Determining the Oleic/linoleic Acid Ratio in a Single Peanut Seed: a Comparison of Two Methods

The Potential of Plum Seed Residue: Unraveling the Effect of Processing on Phytochemical Composition and Bioactive Properties

Bioactive compounds extracted from plum seeds were identified and quantified, aiming to establish how the brandy manufacturing process affects the properties and possible cascade valorization of seed residues. Extraction with n-hexane using Soxhlet has provided oils rich in unsaturated fatty acids (92.24-92.51%), mainly oleic acid (72-75.56%), which is characterized by its heart-healthy properties. The fat extracts also contain tocopherols with antioxidant and anti-inflammatory properties. All the ethanol-water extracts of the defatted seeds contain neochlorogenic acid (90-368 µg·g-1), chlorogenic acid (36.1-117 µg·g-1), and protocatechuate (31.8-100 µg·g-1) that have an impact on bioactive properties such as antimicrobial and antioxidant. Anti-amyloidogenic activity (25 mg·mL-1) was observed in the after both fermentation and distillation extract, which may be related to high levels of caffeic acid (64 ± 10 µg·g-1). The principal component analysis showed that all plum seed oils could have potential applications in the food industry as edible oils or in the cosmetic industry as an active ingredient in anti-aging and anti-stain cosmetics, among others. Furthermore, defatted seeds, after both fermentation and distillation, showed the greatest applicability in the food and nutraceutical industry as a food supplement or as an additive in the design of active packaging.

An Overview of Mapping Quantitative Trait Loci in Peanut (Arachis hypogaea L.)

Quantitative Trait Loci (QTL) mapping has been thoroughly used in peanut genetics and breeding in spite of the narrow genetic diversity and the segmental tetraploid nature of the cultivated species. QTL mapping is helpful for identifying the genomic regions that contribute to traits, for estimating the extent of variation and the genetic action (i.e., additive, dominant, or epistatic) underlying this variation, and for pinpointing genetic correlations between traits. The aim of this paper is to review the recently published studies on QTL mapping with a particular emphasis on mapping populations used as well as traits related to kernel quality. We found that several populations have been used for QTL mapping including interspecific populations developed from crosses between synthetic tetraploids and elite varieties. Those populations allowed the broadening of the genetic base of cultivated peanut and helped with the mapping of QTL and identifying beneficial wild alleles for economically important traits. Furthermore, only a few studies reported QTL related to kernel quality. The main quality traits for which QTL have been mapped include oil and protein content as well as fatty acid compositions. QTL for other agronomic traits have also been reported. Among the 1261 QTL reported in this review, and extracted from the most relevant studies on QTL mapping in peanut, 413 (~33%) were related to kernel quality showing the importance of quality in peanut genetics and breeding. Exploiting the QTL information could accelerate breeding to develop highly nutritious superior cultivars in the face of climate change.

Development of high oleic peanut lines through marker-assisted introgression of mutant ahFAD2 alleles and its fatty acid profiles under open-field and controlled conditions

Peanut is one of the most important oilseed crops grown worldwide. In this study, the mutant ahFAD2 alleles conferring high oleic (HO) content are introgressed into an elite Indian cultivar GPBD4 which is also resistant to the foliar fungal diseases like rust and late leaf spot (LLS). The allele-specific PCR (AS-PCR) and cleaved amplified polymorphic sequences (CAPS) assays were used for the marker-assisted backcross (MABC) approach and 64 HO introgression lines (ILs) were generated. These ILs were tested for the FA compositions under the glasshouse and field conditions. The oleic acid and linoleic acid contents in the ILs were recorded to be between 68.94-82.33% and 1.74-10.87%, respectively, under glasshouse and 67.04-81.71% and 2.00-15.66%, respectively, under field conditions. The increase in the oleic acid content of the ILs over its recurrent parent (RP) was recorded to the tune of 28.78-53.80% and 33.70-62.96% under glasshouse and field conditions, respectively, indicating the stable expression of ahFAD2B gene in two different environments. On the contrary, linoleic acid showed 56.47-93.03% and 40.02-92.34% reduction in the ILs over its RP under glasshouse and field conditions, respectively. These ILs with a healthy FA profile can meet not only the nutritional requirements of a health-conscious society but also the industrial demands for better shelf life of oil and its products.

