The beneficial role of peanuts in the diet – Part 2

Lipid modulation contributes to heat stress adaptation in peanut

At the cellular level, membrane damage is a fundamental cause of yield loss at high temperatures (HT). We report our investigations on a subset of a peanut (Arachis hypogaea) recombinant inbred line population, demonstrating that the membrane lipid remodeling occurring at HT is consistent with homeoviscous adaptation to maintain membrane fluidity. A major alteration in the leaf lipidome at HT was the reduction in the unsaturation levels, primarily through reductions of 18:3 fatty acid chains, of the plastidic and extra-plastidic diacyl membrane lipids. In contrast, levels of 18:3-containing triacylglycerols (TGs) increased at HT, consistent with a role for TGs in sequestering fatty acids when membrane lipids undergo remodeling during plant stress. Polyunsaturated acyl chains from membrane diacyl lipids were also sequestered as sterol esters (SEs). The removal of 18:3 chains from the membrane lipids decreased the availability of susceptible molecules for oxidation, thereby minimizing oxidative damage in membranes. Our results suggest that transferring 18:3 chains from membrane diacyl lipids to TGs and SEs is a key feature of lipid remodeling for HT adaptation in peanut. Finally, QTL-seq allowed the identification of a genomic region associated with heat-adaptive lipid remodeling, which would be useful for identifying molecular markers for heat tolerance.

Spatio-temporal distribution patterns and quantitative detection of aflatoxin B1 and total aflatoxin in peanut kernels explored by short-wave infrared hyperspectral imaging

Aflatoxin contamination in peanut kernels seriously harms the health of humans and causes significant economic losses. Rapid and accurate detection of aflatoxin is necessary to minimize its contamination. However, current detection methods are time-consuming, expensive and destructive to samples. Therefore, short-wave infrared (SWIR) hyperspectral imaging coupled with multivariate statistical analysis was used to investigate the spatio-temporal distribution patterns of aflatoxin, and quantitatively detect the aflatoxin B₁ (AFB₁) and total aflatoxin in peanut kernels. In addition, Aspergillus flavus contamination was identified to prevent the production of aflatoxin. The result of validation set demonstrated that SWIR hyperspectral imaging could predict the contents of the AFB₁ and total aflatoxin accurately, with residual prediction deviation values of 2.7959 and 2.7274, and limits of detection of 29.3722 and 45.7429 μg/kg, respectively. This study presents a novel method for the quantitative detection of aflatoxin and offers an early warning system for its potential application.

Impact of green antioxidants on decreasing the aflatoxins percentage in peanut oil seed (Arachis hypogaea L.) during storage

The present study conducted an experimental investigation to impede the degradation of peanut (Arachis hypogaea L.) seeds and enhance their quality while being stored. The efficacy of eco-friendly chemicals such as ascorbic acid, salicylic acid, acetic acid, and propionic acid in seed preservation was evaluated over a period of six months. After a period of six months of storage in a greenhouse, an examination was conducted on peanut seeds that had undergone treatment. Rhizoctonia was observed after Cephalothorax, whereas Aspergillus, Fusarium, and Penicillium were the prevailing fungi throughout the storage period. The optimal outcomes were obtained from the conversion of acetic acid to propionic acid. The study observed a decline in seed oil, protein, carbohydrates, germination percentage, energy, index, length, vigour index, dead and rotten seeds, rotted seedlings, and surviving healthy seedlings, with an increase in storage duration ranging from zero to six months. The application of 100% propionic acid to peanut seeds throughout the storage duration resulted in decreased occurrences of deceased seeds, decaying seeds, and deteriorated seedlings. Peanut seeds that underwent treatment with green chemical agents of moderate and high intensity were found to be free of aflatoxin B1. The highest levels of chlorophylls a and b, carotenoids, and total phenols were observed in seeds stored in greenhouses and treated with 100% propionic acid and acetic acid extract. The application of propionic acid 100%, acetic acid 100%, salicylic acid 4 g/l and ascorbic acid 4 g/l proved to be the most effective treatments for peanut seeds, exhibiting the lowest total aflatoxin level of 0.40. The correlation coefficient between shoot fresh weight and shoot dry weight was found to be 0.99, whereas the correlation coefficient between root dry weight and shoot length was 0.67. The seed chemical analysis, seedling characteristics, and germination characteristics were subjected to clustering analysis, resulting in the formation of two distinct groups. The first group consisted of germination percentage and energy levels across all time points (0-6 months), while the second group consisted of the remaining characteristics. The findings of this research propose the utilisation of 100% propionic acid as a viable method for preserving peanut seeds and preventing their deterioration during storage. The application of 100% acetic acid has been found to be effective in enhancing the quality of seeds and minimising losses.

