Chemical Composition and Oxidative Stability of Kernel Oils from Two Current Subspecies of Pistacia atlantica in Iran

Pistacia atlantica subsp. mutica (PAM) and kurdica (PAK) kernel oils showed significantly lower unsaturated to saturated fatty acid ratios (6.39, 6.33, respectively) and calculated oxidizability (Cox) values (3.99, 4.13, respectively) than those of the P. vera L. cv. Ohadi (PVO) kernel oil (8.91, 4.41) samples. The highest peroxide value was observed for the PAK oil (4.07 mequiv kg⁻¹) (PAM, 1.94; PVO, 0.37) samples. Iodine values for the PAM, PAK, and PVO oils were 104.26, 104.77, and 110.66, respectively. The saponification number of the PVO oil was significantly greater than the PAM and PAK oils, which were statistically not different. The unsaponifiable contents, which were composed mainly of sterols, ranged from 5.63 to 6.14%. Statistically the total tocopherols contents of the PAM (818.58 mg α-tocopherol kg⁻¹) and PVO (815.90 mg α-tocopherol kg⁻¹) oils were significantly higher than that of the PAK oil (499.91 mg α-tocopherol kg⁻¹). Total phenolics contents differed significantly, the greatest concentration was for the PAM oil (81.12 mg gallic acid kg⁻¹), followed by the PVO (62.84 mg gallic acid kg⁻¹) and PAK (56.51 mg gallic acid kg⁻¹) oil samples. The wax contents of the oil samples were statistically in the same range, namely 5.67–6.48%. Oxidative stability data indicated that the PAM oil is the most resistant to the formation of lipid oxidation products, followed by the PAK and PVO oil samples.     

Protein,Lipid, Aliphatic and Triterpenic Alcohol Content of Caper Seeds “<Emphasis Type="Italic">Capparis spinosa</Emphasis>”

Capparis spinosa has a large natural distribution over the Mediterranean basin. It is used in traditional medicines, and it is one of the most commonly found aromatics in the Mediterranean kitchen. In this paper, the total storage protein and lipids of Tunisian Capparis spinosa seeds were investigated, and the quantities were ca. 27% and ca. 33%, respectively. In this study also the composition of the aliphatic and triterpenic alcohols of C. spinosa was characterized for the first time. Aliphatic alcohol contents were ca. 45 mg kg⁻¹ of total extracted lipids. Three compounds were identified, hexadecanol, octadecanol and tetracosanol, of which octadecanol was the major compound (ca. 28 mg kg⁻¹). Triterpenic alcohol content was 396.82 mg kg⁻¹. Citrostadienol was the major compound (ca. 170 mg kg⁻¹). β-Amyrin, gramisterol, cycloartanol and 2,4 methylcycloartenol were also detected and identified.     

Physico-Chemical Characterization of <Emphasis Type="Italic">Moringa concanensis</Emphasis> Seeds and Seed Oil

The present work reports the characterization and comparison of Moringa concanensis seed oil from Tharparkar (a drought hit area), Pakistan. The hexane-extracted oil content of M. concanensis seeds ranged from 37.56 to 40.06% (average 38.82%). Protein, fiber, moisture and ash contents were found to be 30.07, 6.00, 5.88 and 9.00%, respectively. The extracted oil exhibited an iodine value of 67.00; a refractive index (40 °C) of 1.4648; its density (24 °C) was 0.8660 mg mL⁻¹; the saponification value (mg of KOH g⁻¹ of oil) was 179.00; unsaponifiable matter 0.78%; color (1 in. cell) 1.90R + 19.00Y; and acidity (% as oleic acid) 0.34%. Tocopherols (α, γ, and δ) in the oil accounted for 72.11, 9.26 and 33.87 mg kg⁻¹, respectively. Specific extinctions at 232 and 270 nm were 3.17 and 0.65, respectively. The peroxide and p-anisidine values of the oil were found to be 1.75 and 1.84 meq kg⁻¹, respectively. The induction periods (Rancimat, 20 L h⁻¹, 120 °C) of the crude oil was 10.81 h and reduced to 8.90 h after degumming. The M. concanensis oil was found to contain high levels of oleic acid (up to 68.00%) followed by palmitic, stearic, behenic, and arachidic acids up to levels of 11.04, 3.58, 3.44 and 7.09%, respectively. The results of the present analytical study, compared with those for other Moringa species and different vegetable oils, showed M. concanensis to be a potentially valuable non-conventional seed crop for high quality oil.     

