The influence of sugars and amino acids on the blood-feeding behaviour, oviposition and longevity of laboratory colony of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae, Phlebotominae)

Schneider's Drosophila medium, a complex amino acid rich medium was tested alone and with seven different sugars for some aspects of the biology of Lutzomyia longipalpis. Statistically significant results were obtained when sucrose was used alone, indicating that among the sugars tested, this is still the most suitable and practical one for the maintenance of L. longipalpis colonies. However, the addition of Schneider's medium to a pool of different sugars, was suggested to be related with the acceptance of the first and second blood meals and to longevity, these being, obviously, quite relevant aspects when tansmission experiments are contemplated.

Sugars, organic acids, minerals and lipids in jabuticaba

The aim of this work was to determine the sugar, organic acid and mineral compositions of the whole fruit and fractions (skin, pulp and seed) of the Paulista (Plinia cauliflora) and Sabará (Plinia jaboticaba) jabuticaba tree genotypes, as well as the oil compositions of their skin and seeds. High levels of sugar, especially fructose, followed by glucose and sucrose, were encountered in the fruit. In the Paulista genotype, higher levels of total and reducing sugars were found in the pulp and skin, which was not observed when comparing the whole fruit of both genotypes. Five organic acids were found in the whole fruit and in the fractions of the two jabuticaba genotypes in quantitative order: citric acid > succinic acid > malic acid > oxalic acid > acetic acid. Potassium was the most abundant mineral found. This fruit was also shown to be rich in magnesium, phosphorus, calcium and copper. The seed oil had nearly the same constitution as the oil extracted from the skin in both genotypes and the major compounds were an unidentified phytosterol, palmitic, linoleic and oleic acids, and squalene.

Soluble sugars and germination of Annona emarginata (Schltdl.) H. Rainer seeds submitted to immersion in GA3 up to different water contents

The objective of this study was to evaluate the effect of different water contents achieved by Annona emarginata (Schltdl.) H. Rainer seeds during immersion in GA3 solutions, in variation of soluble sugars levels and germination. Seeds with 10% of initial water content were submitted to imbibition in GA3 solutions with concentrations of 0; 250; 500; 750 and 1000 mg L-1 and when they reached the water content of 15%, 20%, 25%, 30% and 35%, the quantification of soluble sugars levels and germination test were performed. Seeds immersed up to they reach 15% of water with GA3 and immersed up to the water acquisition of 20% without GA3, presented higher soluble sugars levels and germination percentage, which were decreased when the seeds reached 30% and 35% of water, independently of the presence of the plant growth regulator. It was conclude that different water contents reached by the seeds in immersion treatments with GA3 affect the soluble sugars levels and germination percentage of Annona emarginata seeds. Thus, in treatments with Annona emarginata, the seeds must remain immersed in water without GA3 up to they reach 20% of water, as higher water contents (35%) reduce the soluble sugars levels and the seed germination percentage.

Boron influence on concentration of polyols and other sugars in Eucalyptus

Although the functions of the element Boron (B) in plants have not been sufficiently clarified, several hypotheses have been raised. Some of the functions attributed to this element are synthesis and transport of carbohydrates. To evaluate the effect of B on the synthesis of some polyols and sugars in Eucalyptus grandis and hybrids "urograndis", these species were submitted to situations of supply and restriction of B. The experiment was carried out in a greenhouse, arranged in a randomized block design in a 2 x 2 factorial scheme, with 5 replicates of each genotype. The B levels were provided in the form of nutrient solution. No significant difference was observed in the content of mannitol, sorbitol, myo-inositol and scyllo-inositol and sugars α-glucose and β-glucose between E. grandis and hybrids. Arabinose was the only one to present a higher content in E. grandis on restriction of B. The effect of the presence of B was very expressive, but regarding B supply, the plants showed significant increase in the synthesis of the compounds evaluated.

