Bacterial Cellulose as a Raw Material for Food and Food Packaging Applications

Bacterial cellulose (BC) has been produced for a number of applications, mainly focused on the biomedical area. Although there is a variety of interesting applications of BC for food and food packaging, only a few have been explored to the moment, since the high cost of BC production is usually considered as a limiting factor. On the other hand, several cost-effective culture media have been proposed, contributing to reduce BC production costs. This article overviews the bioprocess conditions that affects BC production and the main possible applications of BC for food and food packaging purposes

Probiotic edible films from bacterial cellulose/cashew tree gum

Edible films are thin layers of biopolymer-based materials, which are expected to help the packaging system in protecting food against environmental factors. Besides passive protection, edible films may also be carriers of active/bioactive components. Probiotic films are expected not only to bring health benefits to the consumers, but also to extend food microbial shelf life due to competitive effects of probiotics1. Bacterial cellulose (BC) has been presented as a promising matrix for immobilization of probiotics, protecting them against adverse factors e.g. stomach pH2. In this study, BC was combined to cashew tree gum (CG) to produce an edible film carrying a probiotic bacteria (Bacillus coagulans). CG was used to decrease the viscosity of film forming dispersions. Four films were produced: BC/CG/Pro (containing the probiotic B. coagulans), BC/CG/Pre (containing the prebiotic fructooligosaccharides FOS), BC/CG/Syn (containing both probiotic and prebiotic, making it synbiotic), and BC/CG (a control film). The presence of the probiotic and/or prebiotic affected the tensile properties of the films, especially the tensile strength. The survival rate of the probiotic on film drying and storage was increased by the presence of FOS. An in vitro digestibility test was also carried out on films, demonstrating that the bacteria in BC/CG/Pro films exhibited an enhanced survival rate on gastric environment when compared to the free probiotic.info:eu-repo/semantics/publishedVersio

AVALIAÇÃO DO IMPACTO DE PRÉ-TRATAMENTOS SOBRE A EXTRAÇÃO DE CAROTENÓIDES POR PRENSAGEM SEQÜENCIAL DE BAGAÇO DE CAJU

A extração de carotenóides ocorre geralmente por solventes orgânicos, cujos impactos negativos incentivam sua substituição por processos de prensagem, utilizando água como solvente. A baixa solubilidade dos carotenóides em água pode ser parcialmente compensada por pré-tratamentos que hidrolisem ou rompam as paredes celulares dos tecidos, como congelamento e tratamento enzimático. O objetivo deste trabalho foi avaliar o efeito do congelamento do bagaço de caju (subproduto da produção de suco) e da ação da pectinase sobre a extração de carotenóides por prensagem. O bagaço do caju, previamente congelado ou não, foi macerado em água ou solução de pectinase, prensado e filtrado, gerando o extrato. O bagaço resultante do primeiro ciclo maceração-prensagem passou por mais quatro ciclos, sendo a maceração sempre em água. Os teores de carotenóides do bagaço e dos extratos obtidos de cada ciclo foram analisados. A eficiência da extração de carotenóides tendeu a diminuir ao longo do número de ciclos. Tanto o congelamento quanto o tratamento enzimático aumentaram significativamente a eficiência global do processo de extração, especialmente o primeiro

Bacterial cellulose/cashew gum films as probiotic carriers

This study was carried out to obtain probiotic films with good stability by combining spore-forming, resistant bacteria (Bacillus coagulans) with a biopolymer mix (bacterial cellulose BC and cashew gum - CG) as a carrier matrix. Fructooligosaccharides (FOS) were used as prebiotic. Four different films were produced, namely, Co (control), Pro (added with probiotic), Pre (containing the prebiotic FOS), and Syn (synbiotic films containing probiotic and FOS). Although the tensile and barrier properties of films have been undermined by probiotic and FOS, those properties have remained within the values needed for food applications. Most films (except Pre) exhibited hydrophobic character (contact angles > 90°). FOS enhanced probiotic viability upon processing. The storage stability of probiotics was very good; even at 37 °C, the viability loss did not surpass 1 log cycle, due to the resistance of B. coagulans and the protective role of BC. Moreover, no cytotoxic effect of the films was observed on Caco-2 cells.The authors gratefully acknowledge the financial support of the Brazilian Agricultural Research Corporation (EMBRAPA, Brazil, 23.14.04.007.00.00 and Rede AgroNano, 0114030010300). the Research Support Foundation of Ceará State (FUNCAP/CNPq PR2-0101-00023.01.00/15), as well as the Coordination for the Improvement of Higher Education Personnel (CAPES) and the Portuguese Foundation for Science and Technology (FCT) on a Brazil/Portugal Bilateral Agreement (CAPES/FCT 99999.008530/2014-09). We also thank Sacco Srl (Italy) for providing us with Bacillus coagulans. Author Oliveira thanks FUNCAP (BMD-0008-0026 3.01.08/17) and CAPES (8887.138002/2017-00) for her scholarship. Author Azeredo thanks the National Council for Scientific and Technological Development (CNPq) for her Research Productivity Fellowship (302381/2016-3).info:eu-repo/semantics/publishedVersio