Characterization of yam bean (Pachyrhizus spp.) Seeds as potential sources of high palmitic acid oil

Seeds from 22 accessions of the yam bean species Pachyrhizus ahipa (14 accessions), P. erosus (5), and P. tuberosus (3) were investigated for oil and protein contents, fatty acid composition of the seed oil, and the total tocopherol content and composition. Plants from the accessions were grown under greenhouse conditions during one (P. erosus and P. tuberosus) or two years (P. ahipa). The pattern of the investigated seed quality traits was very similar in the three species. Yam bean seeds were characterized by high oil (from about 20 to 28% in one environment) and protein contents (from about 23 to 34%). Seed oil contained high concentrations of palmitic (from about 25 to 30% of the total fatty acids), oleic (21 to 29%), and linoleic acids (35 to 40%). Levels of linolenic acid were very low, from about 1.0 to 2.5%. Total tocopherol content was relatively low in P. erosus (from 249 to 585 mg kg⁻¹ oil) and P. tuberosus (from 260 to 312 mg kg⁻¹ oil) compared with the levels found in P. ahipa grown under identical conditions (508 to 858 mg kg⁻¹ oil). In all the samples, γ-tocopherol was predominant, accounting for more than 90% of the total tocopherol content. The combination of high oil and protein contents, together with high palmitic acid, low linolenic acid, and high γ-tocopherol concentration, makes these crops an interesting alternative as sources of high palmitic acid oil for the food industry.     

Vertical distribution of heavy metals in wastewater-irrigated vegetable garden soils of three West African cities

Application of untreated wastewater to irrigate urban vegetable gardens is raising serious concern about possible health risks associated with the consumption of these vegetables particularly with regard to the concentrations of heavy metals (HM) in their edible portions. The soil concentrations of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn), were investigated in seven vegetable gardens from the three West African cities of Kano (Nigeria), Bobo Dioulasso (Burkina Faso) and Sikasso (Mali). Also determined were input–output balances of Cd and Zn from five vegetable gardens under 30 years of wastewater irrigation in Kano. In these gardens Cd (2.3–4.8 mg kg⁻¹) and Zn (13–285 mg kg⁻¹) concentrations throughout the profile attained unsafe levels. The concentrations of Cu (0.8–18 mg kg⁻¹), Cr (1.8–72 mg kg⁻¹), Ni (0–17 mg kg⁻¹) and Pb (0.6–46 mg kg⁻¹) were below the safety thresholds for arable soils. Overall, concentrations of Zn, Cd, Pb and Ni were higher in Kano than in Bobo-Dioulasso and Sikasso. Input–output analyses in Kano indicated that irrigation wastewater contributed annually 400–3,700 g Cd ha⁻¹ and 7,200–22,300 g Zn ha⁻¹, fertilizer 30–2,100 g Cd ha⁻¹ 50–17,600 g Zn ha⁻¹, harmattan dust 0.02–0.4 g Cd ha⁻¹ and 40–200 g Zn ha⁻¹ while 300–500 g Cd ha⁻¹ and 2,700–4,700 g Zn ha⁻¹ came from rainwater inputs. Input–output calculations subtracting the amounts of HM taken out in vegetable biomass and that lost to leaching from total inputs yielded an annual net positive balance of 700–4,160 g Cd ha⁻¹ and 9,350–39,700 g Zn ha⁻¹. If such balances remain unchanged for another 10–20 years vegetables raised in these garden fields are likely to be unsuitable for human consumption.     

Microbial desulfurization of dibenzothiophene and 4,6-dimethyldibenzothiophene in dodecane and straight-run diesel oil

The desulfurization of dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT) and their mixture by lyophilized cells ofPseudomonas delafieldii R-8 was studied in the presence of dodecane. The desulfurization rate for 4,6-DMDBT was found to be about 40% in comparison with that for DBT. The desulfurization process for DBT and 4,6-DMDBT proceeded simultaneously without preference for either one. The desulfurization rate for each compound was decreased when they were mixed together. The extent of desulfurization of 4,6-DMDBT was increased with the increase of cell concentration and the decrease of the volume ratio of oil-to-water used. The specific desulfurization rate for 4,6-DMDBT could be reached to 10.4 mmol sulfur kg⁻¹ (cell) h⁻¹ [approximately 0.33 mg sulfur g⁻¹ (cell) h⁻¹].Pseudomonas delafieldii R-8 showed high desulfurization capability for straight-run diesel oil (containing 1,807 mg/L of sulfur). About 1,000 mg/L of sulfur in diesel oil was removed by resting cells of this strain in 24 h of reaction. The specific desulfurization rate was 8.75 mmol sulfur kg⁻¹ (cell) h⁻¹.     

