Analytical investigation of chromium and zinc in sweet, sour and bitter tasting fruits, vegetables and medicinal plants

Sweet, sour and bitter tasting fruits, vegetables and medicinal plants are an important component of human diet. The role of chromium and zinc in carbohydrate metabolism for control of diabetes is highlighted in selected commodities. Average levels of chromium and zinc in sweet taste were 0.69 ± 0.48 mg kg-1 and 4.81 ± 4.31 mg kg-1 respectively with correlation of 0.545, while in sour taste the values were 22.5 ± 22.0 mg kg-1 and 24.5 ± 11.8 mg kg-1 respectively with the correlation of 0.239 and in bitter taste, 0.61 ± 0.33 mg kg-1 and 4.70 ± 3.54 mg kg-1 respectively with correlation of 0.343. Overall, sour tasting commodities were found higher in levels of chromium and zinc and are recommended as food supplement for diabeties. None of these species contain metals above the toxic level.

Optimization of methodology to analyze ascorbic and dehydroascorbic acid in vegetables

In this study, different solutions to extract vitamin C were tested. High-performance liquid chromatography was chosen and the conditions were based on isocratic elution in reverse phase column. Dehydroascorbic acid was determined indirectly after its reduction using dithiothreitol. The use of metaphosphoric acid to stabilize the vitamin C was shown to be required and it was necessary to neutralize the pH of the extract to apply dithiothreitol. The average recovery was 90% in collard and tomato samples. The presence of oil did not interfere in extraction and the methodology can be used to analyze stir fried vegetables.

Removal of organic matter and nutrients from slaughterhouse wastewater by using Eichhornia crassipes and evaluation of the generated biomass composting

The objective of this research was to evaluate the performance of the aquatic macrophyte Eichhornia crassipes applied in situ in a slaughter house treatment system, located in the west of the Paraná state, Brazil, regarding the nutrients removal and organic matter. Moreover, it aimed to obtain data from the production, management and composting practices of the biomass generated in the system. During 11 months of macrophytes development, physic and chemical parameters were monitored and plant density was controlled by periodical removal of excess biomass, which was weekly monitored and it is expressed in kg of aquatic plant per m² covered area. The degradation of the macrophytes removed from the treatment system was evaluated at the pilot scale in eight composting piles of 0.60 m³ that underwent four different treatments and two repetitions: T1 - water hyacinth (Eichhornia crassipes); T2 - water hyacinth and swine excrement (7:1), T3 - water hyacinth, swine excrement and earth (7:1:0,67), and T4 - water hyacinth, swine excrement and cellulosic gut (7:1:0,67), for a period of 90 days. The results indicated maximum removal efficiencies of 77.2% for COD; 77.8% for BOD, 87.9% for total nitrogen, 47.5% for ammonia nitrogen and 38.9% for total phosphorus for a five-day retention time. For biomass stabilization by composting, considering the C:N ratio as an indicator of compost maturity, it was observed that treatment T4 resulted in the shortest stabilization period (60 days). No difference was verified in the biostabilization rates at 5% level by the F test.

Recycling of nutrients with application of organic waste in degraded pasture

The utilization of organic wastes represents an alternative to recover degraded pasture. The experiment aimed to assess the changes caused by the provision of different organic waste (poultry litter, turkey litter and pig manure) in a medium-textured Oxisol in Brazilian Savanna under degraded pasture. It was applied different doses of waste compared to the use of mineral fertilizers and organic mineral and evaluated the effect on soil parameters (pH, organic matter, phosphorus and potassium) and leaf of Brachiariadecumbens (crude protein, phosphorus and dry mass production). It was observed that application of organic waste did not increase the level of soil organic matter and pH in the surface layer, and the application of turkey litter caused acidification at depths of 0.20-0.40 m and 0.40-0.60 m. There was an increase in P and K in the soil with the application of poultry litter and swine manure. All organic wastes increased the productivity of dry matter and crude protein and phosphorus. The recycling of nutrients via the application of organic waste allows efficiency of most parameters similar to those observed with the use of mineral sources, contributing to improving the nutritional status of soil-plantsystem.

