Milk and açaí berry pulp improve sensorial acceptability of kefir-fermented milk beverage / Leite e polpa de açaí aumentam a aceitabilidade sensorial de uma bebida fermentada por kefir

Kefir grains are a symbiotic biomass (yeast and bacteria) commonly used to produce milk probiotic fermented beverages. The aim of this study was to produce a mixed beverage of whole milk and açaí (Euterpe oleracea) berry pulp fermented by two different kefir cultures: one specific for milk and one specific for sugared water, adapted to milk. Based on the fermentation yield, pH and sensory analysis, the culture adapted to milk obtained the best results in a composition (g 100 g-1) of 70 of whole milk and 30 of açaí berry pulp, at room temperature (~25°C), without agitation and fermented for 24 h. The results obtained by this formulation were an increase of 12% in the kefir biomass, 93% of fermentation yield, pH 5.10 and overall sensory acceptance of 7.05.

Kefir é uma biomassa simbiótica (leveduras e bactérias) comumente aplicada na obtenção de bebidas fermentadas probióticas de leite. O objetivo deste trabalho foi produzir uma bebida fermentada mista de leite integral e polpa de açaí (Euterpe oleracea) a partir de duas culturas diferentes de kefir: uma original de leite e outra original de água açucarada e adaptada ao leite. Com base na conversão, pH e análise sensorial, os melhores resultados foram obtidos com a cultura adaptada na composição (g 100 g-1) de 70% de leite e 30% de polpa de açaí, sem controle de temperatura (temperatura ambiente ~25° C) e sem agitação e por 24 h de fermentação. Esta formulação apresentou 12% de aumento da biomassa, 93% de conversão, pH 5,10 e uma aceitação global de 7,05.

Microbiological and physical-chemical characteristics of fermented milk beverages / Características microbiológicas e físico-químicas de bebidas lácteas fermentadas

This study aimed to evaluate some microbiological and physical-chemical characteristics of fermented milk beverages collected at the main supermarkets in Belo Horizonte (MG). 40 samples of the products corresponding to five distinct brands were collected. They were submitted to the following analyses: Most Probable Number (MPN) of total (30ºC) and thermal tolerant coliforms (45ºC), Salmonella spp., coagulase positive Staphylococcus, molds and yeasts, lactic acid bacteria, pH, titratable acidity and contents of moisture, total solids, protein and fat. The analyses were carried out during the last week of shelf life. The microbiological quality of the samples was good and the counts of lactic bacteria were above the minimum established by the official legislation. Streptococcus and Lactobacillus were isolated and identified from the products and Lactobacillus delbrueckii was molecularly identified in three samples. The mean values for the contents of fat and protein, titratable acidity, pH, moisture and total solids ranged from 1.24 to 1.98%; 1.88 to 2.22%; 0.54 to 0.66%; 3.91 to 4.16; 81.18 to 83.25% and 16.75 to 18.82%, respectively. All samples had protein content in agreement with the official legislation.

O objetivo do presente trabalho foi avaliar as características microbiológicas e físico-químicas de bebidas lácteas fermentadas. Foram coletadas 40 amostras de bebidas lácteas fermentadas pertencentes a cinco marcas distintas, em grandes redes de supermercados de Belo Horizonte. Em cada amostra, foram avaliados os seguintes parâmetros: número mais provável de coliformes totais (30ºC), número mais provável de coliformes termotolerantes (45ºC), pesquisa de Salmonella spp., contagem de Staphylococcus coagulase positiva, contagem de bolores e leveduras, contagem total de bactérias lácticas viáveis, umidade, sólidos totais, teor de proteína, teor de gordura, pH e acidez titulável. As análises foram realizadas na última semana do período de validade. As amostras apresentaram qualidade microbiológica satisfatória, bem como contagens totais de bactérias lácticas viáveis superiores ao mínimo estabelecido pela legislação. Streptococcus e Lactobacillus foram identificados em todas as marcas de bebidas lácteas fermentadas analisadas, e em três delas foi possível identificar a espécie Lactobacillus delbrueckii. Os valores médios encontrados para os teores de gordura, proteína, acidez titulável, pH, umidade e sólidos totais variaram de 1,24 a 1,98%, 1,88 a 2,22%, 0,54 a 0,66%, 3,91 a 4,16, 81,18 a 83,25% e 16,75 a 18,82%, respectivamente. Todas as marcas de bebidas lácteas fermentadas apresentaram teor médio de proteína superior ao mínimo preconizado pela legislação.