Extra Virgin Olive Oil Components and Oxidative Stability from Olives Grown in Tunisia

The effects of the contents of lipids, pigments, α-tocopherol and phenols were studied in relation to the antioxidant capacity of five virgin olive oils obtained from five olive cultivars planted in Tunisia (Arbequina, Koroneiki, Leccino, Oueslati and Chemchali). The antioxidant capacities were evaluated by two different radical scavenging activities: radical scavenging activity by the DPPH assay (RSA-DPPH) and total antioxidant status by the ABTS test (TAA-ABTS). The highest contents of antioxidant compounds (75.96, 10.34, 6.32, 15.39 and 241.52 mg kg⁻¹ for oleic acid, O/L ratio, carotenes, chlorophylls and total phenols, respectively) were found for the Koroneiki cultivar except for α-tocopherol and o-diphenols, which had the highest contents (369 and 160.7 mg kg⁻¹, respectively) in the Leccino and Chemchali cultivars (cvs). Furthermore, the highest antioxidant capacity in virgin olive oil was observed in the Koroneiki cultivar (0.24 mmol TE kg⁻¹) followed by the Chemchali and Leccino cvs (0.22 and 0.13 mmol TE kg⁻¹) for the TAA-ABTS test. However, the RSA-DPPH activity was higher for the Chemchali cultivar (19.9%) than for the Koroneiki and Leccino cvs (18.4 and 13.5%, respectively). Correlation between these capacities and the oil composition revealed that they were mainly influenced by the carotene content, followed by chlorophyll and phenolic contents where the ABTS test was more pronounced. Then, the antioxidant capacity of the virgin olive oils was correlated with polar components and the lipid profile which are important for its shelf life.     

Inclusion of antibiotics in feed alters greenhouse gas emissions from feedlot manure during composting

In this study, the effects of dietary inclusion of antibiotics on emissions of greenhouse gases (GHG: CO₂, CH₄ and N₂O) from cattle manure during composting were investigated. Manure was collected at the end of two feeding trials in 2005 and 2006 in which feedlot cattle were assigned to one of five dietary groups: (1) Control: no antibiotics added; (2) TYL11: tylosin at 11 mg kg⁻¹ feed; (3) CTC11: chlortetracycline at 11 mg kg⁻¹ feed; (4) CTC44: chlortetracycline at 44 mg kg⁻¹ feed; and CTC44SMZ44: chlortetracycline and sulfamethazine, each at 44 mg kg⁻¹ feed. Open windrows were constructed and the rate of GHG emission was measured periodically. In both years, CO₂ surface emissions were higher (P < 0.05) for treatments CTC11 and CTC44SMZ44 than for the Control. The CO₂ emission rates in 2005 were lower (P < 0.05) than in 2006, reflecting lower total carbon (TC) content in the manure in 2005 (138 ± 2 g kg⁻¹) than in 2006 (245 ± 2 g kg⁻¹). The rate of CH₄ emission varied from 0.006 to 0.232 g C m⁻² day⁻¹. Average values from all four antibiotic treatments were similar (P > 0.05) to the Control in both years. The N₂O emission rates were higher (P > 0.05) with CTC44SMZ44 (2005), TYL11 (2006) and CTC11 (2006) than with Control. While antibiotics do alter GHG emissions from composted feedlot manure, the mechanisms responsible are not clear and warrant further investigation.     

Determination of Underivatized Long Chain Fatty Acids Using HPLC with an Evaporative Light-Scattering Detector

A high-performance liquid chromatographic method with an evaporative light-scattering detector has been developed for the separation and quantitative analysis of four underivatized long chain fatty acids in four different oil matrices. An isocratic elution mode using methanol/water/acetic acid and an Agilent Eclipse XDB-C18 analytical column was used. Calibration curves of the four fatty acids (FA) were well correlated (r ² > 0.999) within the range of 1–10 mg mL⁻¹ for linoleic acid, 0.8–10 mg mL⁻¹ for stearic acid and 0.5–10 mg mL⁻¹ for the other FA. Four oil samples were examined; camellia oil, olive oil, Brucea javanica oil and sesame oil. Good agreement was found with the standard gas chromatographic (GC) method. The proposed method offers distinct advantages over the official GC method; better separation and precision, and the sample components do not need to be derivatized.     

