Impact of frozen temperature and thawing methods on the Brazilian sensory profile of Nellore beef

We evaluated the effect of frozen storage temperature and thawing methods on acceptance and sensory profile of steaks of Nellore beef strip loin under 30 days of frozen storage. Fresh strip loin (n = 13), collected two days after slaughter, were aged (2 °C) for 14 days and cut into seven steaks subjected to one of the treatments: control (unfrozen), combination of two freezing temperatures (-10 and -20 °C), and three thawing methods (microwave, ambient temperature, and refrigeration thawing). Steaks in the frozen/thawing treatment were frozen using an ultra-fast freezer until the desirable temperature was reached and were stored for 30 days. After cooking, steaks were analyzed by 11 panelists for the Quantitative Descriptive Analysis (QDA®) and by 120 beef consumers for acceptance. Storage temperature and thawing methods showed little or no changes in the sensory quality of strip loin steaks, detected by either panelists or consumers. In the QDA®, apparent juiciness was lower in samples thawed in microwave, while the rancid flavor was lower for samples frozen at -20 °C and thawed in refrigeration ( p < 0.05). The consumer test showed that samples stored at -10 °C and microwave thawing was most accepted in terms of tenderness, juiciness, and overall impression. Fresh steaks (unfrozen) had low acceptance for overall impression in relation to frozen meat. This indicates that consumers could use a household freezer (-10 °C) and quicker thawing methods (microwave or room temperature) without compromising the sensory perception of steaks frozen up to one month.(AU)

Impact of frozen temperature and thawing methods on the Brazilian sensory profile of Nellore beef

We evaluated the effect of frozen storage temperature and thawing methods on acceptance and sensory profile of steaks of Nellore beef strip loin under 30 days of frozen storage. Fresh strip loin (n = 13), collected two days after slaughter, were aged (2 °C) for 14 days and cut into seven steaks subjected to one of the treatments: control (unfrozen), combination of two freezing temperatures (-10 and -20 °C), and three thawing methods (microwave, ambient temperature, and refrigeration thawing). Steaks in the frozen/thawing treatment were frozen using an ultra-fast freezer until the desirable temperature was reached and were stored for 30 days. After cooking, steaks were analyzed by 11 panelists for the Quantitative Descriptive Analysis (QDA®) and by 120 beef consumers for acceptance. Storage temperature and thawing methods showed little or no changes in the sensory quality of strip loin steaks, detected by either panelists or consumers. In the QDA®, apparent juiciness was lower in samples thawed in microwave, while the rancid flavor was lower for samples frozen at -20 °C and thawed in refrigeration ( p < 0.05). The consumer test showed that samples stored at -10 °C and microwave thawing was most accepted in terms of tenderness, juiciness, and overall impression. Fresh steaks (unfrozen) had low acceptance for overall impression in relation to frozen meat. This indicates that consumers could use a household freezer (-10 °C) and quicker thawing methods (microwave or room temperature) without compromising the sensory perception of steaks frozen up to one month.

Anti-Hypertensive Peptides Derived from Caseins: Mechanism of Physiological Action, Production Bioprocesses, and Challenges for Food Applications.

This review is focused on the state-of-art of peptides with inhibitory activity towards angiotensin I-converting enzyme (ACE) - thus, with anti-hypertensive potential - derived from enzymatic hydrolysis of caseins. Firstly, molecular characteristics of caseins relevant to a better understanding of this subject were concisely commented. Next, a brief description of the pathophysiology of hypertension was explained, focusing on the ACE role in regulation of blood pressure in human body. Then, casein-derived peptides with ACE inhibitory capacity were specifically addressed. The main in vitro and in vivo bioassays often reported in literature to assess the anti-hypertensive potential of peptides were presented, illustrated with recently published studies, and discussed in terms of advantages and limitations of both approaches. Characteristics related to amino acid composition and sequence of peptides with high ACE-inhibitory potential were also commented. Process parameters of enzymatic hydrolysis (types and origins of casein substrates, types of enzymes, pH, temperature, and times of reactions) were discussed. Patents dealing with casein-derived anti-hypertensive peptides were examined not only in terms of amino acid sequences, but also regarding their novelty claims in hydrolysis process parameters. Finally, some trends, challenges, and opportunities inferred from this literature analysis were commented, emphasizing the importance of this research topic in food products development.

