Lutein and zeaxanthin content in corn imported from three countries of the American continent and in corn cultivated in Colombian territory / Conteúdo de luteína e zeaxantina em milho importado de três países do continente americano e em milho cultivado em território colombiano

Lutein and zeaxanthin are the major xanthophyll pigments found in corn kernels. These pigments provide the orange-red color of the broiler chicken skin and of the egg yolk. Therefore, knowing the corn xanthophyll content is important for the poultry feed producer. The objective of this study was to determine the lutein and the zeaxanthin content in corn cultivated in Colombia and in corn imported to Colombia from the United States, Argentina, and Brazil. Large differences in total lutein plus zeaxanthin content were found among the corn samples analyzed, with the highest mean level found in Colombian corn (2,758µg/100g), followed by Argentina (1,861µg/100g), United States (1,041µg/100g) and Brazil (947µg/100g). Large differences in lutein plus zeaxanthin content were also found among different corn hybrids cultivated in Colombia. Differences among geographical regions might be due to differences in UV-B radiation or in the light hours received by the crop during its growth. The differences among different corn hybrids might probably be due to genetic differences. Corn growers might be interested in cultivating hybrids higher in lutein and zeaxanthin as these pigments are very important in poultry production and human eye health.

Luteína e zeaxantina são os principais pigmentos xantofilas encontrados nos grãos de milho. Em aves, esses pigmentos naturais conferem a cor vermelho-alaranjada típica da pele do frango de corte e da gema do ovo. Assim, é importante conhecer o teor de xantofilas do milho utilizado nas dietas de aves. O objetivo deste estudo foi determinar o teor de luteína e zeaxantina em milho cultivado na Colômbia e em milho importado para a Colômbia dos Estados Unidos, da Argentina e do Brasil. Foram encontradas diferenças significativas no teor de luteína total mais zeaxantina entre as amostras de milho analisadas, com o nível médio mais elevado no milho colombiano (2.758µg/100g), seguido pelo milho argentino (1.861µg/100g), pelo milho dos Estados Unidos (1.041µg/100g) e pelo milho brasileiro (947µg/100g). Grandes diferenças no teor de luteína e zeaxantina também foram encontradas entre variados híbridos de milho cultivados na Colômbia. As diferenças entre as regiões geográficas podem ser devido a diferenças na radiação UV-B ou nas horas de luz recebida pela cultura durante seu crescimento. As diferenças entre os diversos híbridos de milho provavelmente podem ser devido a diferenças genéticas. Os produtores de milho podem estar interessados ​​em cultivar híbridos mais ricos em luteína e zeaxantina, pois esses pigmentos são muito importantes na produção de aves e na saúde ocular humana.

Attenuation of salt stress by lycopene on common bean seeds

Salinity is a major abiotic stress that adversely affects several physiological and biochemical aspects of plants. Antioxidants can be used as a potential remediation mechanism to promote plant resilience. Therefore, the objective of the present study was to evaluate increasing doses of the antioxidant lycopene on the germination and initial growth of common bean seedlings under conditions of salt stress. Seeds were treated with the following lycopene concentrations: 0.018; 0.036; 0.072; 0.144; and 0.288 g L-1 and two controls (negative and positive) and evaluated under two growth conditions (without and with salt stress) for physiological quality and pigment content. Data were analyzed by completely randomized design, in 2 x 7 factorial (two growth conditions, with paper towel moistened with water or salt solution x seven treatments, including five lycopene doses and two controls), in four replicates of 50 seeds by concentration. With the results of the analysis of variance, growth conditions (without and with salt stress) were compared by the Tukey test (5%), and the effects of lycopene doses were analyzed by polynomial regression. Lycopene promoted tolerance of bean seeds to salt stress and had a positive influence on the attenuation of salt harmful effects to the initial growth of seedlings, mainly at the doses of 0.072 g L-1 and 0.144 g L-1.(AU)

Productive Performance, Egg Quality, and Pigments on Sorghum-Based Feed for Japanese Quail

The study aimed to determine evaluate the use of sorghum as a substitute for maize in the laying quail diet and its effect on performance and quality of the eggs produced the best levels of lutein (Marigold flower extract) and canthaxanthin inclusion in sorghum based Japanese quail feed as well as its influence in storage time of the eggs. A total of 680 Japanese laying quails (Coturnix coturnix japonica), with 64 weeks of age was distributed in a 4 × x4 factorial + 1 control scheme, with four levels of lutein (LUT), and four levels of canthaxanthin (CTX) and control group with no addition of pigments, with five replicates and eight birds per experimental unit. The experiment was divided into three cycles of 21 days, where the performance and egg quality parameters were evaluated. To evaluate the time of deposition and permanence of the pigments in the yolk, three eggs were evaluated per treatment for 12 days at the beginning of the experiment and 12 days at the end, from the last day of consumption of rations containing pigments. For performance and egg quality, no maybe only differences (p> 0.05) were observed, except for the yolk color, with higher color scores according to the increase in lutein and canthaxanthin consumption. Whereas color parameters, it was observed that at the beginning of the period of consumption, canthaxanthin levels influenced the red color reading and lutein levels influenced the yellow color readings, while in the final period the interaction of the levels of 5.4 ppm of lutein and 1.3 ppm of canthaxanthin provided better color parameters up to 10 days after the end of consumption of rations with pigment.(AU)

Effects of Moringa oleifera leaf meal on performance and carcass yield of broilers

This study evaluated the effects of including Moringa oleifera (moringa) leaf meal on performance, carcass yield and characteristics, and relative organ weights of broilers from 10 to 42 days of age. We distributed 420 male Cobb 500 chicks in a completely randomized design with five treatments and six replicates with 14 birds each. Treatments consisted of five experimental diets in which the moringa leaf meal was included at 0, 1.5, 3.0, 4.5, and 6.0% in the diets. The following performance variables were evaluated: weight gain, feed intake, and feed conversion; weights and yields of carcass, carcass traits, organs, and abdominal fat; and feet color. Significant differences between the treatment means were analyzed by Dunnett's test. The meal inclusion levels did not affect performance, carcass characteristics and yield, or organs weight. However, feet pigmentation increased linearly, and abdominal fat was greater only at the 1.5% level when compared with the control group. Moringa leaf meal can be included in the diet of broilers from 10 to 42 days of age, up to the level of 6%, without compromising performance or carcass yield of these birds.(AU)