Electrochemical detection of the neomycin phosphotransferase gene (NPT-II) in transgenic plants with a novel DNA biosensor

A novel DNA electrochemical biosensor is described for the detection of neomycin phosphotransferase gene (NPT-II), a selection marker for transgenic plants. A thiol-modified capture probe immobilized onto the surface of a gold electrode and a biotinylated signaling probe were designed to be complementary to target regions of NPT-II flanked by PCR primers to eliminate false-positive signals from non-specific PCR products. The electrochemical assay of hybrids on the electrode surface was evaluated by means of both cyclic voltammetry (CV) and square wave voltammetry (SWV) after the coupling of biotinylated catalase with streptavidin-modified hybrids based on dendritic signal magnification and subsequent formation of polymerized aniline (PAn). It has been revealed that the sensor showed a linear increase within the target concentration (1.0–100 × 10⁻⁶ mmol L⁻¹). The limit of detection was about 0.2 × 10⁻⁶ mmol L⁻¹ and the specificity was enhanced significantly.     

Effect of organic and inorganic phosphate fertilizers and their combination on maize yield and phosphorus availability in a Yellow Earth in Myanmar

Phosphorus (P) deficiency is a major constraint for crop production in many parts of the world including Myanmar and field research into management of P fertilizers and P responsiveness of crops on infertile soils has been limited. The purpose of this study is to determine maize yield response to different forms of P fertilizers on an acidic (pH 4.9) P deficient (Olsen-P 8 mg kg⁻¹) Yellow Earth (Acrisol) in Southern Shan State, Myanmar and to establish relationships between soil Olsen-P test values (0.5 M sodium bicarbonate extracted P) and maize yield. Field experiments were conducted during two cropping seasons. There were 15 treatments in total: P was applied at seven rates of a soluble P fertilizer as Triple superphosphate (TSP) (0–120 kg P ha⁻¹) to establish a P response curve; one rate of a partially soluble P fertilizer (Chinese partially acidulated phosphate rock, CPAPR) and two organic P fertilizers (farmyard manure (FYM) and Tithonia diversifolia) at 20 kg P ha⁻¹; combination of TSP and CPAPR at 20 kg P ha⁻¹ with FYM and Tithonia at 20 kg P ha⁻¹; an additional treatment (TSP 20 kg P ha⁻¹ plus 2.5 t ha⁻¹ dolomite) for assessing the liming effect of a local dolomite. In Year 1, applications of TSP at 40–60 kg P ha⁻¹ produced near maximum grain yields, whereas in Year 2 this could be achieved with a reapplication of 20–30 kg P ha⁻¹ on top of the residual value of the Year 1 application. In both years, CPAPR, TSP and Tithonia at 20 kg P ha⁻¹ significantly increased maize grain yield, but FYM failed to increase grain yield. In Year 1, CPAPR and TSP effects on grain yield were higher than that of Tithonia but in Year 2 the effects were same for all these three treatments. In both years the combination of FYM (20 kg P ha⁻¹) with TSP (20 kg P ha⁻¹) produced significantly higher grain yield than TSP at 20 kg P ha⁻¹ whereas 40 kg P ha⁻¹ of TSP application did not significantly increase grain yield over the TSP application at 20 kg P ha⁻¹. Similar results were obtained when half the P applied as CPAPR was substituted with P from Tithonia and FMP during the first year. The combined data from the two years experiment suggests that 90% of maximum maize grain yields can be obtained by raising the Olsen-P to 30–35 mg P ha⁻¹ soil at the silking stage of growth. Olsen-P for the treatments at silking in Year 1 was: Control < FYM, Tithonia < TSP, CPAPR and in Year 2 was: Control < FYM < Tithonia < TSP, CPAPR. The results showed that for a long-term approach, repeated annual applications of Tithonia can be considered as a potential P source for improving soil P status in P deficient Yellow Earths.     