Cumulative average nut consumption in relation to lower incidence of hypertension: a prospective cohort study of 10,347 adults

PURPOSE

Maintaining optimal blood pressure (BP) levels can be an effective preventive strategy for reducing disease burden. Nut consumption may play a preventive role against hypertension, which is a lifelong condition. We aimed to prospectively examine the association between cumulative average nut consumption and the incidence of hypertension in Korean adults aged 40 years and older.

METHODS

A total of 10,347 participants who were free of hypertension at baseline, were included. Hypertension was defined as having a physician diagnosis and taking antihypertensive medications or having abnormal BP (systolic ≥ 140 mmHg or diastolic ≥ 90 mmHg). As an exposure, cumulative average nut consumption was calculated using repeated food-frequency questionnaires (mean: 2.1). We used a modified Poisson regression model with a robust error estimator to estimate the incidence rate ratios (IRRs) with 95% confidence intervals (CIs) for hypertension.

RESULTS

We identified 2047 incident cases of hypertension during 44,614 person-years of follow-up. Among both men and women, an average nut consumption of ≥ 1 serving/week (15 g/week]) was inversely associated with hypertension incidence (IRR = 0.74, 95% CI = 0.58-0.96, p for trend = 0.013 for men; IRR = 0.72, 95% CI = 0.59-0.88, p for trend = 0.002 for women) and these significant associations were consistently observed across the strata of potential confounders.

CONCLUSION

An average consumption of at least one serving (15 g) per week of peanuts, almonds, and/or pine nuts may be inversely associated with the risk of hypertension among Korean adults aged 40 years and older, in a dose-response manner.

Maillard Reaction Products and Phenolic Compounds from Roasted Peanut Flour Extracts Prevent Scopolamine-Induced Amnesia Via Cholinergic Modulation and Antioxidative Effects in Mice

Research on the beneficial effects of Maillard reaction products (MRPs) and phenolic compounds derived from roasted peanut flour on the nervous system remains insufficient. This study aimed to evaluate the effect of a 28-day oral administration of defatted peanut extract rich in MPRs and polyphenolic compounds on the cognitive impairments and oxidative injury induced by scopolamine in a mouse model. Light and dark extracts from peanut flour were prepared by heating peanuts at 187°C for two different times (8.6 and 12.7 min) and defatted using soxhlet apparatus. The mice were orally pretreated with either roasted defatted peanuts extracts (100 mg/kg) or donepezil (3 mg/kg) for 21 days. On day 19 and until day 28, mice were injected subcutaneously with water or scopolamine (1 mg/kg body weight) 15 min after roasted defatted peanuts extracts/water feeding. Mice were subsequently subjected to a battery of behavioral tests including open field locomotor activity assay, and Morris water maze test. Brain tissues were collected to measure acetylcholine, acetylcholinesterase, and oxidative parameters (glutathione and malondialdehyde). Roasted defatted peanuts (light and dark) (100 mg/kg) treatment significantly ameliorated cognitive performance and reversed the oxidative damage when compared with the scopolamine group. These data demonstrate the defatted peanuts extracts exert potent anti-amnesic effects via the modulation of cholinergic and antioxidant activities.