Determination of the influence of the variation of reducing and non-reducing sugars on coffee quality with use of artificial neural network

The present study aimed at evaluating the use of Artificial Neural Network to correlate the values resulting from chemical analyses of samples of coffee with the values of their sensory analyses. The coffee samples used were from the Coffea arabica L., cultivars Acaiá do Cerrado, Topázio, Acaiá 474-19 and Bourbon, collected in the southern region of the state of Minas Gerais. The chemical analyses were carried out for reducing and non-reducing sugars. The quality of the beverage was evaluated by sensory analysis. The Artificial Neural Network method used values from chemical analyses as input variables and values from sensory analysis as output values. The multiple linear regression of sensory analysis values, according to the values from chemical analyses, presented a determination coefficient of 0.3106, while the Artificial Neural Network achieved a level of 80.00% of success in the classification of values from the sensory analysis.

Biotechnological production of bioflavors and functional sugars

Bioflavors and oligosaccharides are two classes of substances that may be produced biotechnologically through microbial bioprocesses. These compounds have attracted the interest of pharmaceutical and food industries not only due to their technological properties (sweetening/fiber or flavoring, respectively), but also as a consequence of other functional properties such as, for example, health promoting benefits. The use of agro-industrial residues as substrates in biotechnological processes seems to be a valuable alternative in helping to overcome the high manufacturing costs of industrial fermentations. This manuscript reviews the most important advances in biotechnological production of bioflavors and oligosaccharides. The use of some agro-industrial residues in such processes is also cited and discussed, showing that this is a rising trend in biotechnology.

Development and optimization of a HPLC-RI method for the determination of major sugars in apple juice and evaluation of the effect of the ripening stage

The sugars in apple juice prove its authenticity and its sensory and nutritional properties. The aim of this study was to develop and validate a simple analytical method using high performance liquid chromatography with refractive index detection (HPLC-RI) to determinate and quantify the sugars sucrose, D-glucose, D-fructose, and D-sorbitol polyol in apple juices, as well as to analyze the juices from the Fuji suprema and Lis Gala cultivars at three ripening stages. The analytical performance parameters evaluated indicated that the method was specific for the compounds analyzed, and the linearity of the calibration curves of sugars showed high correlation coefficients (close to 1.0). The limits of detection and quantification are consistent with recommendations available in the literature for this type of matrix. Sample preparation is simple and generates small amount of residues. Over 70% of the sugars were determined in the juices of apples at the pre-ripe stage, with an increase during senescence. This method is applicable for the determination of sugars in juices and evaluation of apple ripening.

Carbohydrates Concentration in leaves of potato plants affected by nitrogen fertilization rates

ABSTRACT At poor conditions of nitrogen (N) in the soil, potato plants may accumulate starch in leaves and be indicative of N nutritional stress. The objective of this work was to determine the effects of N rates (0, 50, 100, 200 and 300 kg ha-1 of N) on the concentrations of carbohydrates (total soluble sugars-TSS, reducing sugars-RS, non-reducing sugars-NRS and starch) in the fourth leaf (FL) of two potato cultivars (Asterix and Atlantic) and their critical levels (CL) associated to the N fertilization rate necessary to obtain the maximum physical (MPE) and economic (MEE) efficiency of tubers. A randomized block design with four replications was used in both experiments. On day 21 after plant emergence, four FL were collected from four plants. Potatoes plants fertilized with low rates of N accumulated less TSS in leaves than those properly fertilized. The opposite occurred with content of starch. The cultivars showed similar responses to five doses of N in relation to contents of starch and TSS. However, the response to the increase in doses of N for RS, NRS and Starch/NRS is cultivar-specific. The correlations between contents of RS, NRS and Starch/NRS with the starch and TSS were dependent on the potato cultivar.

Evaluation of phenotypic markers associated with pathogenicity in the genus Listeria

A total of 130 Listeria strains were tested in order to evaluate lecithinase production and capacity for Congo red adsorption as markers of pathogenicity. The strains were identified according to acid production from sugars and by the CAMP test and the data were correlated with the ability to produce keratoconjunctivitis in guinea pigs. L. monocytogenes cultures presented 51.8% and 88.8% positivity rates for Congo red adsorption and lecithinase production, respectively, whereas 80.8% and 100% for L. innocua cultures were negative for the two test, respectively

Leishmania braziliensis: isolation of carbohydrate-containing antigen and possibility of its use in the immunodiagnosis of American Cutaneous Leishmaniasis