A Novel Approach for Determination of Free Fatty Acids in Vegetable Oils by a Flow Injection System with Manual Injection

A non-aqueous flow injection method for determining free fatty acid (FFA) content in corn and sunflower oil samples was developed. A single-line manifold system was built by modification of an HPLC for flow injection analysis (FIA). Without pre-treatment, oil samples were injected into a n-propanol solution containing KOH and phenolphthalein (PHP). The main parameters, such as flow rate of carrier phase, length, geometry, inner diameters of the coils and reagent concentration were all optimized. The proposed FIA method was validated for precision, accuracy, linear region, limit of detection (LOD) and limit of quantification (LOQ). The intra- and inter-day measurements of the precision of the method were found to be within the limits of acceptance criteria (RSD < 1%), and were rugged when the method was performed by a different analyst. The linear concentration range was calculated as 0.09–1.50 and 0.07–1.40 FFA% for corn and sunflower oils, correspondingly. The LOD and LOQ were found to be 7.53 × 10⁻⁴–2.28 × 10⁻³ oleic acid % and 7.11 × 10⁻⁴–2.23 × 10⁻³ oleic acid % for corn and sunflower oils, respectively. The results were compared with those obtained by the AOCS (Ca-5a-40) method using statistical t and F tests, and a significant difference was not observed between the methods at a 95% confidence level. The proposed method is suitable for quality control of routine applications due to its simplicity, high sample throughput, and economy of solvents and sample, offering considerable promise as a low cost analytical system that needs minimum human intervention over long periods of time.     

Influence of Zataria multiflora Boiss. essential oil on oxidative stability of sunflower oil

In this study, the influence of the application of 0.025%, 0.05% and 0.075% of Zataria multiflora Boiss. essential oil (EO) on oxidative stability of sunflower oil was examined and the EO was compared to butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) during storage at 37°C and 47°C. The main components of EO were identified as carvacrol (45.6%), p‐cymene (18.1%) and thymol (16.3%). Peroxide value (PV), anisidine value (AnV) and thiobarbituric acid (TBA) value measurement in sunflower oil showed that all concentrations of EO had a lower antioxidant effect in comparison to BHA and BHT. Samples supplemented with EO concentration of 0.075% were the most stable during storage at both temperatures (p<0.05). Furthermore, Totox value, antioxidant activity (AA), stabilization factor (F) and antioxidant power (AOP) determination confirmed efficacy of this EO as antioxidant in sunflower oil. EO also was able to reduce the stable 2,2‐diphenyl‐1‐picrylhydrazyl free radical (DPPH ^. ) with a 50% inhibition concentration (IC₅₀) of 34.3 ± 0.8 µg/mL. The results indicate that EO could be used as a natural antioxidant in oils for food uses.     

Efficacy of Microencapsulated Carvacrol in Oxidative Stability of Sunflower Oil

The objective of this study is to improve the oxidative stability of sunflower oil using encapsulated carvacrol during 25 times repeated frying experiments. Microencapsulated carvacrol powders are produced by spray drying using binary and ternary blends of gum arabic (GA), maltodextrin (MD), and corn starch as encapsulating agents. In most cases, the encapsulation efficiency decreases as the amount of GA decreases in the wall mixture. Microencapsulated carvacrol powders prepared with GA (100%), GA + MD (75:25), and GA + MD + starch (67.5: 22.5: 10), which are found to have higher encapsulation efficiency values, are used as antioxidants in dough frying experiments. Frying experiments are performed with the addition of encapsulated and/or unencapsulated forms of carvacrol into the sunflower oil or dough. Encapsulated carvacrol is found to be more effective than unencapsulated carvacrol and butylated hydroxyanisole (BHA) in repeated frying experiments. The addition of carvacrol into oil provides better protection compared to addition into dough. Protective effects of encapsulated and unencapsulated forms of carvacrol in frying trials are successfully discriminated by applying principal component analysis. Practical Application: Carvacrol and thymol are the major constituents of thyme (Thymus vulgaris L.) essential oil. These compounds are responsible for the main bioactive properties of thyme oil. Therefore, in this study, pure commercial carvacrol was encapsulated and tested for its protective effect in sunflower oil during repeated dough frying. The effectiveness of the carvacrol in encapsulated form may be a consequence of the prevention of volatilization. The results of this study are remarkable for food applications requiring high temperatures.     