Yolk color and sensory analysis of eggs of common quails (Coturnix coturnix coturnix) fed sorghum-based diet with the addition of annatto seed meal (Bixa orellana L) / Coloração da gema e análise sensorial de ovos de codornas europeias (Coturnix coturnix coturnix) alimentadas com ração à base de sorgo com adição de farelo de urucum (Bixa orellana L)

This study has aimed to assess the effect of increasing levels of annatto (Bixa orellana L.) seed meal (AM) on yolk pigmentation and the sensory analysis of eggs of common quails fed sorghum-based diets when compared tocorn. Eighty female common quails (Coturnix coturnix coturnix) in the laying phase were used, being them aged from 251 to 316 days. There were three experimental periods of 21 days each (251-272; 273-294; 295-316 days). The quails were distributed in a completely randomized design with five treatments (T1 - corn-based feed; T2 - feed with 100% of sorghum instead of corn without the addition of AM; T3, T4, and T5 - feed with 100% of sorghum replacing corn with the addition of 0.5, 1.0, and 1.5% AM, respectively) and four repetitions. One hundred eggs from each treatment were used for analysis. Sensory evaluation was applied with an untrained panel with 20 evaluators. The eggs were boiled, peeled, and served. The panelists assessed the appearance, flavor, color, aroma, texture, and overall evaluation of the eggs. Annatto seed meal added to sorghum-based diets promoted linear increases in appearance, flavor, color, aroma, texture, and overall evaluation, evaluated during the sensory analysis (p=0.001). The addition of 1.5% AM in the sorghum-based diets of the common quails benefited the characteristics of appearance (4.50), flavor (4.50), color (4.55), aroma (4.25), and texture (4.55) of the assessed quail eggs, being considered more attractive and with greater acceptance (overall evaluation = 5.97) in relation to the other treatments tested. The inclusion of AM in the sorghum-based diets improved the yolk pigmentation of quail eggs in relation to the control treatments. The AM triggers positive effects on yolk pigmentation and sensory characteristics of common quail eggs.(AU)

Objetivou-se avaliar o efeito de níveis crescentes do farelo do resíduo da semente de urucum (Bixa orellana L.) (FU), sobre a pigmentação da gema e análise sensorial dos ovos de codornas europeias alimentadas com dietas à base de sorgo em substituição ao milho. Foram utilizadas 80 codornas europeias (Coturnix coturnix coturnix) fêmeas, na fase de postura, no período de 251 a 316 dias de idade. Foram três períodos experimentais de 21 dias cada (251-272; 273-294; 295-316 dias). As codornas foram distribuídas em delineamento inteiramente casualizado, com cinco tratamentos (T1 - ração à base de milho; T2 - ração com 100% de sorgo em substituição ao milho sem a adição de FU; T3, T4 e T5 ­ ração com 100% de sorgo em substituição ao milho com a adição de 0,5; 1,0 e 1,5% de FU) e quatro repetições. Cem ovos de cada tratamento foram utilizados para a análise. A avaliação sensorial foi aplicada em painel não treinado de 20 avaliadores. Os ovos foram cozidos, descascados e servidos. A aparência, sabor, cor, odor, textura e avaliação global, foram avaliadas pelos painelistas. A farinha de semente de urucum adicionada à ração à base de sorgo promoveu aumentos lineares nos atributos aparência, sabor, cor, odor, textura e avaliação global, avaliados durante a análise sensorial (p=0,001). A adição de 1,5% de FU em dietas a base de sorgo beneficiou as características de aparência (4,50), sabor (4,50) cor (4,55), aroma (4,25) e textura (4,55) dos ovos de codorna avaliados, sendo considerados mais atrativos e com maior aceitação (avaliação global = 5,97), em relação aos demais tratamentos testados. A inclusão do FU nas rações à base de sorgo melhorou a pigmentação da gema dos ovos de codorna em relação aos tratamentos controle. O AM desencadeia efeitos positivos na pigmentação da gema e nas características sensoriais de ovos de codornas comuns.(AU)

Attenuation of salt stress by lycopene on common bean seeds / Attenuation of salt stress by lycopene on common bean seeds

Salinity is a major abiotic stress that adversely affects several physiological and biochemical aspects of plants. Antioxidants can be used as a potential remediation mechanism to promote plant resilience. Therefore, the objective of the present study was to evaluate increasing doses of the antioxidant lycopene on the germination and initial growth of common bean seedlings under conditions of salt stress. Seeds were treated with the following lycopene concentrations: 0.018; 0.036; 0.072; 0.144; and 0.288 g L-1 and two controls (negative and positive) and evaluated under two growth conditions (without and with salt stress) for physiological quality and pigment content. Data were analyzed by completely randomized design, in 2 x 7 factorial (two growth conditions, with paper towel moistened with water or salt solution x seven treatments, including five lycopene doses and two controls), in four replicates of 50 seeds by concentration. With the results of the analysis of variance, growth conditions (without and with salt stress) were compared by the Tukey test (5%), and the effects of lycopene doses were analyzed by polynomial regression. Lycopene promoted tolerance of bean seeds to salt stress and had a positive influence on the attenuation of salt harmful effects to the initial growth of seedlings, mainly at the doses of 0.072 g L-1 and 0.144 g L-1.

Salinity is a major abiotic stress that adversely affects several physiological and biochemical aspects of plants. Antioxidants can be used as a potential remediation mechanism to promote plant resilience. Therefore, the objective of the present study was to evaluate increasing doses of the antioxidant lycopene on the germination and initial growth of common bean seedlings under conditions of salt stress. Seeds were treated with the following lycopene concentrations: 0.018; 0.036; 0.072; 0.144; and 0.288 g L-1 and two controls (negative and positive) and evaluated under two growth conditions (without and with salt stress) for physiological quality and pigment content. Data were analyzed by completely randomized design, in 2 x 7 factorial (two growth conditions, with paper towel moistened with water or salt solution x seven treatments, including five lycopene doses and two controls), in four replicates of 50 seeds by concentration. With the results of the analysis of variance, growth conditions (without and with salt stress) were compared by the Tukey test (5%), and the effects of lycopene doses were analyzed by polynomial regression. Lycopene promoted tolerance of bean seeds to salt stress and had a positive influence on the attenuation of salt harmful effects to the initial growth of seedlings, mainly at the doses of 0.072 g L-1 and 0.144 g L-1.