Leishmania braziliensis is a causative agent of American Cutaneous Leishmaniasis (ACL). The 034-JCG strain, isolated from a patient from the northern region of Paraná State, Brazil, was cultivated in Blood Agar Base medium, lyophilized and submitted to phenol-water extraction. The extract was treated with RNase I. The carbohydrate containing-antigen (Ag-CHO) was immunogenic to rabbits and showed at least a fraction with some negative charge at pH 8.2. This antigen showed cross-reactivity with the phenol-water extract of the growth medium used for the culture of promastigotes and with the surface antigens of promastigotes. Its composition is: 24.3% of total sugars, from which 11.2% of galactose, 7.5% of mannose and 5.6% of ribose. Protein content was 5.4% and phosphate 18.5%. The antigenic activity was maintained after: repeated freezing-thawing; lyophilization; heating at 100ºC for 30 minutes; treatment with RNase, trichloroacetic acid and sodium metaperiodate. The precipitin line obtained is Periodic Acid Schiff positive. The application of the Ag-CHO in counterimmunoelectrophoresis reaction for the immunodiagnosis of ACL showed 60% sensitivity, and no cross-reaction with the five sera of Chagas' disease patients tested. The use of this antigen in a more sensitive technique, with more samples of sera, may improve these results.

Estudos químico-agrícolas sôbre o enxofre

1. Analyses of soluble sulphates in 2 N ammonium chloride extracts of 24 samples of soils of the state of São Paulo, Brazil, S. A., showed a sulphur content varying from 0,0013 g per 100 g (found in the b layer of a genuine "terra roxa") to 0,007 g per 100 g of soil (b layer of a soil of depression without definite characteristics). (The results are expressed as elemental sulphur). Determinations of total sulphur in 56 samples of soils of the same state using the method of fusion with sodium carbonate and sodium nitrate revealed 0.007 g of elemental S per 100 g of soil as the lowest value (found in several soil types) and 0.096 g as the highest one (found in the b layer of an ar-quean soil). Apparently soluble sulphates accumulate in the upper layers and total sulphur does the opposite. It was found a strong correlation between total S and carbon content. 2. Under laboratory conditions, in a compost of fresh soil, powdered sulphur and apatite, it was verified after a three months period of incubation that the pH value lowered from 6.30 to 3.23; the citric acid solubility of apatite increased to 271.1 per cent of the original one. Lupinus sp. grown in soil manured with sulphur and apatite has showed fresh and dry weights higher than the plants in control pots; the results are significant at 5% level of probability; phosphorus content is also higher in the manured plants. It was observed a net influence of the apatite plus sulphur treatment on the weight of root nodosities that was four times greater than in the control plants. 3. Nearly five hundred determinations of S, N and P were carried out in 35 species of plants cultivated in the state of São Paulo. A great variation in the amounts of these elements was observed. As a general rule, the leaves contain more sulphur than the stems and roots show the lowest percentages. The conjunct roots and stem of guar (Cyamopsis psoraloides) revealed only 0.019 per cent sulphur; the leaves of kale showed the highest sulphur content, i. e., 2.114%. Apparently there is no correlation between the amounts of S, N and P. The ratio S/N increases from 0.006 (guar) to 0.485 (kale). The ratio S/P, always higher than the corresponding S/N, increases from 0.082 (guar) to 6.381 (older leaves of tomato plants). It is interesting to mention that several among the most important crops in the state of São Paulo namely, cotton, rice, coffee and sugar cane contain more sulphur than phosphorus. 4. Tomato plants cultivated in nutrient solution lacking sulphur showed the following visual symptons of deficiency : chlorosis first in the younger leaves and afterwards in all the leaves; anthocyanin pigments in the petioles and stems; absence of fruits; primary roots stunted and secondary ones longer than in the control plants; stems slender, hard, woody. The histological study of petioles suffering from sulphur deficiency revealed anthocyanin in the parenchyme layer instead of clo-rophyll pigments observed in normal petioles; in the chlorotic leaves the large chloroplasts present only the stroma but the small ones have a little amount of green pigments. Chemical analysis revealed in the abnormal plants : less sulphur and an increased proportion of phosphorus; older leaves contain more sulphur and less phosphorus than the younger ones probably due to physiological difficulties in translocation of sulphur bearing material; increased amount of total N attributed to accumulation of nitrates; marked decrease in ash, sugars and starch; increased proportion of crude fiber and dry material. In the plants suffering from sulphur deficiency photosyntetic rate decreased 34 per cent. 5. Tomato plants were succesfully cultivated in nutrient solution in absence of mineral sulphur but in presence of cysteine. The plants absorbed sulphur, under that form and were able to grow up quite well; the fruiting was normal. In this way rested cleary demonstrated the possibility of absorption of organic sulphur without previous mineralization and its utilization in the building up of protein molecules.

