To meet the growing interest of utilizing microalgae biomass in the production of biofuels and nutraceutical and pharmaceutical lipids, we need suitable analytical methods and a comprehensive database for their lipid components. The objective of the present work was to demonstrate methodology and provide data on fatty acid composition, lipid class content and composition, characteristics of the unsaponifiables, and type of chlorophylls of five microalgae. Microalgae lipids were fractionated into TAG, FFA, and polar lipids using TLC, and the composition of fatty acids in total lipids and in each lipid class, hydrocarbons, and sterols were determined by GC-MS. Glyco-and phospholipids were profiled by LC/ESI-MS. Chlorophylls and their related metabolites were qualified by LC/APCI-MS. The melting and crystallization profiles of microalgae total lipids and their esters were analyzed by DSC to evaluate their potential biofuel applications. Significant differences and complexities of lipid composition among the algae tested were observed. The compositional information is valuable for strain selection, downstream biomass fractionation, and utilization. ABSTRACT: To meet the growing interest of utilizing microalgae biomass in the production of biofuels and nutraceutical and pharmaceutical lipids, we need suitable analytical methods and a comprehensive database for their lipid components. The objective of the present work was to demonstrate methodology and provide data on fatty acid composition, lipid class content and composition, characteristics of the unsaponifiables, and type of chlorophylls of five microalgae. Microalgae lipids were fractionated into TAG, FFA, and polar lipids using TLC, and the composition of fatty acids in total lipids and in each lipid class, hydrocarbons, and sterols were determined by GC-MS. Glyco-and phospholipids were profiled by LC/ESI-MS. Chlorophylls and their related metabolites were qualified by LC/APCI-MS. The melting and crystallization profiles of microalgae total lipids and their esters were analyzed by DSC to evaluate their potential biofuel applications. Significant differences and complexities of lipid composition among the algae tested were observed. The compositional information is valuable for strain selection, downstream biomass fractionation, and utilization.

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Genetic progress is assessed to estimate its contribution to on‐farm yield increases and to identify traits that have been improved over some period of time. Although Argentina is a major soybean [Glycine max (L.) Merr.] producer, there is limited information about genetic progress in this system. Argentinean soybean cultivars were developed from US commercial cultivars. Because the genetic base of US cultivars is narrow, it would be expected that genetic progress in Argentina to be slower than in the United States. We assessed the genetic gain for yield and related traits in cultivars released in Argentina from 1980 to 2015. One hundred and eighty‐one cultivars belonging to maturity groups (MGs) III, IV, and V were evaluated in three environments in the northern pampas from Argentina. Genetic gain in yield was 43 kg ha−1 yr−1 and was not different across MGs. Relative genetic gain was 1.1% yr−1, similar to reports from the United States or Brazil. Newer cultivars from MGs III and IV had increased days to maturity, while cultivars from MG V showed the opposite trend. Vegetative period was also reduced in newer cultivars from MGs IV and V. Seed protein concentration was reduced over the years. Genetic progress explained 50% of total on‐farm yield increase. Results from this experiment showed that breeding programs in Argentina were able to attain a similar genetic gain to the United States even though the starting parents were only a few US cultivars selected from an already narrow genetic base.

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Maize (Zea mays L.) kernel hardness is of utmost importance for dry‐milling processors. Zeins, maize prolamins, are known to be key proteins affecting this trait. We investigated the response of kernel zein profiles to N fertilization in maize hybrids with contrasting kernel hardness (measured as test weight, vitreousness, kernel density, and floaters percentage). A field experiment was done during two seasons, with three N fertilization treatments and four commercial hybrids with different hardness (two flint and two dent kernel types). We also measured yield, kernel protein concentration, and zein profiles (Z2, or γ and β, and Z1, or α and δ). Flint kernel type always yielded less and showed higher kernel hardness indicators when compared with dents (P < 0.01). N fertilization helped increase yield and kernel hardness in both kernel types. Flint kernel type had consistently more Z2 than dents, while only in 1 yr Z1 was higher in flints. Dent kernel type had a Z1/Z2 ratio similar to or higher than flints. Increasing N resulted in increased concentration of both zein types, but the effect was more pronounced on Z1. Significant correlations were observed between the different zein types (Z1 and Z2) and hardness indicators and total protein concentration, but Z2 showed the highest correlations with all kernel hardness traits. Our results expand previous knowledge on genotype and N fertilization effects over zein profiles and their involvement in kernel physical characteristics relevant for dry milling.

Two extruded-expelled physically refined soybean oils with reduced contents of linolenic acid, ultra-lowlinolenic acid (ULL, 1.5%) and low-linolenic acid (LL, 2.6%), and a extruded-expelled physically refined control oil (control, 5.3% linolenic acid) were evaluated by frying French fries in a commercial-like setting for 6 h day -1 during 23 days. The oils became darker, increased in yellow color at the beginning, and became redder and less green throughout the process. Free fatty acids levels were not different among the oils until day 14, after which, ULL was different from the control for the remainder of frying. The conjugated dienoic acid values were greatest in the control. Generally, ULL and LL oils had lower percentages of polar compounds than did the control, providing a frying life 2 days longer than the control and~30% increase in frying time. A trained sensory panel evaluated the French fries on days 2, 5, and 6. Buttery and potato flavors decreased, and rancid and painty flavors increased over frying time for all products. Rancid flavor was highest in the fries from the control oil. Overall, the ULL and LL oils performed better than did the control oil and ULL tended to perform better than the LL.