Larval Rearing and Nutrition of the Polyphagous Tephritid Pest Anastrepha ludens on Artificial Diets with Calcium Alginate, Agar, or Carrageenan as Gelling Agents at Various Concentrations and across Extreme Larval Density Conditions.

Research on larval rearing and nutrition of tephritid flies on artificial diets is key for the sterile insect technique. Here, we examined the effects of the type of gel (calcium alginate, agar, or carrageenan), at varying percentages in artificial diets for the polyphagous pest Anastrepha ludens, on the physicochemical and nutritional traits of the diets, and the effects of the type of gel, the gel content and the larval density (larvae/g of diet) used in production, quality parameters for mass-reared tephritids, diet removal (an indirect estimation of diet consumption), and nutritional traits of flies. Regardless of the gel content, calcium alginate diets were firmer and more resistant to penetration than the agar and carrageenan diets. The larval recovery, pupation, pupal weight, and flight ability of A. ludens were lower in calcium alginate diets than in agar and carrageenan diets. Diet removal was higher in calcium alginate diets; however, low levels of ammonium and high levels of uric acid in excretions from larvae on these diets suggest an alteration in protein metabolism. The firmness and penetration resistance characteristics of calcium alginate diets may have limited movement and feeding of larvae, but this could be overcome by the collective feeding of large groups of larvae. Our findings provide insights into the mechanism governing gel-diet rearing systems for A. ludens.

Pressurized Hot Water Extraction and Bio-Hydrogels Formulation with Aristotelia chilensis [Mol.] Stuntz Leaves.

Aristotelia chilensis is a plant rich in phenolics and other bioactive compounds. Their leaves are discarded as waste in the maqui berry industry. A new application of these wastes is intended by the recovery of bioactive compounds using pressurized hot water extraction with conventional or microwave heating. Both technologies have been selected for their green character regarding the type of solvent and the high efficiency in shorter operation times. Extractions were performed in the temperature range 140-200 °C with a solid/liquid ratio of 1:15 (w:w). The extracts' total phenolic content, antioxidant capacity, and saccharides content obtained with both heating methods were measured. Additionally, the thermo-rheological properties of the gelling matrix enriched with these extracts were analyzed. Optimum conditions for lyophilized extracts were found with conventional heating, at 140 °C and 20 min extraction; 250.0 mg GAE/g dry extract and 1321.5 mg Trolox/g dry extract. Close to optimum performance was achieved with microwave heating in a fraction of the time (5 min) at 160 °C (extraction), yielding extracts with 231.9 mg GAE/g dry extract of total phenolics and antiradical capacity equivalent to 1176.3 mg Trolox/g dry extract. Slightly higher antioxidant values were identified for spray-dried extracts (between 5% for phenolic content and 2.5% for antioxidant capacity). The extracts obtained with both heating methods at 200 °C contained more than 20% oligosaccharides, primarily glucose. All the formulated gelling matrices enriched with the obtained extracts displayed intermediate gel strength properties. The tested technologies efficiently recovered highly active antioxidant extracts, rich in polyphenolics, and valuable for formulating gelling matrices with potential applicability in foods and other products.

Costreductionin the micropropagation of Solanum lycopersicumL. var.cerasiforme / Redução de custos na micropropagação de Solanum lycopersicumL. var. cerasiforme

The aimof this study was to establish a low-cost alternative protocol for micropropagation ofSolanum lycopersicumL. var.cerasiforme,popularly known as cherry tomato. In the in vitroestablishment, culture mediacontaining Laboratory Reagent-grade (LR)and commercialsucrose and varied concentrations of corn starch and agarwere tested. The replacement of thermal sterilization, usingautoclave,withchemicalsterilization,adding sodium hypochlorite (2%) in the medium, was also evaluated. In the multiplication stage,the mediumwas supplemented with agar and/or corn starch and commercial sucrose.Forrooting, agrowth regulator-free medium withcommercialsucrose supplemented with agar and/or starch was used. Themicroplants were thentransplanted into plasticcontainerscontainingonlygarden substrateandsubsequentlyacclimatized in a greenhouse.The results make it possibleto conclude that the reduction of costs in the micropropagation of cherry tomatocan beobtained by replacing LRsucrose with commercial sucrose,and by the use of chemical sterilization of the culture medium withsodium hypochlorite. The replacement of agar withcorn starch can be done partially, in the stages of establishment and multiplication,and totally, during rooting.(AU)