Estudos sôbre a alimentação mineral da mandioca (Manihot utilissima Pohl.)

1. The present work was carried out to study the effects of mineral nutrients in the yield as well as in the composition of cassava roots. The variety "Branca de Sta. Catarina" was grown by the sand culture method, the following treatments being used: N0 P0 K0, N0 P1 Kl, N1 P0 K1, N2 P1 K0, N2 P1 K1, N1 P2 K1, and N1 P1 K2, where the figures 0, 1, and 2 denote the relative proportion of a given element. The nutrients were given as follows: N = 35 grams of ammonium nitrate per pot loaded with 120 pounds of washed sand; P1 = 35 grams of monocalcium phosphate; Kl = 28 grams of sulfate of potash. Besides those fertilizers, each pot received 26 grams of magnesium sulfate and weekly doses of micronutrients as indicated by HOAGLAND and ARNON (1939). To apply the macronutrients the total doses were divided in three parts evenly distributed during the life cycle of cassava. 2. As far yield of roots and foliage are concerned, there are a few points to be considered: 2.1. the most striking effect on yield was verified when P was omitted from the fertilization; this treatment gave the poorest yields of the whole experiment; the need of that element for the phosphorylation of the starchy reserves explains such result; 2.2. phosphorus and nitrogen, under the experimental conditions, showed to be the most important nutrients for cassava; the effect of potassium in the weight of the roots produced was much less marked; it is noteworthy to mention, that in absence of potassium, the roots yield decreased whereas the foliage increased; as potassium is essential for the translocation of carbohydrates it is reasonable to admit that sugars produced in the leaves instead of going down and accumulate as starch in the roots were consumed in the production of more green matter. 3. Chemical analyses of roots revealed the following interesting points: 3.1. the lack of phosphorus brought about the most drastic reduction in the starch content of the roots; while the treatment N1 P1 K1 gave 32 per cent of starch, with NI PO Kl the amount found was 25 per cent; this result can be explained by the requirement of P for the enzymatic synthesis of starch; it has to be mentioned that the decrease in the starch content was associated with the remarkable drop in yield observed when P was omitted from the nutrient medium; 3.2. the double dosis of nitrogen in the treatment N2 P1 K1, gave the highest yields; however the increase in yield did not produce any industrial gain: whereas the treatment N1 P1 K1 gave 32 per cent of starch, by raising the N level to N2, the starch content fell to 24 per cent; now, considering the total amount of starch present in the roots, one can see, that the increase in roots yield did not compensate for the marked decrease in the starch content; that is, the amount of starch obtained with N1 P1 K1 does not differ statistically from the quantity obtained with N2 P1 K1; as far we know facts similar to this had been observed in sugar beets and sugar cane, as a result of the interaction between nitrogen and sugar produced; the biochemical aspect of the problem is very interesting: by raising the amount of assimilable nitrogen, instead of the carbohydrates polymerize to starch, they do combine to the amino groups to give proteinaceous materials; actually, it did happen that the protein content increased from 2.91 to 5.14 per cent.

O brix na determinação da riqueza em açúcares do mamão como auxiliar no melhoramento do mamoeiro (Carica papaya L.)

There is in the literature a noteworthy lack of sampling methods to be employed in the selection of papaya fruits for genetical improvement purposes. In the present experiment methods applied to melon and watermelon were extended to papaya with good results. The authors tried to correlate the solids content-as determined by a hand refractometer-with total sugars in the fruit. The correlation does exist being significant and positive. A regression equation was worked out; it permits to calculate the total sugar content provided the Brix value determined by the hand refractometer is known. The equation is as follows: a = 0.57 s where a = total amount of sugar as glucose, and s = total solids.