Coloração das gemas de ovos de poedeiras alimentadascom ração à base de sorgo com adição de pigmentantes naturais e sintéticos / Coloring of egg yolks of laying hens fed with sorghum-based feed with addition of natural and synthetic pigments

Objetivou-se avaliar a inclusão de pigmentante sintético (Cantaxantina 10%) aliado a níveis de suplementação de pigmentantes naturais e sintéticos na dieta de poedeiras comerciais em rações a base de sorgo. Foram utilizadas 150 poedeiras comerciais com 67 semanas de idade da linhagem Hisex Brown, distribuídas em delineamento inteiramente casualizado com cinco tratamentos, seis repetições de cinco aves/repetição. Os tratamentos avaliados foram: 25 g/t de carophyll yellow 10% + 20 g/t de carophyll vermelho (T1); 300 g/t de Marigold 2% + 10 g/t de Cantaxantina 10% (T2); 300 g/t de Marigold 2% + 20 g/t de Cantaxantina 10% (T3); 300 g/t de Marigold 2% + 30 g/t de Cantaxantina 10% (T4); 300 g/t de Marigold 2% +20 g/t carophyll vermelho (T5). Foi aplicado o teste de Tukey ao nível de 5% de probabilidade para as variáveis de desempenho e qualidade de ovos. Houve diferença entre os tratamentos apenas para coloração da gema, onde o aumento da coloração teve reflexo de acordo com o aumento dos níveis de pigmentante nas dietas, sendo que as demais variáveis não foram afetadas. O nível de suplementação de 300 g.t-1de pigmento natural amarelo + 30 g.t-1de pigmento vermelho industrial em dietas a base de sorgo para poedeiras proporcionou melhor índice de coloração da gema.

The objective of this study was to evaluate the inclusion of synthetic pigment(Cantaxanthin 10%) combinedwith levels of natural and synthetic pigmentsupplementation in the diet of commercial laying hens in diets based on sorb. We used 150 commercial laying hens with 67 weeks of age of the Hisex Brown strain, distributed in a completely randomized design with five treatments, six replicates of five birds/repetition. The treatments evaluated were: 25 g/t carophyll yellow 10% + 20 g/t red carophyll (T1); 300 g/t of Marigold 2% + 10 g/t of Cantaxanthin 10% (T2); 300 g/t of Marigold 2% + 20 g/t of Cantaxanthin 10% (T3); 300 g/t of Marigold 2% + 30 g/t of Cantaxanthin 10% (T4); 300 g/t of Marigold 2% +20 g/t red carophyll (T5). The Tukey test was applied at the level of 5% probability for the various performance and quality of eggs. There was a difference between treatments only for yolk staining, where the increase in color was reflected according to the increase in pigmenting levels in the diets, and the other variables were not affected. The supplementation level of 300 g.t-1 of natural yellow pigment + 30 g.t-1 ofindustrial red pigment in diets based on sorb for laying hens provided better yolk color index.

Coloração das gemas de ovos de poedeiras alimentadascom ração à base de sorgo com adição de pigmentantes naturais e sintéticos / Coloring of egg yolks of laying hens fed with sorghum-based feed with addition of natural and synthetic pigments

Objetivou-se avaliar a inclusão de pigmentante sintético (Cantaxantina 10%) aliado a níveis de suplementação de pigmentantes naturais e sintéticos na dieta de poedeiras comerciais em rações a base de sorgo. Foram utilizadas 150 poedeiras comerciais com 67 semanas de idade da linhagem Hisex Brown, distribuídas em delineamento inteiramente casualizado com cinco tratamentos, seis repetições de cinco aves/repetição. Os tratamentos avaliados foram: 25 g/t de carophyll yellow 10% + 20 g/t de carophyll vermelho (T1); 300 g/t de Marigold 2% + 10 g/t de Cantaxantina 10% (T2); 300 g/t de Marigold 2% + 20 g/t de Cantaxantina 10% (T3); 300 g/t de Marigold 2% + 30 g/t de Cantaxantina 10% (T4); 300 g/t de Marigold 2% +20 g/t carophyll vermelho (T5). Foi aplicado o teste de Tukey ao nível de 5% de probabilidade para as variáveis de desempenho e qualidade de ovos. Houve diferença entre os tratamentos apenas para coloração da gema, onde o aumento da coloração teve reflexo de acordo com o aumento dos níveis de pigmentante nas dietas, sendo que as demais variáveis não foram afetadas. O nível de suplementação de 300 g.t-1de pigmento natural amarelo + 30 g.t-1de pigmento vermelho industrial em dietas a base de sorgo para poedeiras proporcionou melhor índice de coloração da gema.(AU)

The objective of this study was to evaluate the inclusion of synthetic pigment(Cantaxanthin 10%) combinedwith levels of natural and synthetic pigmentsupplementation in the diet of commercial laying hens in diets based on sorb. We used 150 commercial laying hens with 67 weeks of age of the Hisex Brown strain, distributed in a completely randomized design with five treatments, six replicates of five birds/repetition. The treatments evaluated were: 25 g/t carophyll yellow 10% + 20 g/t red carophyll (T1); 300 g/t of Marigold 2% + 10 g/t of Cantaxanthin 10% (T2); 300 g/t of Marigold 2% + 20 g/t of Cantaxanthin 10% (T3); 300 g/t of Marigold 2% + 30 g/t of Cantaxanthin 10% (T4); 300 g/t of Marigold 2% +20 g/t red carophyll (T5). The Tukey test was applied at the level of 5% probability for the various performance and quality of eggs. There was a difference between treatments only for yolk staining, where the increase in color was reflected according to the increase in pigmenting levels in the diets, and the other variables were not affected. The supplementation level of 300 g.t-1 of natural yellow pigment + 30 g.t-1 ofindustrial red pigment in diets based on sorb for laying hens provided better yolk color index.(AU)

Photosynthesis, growth, and survival in seedlings of four tropical fruit-tree species under intense radiation / Fotosíntesis, crecimiento y supervivencia en plántulas de cuatro especies de árboles frutales tropicales bajo intensa radiación

En la región amazónica, los sistemas agroforestales (SAFs) se recomiendan como una alternativa de producción sustentable para las comunidades locales. Un componente común en los SAFs amazónicos son los árboles frutales tropicales, que pueden formar parte del dosel o crecer en el sotobosque. En este trabajo, estudiamos el efecto de la radiación alta sobre la fotosíntesis, el crecimiento y la supervivencia de cuatro especies de árboles frutales amazónicos: Theobroma cacao, Eugenia stipitata, Inga edulis y Psidium guajava. Se midieron el crecimiento, fluorescencia de clorofila, intercambio de gases y pigmentos foliares en plántulas de cada especie que crecieron durante 12 meses dentro de casa-mallas en baja (8%), media (30%) y alta iluminación relativa (100%). Eugenia stipitata y T. cacao tuvieron la menor capacidad de aclimatación a la radiación solar alta, seguidas por I. edulis. En consecuencia, esas especies deben sembrarse bajo niveles de luz intermedia, para protegerlas del sol directo en las etapas iniciales de crecimiento. En contraste, las plántulas de P. guajava mostraron alta tolerancia a la elevada radiación solar, por lo que esta especie puede ser plantada bajo libre exposición solar.(AU)

