Development of a functional orange juice powder by spray drying

The concept of functional food products has acquired a huge dimension with the enormous number of people concerned about consuming foods with health benefits. An innovative non-dairy functional food would be very attractive, not only to these consumers but also to specific niches in the market (e.g. lactose intolerants and vegetarians). The aim of this work was to develop a powdered functional orange juice. For this, cultures with probiotic characteristics were used and the necessary conditions to obtain the dried product by spray drying were defined. Two cultures were selected, a commercial probiotic, Lactobacillus plantarum 299v and an isolate from a food matrix, Pediococcus acidilactici HA-6111-2. Safety and the presence of some functional characteristics of P. acidilactici were investigated and compared with those of the commercial probiotic. None of the bacteria produced any of the virulence factors investigated; they did not exhibit significant resistance to antibiotics and reductions lower than one logarithmic cycle were observed after exposure to simulated gastro-intestinal tract conditions. It was also verified that both bacteria survived during the spray drying process and subsequent storage for 60 days. Powdered orange juice was initially obtained in a Büchi Mini Spray Dryer at constant feed temperature (ºC), flow rates of feed (mL/min), drying air (%) and compressed air (L/h) and varying inlet and outlet air temperatures (ºC) as well as the ratio of total soluble solids (orange juice): drying aid (10DE maltodextrin or gum Arabic). At selected inlet and outlet air temperatures of 120 ºC and 65 ºC, respectively, and ratio of soluble solids: drying aid of 0.5: 2, high drying yields and powders with low water activities (aw) were obtained. No cell inactivation was observed for each culture after incorporated into orange juice and spray dried. Their survival during storage at 4 ºC was higher than at room temperature under uncontrolled aw. Pediococcus acidilactici was more resistant than L. plantarum, especially during storage at 4 ºC, with logarithmic reductions lower than 1 log-unit during a period of at least seven months. To enhance survival of spray dried bacteria during storage, different pre-spray drying conditions were tested: i) different sugars were added to the culture media used (cell growth in the presence of lactose, followed by glucose resulted in the highest survival) and ii) cells were exposed to different sub-lethal stresses (only survival of L. plantarum cells during storage at room temperature was increased). For both cases, powders obtained were stored under different conditions of temperature, light exposure and aw. Generally, survival was enhanced at 4 °C, aw of 0.03 and absence of light. Cell viability during passage through simulated gastro-intestinal tract conditions was also investigated at the end of the storage at 4 ºC; the viability of both cultures was not enhanced by prior exposure to sub-lethal stresses. Survival of cultures in orange fruit powders obtained by spray-, freeze- and convective hot air drying was investigated during drying and subsequent storage. Cell inactivation was only observed during convective hot air drying (about 2 logarithmic cycle reduction). Minimal reductions were observed for P. acidilactici for most conditions of storage while for L. plantarum only during storage at 4 ºC. Taking into account the initial number of cells obtained after each drying process, the techniques which allowed survival of an increased number of cells after storage, were spray- and freeze drying. Better dissolution, color and vitamin C retention were also obtained when these techniques were used. Despite the scale-up and validation at industrial scale being still necessary, spray drying at pilot scale allowed producing a new functional orange juice powder with probiotic characteristics. The bacteria used demonstrated to be good candidates for the development of this product.O conceito de alimento funcional tem adquirido uma enorme dimensão graças ao grande número de pessoas preocupadas