Comparison of Alkali and Conventional Corn Wet-Milling: 1-kg Procedures

An alkali corn wet-milling process was developed to evaluate the process as a method to produce high purity corn starch and coproducts with added value. Using a single hybrid (R1064 × LH59), the effects of alkali concentration (0.18–0.82% NaOH), time (29–61 min), and temperature (36–75°C) were investigated. Starch yield was not affected by steep time or temperature. Starch yield was optimal at 65.2% using 0.5% alkali. Increasing the concentration of alkali to 0.82% or decreasing it to 0.18% caused a decrease in starch yield of 8–10 percentage points. Other wet-milling products (fiber, germ, and gluten) also were affected. Steep conditions of 0.5% NaOH, 60 min, and 45°C gave optimal starch yield. Comparisons between alkali and sulfur dioxide wet-milling processes, using 1-kg sample size, were performed on 10 commercial yellow dent corn hybrids. The alkali process averaged 1.7 percentage points more starch than the sulfur dioxide process. Each hybrid had a higher starch yield when wet-milled with the alkali method. Alkali wet-milling produced pure corn starch with <0.30% protein (db).     

Effect of LPS on Reproductive System at the Level of the Pituitary of Anestrous Ewes

In our research we focused our attention on the effect of the immune stress induced by bacterial endotoxin–lipopolysaccharide (LPS) on the hypothalamic–pituitary–gonadal axis (HPG) at the pituitary level. We examined the effect of intravenous (i.v.) LPS injection on luteinizing hormone (LH) and follicle‐stimulating hormone (FSH) release from the anterior pituitary gland (AP) in anestrous ewes. The effect of endotoxin on prolactin and cortisol circulating levels was also determined. We also researched the effect of immune challenge on the previously mentioned pituitary hormones and their receptors genes expression in the AP. Our results demonstrate that i.v. LPS injection decreased the plasma concentration of LH (23%; p < 0.05) and stimulates cortisol (245%; p < 0.05) and prolactin (60%; p < 0.05) release but has no significant effect on the FSH release assayed during 6 h after LPS treatment in comparison with the control levels. The LPS administration affected the genes expression of gonadotropins’β‐subunits, prolactin and their receptors in the AP. Endotoxin injection significantly decreased the LHβ and LH receptor (LHR) gene expression (60%, 64%; p < 0.01 respectively), increased the amount of mRNA encoding FSHβ, FSH receptor (FSHR) (124%, 0.05; 166%, p < 0.01; respectively), prolactin and prolactin receptor (PRLR) (50%, 47%, p < 0.01; respectively). The presented, results suggest that immune stress is a powerful modulator of the HPG axis at the pituitary level. The changes in LH secretion could be an effect of the processes occurring in the hypothalamus. However, the direct effect of immune mediators, prolactin, cortisol and other components of the hypothalamic pituitary–adrenal (HPA) axis on the activity of gonadotropes has to be considered as well. Those molecules could affect LH synthesis directly through a modulation at all stages of LHβ secretion as well as indirectly influencing the GnRHR expression and leading to reduced pituitary responsiveness to GnRH stimulation.     

Distribution and stability of organic forms of nitrogen in forest soil profiles in Tanzania

The organic C and total N in Tanzanian forest soil profiles decreased with the depth but the C:N ratio and pH tended to increase. Soil pH ranged from 6.5 in the surface horizon to 7.3 in sub-surface ones.Of the total N in the surface horizon, 69.3–85.6% was hydrolysable in boiling 6 n HCl and 14.4–30.7% was nonhydrolysable. The amounts, expressed as percentage of total soil N, of NH⁺₄-N, hexosamine-N, serine + threonine-N (hydroxy amino acid-N) and amino acid-N in the total hydrolysable-N fraction ranged between 10.8–21.4, 5.2–11.5, 4.6–11.3 and 18.6–31.2, respectively. The amount of identified-N ranged between 43.3 and 60.0%, and that of unidentified-N between 24.1 and 36.0%. Amino acid-N constituted the largest portion of the identified-N. Total, NH⁺₄, hexosamine, amino acid (in Olmotonyi forest profiles only) and identified N fractions generally tended to decrease with depth in the profile but nonhydrolysable-N increased. Hydroxy amino acid-N and unidentified-N followed no definite trend.During aerobic incubation of surface soil, the amounts of total hydrolysable-N, hexosamine-N and hydroxy amino acid-N decreased while those of NH⁺₄-N and nonhydrolysable-N increased. All the organic N fractions underwent transformation during incubation. The hexosamines and hydroxy amino acids were more unstable than the others; the former being more vulnerable than the latter.     

Utilization of deoiled castor cake for crop production

A screen house experiment was undertaken to study effect of time of application of deoiled castor cake on the yield, N and P uptake by wheat crop. The results indicate that the wheat growth decreased significantly with increasing dose of castor cake, when castor cake was applied just before sowing of wheat. When castor cake was applied 10 days before wheat sowing, the dry matter yield (DMY) of wheat increased up to 0.125% dose of castor cake and reduced thereafter. But when the castor cake was applied 20 days before wheat sowing, the DMY was at par under all the doses of castor cake and better than control indicating the degradation of the toxicants produced by the castor cake. Application of castor cake can also be helpful in reducing the cost of phosphatic fertilizer. Thus it can be concluded that castor cake should be applied at least 3 weeks before sowing of the crop and keeping the field moist for degradation of the toxicants.     

Socio-economic status and health awareness are associated with choice of cooking oil in Costa Rica

OBJECTIVE: To examine the socio-economic and lifestyle determinants of cooking oil choice in Costa Rica during the last decade (1994-2004). DESIGN: Cross-sectional study. Subjects (total n = 2274) belonged to the control population of a large case-control study; they were recruited yearly. Data about type of oil used for cooking, dietary intake, socio-economic and demographic characteristics were collected. SETTING: A dietitian visited all subjects and conducted the interviews at their homes; all subjects lived in the Costa Rican central valley region. SUBJECTS: Adult, free-living, rural and urban Costa Ricans with no history of myocardial infarction and physical or mental disability. RESULTS: The odds of choosing soybean over palm oil increased significantly each year (P < 0.05) and was determined by high socio-economic status (SES) and variables that suggest health awareness (self-reported history of hypertension, high cholesterol, multivitamin use and intake of green leafy vegetables). The odds of choosing other unsaturated oils, namely corn and sunflower, over soybean oil also increased yearly (P < 0.05) and was associated with the same two factors (high SES and health awareness). Palm oil users remained in the lowest SES tertile and were more likely to live in rural areas. Across all SES tertiles, high health awareness determined the odds of choosing other unsaturated oils over palm oil, and soybean oil (P < 0.05).CONCLUSION: These data show that, in addition to SES, health awareness is associated with the selection of unsaturated oils over palm oil in a developing country undergoing transition. These data should be considered when targeting nutrition messages and policies that promote better dietary choices.