In the Amazon region, agroforestry systems (AFSs) are recommended as a sustainable production alternative for local communities. A common component in Amazonian AFSs are tropical fruit trees, which can form the canopy or grow in the understory. In this study, we evaluated the effect of high radiation on photosynthesis, growth and seedling survival of four Amazonian fruit-tree species: Theobroma cacao, Eugenia stipitata, Inga edulis and Psidium guajava. Growth, chlorophyll fluorescence, gas exchange, and leaf pigments were measured in seedlings of each species grown for 12 months inside shade houses with low (8%), medium (30%) and high relative illumination (100%). Eugenia stipitata and T. cacao had the lowest acclimation capacity to high solar radiation, followed by I. edulis. Therefore, these species must be grown under intermediate light levels in early growth stages, to protect them from direct sunlight. In contrast, P. guajava seedlings demonstrated high tolerance to elevated radiation, therefore, this species can be planted under full sunlight.(AU)

Production, egg quality, and intestinal morphometry of laying hens fed marine microalga

The objective of the present study was to evaluate production and egg quality as well as the intestinal morphometry of laying hens fed diets supplemented with marine microalga Dunaliella salina. Six hundred laying hens were allocated based on a completely randomized design into five treatments (0, 0.25, 0.50, 0.75, and 1% inclusion of D. salina biomass) with 12 replicates of 10 hens per treatment. The experiment was divided into three periods of four weeks each, totaling 84 days. During this period, the productive performance of laying hens, the physical-chemical quality of the eggs, and the morphometric alterations of the small intestine and liver were determined. The inclusion levels of D. salina biomass had a linear effect on the performance (egg weight, egg mass, and feed conversion), qualitative parameters (yolk weight and yolk index), and physicochemical parameters of eggs (total carotenoids, TBARS, and yolk color). At the same time, villi lengths and the villus:crypt ratio of the duodenum and ileum segments and the metabolization of carotenoids in the liver were increased as an effect of Dunaliella salina dietary supplementation. Thus, the inclusion of marine microalgae D. salina biomass in experimental diets for laying hens improves the performance, the intestinal health, the physical-chemical quality of the eggs, and at the same time increases carotenoid content and improves egg oxidative stability.(AU)

Meloidogyne javanica parasitism on the vegetative growth and nutritional quality of carrots / Parasitismo de Meloidogyne javanica no crescimento vegetativo e na qualidade nutricional de cenouras

Meloidogyne javanica is a plant-parasitic nematode that infects a wide range of vegetables. Its negative effects on crop yield and value are well documented. However, few studies have investigated the impact of the parasite on the nutritional value of vegetables. This study aimed to assess the effect of M. javanica parasitism on the vegetative characteristics, nematological parameters, chemistry composition and antioxidant activity of carrots. Seedlings were inoculated with 0 (control), 1000, 2500, or 5000 eggs and eventual second-stage juveniles (J2) of M. javanica. At 60 days after inoculation, plants were harvested and evaluated. Plants inoculated with 2500 eggs and J2 of M. javanica had higher root and tuber fresh weight than the control. Gall number increased with increasing inoculum density. The number of nematodes in the roots increased until 3000 specimens, decreasing thereafter. Proximate analysis revealed that plants inoculated with 1000 eggs and J2 of M. javanica or more had higher protein content in roots. In contrast, inoculation with 1775 nematodes or more resulted in a decrease in carotenoid content. There was no effect of inoculation on total phenolic content or antioxidant activity. Although, M. javanica infection did not have a marked impact on the nutritional quality of carrots, gall formation resulted in deformed roots of low commercial value.(AU)

Meloidogyne javanica é um nematoide parasita de plantas que infecta uma grande variedade de vegetais. Seus efeitos negativos sobre o rendimento e o valor das culturas estão bem documentados. No entanto, poucos estudos investigaram o impacto do parasita no valor nutricional dos vegetais. Este estudo teve como objetivo avaliar o efeito do parasitismo por M. javanica sobre as características vegetativas, parâmetros nematológicos, composição química e atividade antioxidante de cenouras. As plântulas foram inoculadas com 0 (controle), 1000, 2500 ou 5000 ovos e eventuais juvenis (J2) de M. javanica no segundo estágio. Aos 60 dias após a inoculação, as plantas foram colhidas e avaliadas. As plantas inoculadas com 2500 ovos e J2 de M. javanica apresentaram maior peso fresco das raízes e tubérculos que o controle. O número de galhas aumentou com o aumento da densidade do inóculo. Verificou-se aumento do número de nematoides nas raízes até 3000 espécimes, diminuindo posteriormente. A análise imediata revelou que plantas inoculadas com 1000 ovos e J2 de M. javanica ou mais tinham maior teor de proteína nas raízes. Por outro lado, a inoculação com 1775 nematoides ou mais resultou em diminuição no conteúdo de carotenoides. Não houve efeito da inoculação no conteúdo fenólico total ou na atividade antioxidante. Embora a infecção por M. javanica não tenha impactado significativamente a qualidade nutricional das cenouras, a formação de galhas resultou em raízes deformadas e de baixo valor comercial.(AU)

Fatty acid profile and physicochemical characterization of buriti oil during storage / Perfil de ácido graxo e qualidade físico-química do óleo de buriti sob armazenamento

The objective of this research was to evaluate the fatty acid profile and physicochemical properties of buriti oil under storage conditions. The oil was analyzed for 70 days by evaluating the physicochemical characteristics of acidity index, refractive index, bulk density, absolute viscosity, peroxide index, lipid oxidation by TBARS method, color parameters (L *, a *, b *, C * e h *) and carotenoid profile (alpha-carotene and beta-carotene) for every 10 days of storage, in addition to the beta-carotene/linoleic acid system and fatty acid profile. Variables remained stable over the analysis periods and the total carotenoids ranged from 836.91 to 1036.96 µg/g. Oleic acid accounted for the highest content among fatty acids, with a value of 78.06 g/100 g of fatty acids and a omega6/omega3 ratio of 1.95. Buriti oil has a nutritional quality and a fatty acid profile that justifies recommendations for its consumption, suggesting the need for regulatory bodies to draw up a standardized protocol for extracting oil from the fruit pulp.(AU)