Bebida láctea funcional a base de soro fluido e em pó: qualidade físico-química e microbiológica

A busca por uma alimentação mais saudável e a preocupação com a contaminação ambiental, torna favorável a elaboração de bebidas lácteas funcionais à base de soro de leite. O objetivo deste estudo foi desenvolver uma bebida simbiótica com potencial funcional à base de soro de leite fluido e em pó. Foram testadas formulações com 0, 2, 5, e 8% de soro de leite em pó. O experimento foi realizado em três repetições e submetido a análises físico-química e microbiológica. Verificou-se que a concentração de soro em pó influencia diretamente na composição de algumas características físico-químicas do produto, aumentado o teor de proteína, sólidos totais e viscosidade, reduzindo o teor de pH, porém não interferiu no teor de gordura e acidez do produto final. Todas as bebidas analisadas apresentaram-se dentro dos padrões estabelecidos pela legislação vigente para bebidas lácteas fermentadas. A contagem de coliformes a 35 e 45ºC encontrou-se de acordo com os padrões da legislação (BRASIL, 2005) indicando condição higienicossanitária satisfatória. O desenvolvimento de uma bebida láctea simbiótica caracteriza-se como alternativa inovadora, pois além de ser uma nova forma de aproveitamento do soro gerado pela indústria, trata-se de um produto que proporciona benefícios à saúde do consumidor.(AU)

The search for a healthier diet and concern with environmental contamination, favors the elaboration of functional dairy drinks based on whey. The objective of this study was to develop a milk drink with functional potential based on fluid and powder serum. Formulations were tested at 0, 2, 5, and 8% whey powder. The experiment was conducted in three replicates and subjected to physical-chemical and microbiological analyses. It was found that the concentration of whey powder directly influences the composition of some physic-chemical characteristics of the product, increasing the protein content, total solids and viscosity reducing the pH value, but did not affect the fat content and acidity of the product. All drinks analyzed were within the standards established by the legislation in force for fermented milk drinks. The coliform count at 35ºC and 45ºC within the standards of legislation (BRAZIL, 2005) indicating satisfactory hygienic-sanitary condition. The development of a symbiotic dairy beverage is characterized as an innovative alternative, as well as being a new form of use of whey generated by the industry, this is a product that provides benefits to consumer health.(AU)

Bebida láctea funcional a base de soro fluido e em pó: qualidade físico-química e microbiológica / Functional dairy drink based on whey fluid and powder: physical-chemical and microbiological quality

A busca por uma alimentação mais saudável e a preocupação com a contaminação ambiental, torna favorável a elaboração de bebidas lácteas funcionais à base de soro de leite. O objetivo deste estudo foi desenvolver uma bebida láctea simbiótica com potencial funcional à base de soro de leite fluido e em pó. Foram testadas formulações com 0, 2, 5 e 8% de soro de leite em pó. O experimento foi realizado em três repetições e submetido a análises físico-química e microbiológica. Verificou-se que a concentração de soro em pó influencia diretamente na composição de algumas características físico-químicas do produto, aumentando o teor proteína, sólidos totais e viscosidade, reduzindo o teor de pH, porém não interferiu no teor de gordura e acidez do produto final. Todas as bebidas analisadas apresentaram-se dentro dos padrões estabelecidos pela legislação vigente para bebidas lácteas fermentadas. A contagem de coliformes a 35 e 45 °C encontrou-se de acordo com os padrões da legislação (BRASIL, 2005) indicando condição higienicossanitária satisfatória. O desenvolvimento de uma bebida láctea simbiótica caracteriza-se como alternativa inovadora, pois além de ser uma nova forma de aproveitamento do soro gerado pela indústria, trata- -se de um produto que proporciona benefícios à saúde do consumidor.