Tracer studies in the coffee plant (Coffea arabica L.)

Due to the great importance of coffee to the Brazilian economy, a good deal of the work carried out in the "Laboratório de Isótopos", E. E. A. "Luiz de Queiroz", Piracicaba, S. Paulo, Brazil, was dedicated to the study of some problems involving that plant. The first one was designed to verify a few aspects of the control of zinc deficiency which is common in many types of soils in Brazil. An experiment conducted in nutrient solution showed that the leaf absorption of the radiozinc was eight times as high as the root uptake; the lower surface of the leaves is particularly suited for this kind of absorption. Among the heavy metal micronutrients, only iron did not affect the absorption of the radiozinc; manganese, copper, and molybdenum brought about a decrease of fifty per cent in total uptake. In another pot experiment in which two soils typical of the coffee growing regions were used, namely, a sandy soil called "arenito de Bauru" and a heavy one, "terra roxa", only O.l and 0.2 per cent of the activity supplied to the roots was recovered", respectively. This indicates that under field conditions the farmer should not attempt to correct zinc deficiency by applying zinc salts to the soil: leaf sprays should be used wherever necessary. In order to find out the most suitable way to supply phosphatic fertilizers to the coffee plant, under normal farm conditions, an experiment with tagged superphosphate was carried out with the following methods of distribution of this material: (1) topdressed in a circular area around the trees; (2) placed in the bottom of a 15 cm deep furrow made around the plant; (3) placed in a semicircular furrow, as in the previous treatment; (4) sprayed directly to the leaves. It was verified that in the first case, circa 10 per cent of the phosphorus in the leaves came from the superphosphate; for the other treatments, the results ware, respectively: 2.4, 1.7, and 38.0 per cent. It is interesting to mention that the first and the last methods of distribution were those less used by the farmers; now they are being introduced in many coffee plantations. In a previous trial it was demonstrated that urea sprays were an adequate way to correct nitrogen deficiency under field conditions. An experiment was then set up in which urea-C14 was used to study the metabolism of this fertilizer in coffee leaves. In was verified that in a 9 hours period circa 95 per cent of the urea supplied to the leaves had been absorbed. The distribution of the nitrogen of the urea was followed by standard chemical procedures. On the other hand the fate of the carbonic moiety was studied with the aid of the radiochromatographic technique. Thus, the incorporation of C14 in aminoacids, sugars and organic acids was ascertained. Data obtained in this work gave a definite support to the idea that in coffee leaves, as in a few other higher plants, a mechanism similar to the urea cycle of animals does exist.

Influência do desponte sôbre a composição do côlmo e do caldo da cana-de-açucar, I. Var. Co 421

I. This paper deals with an experiment carried out to evaluate the effect of the sugar cane upper end on the composition of the sugar cane harvest as a raw material for the sugar industry. The variety studied was Co 421. The authors intend to study other varieties in the future. The data were collected from plant cane, at intervals of two weeks, always from the same field, from a small central area of 3.000 square meters approximately. Sixty (60) stalks were cut in each occasion, randomly chosen from the whole area. They were afterwards separated into three groups of 20 stalks, one for each of the treatments, namely: a) Complete stalks, with no leaves or sheaths. b) Stalks harvested by the technique of REYNOSO, that is, as usually done in practice. c) Stalks with the tops completely cut out, that is, cut by technique of REYNOSO and then with 3 other top internodes eliminated. The treatments caused significant differences on the following technological characteristics: a) Weight b) Cane pol c) Available sucrose (pol) per cent cane d) Cane juice pol e) Saline coefficient of juice. II. Except for weight, all changes were favorable to treatment c, even if with differences relatively slight, in percentage. IIII. Treatment differences for cane fiber, brix, reducing sugars, juice ashes, coefficient of purity and glucose coefficient were not significant. IV. Time of harvest was an important factor affecting the composition of the cane and of the juice. V. On the average the available sucrose of cane for treatments, with an standard error of 0.13%, was: Treatment c 13.05% Treatment b 12.65% Treatment a 12.53% This shows that there is no sound basis for the heavy fines applied by some sugar mills to planters who do not cut low enough the tops of the cane stalks.