Nitrogen fertilization by deep bedding swine production and its effects on dry matter production and accumulation of nutrients by maize

The goal of this study was to evaluate the nitrogen fertilization as deep litter for pigs in order to produce biomass and accumulate nutrients by the corn. A deep litter made of rice husk as organic compound, from a commercial pig farm during finishing phase, was used. After three consecutive batches of pigs, the deep litter was subjected to a maturation period of 50 days, and samples of this material were taken for analysis of agronomic value. The experimental design was completely randomized with five replicates. The treatments consisted of doses of 0, 75, 150 and 300mg dm-3 of N of deep litter, as well as an additional treatment with ammonium sulfate, with a dosage of 150mg dm-3 of N. After 45 days, corn plants were harvested in order to evaluate the total dry weight and nutrient concentrations of their aerial parts. Dry matter increases were found with more application of deep litter. Regarding control fertilization, the use of increasing dosages of deep litter allowed accumulation of K, reduced the availability of P, Ca, Mg, Zn and B and did not alter the concentrations of N, Cu, Fe and Mn.

COD, TSS, nutrients and coliforms removals in UASB reactors in two stages treating swine wastewater

The performance of two upflow anaerobic sludge blanket (UASB) reactors was evaluated in pilot scale (908 and 188 L), installed in series (R1 and R2), fed with swine wastewater with TSS around 5 and 13 g L-1. The UASB reactors were submitted to HDT of 36 and 18 h with VOL of 5.5 to 34.4 g COD (L d)-1 in the R1 and HDT of 7.5 e 3.7 h with VOL from 5.1 to 45.2 g COD (L d)-1 in the R2. The average removal efficiencies of COD ranged from 55 to 85% in the R1 and from 43 to 57% in the R2, resulting in values from 82 to 93% in the UASB reactors in two stage. Methane concentrations in the biogas were 69 to 74% with specific production from 0.05 to 0.27 L CH4 (g removedCOD)-1 in the R1 and of 0.10 to 0.12 L CH4 (g removedCOD)-1 in the R2. The average removal efficiencies were 61 to 75% for totalP, 39 to 69% for KN, 82 to 93% for orgN and 20 to 94% for Fe, Zn, Cu and Mn. The amN concentration were not reduced indicating the need to post-treatment for effluent disposal into water bodies. There were reductions of total coliforms from 99.8123 to 99.9989% and of thermotolerant coliforms from 99.9725 to 99.9999%. The conditions imposed to the UASB reactors in two stage provided high conversions of removedCOD into methane (up to 77%) and reductions of organic an inorganic pollution loads from swine wastewater.

Portable flow board for storage of fruits and vegetables in mini-chambers with controlled atmosphere

ABSTRACT A portable flow board system was developed in the present study with the aim to facilitate lab-scale experiments of controlled atmosphere (CA) with fruits and vegetables. This sturdy flow board combines ease fabrication, low cost and gas economy. Its functionality is provided by manifolds and gas mixers. Each gaseous component is supplied by a gas cylinder through a differential valve of adjusted pressure control, generally at 6 kPa, and forced through 13 standardized restrictors coupled to each manifold output. Controlled atmospheres are then formed with one, two or three gases in 13 gas mixers affixed to the flow board base, which are further conducted through flexible tubes to storage mini-chambers that can also be used to study metabolic consumption and production of gaseous components. The restrictors used in the flow gaseous components were manufactured from microhematocrit test-type capillary glass tubes following the hot forming method under continuous air flow. The portable flow board showed to be low cost and simple post-harvest equipment that allows preparing controlled atmospheres in open systems with stable composition and flow, in a manner similar to traditional flow boards with control of gas escape by barostats.