Effects of probiotic fermented milk on biofilms, oral microbiota, and enamel

The aim of this study was to evaluate in vitro and in vivo the effects of 2 brands of probiotic fermented milk on biofilms, oral microbiota, and enamel. For the in situ experiment, ten volunteers wore palatine devices containing four blocks of bovine dental enamel over 3 phases, during which 20% sucrose solution, Yakult® (Treatment A), and Batavito® (Treatment B) were dropped on the enamel blocks. Salivary microbial counts were obtained and biofilm samples were analyzed after each phase. For the in vivo experiment, the same ten volunteers drunk Yakult® (Treatment C) and Batavito® (Treatment D) in two phases. Saliva samples were collected for microbial analysis after each phase. The in situ study showed that in comparison with Treatment A, Treatment B resulted in fewer total cultivable anaerobes and facultative microorganisms in biofilms, higher final microhardness, lower percentage change in surface hardness, and smaller integrated subsurface enamel hardness. In the in vivo study, Treatment D resulted in a reduction in the counts of all microorganisms. The results suggested that the probiotic fermented milk Batavito®, but not Yakult®, reduced the amount of oral microorganisms and mineral loss in bovine enamel.

Detection of cheese whey and caseinomacropeptide in fermented milk beverages using high performance liquid chromatography / Detecção de soro lácteo e caseinomacropeptídeo por cromatografia líquida de alta eficiência em bebidas lácteas fermentadas

Cheese whey level and caseinomacropeptide (CMP) index of fermented milk beverages added with four levels of cheese whey (0, 10, 20, and 40percent) and stored at 8-10oC for 0, 7, 14 and 21 days were determined by high performance liquid chromatography-gel filtration (HPLC-GF). Additionally, the interference of the starter culture and the storage time on the detection of cheese whey and CMP were investigated. Refrigerated storage up to 21 days did not affect (P>0.05) cheese whey and CMP amounts in milk (0 percent of cheese whey) and in fermented milk beverages added with 10 and 20percent of cheese whey (P>0.05). However, cheese whey and CMP amounts were higher than expected (P<0.05) in fermented milk beverages added with 40 percent of cheese whey and stored for 21 days...

O presente trabalho teve como objetivos quantificar o teor de soro e o índice de caseinomacropeptídeo (CMP) de bebidas lácteas fermentadas preparadas em laboratório, adicionadas de diferentes concentrações de soro (0, 10, 20 e 40 por cento), fermentadas e armazenadas em refrigeração (8-10oC) por tempos distintos (zero, sete, 14 e 21 dias), por cromatografia líquida de alta eficiência-filtração em gel (CLAE-FG), bem como verificar a interferência da cultura utilizada no preparo das bebidas lácteas fermentadas e do tempo de armazenamento na detecção de soro lácteo e CMP. Quando os teores de soro lácteo e os índices de CMP obtidos por CLAE-FG de bebidas lácteas fermentadas foram analisados ao longo do tempo de armazenamento, verificou-se que não houve diferença (p>0,05) para o leite (0 por cento de soro) e as bebidas lácteas com 10 e 20 por cento de soro nos tempos de zero, sete, 14 e 21 dias de armazenamento. No entanto, para a bebida láctea fermentada adicionada de 40 por cento de soro, foi observada diferença para o tempo de armazenamento de 21 dias (p<0,05), em que o teor de soro e o índice de CMP obtidos foram maiores que os demais, que se mostraram equivalentes entre si (p>0,05) para os tempos de zero, sete e 14 dias...

Effects of the kefir and banana pulp and skin flours on hypercholesterolemic rats

PURPOSE: To investigate the effect of kefir and banana pulp and skin flours on the serum levels of total cholesterol, HDL-c, LDL-c and triacylglycerols in rats fed cholesterol-rich diet. METHODS: Thirty Male Wistar rats were used. In the first 21 days, the animals were fed purified hypercholesterolemic diets, except the standard group. In the next 21 days, the animals were given modified diets: Group GC: standard diet AIN-93G; Group HIP: hypercholesterolemic diet; Group F: hypercholesterolemic diet added of 1% of banana skin flour and 7% of banana pulp flour; Group Q: hypercholesterolemic diet plus kefir suspension by oral infusion (1.5 ml/animal); Group FQ: hypercholesterolemic diet added of 1% banana skin flour and 7% of banana pulp flour plus kefir suspension (1.5 ml/animal). RESULTS: In spite of the high fiber content, the addition of banana pulp (7%) and skin (1%) flour did not alter the plasma levels of total cholesterol, HDL-c and LDL-c. However, they reduced the TG levels in 22%. Already fermented kefir reduced significantly the levels of VLDL, LDL-c and triacylglycerols, in addition to having increased HDL-c. However, it was not possible to verify the symbiotic effect between both. CONCLUSION: The results reinforce the beneficial effects of kefir in reducing the risks of cardiovascular diseases.