O objetivo deste estudo foi estabelecer um protocolo alternativo de baixo custo para micropropagação de Solanum lycopersicumL. var. cerasiforme, conhecida popularmente como tomate cereja. Noestabelecimento in vitro foram testados meios de cultura contendo sacarose P.A. e comercial e concentrações variadas de amido de milho e ágar. Também avaliou-se a substituição da esterilização física pela esterilização química. Na etapa de multiplicação o meio foi suplementado com ágar e/ou amido de milho e sacarose comercial. Para o enraizamento utilizou-se meio isento de regulador com sacarose comercial suplementado com ágar e/ou amido. As microplantas foramtransplantadas para terra vegetal e aclimatizadas em casa de vegetação. Os resultados permitem concluir que a redução de custos na micropropagação do tomate cereja é obtida pela substituição de sacarose P.A. pela sacarose comercial, substituição parcial (estabelecimento e multiplicação) e total (enraizamento) de ágar por amido de milho e pela utilização de esterilização química do meio.(AU)

Costreductionin the micropropagation of Solanum lycopersicumL. var.cerasiforme / Redução de custos na micropropagação de Solanum lycopersicumL. var. cerasiforme

The aimof this study was to establish a low-cost alternative protocol for micropropagation ofSolanum lycopersicumL. var.cerasiforme,popularly known as cherry tomato. In the in vitroestablishment, culture mediacontaining Laboratory Reagent-grade (LR)and commercialsucrose and varied concentrations of corn starch and agarwere tested. The replacement of thermal sterilization, usingautoclave,withchemicalsterilization,adding sodium hypochlorite (2%) in the medium, was also evaluated. In the multiplication stage,the mediumwas supplemented with agar and/or corn starch and commercial sucrose.Forrooting, agrowth regulator-free medium withcommercialsucrose supplemented with agar and/or starch was used. Themicroplants were thentransplanted into plasticcontainerscontainingonlygarden substrateandsubsequentlyacclimatized in a greenhouse.The results make it possibleto conclude that the reduction of costs in the micropropagation of cherry tomatocan beobtained by replacing LRsucrose with commercial sucrose,and by the use of chemical sterilization of the culture medium withsodium hypochlorite. The replacement of agar withcorn starch can be done partially, in the stages of establishment and multiplication,and totally, during rooting.

O objetivo deste estudo foi estabelecer um protocolo alternativo de baixo custo para micropropagação de Solanum lycopersicumL. var. cerasiforme, conhecida popularmente como tomate cereja. Noestabelecimento in vitro foram testados meios de cultura contendo sacarose P.A. e comercial e concentrações variadas de amido de milho e ágar. Também avaliou-se a substituição da esterilização física pela esterilização química. Na etapa de multiplicação o meio foi suplementado com ágar e/ou amido de milho e sacarose comercial. Para o enraizamento utilizou-se meio isento de regulador com sacarose comercial suplementado com ágar e/ou amido. As microplantas foramtransplantadas para terra vegetal e aclimatizadas em casa de vegetação. Os resultados permitem concluir que a redução de custos na micropropagação do tomate cereja é obtida pela substituição de sacarose P.A. pela sacarose comercial, substituição parcial (estabelecimento e multiplicação) e total (enraizamento) de ágar por amido de milho e pela utilização de esterilização química do meio.

Use of FT-IR, FT-Raman and thermal analysis to evaluate the gel formation of curdlan produced by Agrobacterium sp. IFO 13140 and determination of its rheological properties with food applicability.

Curdlan is a linear polysaccharide composed of glucose units joined by ß-(1,3) bonds that possesses unique gelation properties. This study aimed to characterize the structure and evaluate the gelling properties of curdlan produced by Agrobacterium sp. IFO 13140 and its gels, as well as apply it in food. FT-Raman analysis highlighted the structural changes that occurred during the formation of gels, with variations related to the hydrogen bonds and hydrophobic interactions, which occur with the formation of the low-set and high-set gels, respectively. Rheological analysis showed that the pre-gelled commercial curdlan and the curdlan produced by Agrobacterium sp. IFO 13140 differed in terms of gelation properties, which depends of the degree of polymerization of the polysaccharide, but when applied to pasta products, both improved the texture parameters. The curdlan gels were found to have great potential as gelling agents to improve texture, water retention capacity and stability of food products.

