Simone Weschenfelder

Caracterização físico-química e sensorial de kefir tradicional e derivados

Avaliaram-se diferentes populacoes de graos de kefir tradicional e de seus derivados, o kefir, o kefir leban e o soro de kefir, quanto as caracteristicas fisico-quimicas e sensoriais, quando inoculados em diferentes concentracoes de leite padronizado, levando-se em consideracao as variaveis tempo/temperatura de incubacao, maturacao e filtracao. A manipulacao da populacao de graos de kefir foi eficaz na obtencao de produtos com caracteristicas fisico-quimicas semelhantes. O volume de leite utilizado na incubacao influenciou significativamente as caracteristicas dos derivados. A avaliacao sensorial de antepastos elaborados a partir de kefir leban, condimentados, apresentou boa aceitabilidade.

Aproveitamento da casca de citros na perspectiva de alimentos: prospecção da atividade antibacteriana

Citrus are the most produced fruits in the world. Brazil ranks first in global production and export of orange juice. The State of Rio Grande Do Sul is an important producer of citrus. During farming and processing of citrus, tons of residues are generated, with low commercial value and great potential for use in the field of food production. These residues possess many nutrients, pigments and bioactive compounds, as well as low toxicity and cost. There is evidence that the peel of citrus have antibacterial and antifungal activity. In this work, we aim to determine the antibacterial activity of ethanolic extracts of citrus peels in the perspective of disinfection and preservation of food, presenting sustainable and natural alternatives directed at consumers concerned with health. Ethanolic extracts of crude peel of ripe ponkan tangerine (Citrus reticulata Blanco), pomelo (Citrus maxima (Burm.) Merr.) and rangpur lime (Citrus limonia Osbeck) were obtained from ecological family farms. Their antibacterial activities were evaluated regarding Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) against five different bacterial strains. The rangpur lime extract presented the best antibacterial activity, with about 24 mg.mL-1 MIC and 42 mg.mL-1 MBC for the most resistant strain. Pseudomonas aeruginosa was the most sensitive strain. All ethanolic extracts inhibited or inactivated all tested strains, indicating they could be used as natural alternatives in food disinfection and preservation.

Antibacterial activity of different formulations of cheese and whey produced with kefir grains

The development of different products that confer health benefits on the population is a challenge for those who work with food. The aim of this study was to elaborate two formulations of kefir cheese (C1 and C2) and whey (W1, W2), and to evaluate their in situ antibacterial activity against microorganisms of interest in food. Pasteurized milk, powdered milk and kefir grains were used in preparing the products and their percentage composition was determined. C1, C2, W1 and W2 were contaminated with five different logarithmic fractions (A = 8log to E = 4log CFU/ml) of Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 11229), with antibacterial activity assessed over 0, 24, 48 and 72 hours of exposure. The results demonstrated the antibacterial activity of kefir cheese and whey, especially after 24 hours. Escherichia coli was the most sensitive of the bacteria, with maximum antibacterial activity seen in the cheese at population densities D and E, and in the whey at densities B, C, D and E after 48 and 72 h, showing that the in situ antibacterial activity of foods produced with kefir grains tends to be lower when compared with studies in vitro. The greater the nutrient content of the food, the lower the antibacterial activity seen, probably due to the protective action that the nutrients confer on the microorganisms against bacteriocins and the metabolites from fermentation.

Kefir: composition and evaluation of in situ antagonistic activity against Staphylococcus aureus and Escherichia coli.

The aim of this study was to investigate whether produced kefir meets the identity and quality standards for fermented milks, to check the possibility of assigning a nutrition declaration, and to evaluate the antagonistic activity of the fermented milk against Staphylococcus aureus and Escherichia coli. Two different formulations of kefir (Kefir 1 and Kefir 2) were prepared to determine the percentage composition, minerals, pH, total lactic acid bacteria, and antagonistic activity against Staphylococcus aureus and Escherichia coli. The results of the physicochemical evaluation indicated a statistically significant difference between the formulations, except for the percentage of lipids, Ca, K, Mg and Na. The formulations met the parameters of identity and quality in the fermented milks under evaluation. Possible nutrition declarations for Kefir 1 are ‘source of proteins’ and ‘reduced calorie’, and for Kefir 2, ‘high protein content’ and ‘high zinc content’. The fermented milks showed significant antagonistic activity against the tested microorganisms (> 24 h), with no activity seen after this period. Further studies involving kefir are suggested, exploring its potential as a probiotic food, and its inclusion in the diet of the population.

Food production in solidarity economy: an issue that goes beyond laws

Food production within the context of solidarity economy is an alternative way to offer employment and income for a significant part of the Brazilian population. The purpose of this study was to carry out a business diagnosis in order to evaluate the facilities, the production process and hygiene practices of seven solidarity economy enterprises located in the city of Novo Hamburgo, Southern Brazil, that work with food production and sales. Visits took place at the enterprises and a check-list was used to record data. Although food production happens in places with space and setting restrictions, it guarantees distinctive foods with aggregate value, where handlers follow the whole process, from raw materials selection to sales. Basic hygiene principles are followed, as they guarantee the production of food with quality, which contributes towards income generation for participating families. Specific laws that apply to the characteristics and needs of small-scale food production must be written in order to regulate solidarity economy enterprises.