Effects of milk curd on saliva secretion in healthy volunteer compared to baseline, 2% pilocarpine and equivalent pH adjusted acetic acid solutions.

Background: Dry mouth is a common clinical problem, and different products have been proposed to improve it. In this investigation, the effects of "milk curd" on the amount of saliva secretion were studied. Materials and Methods: A total of 32 patients (aged 20-30) were selected from healthy volunteers. Milk curd concentrations of 0.5, 1, 2 and 4%, and 2% pilocarpine were prepared as drops. The impact of the drugs on the saliva weight was assessed after 1-5 min. To determine the effects of the pH of the milk curd on the amount of saliva secretion, different concentrations of acetic acid were used. Results: At the end of the first minute, the differences between the data for all groups were statistically significant, and the difference between the 2% and 4% milk curd groups was higher than the others (P < 0.0001). The differences in the amount of the saliva secreted at the end of the second minute between the baseline and 4% milk curd groups and between the 0.5% and 4% MC groups were significant (P = 0.006 and P = 0.025, respectively). In total, there was no significant difference between the effect of various pH treatments and the amount of baseline saliva secretion. Conclusion: Milk curd has a significant local impact, and the saliva increase depends on the dose. It seems that this effect is not only related to its acidic taste. As a result, factors other than pH are involved in the effect.

Evaluation of some properties of fermented milk beverages that affect the demineralization of dental enamel

The aim of this in vitro study was to evaluate the erosive capacity of fermented milk beverages, as well as some of their properties that affect the demineralization of dental enamel (pH, buffering capacity, fluoride, calcium and phosphorus contents). Three different batches of 6 commercial brands of fermented milk beverages were analyzed. pH evaluation was accomplished using a potentiometer. The buffering capacity was measured by adding 1 mol L-1 NaOH. Fluoride concentration was assessed by an ion specific electrode after hexamethyldisiloxane-facilitated diffusion, and calcium and phosphorus concentrations were assessed by a colorimetric test using a spectrophotometer. Sixty specimens of bovine enamel were randomly assigned to 6 groups (n = 10). They were exposed to 4 cycles of demineralization in the fermented milk and remineralization in artificial saliva. Enamel mineral loss was determined by surface microhardness ( percentSMHC) and profilometric tests. The samples' pH ranged from 3.51 to 3.87; the buffering capacity ranged from 470.8 to 804.2 µl of 1 mol L-1 NaOH; the fluoride concentration ranged from 0.027 to 0.958 µgF/g; the calcium concentration ranged from 0.4788 to 0.8175 mgCa/g; and the phosphorus concentration ranged from 0.2662 to 0.5043 mgP/g. The percentSMHC ranged from -41.0 to -29.4. The enamel wear ranged from 0.15 µm to 0.18 µm. In this in vitro study, the fermented milk beverages did not promote erosion of the dental enamel, but rather only a superficial mineral loss.

Aislamiento y rendimiento del GMP mediante precipitación de lactosuero con ácido tricloroacético / GMP isolation and yield by whey precipitation with trichloroacetic acid

Durante la elaboración del queso, la k-caseína es hidrolizada por la renina (Quimosina E.C.3.4.23.4) en el enlace peptídico Fen105-Met106 generando dos fracciones: la para-k-caseína y el glicomacropéptido (GMP) que se libera al lactosuero. El GMP presenta una estructura química particular donde predominan los aminoácidos con cadena lateral ramificada, no presenta aminoácidos aromáticos y contiene carbohidratos unidos a residuos de treonina; por esta razón se le ha atribuido una variedad de actividades biológicas. Se ha estimado que en Venezuela se generan alrededor de 713 toneladas de lactosuero anualmente. Un volumen considerable de este subproducto se produce en el estado Zulia, constituyéndose esto en una fuente de péptidos y proteínas de alta calidad nutricional que está siendo subutilizada. Con el propósito de evaluar el aislamiento y rendimiento del GMP a partir de la precipitación de lactosuero de ricotta con ácido tricloroacético 50 por ciento, se realizaron 6 extracciones con este ácido a 50 mL de cada tipo de suero analizado: suero ricotta, suero comercial resuspendido y suero ácido (control negativo). Se verificó mediante pruebas químicas y PAGE-SDS 15 por ciento de manera indirecta, la presencia de GMP en las preparaciones obtenidas. Se observaron bandas de 6,5; 18,3 y 19,0 kDa en suero ricotta y suero comercial resuspendido. Las bandas de 18,3 y 19,0 posiblemente correspondan a la forma trimérica del péptido. El rendimiento del GMP en términos de proteínas fue en promedio 1,17 mg/50mL (1,17 por ciento) y 4,51 mg/50mL (0,81 por ciento), para suero ricotta y suero comercial, respectivamente. Los resultados indican que es factible obtener preparaciones del GMP, sin embargo, para plantear la producción a escala industrial de este péptido para su aprovechamiento, se requiere evaluar otros procedimientos donde se obtenga a bajo costo una preparación purificada del GMP.