em consumir alimentos com benefícios para a saúde. Um alimento funcional inovador, não lácteo, poderá ser de grande interesse não só para este grupo de consumidores, mas também para nichos de mercado específicos (ex. intolerantes à lactose e vegetarianos). Este trabalho teve como objetivo o desenvolvimento de um sumo de laranja funcional desidratado. Foram usadas culturas com características probióticas e definiram-se as condições necessárias para obtenção do produto desidratado através de secagem por atomização. Selecionaram-se duas culturas, um probiótico comercial, Lactobacillus plantarum 299v, e um isolado de uma matriz alimentar, Pediococcus acidilactici HA-6111-2. Testou-se a segurança e a presença de algumas características funcionais de P. acidilactici e comparou-se com o probiótico comercial. Nenhuma das bactérias apresentou quaisquer dos factores de virulência; não exibiram resistências significativas a antibióticos e observou-se uma redução inferior a um ciclo logarítmico após exposição às condições do trato gastro-intestinal simulado. Verificou-se ainda a capacidade de ambas as bactérias sobreviverem ao processo de secagem por atomização e posterior armazenamento durante 60 dias. O sumo de laranja em pó foi obtido, numa primeira fase, por desidratação num Büchi Mini Spray Dryer mantendo constantes a temperatura de alimentação (ºC), as taxas de fluxo de alimentação (ºC), do ar de secagem (%) e do ar comprimido (L/h), variando as temperaturas do ar de entrada e de saída (ºC) e a proporção de sólidos solúveis totais (do sumo): auxiliar de secagem (10DE maltodextrina ou goma arábica). Às temperaturas de entrada e de saída selecionadas de 120 e 65 ºC, respetivamente, e proporção de sólidos solúveis: auxiliar de secagem de 0.5: 2, elevados rendimentos e pós com baixas actividades de água (aw) foram obtidos. Não foi observada inativação celular das culturas após incorporação em sumo de laranja e desidratação por atomização. Observou-se uma sobrevivência superior durante o armazenamento a 4 ºC do que à temperatura ambiente, sob valores de aw não controlados. Pediococcus acidilactici apresentou maior resistência que L. plantarum, especialmente a 4 ºC, com perdas de viabilidade inferiores a um ciclo logarítmico durante um período de, pelo menos, sete meses. Para aumentar a sobrevivência das bactérias desidratadas, diferentes condições pré-secagem foram testadas: i) diferentes açúcares foram adicionados ao meio de cultura (maior sobrevivência após crescimento na presença de lactose e glucose) e ii) exposição das células a diferentes stresses sub-letais (aumento da sobrevivência de L. plantarum durante o armazenamento à temperatura ambiente). Em ambos os casos, os pós obtidos foram armazenados em diferentes condições de temperatura, exposição de luz e aw. Globalmente, a sobrevivência foi superior a 4 ºC, com aw controlada a 0.03 e na ausência de luz. A viabilidade celular das duas culturas durante a passagem pelo trato gastro-intestinal simulado foi também investigada no fim do período de armazenamento a 4 ºC e não aumentou com a exposição aos stresses sub-letais. Avaliou-se a sobrevivência das culturas durante a secagem por diferentes técnicas (atomização, liofilização e convecção por ar quente) e posterior armazenamento nos pós de laranja obtidos. Apenas a secagem por convecção causou inativação celular (redução de 2 ciclos logarítmicos). Reduções mínimas foram observadas para P. acidilactici na maioria das condições de armazenamento, enquanto que para L. plantarum apenas a 4 ºC. Tendo em conta o número inicial de células obtidas após cada processo de secagem, as técnicas que permitiram a sobrevivência de um maior número de células após armazenamento foram as de secagem por atomização e liofilização. Melhor dissolução, cor e retenção de vitamina C foram também obtidas por estas técnicas. Apesar de ser ainda necessário o scale-up e validação à escala industrial, a secagem por atomização à escala piloto permitiu produzir um novo sumo de laranja funcional com características próbioticas. Os microrganismos estudados demonstraram ser bons candidatos para o desenvolvimento desse produto

