A Comparison of Lipid Contents in Different Types of Peanut Cultivars Using UPLC-Q-TOF-MS-Based Lipidomic Study

Peanuts are a rich dietary source of lipids, which are essential for human health. In this study, the lipid contents of 13 peanut cultivars were analyzed using UPLC-Q-TOF-MS and GC–MS. The OXITEST reactor was used to test their lipid oxidation stabilities. A total of 27 subclasses, 229 individual lipids were detected. The combined analysis of lipid and oxidation stability showed that lipid unsaturation was inversely correlated with oxidation stability. Moreover, lipid profiles differed significantly among the different peanut cultivars. A total of 11 lipid molecules (TG 18:2/18:2/18:2, TG 24:0/18:2/18:3, TG 20:5/14:1/18:2, TG 18:2/14:1/18:2, PE 17:0/18:2, BisMePA 18:2/18:2, PG 38:5, PMe 18:1/18:1, PC 18:1/18:1, MGDG 18:1/18:1, TG 10:0/10:1/18:1) might be employed as possible indicators to identify high oleic acid (OA) and non-high OA peanut cultivars, based on the PLS-DA result of lipid molecules with a VIP value greater than 2. This comprehensive analysis will help in the rational selection and application of peanut cultivars.

Study on Key Aroma Compounds and Its Precursors of Peanut Oil Prepared with Normal- and High-Oleic Peanuts

High-oleic acid peanut oil has developed rapidly in China in recent years due to its high oxidative stability and nutritional properties. However, consumer feedback showed that the aroma of high-oleic peanut oil was not as good as the oil obtained from normal-oleic peanut variety. The aim of this study was to investigate the key volatile compounds and precursors of peanut oil prepared with normal- and high-oleic peanuts. The peanut raw materials and oil processing samples used in the present study were collected from a company in China. Sensory evaluation results indicated that normal-oleic peanut oil showed stronger characteristic flavor than high-oleic peanut oil. The compounds methylpyrazine, 2,5-dimethylpyrazine, 2-ethyl-5-methylpyrazine and benzaldehyde were considered as key volatiles which contribute to dark roast, roast peanutty and sweet aroma of peanut oil. The initial concentration of volatile precursors (arginine, tyrosine, lysine and glucose) in normal-oleic peanut was higher than in high-oleic peanut, which led to more characteristic volatiles forming during process and provided a stronger oil aroma of. The present research will provide data support for raw material screening and sensory quality improvement during high-oleic acid peanut oil industrial production.

Soybean as a Model Crop to Study Plant Oil Genes: Mutations in FAD2 Gene Family

Plants have numerous fatty acid desaturase (FAD) enzymes regulating the unsaturation of fatty acids, which are encoded by a FAD gene family. The FAD2 genes belong to such family and play a vital role in converting monounsaturated oleic acid to polyunsaturated linoleic acid. Oleic acid has the health benefits for humans, such as reduction in cholesterol level, antioxidation property, and industrial benefits like longer shelf life. The development of genotypes with high oleic acid content in seeds has become one of the primary goals in breeding oilseed plants. The identification and characterization of the FAD2 genes in plants have been an important step to better manipulate gene expression to improve the seed oil quality. The induction of mutations in FAD2 genes to reduce FAD2 enzyme activity has been an integral approach to generate genotypes with high oleic acid. This chapter will describe the FAD2 gene family in the model organism soybean and the correction of mutations in FAD2 genes with the increase of oleic acid content. Leveraging advanced research of FAD2 gene family in soybean promotes the study of FAD2 genes in other legume species, including peanut. The future perspectives and challenges associated with mutations in FAD2 genes will be discussed.

IDENTIFICATION OF HIGH SEED OIL YIELD AND HIGH OLEIC ACID CONTENT IN BRAZILIAN GERMPLASM OF WINTER SQUASH (Cucurbita moschata D.)

Cucurbita moschata D. seed oil contains approximately 75% unsaturated fatty acids, with high levels of monounsaturated fatty acids and antioxidant compounds such as vitamin E and carotenoid, constituting a promising food in nutritional terms. Associated to this, the Brazilian germplasm of C. moschata exhibits remarkable variability, representing an important source for the genetic breeding of this vegetable and other cucurbits. In this context, the present study evaluated the productivity and profile of the seed oil of 91 C. moschata accessions from different regions of Brazil and maintained in the Vegetable Germplasm Bank of the Federal University of Viçosa (BGH-UFV). A field experiment was conducted between January and July 2016. The tested C. moschata accessions showed high genetic variability in terms of characteristics related to seed oil productivity (SOP), such as the mass of seeds per fruit and productivity of seeds, providing predicted selection gains of 29.39 g and 0.26 t ha -1 , respectively. Based on the phenotypic and genotypic correlations, greater SOP can be achieved while maintaining high oleic acid content and low linoleic acid content, providing oil of better nutritional and chemical quality. In variability analysis, the accessions were clustered into five groups, which presented different averages for SOP and fatty acid content of seed oil; approach that will guide the use of appropriate germplasm in programs aimed at genetic breeding for SOP and seed oil profile. Per se analysis identified BGH-4610, BGH-5485A, BGH-6590, BGH-5556A, BGH-5472A, and BGH-5544A as the most promising accessions in terms of SOP, with average (m+g) of approximately 0.20 t ha -1 . The most promising accessions for higher oleic acid content of seed oil were BGH-5456A, BGH-3333A, BGH-5361A, BGH-5472A, BGH-5544A, BGH-5453A, and BGH-1749, with average (m+g) of approximately 30%, and almost all of these accessions were also the most promising in terms of lower linoleic acid content of seed oil, with average (m+g) of approximately 45%. Overall, part of the C. moschata accessions evaluated in the present study can serve as a promising resource in genetic breeding programs for SOP and fatty acid profile, aiming at the production of oil with better nutritional and physicochemical quality.

THE PROBLEM OF DETECTION OF HETEROZYGOUS GENOTYPES BY MUTATION OF THE FAD 2-1 GENE OF SUNFLOWER (HELIANTHUS ANNUUS L.) USING DNA MARKERS

The development of marker-associated breeding requires the development of DNA marker systems that meet the needs of the breeding process. We are looking for the opportunities to improve the efficiency of breeding for high oleic acid content in sunflower oil. One of the directions is the improvement of the existing marker system for detection the heterozygous status of the alleles of the FAD 2-1 gene. We carried out the search for information published in databases on this DNA locus. We studied the structure of the nucleotide sequences of the mutant allele and the wild-type allele. We proposed the way of improving the existing marker system.