Objetivou-se neste trabalho avaliar o perfil de ácido graxo e a qualidade físico-química do óleo de buriti em condições de armazenamento. O óleo foi analisado durante 70 dias avaliando as características físico-química índice de acidez, índice de refração, densidade aparente, viscosidade absoluta, índice de peróxidos, oxidação lipídica pelo método de TBARS, parâmetros de cor (L*, a*, b*, C* e h*) e carotenoides (alfa-caroteno e beta-caroteno) a cada 10 dias de armazenamento, além do sistema beta-caroteno/ácido linoléico e perfil de ácidos graxos. As variáveis se mantiveram estáveis durante os períodos de análises e os carotenoides totais variaram entre 836,91 a 1036,96 µg/g. O ácido graxo com maior teor foi o ácido oleico com valor de 78,06 g/100 g de ácidos graxos e relação ômega6/ômega3 de 1,95. O óleo de buriti apresenta qualidade nutricional que justifica o estímulo ao consumo devido aos ácidos graxos que apresenta, necessitando dos órgãos reguladores a elaboração de um protocolo de extração do óleo da polpa do fruto.(AU)

Coloração de gema de ovo de poedeiras comerciais recebendo pigmentante comercial na ração / Egg yolk color of commercial laying hens receiving commercial pigment in diet

Objetivou-se avaliar a pigmentação de gemas de ovos de poedeiras alimentadas com produto comercial (PC), à base de cantaxantina e óleo de sementes de urucum. Utilizaram-se 240 poedeiras comerciais com 55 semanas de idade, que receberam cinco diferentes rações: controle (RC) à base de milho e farelo de soja, RC com dois níveis (70 e 140 ppm) do PC e RC com dois níveis de mistura entre pigmentantes comerciais sintéticos Carophyll® Yellow e Red (20 + 10 ppm) e (15 + 30 ppm) e quatro repetições de 12 aves cada. Foram avaliados o desempenho e a cor das gemas, que foi avaliada utilizando o leque colorimétrico. Não houve efeito sobre o desempenho das poedeiras, exceto para a cor da gema, que apresentou interação dos pigmentantes nos diferentes períodos de avaliação. Aos sete dias de fornecimento, houve estabilização da pigmentação, com uso de 70 ppm do produto comercial, enquanto as gemas oriundas dos ovos das aves que receberam a inclusão de 140 ppm estabilizaram a cor aos 14 dias do fornecimento. O produto comercial à base de cantaxantina e óleo de sementes de urucum é eficiente na pigmentação da gema de ovos em rações à base de milho amarelo.

The aim of this study was to evaluate the egg yolk pigmentation of laying hens fed commercial powdered products (CPP) based on canthaxanthin and urucum seed oil. A total of 240 commercial laying hens at 55 weeks of age were used, which received five different rations: control (CR) based on corn and soybean meal, CR with two levels (70 and 140 ppm) of CPP and CR with two levels of mixture between synthetic commercial pigments Carophyll® Yellow and Red (20 + 10 ppm) and (15 + 30 ppm), and four replicates of twelve birds each. The performance and color of the yolk were evaluated, using the colorimetric fan. There was no effect on the performance of the laying hens, except for the color of the yolk, which showed interaction of the pigmentants in the different periods. At seven days of supply there was stabilization of pigmentation with use of 70 ppm of the commercial powdered product, while egg yolks from hens receiving the inclusion of 140 ppm stabilized color at 14 days of delivery. The commercial product based on canthaxanthin and urucum seed oil is efficient in egg yolk pigmentation in yellow maize based diets.

Coloração de gema de ovo de poedeiras comerciais recebendo pigmentante comercial na ração / Egg yolk color of commercial laying hens receiving commercial pigment in diet

Objetivou-se avaliar a pigmentação de gemas de ovos de poedeiras alimentadas com produto comercial (PC), à base de cantaxantina e óleo de sementes de urucum. Utilizaram-se 240 poedeiras comerciais com 55 semanas de idade, que receberam cinco diferentes rações: controle (RC) à base de milho e farelo de soja, RC com dois níveis (70 e 140 ppm) do PC e RC com dois níveis de mistura entre pigmentantes comerciais sintéticos Carophyll® Yellow e Red (20 + 10 ppm) e (15 + 30 ppm) e quatro repetições de 12 aves cada. Foram avaliados o desempenho e a cor das gemas, que foi avaliada utilizando o leque colorimétrico. Não houve efeito sobre o desempenho das poedeiras, exceto para a cor da gema, que apresentou interação dos pigmentantes nos diferentes períodos de avaliação. Aos sete dias de fornecimento, houve estabilização da pigmentação, com uso de 70 ppm do produto comercial, enquanto as gemas oriundas dos ovos das aves que receberam a inclusão de 140 ppm estabilizaram a cor aos 14 dias do fornecimento. O produto comercial à base de cantaxantina e óleo de sementes de urucum é eficiente na pigmentação da gema de ovos em rações à base de milho amarelo.(AU)

The aim of this study was to evaluate the egg yolk pigmentation of laying hens fed commercial powdered products (CPP) based on canthaxanthin and urucum seed oil. A total of 240 commercial laying hens at 55 weeks of age were used, which received five different rations: control (CR) based on corn and soybean meal, CR with two levels (70 and 140 ppm) of CPP and CR with two levels of mixture between synthetic commercial pigments Carophyll® Yellow and Red (20 + 10 ppm) and (15 + 30 ppm), and four replicates of twelve birds each. The performance and color of the yolk were evaluated, using the colorimetric fan. There was no effect on the performance of the laying hens, except for the color of the yolk, which showed interaction of the pigmentants in the different periods. At seven days of supply there was stabilization of pigmentation with use of 70 ppm of the commercial powdered product, while egg yolks from hens receiving the inclusion of 140 ppm stabilized color at 14 days of delivery. The commercial product based on canthaxanthin and urucum seed oil is efficient in egg yolk pigmentation in yellow maize based diets.(AU)

Physicochemical and antioxidant capacity analysis of colored sweet potato genotypes: in natura and thermally processed