Uso de ágar, amido e ácido indolbutírico no enraizamento in vitro do porta-enxerto de macieira MM 111

The agar is one of the most expensive componnts in a tissue culture medium when vitro propagation is concerned. This work was carried out in the tissue culture laboratory at EMBRAPA/CPACT, Pelotas RS. The objective of this work was to test the agar action and its partia1 substitution for cassava starch in the composition of the solidifying agent in the MS basal medium associated winth 0; 2.5; 5.0; 7.5 and 10.0µM indolyl butyric acid (IBA). The solidifying agents were as fallows: agar (6g.L-1) agar (3g.L-1) + cassava starch (50g.L-1). The MS basal medium was reduced to half strength and added to myo-inositol (100mg.L-1); sucrose (30g.L-1) and the pH adjusted to 5.9 before autoclaving. The explants were kept for 30 days in the growth room under 25±2°C, 16-hour photoperiod and about 2000 lux light intensity. The use of agar + starch promoted a higher number of roots, and a maximization was observed in the presence of 5µM IBA. It also antecipated the new roots in about 10 days. The consistency of the agar/starch was quite the same as agar e it appeared less transparent.

O ágar é um dos componentes mais caros do meio de propagação in vitro. Visando a reduzir custos, os estudos foram desenvolvidos no Laboratório de Cultura de Tecidos da EMBRAPA/CPACT, Pelotas RS, objetivando-se testar a ação do ágar e da sua substitução parcial pelo amido de mandioca na composição do agente solidificante (AS) do meio MS, associados às concentrações de 0; 2,5; 5,0; 7,5 e 10µM de ácido indolbutírico (AIB). Os dois AS de meio de cultivo testados: AS1 - 6g/l de ágar e; AS2 - combinação de 3g/l de ágar mais 50g/l de amido de mandioca (fécula), tiveram redução de Vi dos sais de MS e acréscimos de 100mg/l de mio-inositol e 30g/l de sacarose, juntamente com pH ajustado em 5,9 antes da autoclavagem. Os explantes foram mantidos por 30 dias em sala de crescimento sob condições de 25±2°C, 16 horas de fotoperíodo e ±2000lux de intensidade luminosa. O AS2, além de apresentar o maior número de raízes, e maximizá-las na presença de 5µM de AIB, antecipou em cerca de 10 dias o surgimento destas e apresentou consistência semelhante ao AS1, sendo apenas menos transparente.

Uso de ágar, amido e ácido indolbutírico no enraizamento in vitro do porta-enxerto de macieira MM 111

The agar is one of the most expensive componnts in a tissue culture medium when vitro propagation is concerned. This work was carried out in the tissue culture laboratory at EMBRAPA/CPACT, Pelotas RS. The objective of this work was to test the agar action and its partia1 substitution for cassava starch in the composition of the solidifying agent in the MS basal medium associated winth 0; 2.5; 5.0; 7.5 and 10.0µM indolyl butyric acid (IBA). The solidifying agents were as fallows: agar (6g.L-1) agar (3g.L-1) + cassava starch (50g.L-1). The MS basal medium was reduced to half strength and added to myo-inositol (100mg.L-1); sucrose (30g.L-1) and the pH adjusted to 5.9 before autoclaving. The explants were kept for 30 days in the growth room under 25±2°C, 16-hour photoperiod and about 2000 lux light intensity. The use of agar + starch promoted a higher number of roots, and a maximization was observed in the presence of 5µM IBA. It also antecipated the new roots in about 10 days. The consistency of the agar/starch was quite the same as agar e it appeared less transparent.

O ágar é um dos componentes mais caros do meio de propagação in vitro. Visando a reduzir custos, os estudos foram desenvolvidos no Laboratório de Cultura de Tecidos da EMBRAPA/CPACT, Pelotas RS, objetivando-se testar a ação do ágar e da sua substitução parcial pelo amido de mandioca na composição do agente solidificante (AS) do meio MS, associados às concentrações de 0; 2,5; 5,0; 7,5 e 10µM de ácido indolbutírico (AIB). Os dois AS de meio de cultivo testados: AS1 - 6g/l de ágar e; AS2 - combinação de 3g/l de ágar mais 50g/l de amido de mandioca (fécula), tiveram redução de Vi dos sais de MS e acréscimos de 100mg/l de mio-inositol e 30g/l de sacarose, juntamente com pH ajustado em 5,9 antes da autoclavagem. Os explantes foram mantidos por 30 dias em sala de crescimento sob condições de 25±2°C, 16 horas de fotoperíodo e ±2000lux de intensidade luminosa. O AS2, além de apresentar o maior número de raízes, e maximizá-las na presença de 5µM de AIB, antecipou em cerca de 10 dias o surgimento destas e apresentou consistência semelhante ao AS1, sendo apenas menos transparente.