During cheese manufacturing k-casein is hydrolyzed by rennin (Quimosine E.C.3.4.23.4) on peptidic bond Fen105- Met106 releasing two fractions: para-k-casein and glycomacropeptide (GMP). GMP shows a particular chemical structure in which ramified lateral chain aminoacids prevail, without aromatics aminoacids, but with carbohydrates short chains linked to some threonine residues; because of this, a variety of biological activities have been attributed to molecule. It has been considered that in Venezuela, 713 tons of whey are generated annually. An important volume of this byproduct is produced in the Zulia State, becoming itself a source of peptides and proteins of high nutritional quality that has been subused. With the purpose of evaluating GMP isolation and yield from ricotta whey precipitation with 50 percent trichloroacetic acid treatment, 6 extractions where performed with this acid to 50 mL of each analyzed whey: ricotta whey, resuspended commercial whey and acid whey (negative control). By means of chemical tests and PAGE-SDS 15 percent, indirect presence of GMP was verified in all preparations. Bands of 6.5, 18.3 and 19.0 kDa were observed in ricotta and commercial whey. Bands of 18.3 and 19.0 possibly correspond to the peptide trimeric structure. GMP yield in terms of protein content was 1.17 mg/50mL (1.17 percent) and 4.51 mg/50mL (0.81 percent), for ricotta and commercial whey, respectively. Results show that it feasible to obtain preparations of GMP, however, in order to produce this peptide industrially for its use, evaluation of low cost procedures for GMP purification is required.

O efeito da composição de cultura e da suplementação do leite no crescimento, na taxa de acidificação, na sobrevivência e no metabolismo de bactérias probióticas em leite fermentado / The effect of culture composition and the implementation of milk on the growth, acidification rate, survival and metabolism of probiotic bacteria in fermented milk

Os produtos lácteos probióticos e/ou simbióticos são líderes dentro do mercado de alimentos funcionais e têm prioridade de pesquisa em diversos países. Os resultados deste trabalho mostraram que a qualidade do leite fermentado foi fortemente influenciada tanto pela composição das co-culturas probióticas quanto por diferentes prebióticos, como oligofrutose, polidextrose, maltodextrina e inulina. A cinética de acidificação foi influenciada pela composição das culturas probióticas e pelos ingredientes prebióticos no leite fermentado. A suplementação do leite com a inulina reduziu o tempo de fermentação das co-culturas Streptococcus thermophilus + Lactobacillus acidophilus (St-La); Streptococcus thermophilus + Lactobacillus rhamnosus (St-Lr) e Streptococcus thermophilus + Bifidobacterium lactis (St-Bl), além de melhorar a firmeza do leite fermentado probiótico. Foram também relatadas que as quantidades de ácido linoléico conjugado (CLA) aumentaram no leite fermentado pela co-cultura de S. thermophilus + L. acidophilus, suplementado com maltodextrina. No que diz respeito às contagens, a adição de inulina favorece a viabilidade das bactérias probióticas durante o armazenamento a 4°C além de causar um efeito bifidogênico, in vitro, estimulando o crescimento de B. lactis. Em relação ao estudo metabólico entre as co-culturas homofermentativas (St-La e St-Lb), feitas neste presente trabalho, pode-se dizer que a lactose foi apenas parcialmente fermentada a ácido lático, a galactose foi metabolizada em certa medida, e se formaram diacetil e acetoína em níveis apreciáveis. A acetoína e o diacetil provavelmente foram produzidos pelas atividades da α-acetolactato sintase e da α-acetolactato descarboxilase de S. thermophilus.