Portuguese regional innovation systems efficiency in the European Union context

Current evidence on European regional innovation systems efficiency shows some conflicting results. Whereas some studies find support to a core-periphery distribution of efficiency, others find that lagging regions can be as well or even more efficient than rich regions in using their resources. This paper contributes to this debatable topic by providing additional evidence on the main determinants of the region's innovation efficiency and on efficiency differentials across EU regional innovation systems. Using data from 206 European regions and applying a stochastic production frontier methodology, our results corroborate the importance of interactions among regional agents on the region's efficiency score. More importantly, the distribution of efficiency scores across regional innovation systems does not entirely confirm the core-periphery divide among European regions. Instead, the mode of doing innovation appears to be a crucial explanatory factor of innovation efficiency at regional level. In the case of Portuguese regional innovation systems, they perform slightly below the average of their EU counterparts, except Lisbon's, and appear to be constrained by their mode of doing innovation.This work was carried out within the funding with COMPETE reference POCI-01-0145-FEDER-006683 (UID/ECO/03182/2013), with the FCT/MEC's (Fundacao para a Ciencia e Tecnologia) financial support through national funding and by the ERDF through the operational program on "Competitiveness and Internalization-COMPETE 2020 under the PT2020 Partnership Agreement.

Assessing antimicrobial efficacy on plastics and other non-porous surfaces: a closer look at studies using the ISO 22196:2011 standard

The survival and spread of foodborne and nosocomial-associated bacteria through hightouch surfaces or contamination-prone sites, in either healthcare, domestic or food industry settings, are not always prevented by the employment of sanitary hygiene protocols. Antimicrobial surface coatings have emerged as a solution to eradicate pathogenic bacteria and prevent future infections and even outbreaks. Standardised antimicrobial testing methods play a crucial role in validating the effectiveness of these materials and enabling their application in real-life settings, providing reliable results that allow for comparison between antimicrobial surfaces while assuring end-use product safety. This review provides an insight into the studies using ISO 22196, which is considered the gold standard for antimicrobial surface coatings and examines the current state of the art in antimicrobial testing methods. It primarily focuses on identifying pitfalls and how even small variations in methods can lead to different results, affecting the assessment of the antimicrobial activity of a particular product.info:eu-repo/semantics/publishedVersio

Effectiveness and durability of a quaternary ammonium compounds-based surface coating to reduce surface contamination

Foodborne diseases are of major concern as they have a significant impact on public health, both socially and economically. The occurrence of cross-contamination of food in household kitchens is a serious threat and the adoption of safe food practices is of paramount importance. This work aimed to study the effectiveness and durability of a commercial quaternary ammonium compound-based surface coating which, according to the manufacturer, retains its antimicrobial activity for 30 days, and is suitable for all types of hard surfaces for the prevention and/or control of cross-contamination. For that, its antimicrobial efficacy, killing contact time and durability on three different surfaces—polyvinyl chloride, glass, and stainless-steel—against three pathogens—Escherichia coli ATCC 25922, Acinetobacter baumannii ESB260 and Listeria monocytogenes Scott A—were tested according to the current antimicrobial treated surfaces efficacy test (ISO22196:2011). The results showed that the antimicrobial coating was effective against all pathogens with a reduction of >5.0 log CFU/cm2 in less than one minute for the three surfaces, but its durability was less than one week on all surfaces cleaned in the usual manner. Additionally, trace amounts (≤0.2 mg/kg) of the antimicrobial coating, which may migrate into food when contacting the surface, did not show cytotoxicity to human colorectal adenocarcinoma cells. The suggested antimicrobial coating has the potential to significantly reduce surface contamination, ensure surface disinfection and reduce the likelihood of cross-contamination in domestic kitchens, although it is less durable than suggested. The use of this technology in household settings is an attractive complement to the existing cleaning protocols and solutions that are already in place.info:eu-repo/semantics/publishedVersio

Analysis of bacterial communities of squid and shrimp skewers after immersion in a red wine vinegar-based solution

Seafood is a highly nutritious and essential component of a healthy diet.1 However, due to its perishable nature, seafood products have short shelf lives, leading to high prices and reduced desirability. In order to address this issue, various innovative techniques, such as High Pressure Processing and Ozonation, have been explored to extend the shelf life of seafood. While efficiency of such techniques varies, the cost of their application is usually high, increasing final price or reducing profit margins. Therefore, easier and cheaper, methods such as the pulverization or immersion of the product in antibacterial solutions are gaining popularity.2 To achieve the required bacterial inhibition and maintain an all-natural label, a seafood product, composed mainly of raw squid (Loligo duvauceli) andshrimp (Parapenaeopsis, Penaeus and Metapenaeus genus) was sprayed and immersed in a red wine vinegar-based solution. To perceive the efficiency of the treatment in the inhibition of unwanted spoilage bacteria, analysis of bacterial communities through sequencing of the 16S rRNA gene amplicons with NGS technologies (paired-end Illumina) was performed.info:eu-repo/semantics/publishedVersio

Spray drying encapsulation of probiotics and enzymes

Spray drying is one of the most frequently used encapsulation techniques. The incorporation of different active compounds in small capsules contributes to their protection and stability. Applications of spray drying of food ingredients are constantly being developed for the food industry due to the simplicity, low cost, effectiveness and versatility of this technique. Probiotics and other active compounds, such as enzymes, can be encapsulated by spray drying by combining various carrier materials, such as maltodextrins, gums, modified starch or alginate. However, exposure to high temperatures can be injurious to the integrity of probiotic cells or enzyme activity and can cause irreversible changes. Approaches such as enhancing pre- and post- spray drying steps are crucial to maintaining the integrity of these active compounds in the dried powders. This review focuses mainly on two major factors affecting the survival of probiotics and the activity of enzymes during spray drying, namely, the choice of carrier/wall material and drying temperature, bringing new light on how these influence post-drying characteristics of the final products.info:eu-repo/semantics/acceptedVersio

Incorporation of an acrylic fatty acid derivative as comonomer for oxidative cure in acrylic latex

An acrylic fatty acid derivative (AcFAD) was evaluated as comonomer for promotion of oxidative cure in waterborne latexes. AcFAD was polymerized by solvent homopolymerization and copolymerization and by emulsion copolymerization, and the final products characterized. In the two polymerization processes, NMR analyses confirmed that the reaction occurred involving both the terminal acrylic double bond and the conjugated double bonds of the aliphatic chain. Compared with a reference acrylic latex, the results obtained after AcFAD incorporation showed a time-dependent increase in gel content and in solvent resistance of dry films. These were ascribed to oxidative cure and consequent self-crosslinking of the acrylic polymer, involving the conjugated double bonds in AcFAD side chains. Oxidative cure was also confirmed by FTIR analyses. In addition, reduction in minimum film-forming temperature evidenced that AcFAD has an internal plasticization effect during film formation. Incorporation of this comonomer in acrylic paint binder formulations constitutes a promising alternative to the use of volatile coalescing agents

