada correlação entre atividade de água, umidade e atributos reológicos. A combinação dos atributos físico-químicos e reológicos mostra-se útil para caracterização e avaliação da qualidade do doce de leite. Os resultados obtidos neste trabalho contribuem para ampliar os conhecimentos científicos e podem servir de subsídios para as indústrias de laticínios e a comunidade

Fermentation of Petit Suisse obtained with whey retention, lactase addition and less amount of added sugars versus traditional formulation

Current market trends indicate lactose free or low lactose products. In addition, economic and ecological issues lead to the adaptation of traditional technologies to other ones that allow process modification to meet the new reality without losing quality. However, the development of new technologies demands studies to optimize them in order to meet industries and consumers necessities. The present work aimed to evaluate the impacts of the use of lactase and the reduction of sugar addition in the fermentation of Petit Suisse made with the method of whey retention.The applying of lactase during Petit Suisse production allows the reduction in fermentation time in two hours according to the experimental protocol of the experiment. The fermentation profile differs among treatments and mathematical relations between pH and time were established

Food innovation in Brazil from the point of view of industries: an evaluation of PINTEC data

Data published in 2016 PINTEC (Innovation Survey), conducted by the Brazilian Institute of Geography and Statistics for the 2012-2014 triennium with 13,846 food companies, showed that only 45% innovated in products and/or processes. Acquisition of machinery / equipment was considered the most important innovative activity followed by personnel training. The products quality improvement and the productive capacity increase were the greater impacts observed. Only 9% of companies claim to spent on R&D activities. The high cost of innovation, the lack of appropriate funding and the excessive economic risks were the main problems pointed out by companies, followed by qualified personnel lack

Whey: concentration, lactose crystallization and drying

O objetivo deste estudo foi determinar atributos de processamento para a concentração, a cristalização da lactose e a secagem de soro integral em escala semi-industrial. O soro em pó integral empregado neste estudo foi concentrado à vácuo em evaporador a placas de único efeito e a secagem foi realizada em spray dryer de único estágio. Relacionadas ao estudo em escala semi-industrial foram realizadas a cristalização da lactose em soro concentrado e a produção de leites e soros em pó em escala laboratorial. A refratômetria foi empregada para determinar a cinética de cristalização da lactose em soro integral concentrado submetido à nucleação primária e à nucleação secundária pela adição de sementes de lactose. A extensão da cristalização e a taxa global de cristalização foram determinadas. As isotermas de sorção de água foram obtidas via gravimetria para o soro desnatado, soro integral, leite desnatado e o leite integral em pó. Foram determinadas as relações matemáticas entre a concentração de lactose no soro integral concentrado e a taxa de cristalização. O processo de nucleação secundária pela adição de sementes de lactose levou a uma cristalização de lactose superior a 70 %. A produção de leite e de soro em pó em escala laboratorial demonstrou que o aumento da porcentagem de soro em misturas de leite e de soro, antes da secagem, produz pós com baixa estabilidade ao armazenamento. As variáveis tecnológicas para a concentração a vácuo do soro, cristalização da lactose e secagem obtidas neste estudo possibilitaram a produção de soro em pó integral com alta estabilidade ao armazenamento. Estes atributos são necessários para otimizar a produção industrial de soro em pó integral.The objective of this study was to develop the attributes of concentration, crystallization of lactose and spray drying of whole whey in semi industrial scale. The whole whey powder used in this study was concentrated by single stage vacuum plate evaporator and the spray drying was performed at a single stage spray-dryer. In addition to the semi industrial study were evaluated the lactose crystallization in concentrated whey and the milk and whey powders productions in laboratory scale. Refractometry was used to follow the kinetics of lactose crystallization in concentrated whole whey submitted to primary nucleation and to secondary nucleation by lactose addition. The extent of crystallization and the overall crystallization rate were then deduced. Water vapor sorption wasmeasured gravimetrically for skim whey, whole whey, skim milk and whole milk powders. Were determined the mathematical relations between lactose concentration in concentrated whole wheyand the rate of lactose crystallization. The secondary nucleation process by lactose addition permitted more than 70 % of lactose crystallization. In laboratory scale production of milk and whey powders showed that increasing whey percentage in the mixture of milk and whey before drying led to powders with worst storage stability. The technological parameters for vacuum concentration, lactose crystallization and spray drying applied in this study enabled whole whey powder production with good storage stability. These parameters can assist the industrial production of whole whey powders

OSMOSE REVERSA NA PRODUÇÃO DE LEITE CONDENSADO: UMA POSSIBILIDADE TECNOLÓGICA

O objetivo deste trabalho é apresentar uma revisão sobre as tecnologias de produção do leite condensado e de concentração do leite por membranas de osmose reversa. Diferentes aspectos destas tecnologias foram apresentados: mercado de leite condensado, proteínas lácteas, concentração do leite, regulamentações sobre leite condensado, adição de açúcar, filtração por membranas e osmose reversa. Estas duas tecnologias podem ser acopladas objetivando a redução dos gastos com a evaporação durante a produção do leite condensado