Elabora??o de fermentados alco?licos de jabuticaba conduzidos com leveduras livres e imobilizadas

A jabuticaba ? um fruto de consider?vel valor nutricional e caracter?sticas organol?pticas agrad?veis que possuem sazonalidade e alta perecibilidade. Visando minimizar as perdas p?s-colheita desse fruto, a busca por t?cnicas e tecnologias que visem atender esse gargalo se tornam valorosas e merecem destaque. Nesse sentido, a presente pesquisa teve por objetivo elaborar bebidas alco?licas fermentadas de jabuticaba com diferentes teores alco?licos, utilizando leveduras livres e imobilizadas como agentes do bioprocesso. Os frutos de jabuticaba foram caracterizados quanto aos aspectos f?sicos e a polpa, obtida por meio de despolpadeira, foi caracterizada f?sico-quimicamente. As fermenta??es foram conduzidas em batelada simples por at? 18 dias a 22?C com c?lulas livres e imobilizadas em alginato de c?lcio. Os processos foram monitorados quanto aos s?lidos sol?veis totais, pH, crescimento e desprendimento celular e ainda avaliados, no in?cio e ao final da fermenta??o, quanto aos a??cares redutores, compostos fen?licos, flavonoides, antocianinas, etanol, glicerol, metanol, a??cares e ?cidos org?nicos. Al?m destas foram avaliadas as seguintes vari?veis de resposta: taxa espec?fica de crescimento celular (?x); rendimento em produto em rela??o ao substrato consumido (YP/S); produtividade (QP); rendimento de c?lulas em rela??o ao substrato consumido (YX/S); velocidade de consumo do substrato (rs); taxa espec?fica de consumo de substrato (?s); e efici?ncia fermentativa (Ef). As bebidas obtidas foram maturadas a 5?C por 90 dias e ao final deste per?odo foram caracterizadas quanto a cor, pH, a??cares redutores totais, compostos fen?licos, flavonoides, antocianinas, etanol, glicerol, metanol, a??cares, ?cidos org?nicos e capacidade antioxidante e ainda, quanto ?s caracter?sticas sensoriais (teste descritivo e aceitabilidade). Todas as bebidas apresentaram Ef acima de 80% e YP/S de no m?nimo 0,41 g g-1, al?m de caracter?sticas f?sico-qu?micas satisfat?rias, principalmente em rela??o aos compostos antioxidantes. A imobiliza??o celular apresentou bons resultados quanto ? estabilidade mec?nica das bioesferas durante o processo. Quanto ?s caracter?sticas sensoriais, quatro das doze bebidas obtidas se sobressa?ram por serem bem aceitas, sendo estas, LIC1D, LIC2D, LLC1D e LLC2D com aceita??o m?dia de 72% e caracter?sticas sensoriais agrad?veis. Foi observada uma maior aceita??o dos julgadores por amostras ado?adas e de menor teor alco?lico. Em rela??o ? forma de elabora??o das bebidas, n?o houve diferen?a percept?vel sensorialmente quanto ao uso de leveduras livres ou imobilizadas, por?m o uso de leveduras imobilizadas mostrou-se mais eficiente quanto a vari?vel Qp.Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG)Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Ci?ncia e Tecnologia de Alimentos, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2018.The jabuticaba is a considerable nutrition value fruit that has a pleasant organoleptic characteristics, seasonality and high perishability. In order to minimize post-harvest losses of this fruit, the search for techniques and technologies that can solve this problem has become valuable and deserves attention. In this context, the aim of the present research is to develop fermented alcoholic beverages of jabuticaba in different alcoholic contents with free and immobilized yeasts as bioprocesses agents. This study characterized the jabuticaba fruit and its pulp in physical and physicochemical characteristics. The fermentations were produced in batchwise for up to 18 days at 22?C by free and immobilized cells in calcium alginate. During the processes, the total soluble solids, the pH and the cell?s growth and detachment were determinate. The processes were evaluated at the beginning and in the end of fermentation by reducing sugars, phenolic compounds, flavonoids, anthocyanins, ethanol, glycerol, methanol, sugars and organic acids. In addition, the following response variables were evaluated: specific growth rate of cell (?x); product yield in relation to the substrate consumed (Yp/s); productivity (Qp); yield of cells in relation to the substrate consumed (Yx/s); substrate consumption rate (rs); specific rate of substrate consumption (?s); and fermentative efficiency (Ef). The beverages obtained were matured at 5?C for 90 days and in the end of this period were characterized as color, pH, total reducing sugars, phenolic compounds, flavonoids, anthocyanins, ethanol, glycerol, methanol, sugars, organic acids and antioxidant capacity, as well as sensory characteristics (descriptive test and acceptability). All beverages had Ef above 80% and Yp/s of at least 0.41 g g-1 also presented satisfactory physico-chemical characteristics, mainly in relation to the antioxidant compounds. The cell immobilization showed good results on the mechanical stability according to the biospheres during the process. Regarding the sensorial characteristics, four of the twelve beverage obtained stand out for being well accepted, being these as LIC1D, LIC2D, LLC1D and LLC2D with average acceptance of 72% and pleasant sensorial characteristics. It was observed a greater acceptance of the consumer by sweetened samples and of lower alcohol content. Regarding the beverage preparation, there was no perceptible sensory difference regarding the use of free or immobilized yeasts, but the use of immobilized yeasts proved to be more efficient than the Qp variable

Pregled primjene eteričnih ulja i biljnih ekstrakata kao konzervansa i prirodnih antioksidansa u mesu i mesnim prerađevinama

The meat and meat product industry has evolved according to the needs of the market. Consumers are increasingly seeking quality in food. Thus, the concern regarding the excessive use of additives such as preservatives and antioxidants has driven research towards natural, healthy and safe substitutes. Essential oils and plant extracts have been shown to be a good option for resolving this problem. They are completely natural with biological activity, which mainly includes prevention of oxidation and the proliferation of microorganisms, thus arousing the interest of the industry and consumers. This review will present studies published in the last five years regarding the potential of essential oils and plant extracts to act as preservatives and antioxidants in meat and meat products. The forms of application, innovations in the area, alternatives to the incorporation of essential oils and extracts in meat products, effects caused in food, and limitations of applications will be detailed and discussed.Proizvodnja mesa i mesnih prerađevina se prilagođava potrebama tržišta. Potrošači sve više traže da hrana bude kvalitetna. Stoga je zabrinutost zbog pretjerane uporabe aditiva, kao što su konzervansi i antioksidansi, potaknula istraživanja o njihovim prirodnim, zdravim i sigurnim zamjenama. Eterična ulja i biljni ekstrakti pokazali su se kao dobro rješenje tog problema. Potpuno su prirodni, a njihova biološka aktivnost se uglavnom zasniva na sprečavanju oksidacijskog oštećenja i rasta mikroorganizama, zbog čega pobuđuju interes prehrambene industrije i potrošača. Ovaj rad donosi pregled istraživanja o mogućnostima primjene eteričnih ulja i biljnih ekstrakata kao konzervansa i antioksidansa u mesu i mesnim prerađevinama, objavljenih u posljednjih pet godina. Detaljno su opisani i raspravljeni načini primjene eteričnih ulja i biiljnih ekstrakata u mesnim proizvodima, inovacije u području, alternativna rješenja, učinci na hranu i ograničenja njihove primjene