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To facilitate selective breeding of polyphenol-rich peanuts, we looked for mass spectrometry-based proteomic evidence, investigating a subset of recombinant inbred lines (RILs) developed by the Australian peanut breeding program. To do this, we used label-free shotgun proteomics for protein and peptide quantitation, statistically analyzed normalized spectral abundance factors using R-package, as well as assayed important antioxidants. Results revealed statistically significant protein expression changes in 82 proteins classified between high or low polyphenols expressing RILs. Metabolic changes in polyphenol-rich RIL p27-362 point towards increased enzymatic breakdown of sugars and phenylalanine biosynthesis. The study revealed phenylpropanoid pathway overexpression resulting in increased polyphenols biosynthesis. Overexpression of antioxidant enzymes such as catalase, by 73.4 fold was also observed. A strong metabolic correlation exists with the observed phenotypic traits. Peanut RIL p27-362 presents a superior nutritional composition with antioxidant-rich peanut phenotype and could yield commercial profits. Data are available via ProteomeXchange with identifier PXD015493.

Five peanut ( Arachis hypogaea L.) genotypes with diverse antioxidant capacity were quantitatively profiled for p -coumaric acid, salicylic acid, resveratrol, and daidzein. The co-eluting compounds, caffeic/vanillic acid and ferulic/sinapic acid, were quantified on caffeic acid equivalent and ferulic acid equivalent bases, respectively. The HPLC analysis established significant genotypic differences ( P p -coumaric acid, 44–53% of the ferulic/sinapic acid, 71–89% of the salicylic acid, 59–68% of the resveratrol, and 89–97% of the daidzein in raw peanut kernels were present in bound forms. D147-p8-6F and Sutherland were sister-lines (derived from the same F2 plant) that had high foliar disease tolerance, high antioxidant capacity, and similar phytochemical profiles, which was consistent with associations between phytoalexin production and genetically determined disease resistance made by previous researchers. Principal components analysis linked high antioxidant capacity with a combination of phytochemicals that were not directly correlated in bivariate analysis (e.g., resveratrol was negatively correlated with caffeic/vanillic and p -coumaric acid) and that were not delineated by genotype.

The potential to select for antioxidant traits in peanut ( Arachis hypogaea L.) kernels by conventional plant breeding was investigated by oxygen radical absorbance capacity (ORAC) assay of (a) 32 full-season maturity genotypes grown at Kairi Research Station in 2008/09; and (b) a subset of ten genotypes with diverse antioxidant capacities grown in five different production regions in Queensland in 2009/10 and 2010/11. There were significant levels of variation of more than 25% relative standard deviation (RSD) in antioxidant capacity among the 32 tested genotypes; and that genotype, environment, and genotype-by-environment (G × E) interaction all significantly ( P

Validated methods to measure the essential mineral composition of food matrices are needed to satisfy the analytical requirements of product development, quality control, and food regulatory authorities. We investigated the use of inductively coupled plasma–optical emission spectroscopy (ICP–OES) and -mass spectrometry (ICP-MS), with and without the use of a dynamic reaction cell (DRC), to analyse 15 essential minerals in peanut kernels. We validated methods for Ca, Cu, Fe, K, Mg, Mn, Mo, P, and Zn analyses; however further tests are needed for validation of the B, Co, Cr, Na, Ni, and Se analyses. ICP–OES was applied to a study of genotypic variation among 56 breeding lines grown in the Australian peanut improvement program. We found promising levels of genotypic variation (>10%) in essential mineral traits, especially Ca (18–23%) and Mn (24%). Further investigation of the plant breeding potential for mineral traits may aid in the future development of peanut cultivars with enhanced micronutrients.

The concentrations of 15 essential minerals (B, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Se, and Zn) in kernels of nine diverse peanut genotypes, which were cultivated in five distinct growing environments, were analyzed by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and -mass spectrometry (ICP-MS). The effects of genotype, environment, and genotype-by-environment (G × E) interactions were significant (P0.05) for all elements excluding Cr. Genetic control of mineral composition was demonstrated by large (P0.05) genotypic differences in Ca, Mo, K, Na, and P contents, and clustering of some genotypes in environment-centered principal components analysis (PCA) along axes comprising both macro (Ca, Mg, P, and K)- and microelements (Co, Cu, Fe, Mn, and Zn). Mo and Na concentrations were strongly influenced (P0.05) by the growing environment, with very high levels measured in samples from Bundaberg. The results confirm that that there is breeding potential for several important minerals in peanuts, although significant G × E interactions will complicate the response to selection. From a practical viewpoint, combining genetic improvement with agronomic management may be a useful strategy to consistently achieve desirable mineral concentrations in peanut kernels.

Snack foods can contribute a high proportion of energy intake to the diet. Peanuts are a snack food rich in unsaturated fatty acids, protein and fibre which have demonstrated satiety effects and may reduce total energy intake, despite their high energy density. This study examined the effects of consuming Hioleic (oleic acid ~75% of total fatty acids) peanuts and regular peanuts (oleic acid ~50% and higher in polyunsaturated fatty acids) compared with a high carbohydrate snack (potato crisps) on satiety and subsequent energy intake. Using a triple crossover study design, 24 participants (61 ± 1 years) consumed isoenergetic amounts (56-84 g) of Hi-oleic or regular peanuts or (60-90 g) potato crisps after an overnight fast. Hunger and satiety were assessed at baseline, 30, 60, 120 and 180 minutes following snack consumption using visual analogue scales, after which a cold buffet meal was freely consumed and energy intake measured. The same snack was consumed on 3 subsequent days with energy intake assessed from dietary records. This protocol was repeated weekly with each snack food. Total energy intake was lower following consumption of Hi-oleic and regular peanuts compared with crisps, both acutely during the buffet meal (−21%; p < .001 and −17%; p < .01) and over the 4 days (−11%; p < .001 and −9%; p < .01). Despite these reductions in energy intake, no differences in perceived satiety were observed. The findings suggest peanuts may be a preferred snack food to include in the diet for maintaining a healthy weight. Refereed/Peer-reviewed