Transition management and the sustainable nutrients economy in the Netherlands; positioning paper

In this positioning paper transition management (TM) and the sustainable nutrient economy are addressed. We discuss TM from its scholarly origins in the 1990’s to its implementation as a comprehensive sector-wide policy program on sustainability in The Netherlands during the first decade of the 2000´s. Although the program was innovative and provoked a new approach to environmental policy and governance, the program at large failed to set the right conditions under which sustainable transition take place. Lessons from the Netherlands, both successful and less successful, are addressed in this positioning paper to inform Finnish governmental and knowledge institutes on how (not) to implement TM on environmental issues. When looking at sustainable nutrient economy the paper takes a historical view at how problems with nutrients (especially phosphates) were dealt with in the Netherlands during the post World War II era. This transition did not occur easily. In the agricultural sector environmental policies to prevent nutrient problems were not easily accepted, as large agricultural economic interests were at stake and the sector’s main actors were generally opposed to (radical) environmental transition. Currently, sustainable nutrient economy initiatives are starting to receive attention on the political agenda once again. In 2011 a sector- and chain-wide covenant was signed, showing that sustainable nutrient transition goals get commitment from stakeholders throughout the nutrient chain. We judge that TM provides useful elements that are applicable to Finnish governance modes to support sustainable nutrient economy transition. However, the Finnish government should be careful when implementing TM to prevent making the same mistakes the Dutch government made in previous years.

Levels of nutrients and grain yield of maize intercropped with signalgrass (Brachiaria) in different arrangements of plants

Competition between maize and signalgrass can economically cripple the intercropping by the reduced yield of maize and dry matter content of the forage. In seeking to define plant arrangements which make this system more efficient, this research was held with the objective of assessing the effects of interference of densities of signalgrass (Urochloa Brizantha) on nutrition and on maize grain yield. Two field experiments were conducted in a randomized block design with four replications. Treatments were arranged similarly in both experiments, in a 2 x 4 factorial design, the first factor being the dose of Nicosulfuron herbicide applied (0 and 8 g ha-1) and the second factor being the forage seeding rates (0, 2, 4 and 6 kg of seeds per hectare). The interference of signalgrass reduced foliar nitrogen, potassium and phosphorus content in maize plants intercropped with the forage. Higher values of grain yield were observed with the reduction of the spacing and the application of the recommended herbicide underdose (8 g ha-1). It was concluded that, regardless of the seeding density of U. Brizantha, reducing the maize seeding inter-rows spacing, combined with the application of an underdose of Nicosulfuron, caused a positive effect by reducing the initial forage growth, resulting in less interference of Urochloa brizantha on nutrient uptake by the maize plants and grain yield of the crop.

Feasibility of the use of recycled nutrients in fast growing pulpwood production

The application of pulp and paper mill (PPM) sludge in agriculture and forestry has been acknowledged as soil amendments and a plant nutrient source. The main objectives of this study were to evaluate the total cost of the use of recycled nutrients from PPM sludge in fast growing pulpwood production, and the financial profitability of fast growing pulpwood production with the use of these recycled nutrients. The investment and production costs of fast growing pulpwood plantation were directly acquired from a previous research, while the other data was compiled through different studies. The total cost of the use of PPM sludge was evaluated based on assumed factors. Discounted cash flow method was used to evaluate the financial profitability, using NPV and IRR as indicators. The results of estimated sludge nutrient contents were 16.2 g N, 2.9 g P, and 2.4 g K kg-1 of dry sludge. The sludge application rate was estimated at 1.36 Mg/ha in the first year. The total cost of the use of PPM sludge involved transport and spreading cost of US$49.15/dry ton. The fertilization cost applied in the financial model was designed in 3 different options and their results were as follows: option (1) was taken directly from the reference research (US$97/ha); option (2) was the use of sludge alone (US$66.75/ha); and option (3) was the use of sludge and TSP fertilizer (US$83.80/ha). The average NPV without discounting was US$248,180 while the IRRs ranged between approximately 3-4% with an average of 3.63%. Although option (2) and (3) contributed to higher IRRs compared to option (1), this increase was still not significant as the IRR was not sensitive to the total fertilization cost. The advantages are that this practice can be performed at a lower cost and the application rate can be still increased if necessary. It is better for forest plantations compared to agriculture and consequently supports reforestation program. In addition, it can be similarly applied in wood biomass production. A disadvantage is that the IRRs were not very favorable compared to the criterion of 11%. The sludge high in C:N ratio can cause nitrogen immobilization, and regulatory concerns may restrict and complicate the use of sludge landspreading and contribute to additional costs and processes.

