Valorisation of rejected unripe plantain fruits of Musa AAB Simmonds: from nutritional characterisation to the conceptual process design for prebiotic production.

The increasing consumption of plantain fruits with specific quality standards generates high agricultural waste. This work aimed at valorising the rejected unripe pulp of Dominico-Hartón plantain fruits (Musa AAB Simmonds). The pulp was characterised physico-chemically, thermally and functionally. The data gathered experimentally and collected from different databases were used to design a production process of isomalto-oligosaccharides (IMO) syrup. The plantain flour contains high levels of starch (87 ± 2%) and amylose (31.2 ± 0.8%). The flour showed stability at high temperatures (pasting temperature of 79.26 ± 0.02 °C), allowing its use in high temperature processes. In vitro gastrointestinal digestion of the plantain flour showed that when cooked, the glycemic index of the flour increased from 47.7 ± 2.2 to 84.2 ± 1.8, while its resistant starch content only slightly decreased from 71.7 ± 1% to 52.6 ± 2%, suggesting that this type of flour preserves high content of dietary fibre after digestion. The conceptual process design showed that 24.48 g of IMO are theoretically obtained from 53.24 g of plantain flour maltose. These results suggest that the rejected plantain pulp holds high potential as an ingredient for the production of prebiotic compounds such as IMO.

Review of Lactobacillus in the food industry and their culture media / Revisión de Lactobacilos en la industria alimentaria y sus medios de cultivo

ABSTRACT Lactic acid bacteria (LAB) are currently of great importance given their increasing use in the improvement of human and anima health and nutrition. They exhibit complex nutritional requirements, which is the reason why their production costs are high. Research efforts are being made aimed at evaluating different substrates for their production as well as the production of valuable metabolites from them. The purpose of this paper is to expose the main research and development trends for LAB production for industrial purposes with emphasis on the culture media required for their growth. The web of Science databases as well as the Google Patent Search tool were used in order to gather and analyze the scientific and technical information published in the last twelve years relating to LAB and their culture media. The use of milk, industrial cheese whey, cane molasses, hydrolyzed starches, lignocellulosic materials, organic food waste and bovine blood plasma, among others, have been proposed for Lactobacillus cultivation with the purpose of reducing costs and increasing performance in their production. Research groups and centers have the responsibility of intensifying their efforts to offer highly efficient technological alternatives to the industry that allow the production and application of LAB as a growth factor for the food sector. Also, research in prebiotic ingredients or additives derived from LAB that allow the enhancement of the benefits to the consumer must be continued. In this regard, it is necessary to increase the international visibility of Colombian scientific production in this area.

RESUMEN Las bacterias del ácido láctico (LAB) son actualmente de gran importancia dado su uso creciente en la mejora de la salud y nutrición humana y animal. Presentan requerimientos nutricionales complejos, por lo que sus costos de producción son altos. Se están realizando esfuerzos de investigación para evaluar diferentes sustratos para su producción, así como la producción de metabolitos valiosos a partir de ellos. El propósito de este documento es exponer las principales tendencias de investigación y desarrollo para la producción de LAB con fines industriales, con énfasis en los medios de cultivo necesarios para su crecimiento. Las bases de datos de Web of Science y la herramienta de búsqueda de patentes de Google se utilizaron para recopilar y analizar la información científica y técnica publicada en los últimos doce años relacionada con LAB y sus medios de cultivo. Se ha propuesto el uso de leche, suero de queso industrial, melaza de caña, almidones hidrolizados, materiales lignocelulósicos, desechos de alimentos orgánicos y plasma sanguíneo bovino, entre otros, para el cultivo de Lactobacillus con el fin de reducir costos y aumentar el rendimiento de su producción. Los grupos y centros de investigación tienen la responsabilidad de intensificar sus esfuerzos para ofrecer alternativas tecnológicas altamente eficientes a la industria que permitan la producción y aplicación de LAB como factor de crecimiento para el sector alimentario. Además, la investigación en ingredientes prebióticos o aditivos derivados de LAB que permite la mejora de los beneficios para el consumidor debe continuar. En este sentido, es necesario aumentar la visibilidad internacional de la producción científica colombiana en esta área.

Compost supplementation with nutrients and microorganisms in composting process.

