Christian Turra

RARE EARTH ELEMENTS IN CITRUS PRODUCTION SYSTEMS

This work focuses on the determination of rare earth elements (REE) in citrus ecosystem using instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectrometry (ICP-MS). A comprehensive sampling was carried out in two organic and two conventional farms in the vicinity of Borborema city, São Paulo State, Brazil. The concentrations of lanthanum (La) in leaves were similar to those found in the soil with soil-to-plant transfer factors ranging from 0.65 to 1.05. The amount of REE decreased sequentially in the compartments soil, leaf, peel, pulp, seed and juice. Citrus plants can be considered accumulators of REE.

Arsenic and Chromium in Brazilian Agricultural Supplies

Arsenic (As) and chromium (Cr) contents were measured in agricultural supplies used at different farms in São Paulo State, Brazil. The highest mass fractions of As were found in thermophosphates, reaching levels of 4 mg/kg. The highest mass fractions of Cr (21 g/kg) were found in calcium magnesium silicate, while the thermophosphates also presented high values reaching approximately 1 g/kg. The levels of As were within Brazilian guidelines, but the values of Cr in thermophosphates exceeded the levels permitted in Brazil. The As content in fertilizers may be considered safe (<5 mg/kg) in terms of environmental pollution. However, the Cr content in calcium magnesium silicate following continuous use may constitute a significant problem in Brazil due to potentially increasing levels of this metal in soils.

Informational Asymmetry in the Brazilian Orange Juice Market

Certification, labeling, standardization, traceability, and origin seals take part of a context where the information plays a key role for the guarantee of food safety. However, the available information about food quality attributes is frequently imperfect to consumers, producers, and industry. In the agri-food chain, the consumer is the actor with the lowest degree of information. The main qualitative-quantitative variables of the juice characteristics from different production systems were confronted with an analysis of the consumer perception, in order to clarify the main questions related to the quality of different types of orange juice. The research (185 questionnaires) carried out with consumers of orange juice in the campus “Luiz de Queiroz,” University of São Paulo, Piracicaba, São Paulo state, Brazil, showed that the majority of consumers consider that the information on the labels is not clear. Moreover, about 70% of the interviewed participants did not know the difference between orange juice and nectar. The main reason for consumption of orange juice was the flavor and the main reason for buying a specific brand was the price. The results suggest that the orange juice industries practice an opportunistic attitude, taking advantage of the fact that the consumer is unaware of the legal definition of nectar, different types of orange juices, and information on the labels of different orange juices and nectars.

Survey of lanthanoids in plants from a tropical region

Several anthropogenic sources may provide lanthanoids (La, Ce, Nd, Sm, Eu, Tb and Yb) to the agricultural and forestry landscapes. Because little information is available on the distribution of these chemical elements in Brazilian tropical ecosystems, this work focuses on the survey in leaves of diverse plant species (native trees, epiphytes and crops) from different ecosystems. Soil under crown projection was also analysed, thereby estimating the influence of its chemical composition on accumulation in leaves. The degree of lanthanoids accumulation varied substantially even for species growing in the same habitat. The most accumulator species, Alsophila sternbergii, presented the typical distribution pattern for lanthanoids, different from Pachystroma longifolium, a native species from the urban fragment, and the cultivated Citrus sp., in which the altered patterns revealed lanthanum enrichment in spite of cerium depletion in the leaves.

Chemical Elements in Organic and Conventional Sweet Oranges

This work focuses on the determination of chemical elements in sweet oranges of variety Valencia produced under organic and conventional systems using instrumental neutron activation analysis and inductively coupled plasma mass spectrometry. The distribution of chemical elements was variable among the fruit parts with usually higher concentrations of Br, Ca, Ce, K, La, Na, Rb, and Sc in the peel. However, K, Na, and Rb also presented high values in the juice samples, while Fe and Zn were higher in the seeds. Differences between organic and conventional oranges were found for Br and Cu.

Sustainability of rare earth elements chain: from production to food – a review

Abstract Rare earth elements (REE) are a group of chemical elements that include lanthanoids (lanthanum to lutetium), scandium and yttrium. In the last decades, the REE demand in the industry and other areas has increased significantly. In general, REE have shown low concentrations in soils, plants, water and atmosphere, but they may accumulate in such environments due to anthropogenic inputs. In areas where there is REE contamination, the slow accumulation of these elements in the environment could become problematic. Many studies have shown environmental areas contaminated with REE and their toxic effects. Thus, it is important to review, in order to improve the current understanding of these elements in the environment, showing the effects of REE exposure in mining, soil, water, plants and food. Besides, there are few suppliers and a limited quantity of these elements in the world. This paper suggests options to improve the sustainability management of REE chain.

Finding the Most Significant Elements for the Classification of Organic Orange Leaves: A Data Mining Approach

ABSTRACT Brazil is the world’s largest producer of oranges. The Brazilian conventional citrus crop requires repeated application of agrochemicals to achieve satisfactory levels of productivity. The organic citriculture is an alternative production system, which is environmentally friendly and offers a safe food to consumers. However, it is difficult to determine if a food or plant was cultivated in organic or conventional system by just common observation, which makes the customers of organic food market vulnerable against fraudulent entrepreneurs. In this study, we present a data mining approach for the study of Brazilian organic citrus leaves which can aid in the certification of authenticity of the citrus leaves. The elemental composition is determined by inductively coupled plasma-mass spectrometry (ICP-MS). We developed classification models based on support vector machines and artificial neural networks capable of predicting whether a citrus leaf is organic or conventional through analysis of the concentration levels of the 14 chemical elements (Al, Ba, Co, Cr, Cs, Cu, Fe, Mg, Mn, Ni, Rb, Si, Sr, and V) found in both types of leaves. Feature selection filter methods are used to determine the most relevant elements for the classification process. Our best model obtained was a support vector machine with approximately 88% prediction accuracy. The elements Mn, Mg, and Rb were evaluated as the most significant for the classification decision. This is the first paper which addresses the problem of classification of organic orange leaves based on chemical composition. The presented methodology is useful for attesting authenticity of organic citrus leaves and can be adapted for other organic food or substances.