A Comprehensive Study on the Effect of Roasting and Frying on Fatty Acids Profiles and Antioxidant Capacity of Almonds, Pine, Cashew, and Pistachio

The aim is to evaluate the effects of frying and roasting on nuts. Frying and roasting were performed according to the local Jordanian home-made cuisine, and the nuts under experiment were raw almonds, pine, cashew, and pistachio. Nuts samples were roasted at 110°C for 16 minutes and fried at 175°C for 2.5 minutes. The results show that both roasting and frying of nuts did not affect the flavonoids content except for roasted pistachios where significant rise of flavonoids content was detected. Total phenolic content showed no significant differences except for pine nuts in which it increased significantly in both roasting and frying. Oxidative stability, presented by 1,1-diphenyl-2-picryl-hydrazyl (DPPH), was significantly different in all nuts except for pistachio nuts that have shown no differences. Fatty acids profile, presented by saturated fatty acids (SFA), oleic acid (OL), and essential fatty acids (EFA), was affected significantly by roasting and frying, especially for SFA in almonds and pine nuts and α-linoleic acid (ALA) contents of pine. In conclusion, the effects of roasting and frying on the aforementioned nuts species were positive for fatty acids profile and antioxidants activity.

Utilization of spectral-spatial characteristics in shortwave infrared hyperspectral images to classify and identify fungi-contaminated peanuts

It's well-known fungi-contaminated peanuts contain potent carcinogen. Efficiently identifying and separating the contaminated can help prevent aflatoxin entering in food chain. In this study, shortwave infrared (SWIR) hyperspectral images for identifying the prepared contaminated kernels. Feature selection method of analysis of variance (ANOVA) and feature extraction method of nonparametric weighted feature extraction (NWFE) were used to concentrate spectral information into a subspace where contaminated and healthy peanuts can have favorable separability. Then, peanut pixels were classified using SVM. Moreover, image segmentation method of region growing was applied to segment the image as kernel-scale patches and meanwhile to number the kernels. The result shows that pixel-wise classification accuracies are 99.13% for breed A, 96.72% for B and 99.73% for C in learning images, and are 96.32%, 94.2% and 97.51% in validation images. Contaminated peanuts were correctly marked as aberrant kernels in both learning images and validation images.

Peanuts as functional food: a review

Peanut is an important crop grown worldwide. Commercially it is used mainly for oil production but apart from oil, the by-products of peanut contains many other functional compounds like proteins, fibers, polyphenols, antioxidants, vitamins and minerals which can be added as a functional ingredient into many processed foods. Recently it has also revealed that peanuts are excellent source of compounds like resveratrol, phenolic acids, flavonoids and phytosterols that block the absorption of cholesterol from diet. It is also a good source of Co-enzyme Q10 and contains all the 20 amino acids with highest amount of arginine. These bioactive compounds have been recognized for having disease preventive properties and are thought to promote longevity. The processing methods like roasting and boiling have shown increase in the concentration of these bioactive compounds. In the present paper an overview on peanut bioactive constituents and their health benefits are presented.

Human metabolome associates with dietary intake habits among African Americans in the atherosclerosis risk in communities study

The human metabolome is a measurable outcome of interactions among an individual's inherited genome, microbiome, and dietary intake. We explored the relationship between dietary intake and serum untargeted metabolomic profiles in a subsample of 1,977 African Americans from the Atherosclerosis Risk in Communities (ARIC) Study in 1987-1989. For each metabolite, we conducted linear regression to estimate its relationships with each food group and food category. Potential confounding factors included age, sex, body mass index (weight (kg)/height (m)(2)), energy intake, kidney function, and food groups. We used a modified Bonferroni correction to determine statistical significance. In total, 48 pairs of diet-metabolite associations were identified, including multiple novel associations. The food group "sugar-rich foods and beverages" was inversely associated with 5 metabolites in the 2-hydroxybutyrate-related subpathway and positively associated with 5 γ-glutamyl dipeptides. The hypothesized mechanism of these associations may be through oxidative stress. "Sugar-rich foods and beverages" were also inversely associated with 7 unsaturated long-chain fatty acids. These findings suggest that the contribution of a sugar-rich dietary pattern to increased cardiovascular disease risk may be partially attributed to oxidative stress and disordered lipid profiles. Metabolomics may reveal novel metabolic biomarkers of dietary intake and provide insight into biochemical pathways underlying nutritional effects on disease development.