Nutrients in the cassava (Manihot esculenta Crantz) leaf meal at three ages of the plant

The high number of cassava cultivars adapted to many different regions provides a wide variation in the chemical composition of cassava leaves meal (CLM). Therefore, the contents of some nutrients in CLM from five cultivars at three ages of the plant were investigated in order to select the cultivars and ages with superior levels of these nutrients. When the plants were 12 months old, the highest levels of crude protein (CP), beta-carotene, iron, magnesium, phosphorus and sulfur were observed. The IAC 289-70 cv. showed the highest levels of magnesium, as well as considerable contents of CP, beta-carotene, iron, zinc and sulfur, which did not differ statistically from the cultivars showing the highest levels of these nutrients.

The Brazilian consumer's understanding and perceptions of organic vegetables: a Focus Group approach

Focus Group is a tool which generates, through interview sessions with a small number of participants, preliminary data to be used in subsequent quantitative stages. Many consumer studies use qualitative research with the aim of obtaining information and opinions on a specific product or situation. The objective of the present study was to obtain knowledge on the opinion, understanding and perception of the Brazilian consumer with respect to vegetables, focusing on organic products, using Focus Group Sessions. Four Focus Group Sessions were held with men and women in different environments, following a previously elaborated interview guide. In this study, it was observed that the consumers demonstrated being interested in having a healthy diet, based on fruit, vegetables and natural products. However, only a few declared consuming organic foods. Some participants did not know what the term organic meant, and most of them think that organic products are still very expensive, are not easily available in the supermarkets, do not have a good appearance, mainly in terms of size and packaging, and their certification is not always trustworthy. Almost all participants stated that they read package labels and among the items most observed were best-before date, nutritional information, production system and price. This study has identified important vegetable attributes perceived by the consumer, favouring the planning of a subsequent quantitative research. The results suggest that more information on the benefits of organic agriculture has to be passed on to consumers in order to contribute to a higher consumption of such products.

Fatty acids and nutrients in the flour made from tilapia (Oreochromis niloticus) heads

The objective of this work was to analyze the fatty acid composition and nutrient potential of flour made from tilapia heads, which are normally discarded during the filleting operation. Significant differences were found between the proximate composition (moisture, ash, protein and total lipids) of the in natura tilapia and the flour, due to the drying process. The predominant fatty acids in the heads (in natura and in the flour) were palmitic acid (1,999 mg.100 g-1 and 7,699 mg.100 g-1, respectively), oleic acid (3,128 mg.100 g-1 and 11,447 mg.100g-1, respectively), and linoleic acid (1,018 mg.100 g-1 and 3,784 mg.100 g-1, respectively). The results lead us to conclude that tilapia head flour offers high levels of protein (38.41%), total lipids (35.46%), and ash (minerals) (19.38%). The content of omega-3 (731 mg.100 g-1) were proved to be satisfactory. Also, n-6/n-3 ratio was 6.15 and PUFA/SFA ratio was 0.47, which are in agreement with the recommended levels. Thus, tilapia heads can be used as a low-cost raw material for food fit for human consumption.

Hygienic-sanitary quality of vegetables and evaluation of treatments for the elimination of indigenous E. coli and E. coli O157:H7 from the surface of leaves of lettuce (Lactuca sativa L.)

The purpose of this study is to evaluate the hygienic-sanitary quality of vegetables and irrigation water and assess the effectiveness of lemon juice and vinegar in reducing E. coli strains inoculated on lettuce. One hundred and forty samples of vegetables and 45 samples of irrigation water were investigated for thermotolerant coliforms and Salmonella spp. In order to verify the effectiveness of natural household sanitizers in reducing E. coli in inoculated lettuce, four treatment solutions were tested: fresh lemon juice, alcohol vinegar, lemon juice-vinegar mixture, and lemon juice-vinegar-water mixture. The microbiological analysis revealed high rates of contamination by thermotolerant coliforms and identified the presence of E. coli in 32% of the tested vegetable samples and 56% of the water samples. While no significant statistical difference (p < 0, 05) was identified in the tested solutions, the treatment with a combination of lemon juice and vinegar resulted in the highest Decimal Reductions (DR) of E. coli O157: H7 while the treatment with vinegar alone was the most effective against the indigenous E. coli strain