Quality Characteristics and Antioxidants of Mavrolia cv. Virgin Olive Oil

The quality characteristics and bioactive microconstituents of virgin olive oil produced by Mavrolia cv, an Olea europaea variety grown in Southern Peloponnesus, Greece, are reported for the first time. The oil samples of Mavrolia cv. studied fell within the limits established for the extra virgin olive oil (EVOO) category and were characterized by higher levels of campesterol (88.7 ± 14.8 vs. 56.1 ± 6.1 mg kg⁻¹ oil) and β-sitosterol (1692.6 ± 100.3 vs. 1356.2 ± 85 mg kg⁻¹ oil) and relatively lower oxidative stability (19.35 ± 2.62 vs. 37.44 ± 1.97 h) compared to Koroneiki cv. The lower oxidative stability was positively correlated to significantly lower polyphenols (88.95 ± 2.33 vs. 233.75 ± 34.29) and α-tocopherol (517.2 ± 6.50 vs. 655.37 ± 17.78) and to higher polyunsaturated fatty acids content (9.27 ± 0.35 vs. 6.41 ± 0.38). Tyrosol, ferulic acid and protocatechuic acid contents were significantly higher in Mavrolia cv. samples compared to Koroneiki cv. (218.80 ± 44.8 vs. 83.7 ± 23.1, 1.82 ± 0.11 vs. 0.97 ± 0.31, and 1.55 ± 0.39 vs. 0.35 ± 0.60 mg kg⁻¹, respectively). Also, the bitter and pungent attributes were found in lower intensities compared to Koroneiki cv. EVOO for the same period (1.9 vs. 2.5 and 2.3 vs. 3.9, respectively). The ripe fruity intensity with walnut olfactory attribute of the Mavrolia cv., was also light to medium.     

Electrocatalytic oxidation of glutathione at carbon paste electrode modified with 2,7-<Emphasis Type="Italic">bis</Emphasis> (ferrocenyl ethyl) fluoren-9-one: application as a voltammetric sensor

Electrooxidation of glutathione (GSH) was studied at the surface of 2,7-bis (ferrocenyl ethyl) fluoren-9-one modified carbon paste electrode (2,7-BFEFMCPE). Cyclic voltammetry (CV), double potential-step chronoamperometry, and differential pulse voltammetry (DPV) were used to investigate the suitability of this ferrocene derivative as a mediator for the electrocatalytic oxidation of GSH in aqueous solutions with various pH. Results showed that pH 7.00 is the most suitable pH for this purpose. At the optimum pH, the oxidation of GSH at the surface of this modified electrode occurs at a potential of about 0.410 V versus Ag|AgCl|KCl_sat. The kinetic parameters such as electron transfer coefficient, α = 0.61, and rate constant for the chemical reaction between GSH and redox site in 2,7-BFEFMCPE, k _h = 1.73 × 10³ cm³ mol⁻¹ s⁻¹, were also determined using electrochemical approaches. Also, the apparent diffusion coefficient, D _app, for GSH was found to be 5.0 × 10⁻⁵ cm² s⁻¹ in aqueous buffered solution. The electrocatalytic oxidation peak current of GSH showed a linear dependence on the glutathione concentration, and linear calibration curves were obtained in the ranges of 5.2 × 10⁻⁵ M to 4.1 × 10⁻³ M and 9.2 × 10⁻⁷ M to 1.1 × 10⁻⁵ M with cyclic voltammetry and differential pulse voltammetry methods, respectively. The detection limits (3σ) were determined as 1.4 × 10⁻⁵ M and 5.1 × 10⁻⁷ M for the CV and DPV methods, respectively. This method was also examined as a selective, simple, and precise new method for voltammetric determination of GSH in real sample such as hemolysed erythrocyte.     