Probiotics dairy products and/or symbiotic are leaders in the functional foods market and have the research priority in several countries. The results of this study showed that the quality of fermented milk was strongly influenced by composition of probiotic co-cultures and different prebiotics, such as oligofructose, polydextrose, maltodextrin and inulin. The acidification kinetics was influenced by the composition of the probiotic co-cultures and prebiotic ingredients in the fermented milk. The milk supplementation with inulin reduced the fermentation time of the co-cultures of Streptococcus thermophilus + Lactobacillus acidophilus (St-La); Streptococcus thermophilus + Lactobacillus rhamnosus (St-Lr) and Streptococcus thermophilus + Bifidobacterium lactis (St-Bl), and improved the firmness of the probiotic fermented milk. It has also been observed that the amount of conjugated linoleic acid (CLA) increased in the milk fermented by the co-culture S. thermophilus + L. acidophilus supplemented with maltodextrin. As far as the bacterial counts are concerned, the inulin addition promoted the viability of probiotic bacteria during storage at 4°C and led to a bifidogenic effect, in vitro, stimulating the growth of B. lactis. As regards to the metabolic studies of the homofermentative co-cultures (St-La and St-Lb), studied in this work, it can be said that lactose was only partially fermented to lactic acid, galactose was metabolized to some extent, diacetyl and acetoin formed at appreciable levels. The acetoin and diacetyl were probably produced by the activities of α-acetolactate synthase and α-acetolactate decarboxylase of S. thermophilus.

Bebida fermentada probiótica de soro de leite / Probiotic drink of milk serum

O presente trabalho propôs desenvolver uma bebida composta por soro de leite fermentado com microrganismos probióticos, saborizada com polpa de frutas, caracterizando-a em seus aspectos físico-químicos, microbiológicos e sensoriais. Foram elaborados três tratamentos diferidos apenas pelo tipo de fermento lácteo empregado. Os resultados mostraram a viabilidade tecnológica de apenas um tratamento composto por fermento YC-X11, contendo cepas mistas de L.delbrueckii subsp. bulgaricus e S.salivarius subsp. thermophilus, o qual foi submetida a análise físico-químicas e microbiológicas para caracterização do produto e posterior avaliação sensorial pelo método de escala hedônica. Obteve-se uma bebida probiótica inovadora, de excelente valor nutritivo, dentro dos parâmetros de identidade microbiológica e físico-química e de grande aceitação pelo consumidor final.

Chemical and nutritional evaluation of some Egyptian milk and milk products

Comparison studies of chemical and mineral content of different milk and dairy products from Egyptian markets. One hundred eighty seven [187] milk samples were obtained at random from supermarkets and retail stores in Egypt. Chemical constituents, protein, fat, carbohydrates, moisture, ash and lactose were determined. Mineral contents, calcium [Ca] and phosphorous [P] were measured in the ash. Fat content of skimmed or half skimmed milk is significantly lower than full cream milk. There is no significant change between Ca and P content of pasteurized and sterilized milk, but pasteurized milk show higher Ca content, [241.5 vs 179.74 mg /100gm]. Consequently Ca/P ratio of pasteurized milk is higher. Buffalo's milk has higher fat content than cow's milk. The addition of fruits to the milk leads to a significant decrease in moisture and ash content when compared with plain half skimmed, sterilized, milk [-10.25; -25.27% respectively] while fat content showed a non significant increase [1.61 vs 1.34 gm%; 20.30%]. Calcium content of milk with fruits is significantly higher than plain half skimmed, milk content [42.27% increase, 245.36 vs 186.16 mg/l00gm]. Consequently Ca/P ratio of milk with fruits is higher. The addition of fruits to the rayeb leads to a significant decrease in moisture, protein and fat content when compared with plain rayeb [-8.97; -11.57%; -44.26% respectively], while ash content showed a non significant decrease [0.89 vs 0.96 gm%; -6.50%]. The carbohydrate content of rayeb with fruits is significantly higher when compared with plain rayeb. There is no significant change between Ca and P content and Ca/P ratio of plain rayeb and rayeb with fruits. There is no significant change between content of cow or buffalo yogurt except for fat and lactose where buffalo milk showed a significant increase in fat content and a significant decrease in lactose milk when compared with cow yogurt. There is no significant change between plain yogurt and plain rayeb. Unlike rayeb with fruits, here yogurt with fruits is significantly different from plain yogurt. Yogurt with fruits is significantly different from rayeb with fruits or milk with fruits. The data reveals that there is no significant change between Ca and P content and Ca/P ratio of plain yogurt of either cow or buffalo origin. Calcium and phosphorous content of yogurt with fruits is slightly higher than plain yogurt, [8.31; 19.75% respectively]. Gouda and Roquefort cheese are to somewhat comparable to each other. There is a wide differences between spread cooked and spread cooked paste cheese. There is a wide variation in Ca and P Content among different types of cheese. Gouda and Roquefort cheese has the highest Ca and P content. All tested samples [milk, rayeb, rayeb with fruits, yogurt, yogurt with fruits and cheeses] agreed with the Egyptian Standard Guides