http://pubs.acs.org/doi/full/10.1021/jf071877l

Nutrition Panel

Yvonne Chukwumah †, Lloyd Walker *†, Bernhard Vogler ‡ and Martha Verghese †

Department of Food and Animal Sciences, Alabama A&M University, P.O. Box 1628, Normal, Alabama 35762, and Department of Chemistry, University of Alabama in Huntsville, 301 Sparkman Drive, Huntsville, Alabama 35899

J. Agric. Food Chem., 2007, 55 (22), pp 9266–9273

DOI: 10.1021/jf071877l

Publication Date (Web): October 9, 2007

Copyright © 2007 American Chemical Society

* Corresponding author. Telephone: (256) 372-4166 . Fax: (256) 372-5432. E-mail: lloyd.walker@email.aamu.edu., † Alabama A&M University., ‡ University of Alabama in Huntsville.

Abstract

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 ≤ 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.

The consumption of nuts has been shown to be beneficial to health. This is primarily due to their desirable lipid profile, which is higher in unsaturated fatty acids than in saturated fatty acids. Although classified as a legume, peanuts also have a high lipid content (ca. 46%) that is rich in monounsaturated fatty acids, and they do not contain cholesterol (1). Epidemiological and intervention studies have shown that the frequent consumption of peanuts promotes cardiovascular health by lowering serum low density lipoprotein (LDL)-cholesterol levels and reduces the risk of development of type II diabetes (2-6). It has also been shown to promote weight management when consumed as part of a moderate fat diet as a result of its satiating effect (7). In addition to their nutrient composition, peanuts contain certain bioactive compounds that may also play a role in the reduction of the risk for the development of chronic diseases such as cancer, diabetes, and coronary heart diseases (1, 8, 9). These compounds, such as the isoflavones and trans-resveratrol, have been previously identified and quantified in peanuts by several authors (10-13); however, there has been no study on the effect of processing, especially boiling, on the phytochemical composition of the peanuts.

Boiled peanuts had significantly (p ≤ 0.05) higher total polyphenol content (36.4–38.6 mg GAE/g) than raw and roasted peanuts (20.1–28.8 mg GAE/g).

http://www.nutrition-and-you.com/peanuts.html

Health benefits of Peanuts

• Peanuts are rich in energy (567 calories per 100 g) and contain health benefiting nutrients, minerals, antioxidants and vitamins that are essential for optimum health.
• They compose sufficient levels of mono-unsaturated fatty acids especially oleic acid. It helps lower LDL or "bad cholesterol" and increase HDL or "good cholesterol” level in the blood. Research studies suggest that Mediterranean diet, which is rich in monounsaturated fatty acids help to prevent coronary artery disease and strokes by favoring healthy blood lipid profile.
• The kernels are a good source of dietary protein; compose fine quality amino acids that are essential for growth and development.
• Research studies have shown that peanuts contain high concentrations of poly-phenolic antioxidants, primarily p-coumaric acid. This compound has been thought to reduce the risk of stomach cancer by limiting formation of carcinogenic nitrosamines in the stomach.
• Peanuts are an excellent source of resveratrol, another polyphenolic antioxidant. Resveratrol has been found to have protective function against cancers, heart disease, degenerative nerve disease, Alzheimer's disease, and viral/fungal infections.
• Furthermore, studies suggest that resveratrol reduce stroke risk by altering molecular mechanisms in the blood vessels (reducing susceptibility to vascular damage through decreased activity of angiotensin, a systemic hormone responsible for blood vessel constriction that would elevate blood pressure), and by increasing production of vasodilator hormone, nitric oxide.
• Recent research studies suggest that roasting/boiling enhances antioxidant bio-availability in the peanuts. It has been found that boiled peanuts have two and four-fold increase in isoflavone antioxidants biochanin-Aand genistein content, respectively. (Journal of agricultural and food chemistry).
• The kernels are an excellent source of vitamin E (α-tocopherol); containing about 8 g per100 g. vitamin E is a powerful lipid soluble antioxidant which helps maintain the integrity of cell membrane of mucus membranes and skin by protecting from harmful oxygen free radicals.
• The nuts are packed with many important B-complex groups of vitamins such as riboflavin, niacin, thiamin, pantothenic acid, vitamin B-6, and folates. 100 g of peanuts provide about 85% of RDI of niacin, which contribute to brain health and blood flow to brain.
• The nuts are rich source of minerals like copper, manganese, potassium, calcium, iron, magnesium, zinc, and selenium.

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1. Boiled peanuts contain more antioxidants than roasted or raw peanuts. A 2007 study conducted by researchers from Alabama A&M University’s Department of Food and Animal Sciences found that boiled peanuts bring out up to four times more phytochemicals that help protect against disease than raw, dry or oil-roasted nuts. These phytochemicals have antioxidant qualities that protect cells against the risk of degenerative diseases, including cancers, diabetes and heart disease.

2. Boiled peanuts support a healthy heart. Boiled Peanuts contain resveratrol, a plant chemical also found in red wine, which studies have shown to have a protective effect against cancer and heart disease. A 2013 study published in the journal Science Translational Medicine found that resveratrol still remains effective even after the body has metabolized it. The lead researcher of this study believes that this regeneration effect could be beneficial in treating a wide variety of human diseases.

3. Boiled peanuts are an excellent source of nutrients. Peanuts are loaded with many vitamins and minerals and are high in plant protein. Also, the fat content is primarily the good kind which includes monounsaturated and polyunsaturated. According to the American Heart Association, replacing saturated and trans fat with unsaturated fat as part of a healthy diet can help lower LDL “bad” cholesterol levels.

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