Soil nitrogen conservation with continuous no-till management

Tillage management is an important regulator of organic matter decomposition and N mineralization in agroecosystems. Tillage has resulted in the loss of considerable organic N from surface soils. There is potential to rebuild and conserve substantial amounts of soil N where no-till management is implemented in crop production systems. The objectives of our research were to measure N conservation rate with continuous no-till management of grain cropping systems and evaluate its impact on mineralizable and inorganic soil N. Samples were collected from 63 sites in production fields using a rotation of corn (Zea mays L.)—wheat (Triticum aestivum L.) or barley (Hordeum vulgare L.)—double-crop soybean (Glysine max L.) across three soil series [Bojac (Coarse-loamy, mixed, semiactive, thermic Typic Hapludults), Altavista (Fine-loamy, mixed semiactive, thermic Aquic Hapludults), and Kempsville (Fine-loamy, siliceous, subactive, thermic Typic Hapludults)] with a history of continuous no-till that ranged from 0 to 14 yrs. Thirty-two of the sites had a history of biosolids application. Soil cores were collected at each site from 0–2.5, 2.5–7.5 and 7.5–15 cm and analyzed for total N, Illinois soil N test-N (ISNT-N), and [NH₄ + NO₃]-N. A history of biosolids application increased the concentration of total soil N by 154 ± 66.8 mg N kg⁻¹ (310 ± 140 kg N ha⁻¹) but did not increase ISNT-N in the surface 0 – 15 cm. Continuous no-till increased the concentration of total soil N by 9.98 mg N kg⁻¹ year⁻¹ (22.2 ± 21.2 kg N ha⁻¹ year⁻¹) and ISNT-N by 1.68 mg N kg⁻¹ year⁻¹ in the surface 0–15 cm. The implementation of continuous no-till management in this cropping system has resulted in conservation of soil N.

Ultrasonic attenuation of edible oils

The frequency dependence (1–60 MHz) of the ultrasonic attenuation coefficient of canola oil, corn oil, olive oil, peanut oil, safflower oil, soybean oil, and sunflower oil was measured at 25°C. The attenuation coefficient of all the oils could be described by the relation: α ∼ Af ⁿ(with A between 6 and 40 × 10⁻¹², and n between 1.74 and 1.86).     

Greenhouse gas emissions and final compost properties from co-composting bovine specified risk material and mortalities with manure

The increased disposal costs of cattle specified risk materials (SRM) have reduced the competitiveness of the Canadian beef industry. The SRM materials include the skull, brain, trigeminal ganglia, eyes, palatine tonsils, spinal cord and dorsal root ganglia. This study investigates greenhouse gas (GHG) emissions and final compost properties from open windrow co-composting of manure with bovine SRM and mortalities. There were two compost treatments with four replications: SRMC consisting of SRM, cattle manure and barley straw and COWC consisting of cattle mortalities, cattle manure and barley straw. Average windrow temperature was higher (P < 0.05) for SRMC (47.1°C) than for COWC (44.1°C) over the first 139 days. The final compost coliform count, moisture, pH and TC contents were not significantly different between treatments while TN and available N (NH₄ ⁺ + NO₃ ⁻ + NO₂ ⁻) were lower for SRMC than for COWC. The average surface GHG flux from SRMC were 24.3 g C day⁻¹ m⁻² and 0.17 g N day⁻¹ m⁻² for CO₂ and N₂O, respectively, and were not significantly different from those from COWC (31.6 g C day⁻¹ m⁻² and 0.17 g N day⁻¹ m⁻² for CO₂ and N₂O, respectively), but CH₄ emissions from SRMC (0.47 g C day⁻¹ m⁻²) were lower than from COWC (1.57 g C day⁻¹ m⁻²). While a few large bones were left in the cattle mortality treatment, composting decomposed all SRM suggesting that it may be a viable alternative to rendering for SRM disposal.     

The Effect of Operational Parameters of the Rancimat Method on the Determination of the Oxidative Stability Measures and Shelf-Life Prediction of Soybean Oil

Operational parameters of the Rancimat method, including oil sample size, airflow rate, and temperature, were evaluated to determine their effects on the oxidative stability index (OSI), temperature coefficient, Q ₁₀ number, and shelf-life prediction for soybean oil. Operational parameters of the Rancimat method had statistically significant effects (P < 0.05) on the OSI. Whenever the oil sample size and airflow rate at a given temperature were such that the air-saturated condition could be established, the OSIs showed no statistically significant differences. As temperature increased, OSIs decreased, while their average coefficient of variation (CV) increased. In general, the conditions where the sample was saturated with air and had a relatively lower CV were an oil sample size of 6 g at all temperatures and airflow rates, then 3-g oil sample size at low temperatures (100 and 110 °C) and low airflow rates (10 and 15 L h⁻¹). The temperature coefficient and Q ₁₀ number were found to be independent of the oil sample size and airflow rate, and their mean values for soybean oil were calculated to be −3.12 × 10⁻² °C⁻¹ and 2.05, respectively. Oil sample size and airflow rate showed a significant effect on shelf-life prediction for soybean oil. Therefore, choosing the right levels of these operational parameters in the Rancimat method may produce the least possible difference between predictions from long-term storage studies and the OSI test.