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Lactococcus lactis subsp. lactis bv. diacetylactis strains are often used as starter cultures by the dairy industry due to their production of acetoin and diacetyl, important substances that add buttery flavor notes in dairy products. Twenty-three L. lactis subsp. lactis isolates were obtained from dairy products (milk and cheese) and dairy farms (silage), identified at a biovar level, fingerprinted by rep-PCR and characterized for some technological features. Fifteen isolates presented molecular and phenotypical (diacetyl and citrate) characteristics coherent with L. lactis subsp. lactis bv. diacetylactis and rep-PCR allowed the identification of 12 distinct profiles (minimum similarity of 90%). Based on technological features, only two isolates were not able to coagulate skim milk and 10 were able to produce proteases. All isolates were able to acidify skim milk: two isolates, in special, presented high acidifying ability due to their ability in reducing more than two pH units after 24 h. All isolates were also able to grow at different NaCl concentrations (0 to 10%, w/v), and isolates obtained from peanut and grass silages presented the highest NaCl tolerance (10%, w/v). These results indicate that the L. lactis subsp. lactis bv. diacetylactis isolates presented interesting technological features for potential application in fermented foods production. Despite presenting promising technological features, the isolates must be assessed according to their safety before being considered as starter cultures.

Lactococcus lactis subsp. lactis bv. diacetylactis is a relevant microorganism for the dairy industry because of its role in the production of aromatic compounds. Despite this technological property, the identification of bacteriocinogenic potential of obtained strains can offer the additional positive aspect of biosafety. A panel of 15 L. lactis subsp. lactis bv. diacetylactis strains was characterised for the presence and expression of bacteriocin related genes, and further investigated regarding the nisin operon. Eight strains were positive only for nisA, and one strain (SBR4) presented a full nisin operon, with sequencing that was shown to be similar to nisin Z. Only SBR4 presented inhibitory activity against 16 microbial target strains. The growth curves of selected targets strains confirmed the inhibitory activity of SBR4 and consequently the nisin production. This research has demonstrated the inhibitory potential of L. lactis subsp. lactis bv. diacetylactis strain, SBR4, due to its ability to produce nisin Z. This biopreservative potential, associated to previously characterised technological properties, allow the indication of this strain as a promising candidate to be used by the dairy industry as a starter or adjunct culture.

A importancia primaria das micelas de caseína reside no fato de que os processos empregados na transformaçao do leite em quaisquer de seus derivados dependem, direta ou indiretamente, de sua estabilidade ou de sua desestabilizaçao controlada. Assim, o objetivo do presente trabalho é apresentar uma revisao atualizada sobre a organizaçao estrutural das micelas de caseína. Em termos físico-químicos, as micelas de caseína podem ser definidas como agregados supramoleculares esféricos e porosos, altamente hidratados, carregados negativamente, com diámetro médio de 200 nm, e que apresentam aproximadamente 104 cadeias polipeptídicas. Além de agua, as micelas sao constituídas por quatro tipos de caseínas, chamadas de aS1, aS2, ß, e κ-caseínas, que estao unidas por meio de interaçöes hidrofóbicas e eletrostáticas, e pela presença de minerais, sobretudo sais de fosfato de calcio, os quais sao os principais responsáveis pela manutençao da estrutura micelar. A estabilidade das micelas de caseína é atribuída å presença de uma camada externa difusa, formada basicamente por κ-caseína. Apesar de as propriedades coloidais das micelas de caseína serem conhecidas, ainda nao há consenso sobre como as moléculas de caseína estao estruturadas em seu interior. Portanto, os principais modelos que descrevem a organizaçao interna das micelas de caseína sao apresentados na parte final do artigo.

Consumers worldwide are increasingly demanding food with fewer ingredients, preferably without chemical additives. The trend called “Clean Label” has stimulated the development and commercialization of new types of bioprotective bacterial cultures. These bacteria are not considered new, and several cultures have been available on the market. Additionally, new bioprotective bacteria are being identified to service the clean label trend, extend the shelf life, and, mainly, improve the food safety of food. In this context, the lactic acid bacteria (LAB) have been extensively prospected as a bioprotective culture, as they have a long history in food production and their antimicrobial activity against spoilage and pathogenic microorganisms is well established. However, to make LAB cultures available in the market is not that easy, the strains should be characterized phenotypically and genotypically, and studies of safety and technological application are necessary to validate their bioprotection performance. Thus, this review presents information on the bioprotection mechanisms developed by LAB in foods and describes the main strategies used to identify and characterize bioprotective LAB with potential application in the food industry.