The composting is an aerobic, microorganism-mediated, solid-state fermentation process by which different organic materials are transformed into more stable compounds. The product obtained is the compost, which contributes to the improvement of physical, chemical and microbiological properties of the soil. However, the compost usage in agriculture is constrained because of its long-time action and reduced supply of nutrients to the crops. To enhance the content of nutrients assimilable by the plants in the compost, its supplementation with nutrients and inoculation with microorganisms have been proposed. The objective of this work was to review the state of the art on compost supplementation with nutrients and the role played by the microorganisms involved (or added) in their transformation during the composting process. The phases of composting are briefly compiled and different strategies for supplementation are analyzed. The utilization of nitrogenous materials and addition of microorganisms fixing nitrogen from the atmosphere or oxidizing ammonia into more assimilable for plants nitrogenous forms are analyzed. Several strategies for nitrogen conservation during composting are presented as well. The supplementation with phosphorus and utilization of microorganisms solubilizing phosphorus and potassium are also discussed. Main groups of microorganisms relevant during the composting process are described as well as most important strategies to identify them. In general, the development of this type of nutrient-enriched bio-inputs requires research and development not only in the supplementation of compost itself, but also in the isolation and identification of microorganisms and genes allowing the degradation and conversion of nitrogenous substances and materials containing potassium and phosphorus present in the feedstocks undergoing the composting process. In this sense, most important research trends and strategies to increase nutrient content in the compost are provided in this work.

Conceptual design of cost-effective and environmentally-friendly configurations for fuel ethanol production from sugarcane by knowledge-based process synthesis.

In this work, the hierarchical decomposition methodology was used to conceptually design the production of fuel ethanol from sugarcane. The decomposition of the process into six levels of analysis was carried out. Several options of technological configurations were assessed in each level considering economic and environmental criteria. The most promising alternatives were chosen rejecting the ones with a least favorable performance. Aspen Plus was employed for simulation of each one of the technological configurations studied. Aspen Icarus was used for economic evaluation of each configuration, and WAR algorithm was utilized for calculation of the environmental criterion. The results obtained showed that the most suitable synthesized flowsheet involves the continuous cultivation of Zymomonas mobilis with cane juice as substrate and including cell recycling and the ethanol dehydration by molecular sieves. The proposed strategy demonstrated to be a powerful tool for conceptual design of biotechnological processes considering both techno-economic and environmental indicators.

Process integration possibilities for biodiesel production from palm oil using ethanol obtained from lignocellulosic residues of oil palm industry.

In this paper, integration possibilities for production of biodiesel and bioethanol using a single source of biomass as a feedstock (oil palm) were explored through process simulation. The oil extracted from Fresh Fruit Bunches was considered as the feedstock for biodiesel production. An extractive reaction process is proposed for transesterification reaction using in situ produced ethanol, which is obtained from two types of lignocellulosic residues of palm industry (Empty Fruit Bunches and Palm Press Fiber). Several ways of integration were analyzed. The integration of material flows between ethanol and biodiesel production lines allowed a reduction in unit energy costs down to 3.4%, whereas the material and energy integration leaded to 39.8% decrease of those costs. The proposed integrated configuration is an important option when the technology for ethanol production from biomass reaches such a degree of maturity that its production costs be comparable with those of grain or cane ethanol.

Trends in biotechnological production of fuel ethanol from different feedstocks.

Present work deals with the biotechnological production of fuel ethanol from different raw materials. The different technologies for producing fuel ethanol from sucrose-containing feedstocks (mainly sugar cane), starchy materials and lignocellulosic biomass are described along with the major research trends for improving them. The complexity of the biomass processing is recognized through the analysis of the different stages involved in the conversion of lignocellulosic complex into fermentable sugars. The features of fermentation processes for the three groups of studied feedstocks are discussed. Comparative indexes for the three major types of feedstocks for fuel ethanol production are presented. Finally, some concluding considerations on current research and future tendencies in the production of fuel ethanol regarding the pretreatment and biological conversion of the feedstocks are presented.

Fuel ethanol production: process design trends and integration opportunities.

Current fuel ethanol research and development deals with process engineering trends for improving biotechnological production of ethanol. In this work, the key role that process design plays during the development of cost-effective technologies is recognized through the analysis of major trends in process synthesis, modeling, simulation and optimization related to ethanol production. Main directions in techno-economical evaluation of fuel ethanol processes are described as well as some prospecting configurations. The most promising alternatives for compensating ethanol production costs by the generation of valuable co-products are analyzed. Opportunities for integration of fuel ethanol production processes and their implications are underlined. Main ways of process intensification through reaction-reaction, reaction-separation and separation-separation processes are analyzed in the case of bioethanol production. Some examples of energy integration during ethanol production are also highlighted. Finally, some concluding considerations on current and future research tendencies in fuel ethanol production regarding process design and integration are presented.