ABSTRACT: Sweet potato ( Ipomoea batatas (L.) Lam) is one of the most popular and ancient roots of Brazil and it can be consumed at different forms such as boiled, roasted or as sweets. Its cooking can lead to physicochemical transformations altering the nutritional properties. The objective of this study was to evaluate the physicochemical characteristics, bioactive compounds and antioxidant capacity of twelve sweet potato genotypes of varying pulp color in natura and roasted. Soluble solids, acidity, sugars, carotenoids, anthocyanins, phenolic compounds and antioxidant capacity were analyzed in the following sweet potatoes genotypes: cream pulp (Rubissol, Cuia, ILS03, ILS10, ILS12, ILS24 and ILS44); orange pulp (Amelia and Beauregard); and purple pulp (ILS56, ILS16 and ILS71). According to the results, it was observed a wide variation among the sweet potato genotypes for all analyzed parameters, in both preparation forms. The antioxidant capacity was a parameter with wide variation among genotypes, 210.29 to 7870.57µg trolox equivalent/g in in natura form and 673.26 to 17306.22µg trolox equivalent/g in roasted form. Soluble solids, acidity, sugars and bioactive compounds, with the exception of carotenoids, tended to be concentrated, also increases the total antioxidant capacity, in roasted sweet potatoes. In conclusion, genotype and the color of sweet potatoes were parameters that had an influence on its chemical composition. Cultivars such as Amelia and Beauregard stood out by the amounts of total soluble solids and carotenoids, respectively. The selections ILS 16 and ILS 56 are recommended as sources of anthocyanins. Thermal process influenced the concentration of antioxidant compounds and changed some physicochemical characteristics.

RESUMO: A batata-doce ( Ipomoea batatas (L.) Lam) é uma das raízes mais populares e antigas do Brasil, podendo ser consumida cozida, assada ou na forma de doces. A sua cocção pode levar à transformações físico-químicas alterando as propriedades nutricionais. O objetivo deste trabalho foi avaliar as características físico-químicas, compostos bioativos e atividade antioxidante de doze genótipos de batata-doce, de coloração de polpa variada, na forma in natura e assada. Foram determinados sólidos solúveis totais, acidez, açúcares, carotenoides, antocianinas, compostos fenólicos e atividade antioxidante nos seguintes genótipos de batatas-doces: polpa creme (Rubissol, Cuia, ILS03, ILS10, ILS12, ILS24 e ILS44); polpa laranja (Amélia e Beauregard) e polpa roxa (ILS56, ILS16 e ILS71). Quanto aos resultados foi observada ampla variação entre os genótipos de batata-doce, para todos os parâmetros analisados, em ambas as formas de preparo. A atividade antioxidante foi um parâmetro que demonstrou grande variação entre os genótipos, de 210,29 a 7870,57µg de equivalente trolox/g nos genótipos in natura e de 673,26 a 17306,22µg de equivalente trolox/g nos genótipos assados. Foi observado que em batatas-doces assadas os sólidos solúveis, acidez, açúcares e os compostos bioativos, com exceção dos carotenoides, tenderam a ser concentrados, elevando também a atividade antioxidante total. Em conclusão, o genótipo e a coloração da batata-doce foram parâmetros que exerceram influência sob a sua composição química. Cultivares como Amélia e Beauregard se destacaram pela quantidade de sólidos solúveis totais e carotenoides, respectivamente. Como fonte de antocianinas, as seleções ILS 16 e ILS 56 são recomendadas. O processo térmico influenciou a concentração de compostos antioxidantes e alterou algumas características físico-químicas.

Physicochemical and antioxidant capacity analysis of colored sweet potato genotypes: in natura and thermally processed / Análises físico-químicas e capacidade antioxidante de genótipos coloridos de batata-doce in natura e termicamente processados

Sweet potato (Ipomoea batatas (L.) Lam) is one of the most popular and ancient roots of Brazil and it can be consumed at different forms such as boiled, roasted or as sweets. Its cooking can lead to physicochemical transformations altering the nutritional properties. The objective of this study was to evaluate the physicochemical characteristics, bioactive compounds and antioxidant capacity of twelve sweet potato genotypes of varying pulp color in natura and roasted. Soluble solids, acidity, sugars, carotenoids, anthocyanins, phenolic compounds and antioxidant capacity were analyzed in the following sweet potatoes genotypes: cream pulp (Rubissol, Cuia, ILS03, ILS10, ILS12, ILS24 and ILS44); orange pulp (Amelia and Beauregard); and purple pulp (ILS56, ILS16 and ILS71). According to the results, it was observed a wide variation among the sweet potato genotypes for all analyzed parameters, in both preparation forms. The antioxidant capacity was a parameter with wide variation among genotypes, 210.29 to 7870.57µg trolox equivalent/g in in natura form and 673.26 to 17306.22µg trolox equivalent/g in roasted form. Soluble solids, acidity, sugars and bioactive compounds, with the exception of carotenoids, tended to be concentrated, also increases the total antioxidant capacity, in roasted sweet potatoes. In conclusion, genotype and the color of sweet potatoes were parameters that had an influence on its chemical composition. Cultivars such as Amelia and Beauregard stood out by the amounts of total soluble solids and carotenoids, respectively. The selections ILS 16 and ILS 56 are recommended as sources of anthocyanins. Thermal process influenced the concentration of antioxidant compounds and changed some physicochemical characteristics.

A batata-doce (Ipomoea batatas (L.) Lam) é uma das raízes mais populares e antigas do Brasil, podendo ser consumida cozida, assada ou na forma de doces. A sua cocção pode levar à transformações físico-químicas alterando as propriedades nutricionais. O objetivo deste trabalho foi avaliar as características físico-químicas, compostos bioativos e atividade antioxidante de doze genótipos de batata-doce, de coloração de polpa variada, na forma in natura e assada. Foram determinados sólidos solúveis totais, acidez, açúcares, carotenoides, antocianinas, compostos fenólicos e atividade antioxidante nos seguintes genótipos de batatas-doces: polpa creme (Rubissol, Cuia, ILS03, ILS10, ILS12, ILS24 e ILS44); polpa laranja (Amélia e Beauregard) e polpa roxa (ILS56, ILS16 e ILS71). Quanto aos resultados foi observada ampla variação entre os genótipos de batata-doce, para todos os parâmetros analisados, em ambas as formas de preparo. A atividade antioxidante foi um parâmetro que demonstrou grande variação entre os genótipos, de 210,29 a 7870,57µg de equivalente trolox/g nos genótipos in natura e de 673,26 a 17306,22µg de equivalente trolox/g nos genótipos assados. Foi observado que em batatas-doces assadas os sólidos solúveis, acidez, açúcares e os compostos bioativos, com exceção dos carotenoides, tenderam a ser concentrados, elevando também a atividade antioxidante total. Em conclusão, o genótipo e a coloração da batata-doce foram parâmetros que exerceram influência sob a sua composição química. Cultivares como Amélia e Beauregard se destacaram pela quantidade de sólidos solúveis totais e carotenoides,respectivamente. Como fonte de antocianinas, as seleções ILS 16 e ILS 56 são recomendadas. O processo térmico influenciou a concentraçãode compostos antioxidantes e alterou algumas características físico-químicas.