Chemical composition and biological activities of Arachis species

Arachis hypogaea , known as the peanut, is native to South America. Peanut contains several active components including flavonoids, phenolic acids, phytosterols, alkaloids, and stilbenes. Some therapeutic effects have been reported for peanut seed extracts, such as antioxidative, antibacterial, antifungal, and anti-inflammatory activities. This paper aims to give an overview of the chemical composition, focusing on secondary metabolites, and of the biological activity of A. hypogaea, to stimulate new studies about species of the Arachis genus.

Functional components in peanuts

Peanut is one of the most widely used legumes due to its nutrition and taste. The fact that is has been recognized recently as a functional food, its evaluation for its role in a heart-healthy diet has received tremendous attention. Functional compounds have been isolated, identified, quantified, and even enhanced to maximize the amount for adequate health benefits. The peanut industry's byproducts such as peanut hulls and shells, skins, and even leaves and roots have also been identified as possible sources of bioactive compounds. New uses for these underutilized renewable sources can create new market opportunities and increase the value of agricultural residues.

Peanut (Arachis hypogaea) consumption improves Glutathione and HDL-cholesterol levels in experimental diabetes

The aim of this investigation was to assess the influence of peanut (Arachis hypogaea) consumption on oxidant-antioxidant status and lipid profile in Streptozotocin (STZ) induced diabetic rats. 32 rats were divided into 4 groups as control, control+peanut, diabetic, diabetic+peanut. Control and diabetic groups were fed on standard rat chow whereas control+peanut and diabetic+peanut were fed on standard rat chow supplemented with 0.63 g % peanut for 12 weeks. Serum glucose levels, lipids, Glutathione (GSH), lipid peroxidation (LPO) and atherogenic index (AI) levels were determined at the end of the experiment. In the diabetic group TG (Triglyceride), TC (Total cholesterol), LDL-C (LDL-cholesterol) levels and atherogenic indexes increased significantly whereas HDL-C (HDL-cholesterol) level decreased significantly compared to the control group. The supplementation with peanut in the diabetic group led to significantly higher HDL-C levels and lower AI levels compared to diabetic group. Peanut consumption increased GSH levels significantly both in control and diabetic groups. In conclusion, this study shows that peanut consumption may improve oxidant-antioxidant status in healthy and diabetic status without increasing blood lipids. Moreover, increased HDL-C levels and decreased AI levels in diabetic rats indicate that, peanut consumption may have protective effects against cardiovascular complications of diabetes.

Changes in the phytochemical composition and profile of raw, boiled, and roasted peanuts

Peanuts are consumed mostly as processed products. Although the effect of processing on isoflavone composition of legumes has been extensively studied, there has been no such study on peanuts. The objective of this study was to evaluate the effect of processing (boiling, oil- and dry-roasting) on the phytochemical composition of peanuts. Boiling had a significant effect on the phytochemical composition of peanuts compared to oil- and dry-roasting. Boiled peanuts had the highest total flavonoid and polyphenol content. The biochanin A and genistein content of boiled peanut extracts were two- and fourfold higher, respectively. trans-Resveratrol was detected only in the boiled peanuts, with the commercial product having a significantly (p < or = 0.05) higher concentration. Ultraviolet and mass spectrometry chromatograms for the boiled peanut extracts show the presence of four additional peaks that were not observed in the raw peanut extracts.