Desidratação osmótica de abacaxi aplicada à tecnologia de métodos combinados

O objetivo deste trabalho foi a otimização do processo de desidratação osmótica de abacaxi, visando a obtenção de um produto com máxima perda de água e mínima incorporação de sólidos. O processo foi aplicado à Tecnologia de Métodos Combinados, em que a redução na atividade de água foi combinada a redução no pH e uso de conservantes, todos aplicados em baixos níveis, a fim de se obter um produto similar à fruta fresca. O experimento foi dividido em 3 tratamentos, a saber: pedaços de abacaxi não revestidos (A), revestidos com cobertura de alginato (B) e revestidos com cobertura de pectina de baixa metoxilação (C). O processo envolveu as etapas principais: inativação enzimática de pedaços da fruta; para os tratamentos B e C, revestimento da fruta com as respectivas coberturas; e desidratação osmótica em solução de sacarose contendo sorbato de potássio e ácido cítrico. As condições ótimas do processo, determinadas a partir da Metodologia de Superfície de Resposta, foram as seguintes: desidratação da fruta revestida com alginato, a temperaturas na faixa de 42 a 47° C, em xarope de sacarose a 66-69° Brix, por 220 a 270 minutos. Os resultados indicaram que as coberturas afetaram significativamente as transferências de massa do processo, reduzindo a incorporação de sólidos e aumentando a perda de umidade, com conseqüente aumento na perda de massa e aumento na relação de performance (perda de umidade: incorporação de sólidos); a atividade de água final do produto não foi afetada de forma marcante pela presença das coberturas. O produto obtido sob condições otimizadas foi submetido a avaliação sensorial de aceitação, tendo apresentado boa aceitação geral. Uma avaliação da estabilidade microbiológica do produto, feita por meio de contagem de bolores e leveduras, mostrou boa estabilidade do produto por pelo menos 60 dias a 30ºC

Optimization of osmotic dehydration of pineapple applied to combined methods technology

The aim of this research was to optimize osmotic dehydration of pineapple, according to two criteria: maximize water loss and minimize solid gain. The process was made as an application to Combined Methods Technology, in which three preservation factors were combined: water activity, pH and chemical preservatives, all being applied at low levels, in order to get a product resembling non-processed fruit. The experiment was divided into three treatments, being: non-coated pineapple pieces (A), pieces coated with alginate (B) and coated with low-methoxyl pectin (C). Process involved the following main steps: enzymatic inactivation of fruit pieces; in treatments B and C, incorporation of their respective coatings; and osmotic dehydration, in sucrose syrup containing potassium sorbate and citric acid. Optimum conditions, determined from Response Surface Methodology, were the following: dehydration of fruit pieces coated by alginate, at 42-47° C, in sucrose syrup at 66-69° Brix, for 220 to 270 minutes. Results indicated that both coatings significantly affected the mass transfers of the process, reducing solid incorporation and increasing water loss; therefore, increasing weight loss and performance ratio (water loss: solid incorporation) took place. Water activity was not significantly affected by the coatings. The product obtained under optimum conditions was submitted to sensorial evaluation, and presented a good general acceptance. Moulds and yeasts countings indicated good microbiological stability of the product for at least 60 days at 30ºC.O objetivo deste trabalho foi a otimização do processo de desidratação osmótica de abacaxi, visando a obtenção de um produto com máxima perda de água e mínima incorporação de sólidos. O processo foi aplicado à Tecnologia de Métodos Combinados, em que a redução na atividade de água foi combinada a redução no pH e uso de conservantes, todos aplicados em baixos níveis, a fim de se obter um produto similar à fruta fresca. O experimento foi dividido em 3 tratamentos, a saber: pedaços de abacaxi não revestidos (A), revestidos com cobertura de alginato (B) e revestidos com cobertura de pectina de baixa metoxilação (C). O processo envolveu as etapas principais: inativação enzimática de pedaços da fruta; para os tratamentos B e C, revestimento da fruta com as respectivas coberturas; e desidratação osmótica em solução de sacarose contendo sorbato de potássio e ácido cítrico. As condições ótimas do processo, determinadas a partir da Metodologia de Superfície de Resposta, foram as seguintes: desidratação da fruta revestida com alginato, a temperaturas na faixa de 42 a 47° C, em xarope de sacarose a 66-69° Brix, por 220 a 270 minutos. Os resultados indicaram que as coberturas afetaram significativamente as transferências de massa do processo, reduzindo a incorporação de sólidos e aumentando a perda de umidade, com conseqüente aumento na perda de massa e aumento na relação de performance (perda de umidade: incorporação de sólidos); a atividade de água final do produto não foi afetada de forma marcante pela presença das coberturas. O produto obtido sob condições otimizadas foi submetido a avaliação sensorial de aceitação, tendo apresentado boa aceitação geral. Uma avaliação da estabilidade microbiológica do produto, feita por meio de contagem de bolores e leveduras, mostrou boa estabilidade do produto por pelo menos 60 dias a 30ºC.788