Influence of cooking methods on bioactive compounds in beetroot / Compostos bioativos em beterrabas submetidas a diversas formas de cozimento

Beetroot is rich in bioactive compounds that may provide health benefits. However, vegetable tissues are physically and chemically damaged by cooking, causing major changes to compounds in cell membranes. The current study aimed to evaluate the influence of several cooking methods on bioactive compounds in beetroot. Four heat treatments were carried out: steam cooking, pressure cooking, baking in an oven, and boiling in water. Beets were matched in uniformity of size, color, and absence of defects. They were washed thoroughly in running water to remove dirt. Next, one of the four cooking methods was applied. After cooking, beets were peeled by hand. Analysis was carried out on both uncooked and cooked beets to evaluate antioxidant activity, content of phenolic compounds, pigments, flavonoids, and betalains. The experiment was completely randomized design (CRD) and carried out in triplicate. Data were subjected to analysis of variance (F test, p < 0.05) and mean values compared by Tukey test at 5% probability. There was no change in antioxidant activity or total phenolic and anthocyanin content by any of the cooking methods compared to that in raw beetroots. However, pressure-cooking resulted in lower carotenoid levels compared to that in raw beet. Furthermore, flavonoid and betalain content decreased by all the cooking methods.

A beterraba é rica em compostos bioativos, que possuem efeitos benéficos para o organismo humano. Porém o cozimento dos tecidos vegetais altera física e quimicamente as propriedades da parede celular, afetando o teor desses compostos. O objetivo do trabalho foi avaliar os compostos bioativos em beterrabas in natura e submetidas a diversas formas de cozimento. Foram realizados quatro tratamentos térmicos, sendo eles cocção a vapor, cocção na panela de pressão, no forno e na água em imersão. As beterrabas foram selecionadas visando a homogeneização do lote quanto ao tamanho, cor e ausência de injúrias e defeitos. Foram lavadas em água corrente para tirar as sujidades. Em seguida, levadas às quatro formas de cocção. Após os tratamentos térmicos, foram descascadas manualmente. As análises realizadas nas beterrabas in natura e cozidas foram a atividade antioxidante, teor de compostos fenólicos totais, pigmentos, flavonoides e betalaínas. O experimento seguiu o Delineamento Inteiramente Casualizado (DIC) com três repetições. Os dados foram submetidos a análise de variânca, teste F, e as médias comparadas pelo Teste de Tukey (p < 0,05). Não houve perdas na atividade antioxidante, fenólicos totais e antocianinas em todas as formas de cocção estudadas em relação à beterraba crua. Somente a cocção na pressão apresentou menores teores de carotenoides em relação a crua. As concentrações de flavonoides e de betalaínas diminuíram em todas as formas de cozimento.

Influence of cooking methods on bioactive compounds in beetroot / Compostos bioativos em beterrabas submetidas a diversas formas de cozimento

Beetroot is rich in bioactive compounds that may provide health benefits. However, vegetable tissues are physically and chemically damaged by cooking, causing major changes to compounds in cell membranes. The current study aimed to evaluate the influence of several cooking methods on bioactive compounds in beetroot. Four heat treatments were carried out: steam cooking, pressure cooking, baking in an oven, and boiling in water. Beets were matched in uniformity of size, color, and absence of defects. They were washed thoroughly in running water to remove dirt. Next, one of the four cooking methods was applied. After cooking, beets were peeled by hand. Analysis was carried out on both uncooked and cooked beets to evaluate antioxidant activity, content of phenolic compounds, pigments, flavonoids, and betalains. The experiment was completely randomized design (CRD) and carried out in triplicate. Data were subjected to analysis of variance (F test, p < 0.05) and mean values compared by Tukey test at 5% probability. There was no change in antioxidant activity or total phenolic and anthocyanin content by any of the cooking methods compared to that in raw beetroots. However, pressure-cooking resulted in lower carotenoid levels compared to that in raw beet. Furthermore, flavonoid and betalain content decreased by all the cooking methods.(AU)

A beterraba é rica em compostos bioativos, que possuem efeitos benéficos para o organismo humano. Porém o cozimento dos tecidos vegetais altera física e quimicamente as propriedades da parede celular, afetando o teor desses compostos. O objetivo do trabalho foi avaliar os compostos bioativos em beterrabas in natura e submetidas a diversas formas de cozimento. Foram realizados quatro tratamentos térmicos, sendo eles cocção a vapor, cocção na panela de pressão, no forno e na água em imersão. As beterrabas foram selecionadas visando a homogeneização do lote quanto ao tamanho, cor e ausência de injúrias e defeitos. Foram lavadas em água corrente para tirar as sujidades. Em seguida, levadas às quatro formas de cocção. Após os tratamentos térmicos, foram descascadas manualmente. As análises realizadas nas beterrabas in natura e cozidas foram a atividade antioxidante, teor de compostos fenólicos totais, pigmentos, flavonoides e betalaínas. O experimento seguiu o Delineamento Inteiramente Casualizado (DIC) com três repetições. Os dados foram submetidos a análise de variânca, teste F, e as médias comparadas pelo Teste de Tukey (p < 0,05). Não houve perdas na atividade antioxidante, fenólicos totais e antocianinas em todas as formas de cocção estudadas em relação à beterraba crua. Somente a cocção na pressão apresentou menores teores de carotenoides em relação a crua. As concentrações de flavonoides e de betalaínas diminuíram em todas as formas de cozimento.(AU)

Physicochemical and antioxidant capacity analysis of colored sweet potato genotypes: in natura and thermally processed / Análises físico-químicas e capacidade antioxidante de genótipos coloridos de batata-doce in natura e termicamente processados