Microbial contamination of main contact surfaces of automated teller machines from metropolitan Area of Porto

Automated Teller Machines (ATM) are likely to be contaminated with various microorganisms because of their contact with the hands of many users daily. The main objective of this study was to investigate ATMs as a potential source of bacterial contamination. This study was conducted in the Metropolitan Area of Porto, in which 50 swab samples were cultured on selective media. Some isolates were identified based on colonial, morphological and biochemical characteristics. Susceptibility to several antibiotics was also evaluated for each isolated organism. Most contaminated ATMs had high numbers of Enterobacteriaceae and Enterococci. Staphylococci and Enterobacteriaceae were the most prevalent bacteria found. The recovered bacterial isolates varied in their antibiotic resistance pattern; Staphylococcus spp. demonstrated the most resistant profiles. With this pioneering study in Portugal, it was demonstrated that although ATMs in metropolitan area of Porto were not highly contaminated, some potentially pathogenic bacteria were present and resistant to some commonly used antibiotics.N/Ainfo:eu-repo/semantics/publishedVersio

Inhibition of several bacterial species isolated from squid and shrimp skewers by different natural edible compounds

Seafood is an excellent source of nutrients, essential for a healthy diet, ranging from proteins and fatty acids to vitamins and minerals. Seafood products are highly perishable foods due to their nutritional characteristics and composition. The application of nontoxic, natural, and edible preservatives to extend the shelf-life and inhibit bacterial proliferation of several foods has been a hot topic. Consequently, this work aimed to perform the microbiological characterization of squid and shrimp skewers during their shelf-life (five days) and evaluate the susceptibility of randomly isolated microorganisms to several natural edible compounds so that their application for the preservation and shelf-life extension of the product might be analyzed in the future. The product had considerably high total microorganisms loads of about 5 log CFU/g at day zero and 9 log CFU/g at day five. In addition, high bacterial counts of Pseudomonas spp., Enterobacterales, and lactic acid bacteria (LAB) were found, especially on the last day of storage, being Pseudomonas the dominant genus. However, no Escherichia coli or Listeria monocytogenes were detected on the analyzed samples. One hundred bacterial isolates were randomly selected and identified through 16s rRNA sequencing, resulting in the detection of several Enterobacterales, Pseudomonas spp., and LAB. The antibacterial activity of carvacrol, olive leaf extract, limonene, Citrox®, different chitosans, and ethanolic propolis extracts was evaluated by the agar diffusion method, and the minimum inhibitory concentration was determined only for Citrox® since only this solution could inhibit all the identified isolates. At concentrations higher than or equal to 1.69% (v/v), Citrox® demonstrated bacteriostatic and bactericidal activity to 97% and 3% of the isolates, respectively. To our knowledge, there are no available data about the effectiveness of this commercial product on seafood isolates. Although preliminary, this study showed evidence that Citrox® has the potential to be used as a natural preservative in these seafood products, improving food safety and quality while reducing waste. However, further studies are required, such as developing a Citrox®-based coating and its application on this matrix to validate its antimicrobial effect.info:eu-repo/semantics/publishedVersio

Novel approach for a controlled delivery of essential Oils during long-term maize storage: clove bud and pennyroyal oils efficacy to control sitophilus zeamais, reducing grain damage and post-harvest losses

Maize grains represent a significant contribution for assuring food safety all over the globe. Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae), also known as the maize weevil, is one of the most destructive pests in stored maize, causing qualitative and quantitative losses. To control S. zeamais populations in maize storage sites, synthetical chemical insecticides are applied. However, these are often used wastefully, have environmental implications, and can induce the development of resistant populations. In this work, the insecticidal and grain protecting efficacy of an innovative macro-capsule delivery device, loaded with essential oils from Clove bud and Pennyroyal, as well as their combined solutions, was tested against naturally S. zeamais-infested maize grains. The blend of both compounds incorporated in a controlled release device reduced losses by more than 45% over a long storage period of twenty weeks, diminishing the survivability of maize weevils by over 90%. The usage of the blend at a concentration of 370 L L1 air with an antioxidant showed the best results, however, by halving the concentration 185 L L1 air , a significant control of S. zeamais populations was still achieved.info:eu-repo/semantics/publishedVersio