Adriane Elisabete Costa Antunes

Desenvolvimento de buttermilk probiótico

New food products are launched on the market nearly every day and the main focus of the dairy industry is on functional products. The aim of this research project is to develop a fermented probiotic dairy product - buttermilk -, in a variety of flavors - including diet versions - in compliance with Brazilian regulations. As a first step, the manufacturing process of buttermilk was tested and evaluated to determine the best method and process step to add sucrose, sucralose and the probiotic culture. The next step consisted of evaluating the microbiological quality of coloring agents and flavor compounds intended to be added - without prior heat treatment - to the fermented product. In the next stage of the project, buttermilk samples of different flavors were analyzed during cold storage to observe whether sugar, sweetener, flavor compounds and coloring agents would interfere with microbiological counts. The results obtained at the end of the storage period indicated that the probiotic culture should be added prior to fermentation, while flavor compounds and coloring agents could be added directly to the fermented product after completing the culturing process. It was observed that the buttermilk samples containing sucrose and added with flavor compounds and coloring agents tended to show lower bifidobacterial counts after storage. Nevertheless, all the flavor versions of buttermilk tested met the legal requirements regarding hygiene indicators and the number of viable probiotic bacteria. B. animalis subsp. lactis showed excellent viability exhibiting an average count of 1.3.108 cfu.mL-1. As a result, the buttermilk samples were considered safe and potentially functional.

Selective enumeration and viability of Bifidobacterium animalis subsp. lactis in a new fermented milk product

One of the key focuses of today’s dairy industry worldwide is the continued development of new products, especially probiotic-based products. Buttermilk is originally a by-product of butter making fermented by Mesophilic Aromatic Cultures (MAC). It can also be made by fermentation of pasteurized whole milk or skimmed milk. This product is not marketed in Brazil. The objectives of this work were: (1) to develop a selective medium for Bifidobacterium animalis subsp. lactis enumeration and (2) to determine the viability of this microorganism during the shelf life of the buttermilk. Skim milk added with 10% sucrose or 0.03% sucralose was pasteurized and inoculated with a composite starter culture consisting of 1% MAC (containing Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. lactis biovar. diacetylactis and Leuconostoc mesenteroides subsp. cremoris) and 2% Bifidobacterium animalis subsp. lactis. To attain selective counts of Bif. animalis subsp. lactis the MRS agar supplemented with 0.5% L-cysteine hydrochloride at 10%, 1% lithium chloride at 10%, 0.01% aniline blue and 0.5% dicloxacillin at 0.1% was modified by increasing the antibiotic concentration, addition of NaCl, adjusting pH to 4.8 or increasing the incubation temperature (from 37 to 45oC). Raising the incubation temperature to 45oC was found to be efficient in inhibiting the MAC cultures, even in media not added with dicloxacillin. Bif. animalis subsp. lactis exhibited high viability in the product. The buttermilk product prepared with sucrose and sweetener contained in excess of 10 8 cfu.ml -1 bifidobacteria throughout the shelf life of the product (28 days).

Perfil de textura e capacidade de retenção de água de géis ácidos de concentrado protéico de soro de leite

A capacidade dos concentrados proteicos de soro de leite (CPS) de formar geis e importante propriedade funcional. O objetivo deste estudo foi avaliar a influencia das variaveis concentracao de proteina, pH, temperatura e tempo de desnaturacao, nos intervalos de 8 a 12%; 4,0 a 5,2; 81 a 89oC e 15 a 27 minutos, respectivamente, no perfil de textura e capacidade de retencao de agua de geis acidos de CPS. O perfil de textura foi determinado em texturometro TAXT2 e a capacidade de retencao de agua avaliada atraves da umidade espremivel dos geis. O delineamento estatistico foi um planejamento fatorial 24 completo. Os geis de CPS apresentaram os maiores valores de firmeza, coesividade, elasticidade e capacidade de retencao de agua, de maneira geral, nas maiores faixas de concentracao proteica, tempo e temperatura de desnaturacao. Com relacao a variavel pH, geis formados em pH 4,0 apresentaram-se mais elasticos e com maior capacidade de retencao de agua, enquanto que os geis formados em pH 4,9 a 5,2 mostraram-se mais firmes e coesos.

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.