The aim of this study was to analyze the influence of dietary supplementation with whey protein concentrate (WPC) in the incidence of oral mucositis (OM) in patients undergoing hematopoietic stem cell transplantation (HSCT). Patients were supplemented with a daily intake of WPC delivering 50% of the daily protein requirements (DPR) according to the Dietary Reference Intakes and classified later based on the amount of ingested supplement until OM median onset. We evaluated 73 patients. Forty-three were part of the historical control and 30 were supplemented with WPC. The OM had a mean duration of 5.3 d (SD 4.5), ranging from the day of the infusion of stem cells until the 17th day after infusion and a median of 5 d after infusion. OM duration was influenced by the conditioning protocol (P < 0.01) and WPC (P = 0.01). Patients who consumed the WPC in an amount ≥40% of DPR had a 35% reduction in duration of OM, and the incidence of OM grades 3 and 4 was 11 times smaller. Body mass index, serum albumin, and adverse reactions, such as diarrhea, nausea and vomiting, dysphagia, dry mouth and drooling, showed no statistically significant differences. WPC intake ≥40% of DPR helped to reduce the severity and duration of OM. The use of WPC in patients undergoing HSCT was shown to be safe, encouraging new studies in this population to assess its action mechanism.

Weissella is a genus containing Gram-positive, heterofermentative bacteria belonging to the lactic acid bacteria (LAB) group. These bacteria are endowed with promising technological and antimicrobial attributes. Weissella cibaria W25 was isolated from a dairy environment where raw milk cheeses are produced. Therefore, we sequenced and assembled the W25 draft genome sequence, which consists of 41 contigs totaling ~2.4 Mbp, with a G + C content of 45.04%. Then we carried out a comprehensive comparative genomic analysis with W. cibaria 110, known to produce the weissellicin 110 bacteriocin, and four other non-bacteriocin-producing W. cibaria strains.

Whey, a greenish-yellow liquid resulting from curd separation in cheese manufacturing, was historically considered economically insignificant in the dairy industry and often discarded into the environment without proper oversight. However, recognizing its high nutritional value, whey has become a valuable ingredient in the food industry. Unprocessed whey (raw material) is highly susceptible to contamination, as it can serve as a substrate for the multiplication of a range of microorganisms, including spoilage, spore forming, pathogenic and toxin producing bacteria, particularly if stored at inappropriate temperatures. Staphylococcus aureus is one of these potential pathogenic bacteria often associated to dairy, that can also persist in the environment through biofilm formation and, once reaching the food matrix, can grow and produce enterotoxins. During the processing of whey powder production, there are points where S. aureus might find its way into the final product. Here we demonstrate critical contamination steps, and we highlight the need for more research to assess the microbiological integrity of whey powder, especially in Brazil, where its production has been growing in recent years. Considering the increasing use of whey powder as an ingredient for various formulations, continuous surveillance for the presence of spoilage microbiota and potentially pathogens, including S. aureus and associated enterotoxins is indispensable to prevent food poisoning outbreaks.

This study aimed to develop and characterize beverages formulated with whey protein and added lutein. Beverages formulated with 0.5 (F1), 2.0 (F2), 4.0 (F3) and 6.0% w/v (F4) whey protein were physicochemically and microbiologically characterized, and sensory evaluated. The physicochemical analyses indicated that the protein content significantly changed (P<0.05) the acidity values, soluble solids and the colorimetric coordinates, making possible to adjust mathematical models for all these variables. Microbiological analyses showed no significant contamination (P<0.05) during processing that would compromise drinks quality of the drinks. Carotenoid content and the antioxidant activity did not change significantly (p>0.05) with increased protein content. The F2 formulation showed the highest sensory acceptance. Beverages offer a promising alternative to whey use and enhance the value of the product by the addition of lutein.

This study investigated the synergistic effects of three protein concentrates from legumes (pea, lentil, and lima bean) as emulsifiers and stabilizers of oil-in-water (O/W) emulsions using a simplex-centroid mixture design. The aim was to check whether proteins combined in different proportions have better emulsifying properties than isolated proteins. During this study, each protein concentrate was characterized by different evaluated parameters: emulsifying activity, emulsion stability, accelerated stability test, thermal coagulation time, stability to coalescence, and others. After statistical analysis mixture optimization, it was found that the best formulation for stabilizing O/W emulsion under the tested conditions (2% total protein; 3% sunflower oil) was the protein blend containing 21.21% pea, 32.78% lentil, and 46.01% fava bean. This blend exhibited better emulsification properties compared to the individual proteins.

The aim in this research paper was to investigate the effect of using calcium monophosphate (MCP) and MCP mixed with commercial phosphates salts, in total or partial replacement of calcium chloride (CaCl2) in the manufacture of Minas Frescal cheese. Initially, model cheeses were made to perform the rheological analysis during the coagulation process. Of these, the five best treatments were chosen to carry out the production of Minas Frescal cheese, used only CaCl2 and MCP, and partial replacements of MCP + polyphosphate, MCP + potassium monophosphate (MKP) and MCP. The cheeses showed no significant difference in physicochemical composition, yield and syneresis, however, the cheese with partial replacement of CaCl2 by MCP + polyphosphate and MCP + MKP showed the highest hardness values, like the control. This demonstrates that it is possible to replace calcium chloride without significant changes in the physicochemical characteristics and yield of Minas Frescal cheese, and it is still possible to modulate the hardness of the cheese produced according to the type of calcium/phosphate source used. This allows the industry to replace the source of calcium in the manufacture of Minas Frescal cheese according to the desired hardness.