Freeze-Dried Banana Slices Carrying Probiotic Bacteria

Findings on diet–health relationships have induced many people to adopt healthier diets, including the substitution of energy-dense snacks with healthier items, e.g., those containing probiotic microorganisms. The aim of this research was to compare two methods to produce probiotic freeze-dried banana slices—one of them consisting of impregnating slices with a suspension of probiotic Bacillus coagulans, the other based on coating the slices with a starch dispersion containing the bacteria. Both processes resulted in viable cell counts above 7 log ufc.g−1, although the presence of the starch coating prevented a significant loss in viability during freeze-drying. The coated slices were less crispy than the impregnated ones, according to the shear force test results. However, the sensory panel (with more than 100 panelists) did not perceive significant texture differences. Both methods presented good results in terms of probiotic cell viability and sensory acceptability (the coated slices being significantly more accepted than the non-probiotic control slices)

Edible films from alginate-acerola puree reinforced with cellulose whiskers

Fruit purees, combined or not with polysaccharides, have been used in some studies to elaborate edible films. The present study was conducted to evaluate tensile properties and water vapor barrier of alginate-acerola puree films plasticized with corn syrup, and to study the influence of cellulose whiskers from different origins (cotton fiber or coconut husk fiber, the latter submitted to one- or multi-stage bleaching) on the film properties. The whiskers improved the overall tensile properties (except by elongation) and the water vapor barrier of the films. The films with coconut whiskers, even those submitted only to a one-stage bleaching, presented similar properties to those of films with cotton whiskers, despite the low compatibility between the matrix and the remaining lignin in coconut whiskers. This was probably ascribed to a counterbalancing effect of the higher aspect ratios of the coconut whiskers. (C) 2011 Elsevier Ltd. All rights reserved.CNPqCNPqEmbrapaEmbrap

Nanostructured antimicrobials in food packaging-recent advances

Active food packaging systems promote better food quality and/or stability, such as by releasing antimicrobial agents into food. Advantages of adding antimicrobials to the packaging material instead of into the bulk food include controlled diffusion, reduced antimicrobial contents, and improved cost effectiveness. Nanostructured antimicrobials are especially effective due to their high specific surface area. The present review is focused on recent advances and findings on the main nanostructured antimicrobial packaging systems for food packaging purposes. Several kinds of nanostructures, including both inorganic particles and organic structures, have been proven effective antimicrobials by different mechanisms of action and with different application scopes. Moreover, there are systems containing nanocarriers to protect antimicrobials and deliver them in a controlled fashion. On the other hand, scientific data about migration of nanostructures onto food and their toxicity are still limited, requiring special attention from researchers and regulation sectors1412CNPQ - Conselho Nacional de Desenvolvimento Científico e TecnológicoEMBRAPA – Empresa Brasileira de Pesquisa AgropecuáriaFAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulo01140300103002017/07013‐1; 2017/12174‐4302381/2016‐3; 303796/2014‐6; 304109/2017‐7; 306138/2015‐8; 310355/2015‐0; 402287/2013‐