Encapsulated thyme (Thymus vulgaris) essential oil used as a natural preservative in bakery product

The objective of this work was to design a particle using thyme (Thymus vulgaris) essential oil through complex coacervation. In vitro activity against bacteria and molds of free oil as well as the encapsulated oil was verified and then in situ assay was done. The free thyme oil presented high in vitro activity, with values below 0.50mg/mL for almost all the microorganisms tested. Also, MIC values for the encapsulated oil was lower than for the free oil, probably due to the protective micro-environment promoted by the particle wall. The microparticles applied to cakes samples conferred protection against the volatilization of the encapsulated oil and promoted a minimum shelf life of 30days without the use of synthetic preservatives.

CARACTERIZAÇÃO DE BEBIDA OBTIDA A PARTIR DE LEITE FERMENTADO SIMBIÓTICO ADICIONADO DE POLPA DE GOIABA E AVALIAÇÃO DA VIABILIDADE DAS BIFIDOBACTÉRIAS

Fermented milks and yogurts containing probiotics are the main products in the world with health claims, attending to a growing market demand. However, to maintain the viability of probiotic cultures during manufacture and storage of food products is a technological challenge. The main objective of this study was to evaluate the physicalchemical composition and viability of probiotics after 1, 15 and 30 days of refrigerated storage (4oC ± 1) of a beverage made with guava pulp pasteurized and fermented milk with cultured yoghurt (50/50%), mixed cultures of bifidobacteria, with and without the addition of 1.7% of prebiotics (FOS). The viability of probiotic beverages after 30 days of refrigerated storage has remained within the limit proposed by the Brazilian legislation for food with claims of functional properties with values from 10 6 to 10 7 UFC.mL -1 , even in unfavorable condition of pH ( < 4,4). The addition of 1.7% of FOS did not increase the viability of bifidobacteria. However, the addition of 1.7% FOS enables the intake of 3.4 grams of fiber in the daily portion (200 ml) which meets the recommendation for functional properties.

Microbiological Quality of Organic and Conventional Leafy Vegetables

The aim of this study was to assess the microbiological profile of leafy vegetables from organic and conventional farming ( ). The microbiological parameters analyzed consisted of aerobic mesophilic bacteria, yeasts and molds, coliforms at 30 and 45°C, and Salmonella ssp. A biochemical identification of the Enterobacteriaceae species was carried out. Some Enterobacteriaceae species were identified in the produce from both farming systems and Hafnia alvei was the most widespread specie observed. Salmonella spp. was not detected in the samples analyzed. The microbial counts for indicator microorganisms were, in general, higher for conventional leaves when compared to those produced by organic farming.

Brazilian Yogurt-like Products

Fermented milk, yogurts, and whey beverages are products that are very appreciated in Brazil, ranging from infants to older people. They are dairy products with similar technological processes, but differ in chemical composition, ingredients used, and sensory characteristics. This chapter will focus on the production of fermented milk, yogurts, and whey beverages in Brazil, discussing the regulatory aspects, consumer market, processing steps, and products available on the market, including those containing functional ingredients (probiotic and prebiotic), or for particular nutritional uses (lactose-free and light and diet formulations).

AVALIAÇÃO DO PROBIÓTICO IDEAL PARA APLICAÇÃO EM NOVA BEBIDA ESPORTIVA CONTENDO POLPA DE ROMÃ E ISOLADO PROTEICO DO SORO DE LEITE

Resumo O consumo de alimentos funcionais, como leite fermentado contendo probióticos vêm aumentando significativamente, uma vez que estes despertam o interesse da indústria e dos consumidores por conferirem benefícios à saúde através de seu consumo regular. Sendo assim, o presente trabalho buscou verificar a seletividade e taxas de recuperação de 7 probióticos em diversos meios de cultura, e também desenvolver leite fermentado acrescido da melhor linhagem frente á sua viabilidade na presença do leite fermentado contendo polpa de romã e isolado proteico do soro de leite, a vida de prateleira foi acompanhada durante 28 dias, sob refrigeração. Obtevese que o meio MRS acidificado proporcionou boa recuperação para todos os probióticos exceto a BI 07 e foi eficiente para inibir a cultura S. thermophilus (TA 072). O MRS adicionado de clindamicina proporcionou boa recuperação de todos os lactobacilos avaliados com exceção do L. plantarum e das bifidobactérias (BB12 e BI07).