Peanut Oil Stability and Physical Properties Across a Range of Industrially Relevant Oleic Acid/Linoleic Acid Ratios

High oleic cultivars are becoming increasing prevalent in the peanut industry due to their increased shelf life compared to conventional cultivars. High oleic peanuts are typically defined as having oleic acid/linoleic acid (O/L) ratios ≥ 9, whereas most traditional varieties have O/L ratios near 1.5-2.0. In practice, this ratio can vary substantially among commercial material; accordingly, the goal of this study was to gain an understanding of the shelf life and physical properties of 16 model oil blends with O/L ratios systematically prepared from 1.3 to 38.1. Across these samples, % oleic acid, % linoleic acid, refractive index, density and dynamic viscosity were all highly (R2 > 0.99) linearly correlated. Increasing concentrations of oleic acid and corresponding decreases in linoleic acid were associated with decreasing oil density, decreasing refractive index, and increasing viscosity. Oxidative stability index (OSI), an established method for predicting relative oil shelf life, increased more than 7X from an O/L of 1.3 to 33.8 and this response was well described by a 2nd order polynomial. Oil stability was also assessed by storing oil blends at 24 C with 50% R.H. for 24 wk and periodically sampling these oils to measure peroxide value (PV) and describe oil flavor via sensory analysis. Excellent correlations were observed among O/L chemistry and off-flavor (oxidized/cardboard/rancid) development during storage, PV development during storage, and OSI. While viscosity was greatest for high oleic samples when comparing fresh oils, after storage under abusive conditions oil viscosity increased exponentially with decreasing O/L ratio due to oxidation/polymerization reactions. Overall, these data and observations will aid processors in selection of high O/L peanuts for various food applications and better determine final product shelf life.

Insights into the Indian Peanut Genotypes for ahFAD2 Gene Polymorphism Regulating Its Oleic and Linoleic Acid Fluxes

In peanut (Arachis hypogaea L.), the customization of fatty acid profile is an evolving area to fulfill the nutritional needs in the modern market. A total of 174 peanut genotypes, including 167 Indian cultivars, 6 advanced breeding lines and "SunOleic95R"-a double mutant line, were investigated using AS-PCRs, CAPS and gene sequencing for the ahFAD2 allele polymorphism, along with its fatty acid compositions. Of these, 80 genotypes were found having substitution (448G>A) mutation only in ahFAD2A gene, while none recorded 1-bp insertion (441_442insA) mutation in ahFAD2B gene. Moreover, 22 wild peanut accessions found lacking both the mutations. Among botanical types, the ahFAD2A mutation was more frequent in ssp. hypogaea (89%) than in ssp. fastigiata (17%). This single allele mutation, found affecting not only oleic to linoleic acid fluxes, but also the composition of other fatty acids in the genotypes studied. Repeated use of a few selected genotypes in the Indian varietal development programs were also eminently reflected in its ahFAD2 allele polymorphism. Absence of known mutations in the wild-relatives indicated the possible origin of these mutations, after the allotetraploidization of cultivated peanut. The SNP analysis of both ahFAD2A and ahFAD2B genes, revealed haplotype diversity of 1.05% and 0.95%, while Ka/Ks ratio of 0.36 and 0.39, respectively, indicating strong purifying selection pressure on these genes. Cluster analysis, using ahFAD2 gene SNPs, showed presence of both mutant and non-mutant genotypes in the same cluster, which might be due the presence of ahFAD2 gene families. This investigation provided insights into the large number of Indian peanut genotypes, covering various aspects related to O/L flux regulation and ahFAD2 gene polymorphism.