Sweet potato (Ipomoea batatas (L.) Lam) is one of the most popular and ancient roots of Brazil and it can be consumed at different forms such as boiled, roasted or as sweets. Its cooking can lead to physicochemical transformations altering the nutritional properties. The objective of this study was to evaluate the physicochemical characteristics, bioactive compounds and antioxidant capacity of twelve sweet potato genotypes of varying pulp color in natura and roasted. Soluble solids, acidity, sugars, carotenoids, anthocyanins, phenolic compounds and antioxidant capacity were analyzed in the following sweet potatoes genotypes: cream pulp (Rubissol, Cuia, ILS03, ILS10, ILS12, ILS24 and ILS44); orange pulp (Amelia and Beauregard); and purple pulp (ILS56, ILS16 and ILS71). According to the results, it was observed a wide variation among the sweet potato genotypes for all analyzed parameters, in both preparation forms. The antioxidant capacity was a parameter with wide variation among genotypes, 210.29 to 7870.57µg trolox equivalent/g in in natura form and 673.26 to 17306.22µg trolox equivalent/g in roasted form. Soluble solids, acidity, sugars and bioactive compounds, with the exception of carotenoids, tended to be concentrated, also increases the total antioxidant capacity, in roasted sweet potatoes. In conclusion, genotype and the color of sweet potatoes were parameters that had an influence on its chemical composition. Cultivars such as Amelia and Beauregard stood out by the amounts of total soluble solids and carotenoids, respectively. The selections ILS 16 and ILS 56 are recommended as sources of anthocyanins. Thermal process influenced the concentration of antioxidant compounds and changed some physicochemical characteristics.(AU)

A batata-doce (Ipomoea batatas (L.) Lam) é uma das raízes mais populares e antigas do Brasil, podendo ser consumida cozida, assada ou na forma de doces. A sua cocção pode levar à transformações físico-químicas alterando as propriedades nutricionais. O objetivo deste trabalho foi avaliar as características físico-químicas, compostos bioativos e atividade antioxidante de doze genótipos de batata-doce, de coloração de polpa variada, na forma in natura e assada. Foram determinados sólidos solúveis totais, acidez, açúcares, carotenoides, antocianinas, compostos fenólicos e atividade antioxidante nos seguintes genótipos de batatas-doces: polpa creme (Rubissol, Cuia, ILS03, ILS10, ILS12, ILS24 e ILS44); polpa laranja (Amélia e Beauregard) e polpa roxa (ILS56, ILS16 e ILS71). Quanto aos resultados foi observada ampla variação entre os genótipos de batata-doce, para todos os parâmetros analisados, em ambas as formas de preparo. A atividade antioxidante foi um parâmetro que demonstrou grande variação entre os genótipos, de 210,29 a 7870,57µg de equivalente trolox/g nos genótipos in natura e de 673,26 a 17306,22µg de equivalente trolox/g nos genótipos assados. Foi observado que em batatas-doces assadas os sólidos solúveis, acidez, açúcares e os compostos bioativos, com exceção dos carotenoides, tenderam a ser concentrados, elevando também a atividade antioxidante total. Em conclusão, o genótipo e a coloração da batata-doce foram parâmetros que exerceram influência sob a sua composição química. Cultivares como Amélia e Beauregard se destacaram pela quantidade de sólidos solúveis totais e carotenoides,respectivamente. Como fonte de antocianinas, as seleções ILS 16 e ILS 56 são recomendadas. O processo térmico influenciou a concentraçãode compostos antioxidantes e alterou algumas características físico-químicas.(AU)

Does competition between soybeans and Wild Poinsettia with low-level resistance or susceptibility to glyphosate affect physiology and secondary metabolism? / A competição entre soja e leiteira com resistência de nível baixo e suscetível ao glyphosate interfere na fisiologia e metabolismo secundário?

The Wild Poinsettia (Euphorbia heterophylla L.) has elevated potential to reduce the soybean yield and is a difficult to control plant due to herbicide resistance. The objectives of this study were to determine the changes in the photosynthetic physiological parameters, secondary metabolite levels, cellular damage, and antioxidant system activity in soybean plants and Wild Poinsettia biotypes with a low level of resistance or susceptibility to glyphosate in competition with soybeans. Two replacement series experiments were conducted in a greenhouse under competition between soybeans and the low-level resistant biotype (experiment I) or susceptible biotype (experiment II). The treatments consisted of different proportions of soybean plants and Wild Poinsettia [100:0 (pure stand of soybean), 50:50, and 0:100 (pure stand of Wild Poinsettia)] and different evaluation periods (the 2013/14 and 2014/15 growing seasons). The following parameters were analyzed: the chlorophyll, carotenoid (CRT), total phenol, hydrogen peroxide (H2 O2 ), and lipid peroxidation levels and the catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) enzyme activity. Generally, competition between the soybeans and the Wild Poinsettia biotypes did not alter the photosynthetic parameters or the photosynthetic pigment levels of the crop. For the weed biotypes, competition with the soybeans negatively affected photosynthesis. Greater losses of chlorophylls and CRTs were observed for the susceptible biotype when in competition with soybeans, whereas the opposite trend was observed for the biotype with a low level of resistance. No cellular damage or alterations in antioxidant system enzyme activity was observed, which indicated a lack of oxidative stress.

A leiteira (Euphorbia heterophylla L.) apresenta elevado potencial de redução da produtividade de soja, sendo uma planta de difícil controle devido aos casos de resistência a herbicidas. Os objetivos desse trabalho foram determinar a alteração nos parâmetros fisiológicos fotossintéticos, o conteúdo de metabólitos secundários, os danos celulares e a atividade do sistema antioxidante em soja e em biótipo de leiteira resistente de nível baixo ou suscetível ao glyphosate, quando em competição com a soja. Foram realizados dois experimentos em casa de vegetação, em série de substituição, com a competição de soja com o biótipo resistente de nível baixo (experimento I) ou suscetível (experimento II). Os tratamentos constaram das proporções de plantas de soja e leiteira 100:0 (estande puro de soja), 50:50, e 0:100% (estande puro de leiteira); e, das diferentes épocas de condução dos experimentos (safras 2013/14 e 2014/15). Foram analisados o teor de clorofila e carotenoides, fenóis totais, peróxido de hidrogênio, peroxidação lipídica e atividade das enzimas catalase, ascorbato peroxidase e superóxido dismutase. A competição de soja com os biótipos de leiteira, em geral, não alterou os parâmetros fotossintéticos e o teor de pigmentos fotossintéticos da cultura. Para os biótipos da planta daninha, a competição com a soja interferiu negativamente na fotossíntese, havendo maiores perdas de clorofilas e carotenoides para o biótipo suscetível quando em competição com a soja, sendo o contrário observado para o biótipo resistente de nível baixo. Não foram observados danos celulares ou alteração na atividade das enzimas do sistema antioxidante, indicando não haver estresse oxidativo.