BOILED PEANUTS- GOOD FOR LONGEVITY?-A REALITY CHECK!

Peanuts are nutritionally a much acclaimed food with high levels of protein, fat, fiber and some micro nutrients. The "war of nuts" between peanut and soybean for market supremacy has given prominence to both these oil seeds though the protein in peanut is always looked down because of low levels of the essential amino acid Lysine present in this oil seed. In contrast peanut oil has much better stability as a cooking oil while soybean oil is more nutritious because of higher content of unsaturated fats. As a food peanut is a main stream component of diets in India and a few other countries. Soybean is invariably called the "cow of the orient" because of the popularity of soy milk among people in South East Asia. With relatively low consumption of animal milk in many Asian countries, soybean milk presents itself as a highly acceptable alternative. Industrially peanut lags behind soybean which is used extensively to manufacture hundreds of products with high consumer acceptability. Meat substitutes made from soybean are relatively cheap and are considered poor man's meat with almost same texture.

Peanut is consumed at the consumer level as snack items and products like roasted, coated and fried peanut snacks are popular in many countries. Confectionery products made from peanuts, called "Chikkis" using Jaggery or sugar are produced in India by thousands of cottage scale units working in the informal sector. Soybean takes a beating on this score as its major use is confined to extraction of oil and using the residue in animal feed formulations. Soybean curd or Toffu is a favored item liked by Asians and is becoming popular like cheese in other countries also. The processing methods are distinctively different with these two crops. While peanut seeds are processed in Expeller presses followed by solvent extraction, soybean, due to its low oil content goes straight for solvent extraction and refining. 

Peanuts hit the headlines recently because of the claims made by some scientific groups that it is rich in a rare phytochemical Resveratrol with supposed credentials for achieving longevity. It was a news because a major source of Resveratrol was red wine about which lot has been written. While Red wine contains this chemical in the range of 0.2 to 12.59 mg per liter, raw Peanut has less than 2 mg per kg. What caught the attention of the world was that the same peanut when boiled increased its Resveratrol level to about 9 mg per kg. However such arithmatic jugglery cannot conceal the fact that while wine can be easily consumed one or two glasses a day, it is unimaginable that one can eat 300 gm of peanut a day to deliver the same quantity. Also not understandable is the loud claims being made about the capability of Resveratrol to prolong life without any human trials so far. At best this phytochemical has been proved to be helpful in keeping at bay diseases like cancers, diabetes etc only in animal experiments. Probably sensationalism and vested commercial interests seem to be floating such claims with practically no scientific basis.

It is true that nature has equipped many plants with toxic chemicals for fighting against pathogens and  other marauders and Resveratrol present mostly in the skin of fruits like Red grapes is a proven fighter against bacteria and fungi. Interestingly, during wine production the pomace, rich in Resveratrol is discarded and only a small portion of this chemical is passed on to the juice. Therefore it makes more sense to eat fresh grapes or drink crushed grape juice than the wine to get full benefit of the fruit's Resveratrol content. Is it not a commercial ploy by the wine industry to tout about the ability of wine to prolong life? Same appears to be true in the case of peanuts also as consumption of this oil seed directly as food is limited and a major portion goes for recovery of edible oil leaving the residue for feeding cattle. Whether Resveratrol is more concentrated in the pressed residue or in the oil fraction is some what not clear but refined peanut oil

definitely cannot be a source because of the severe refining process the raw oil has to go through under which Resveratrol cannot be expected to be stable.

Another side of Resveratrol story is still more fascinating. It concerns about its solubility, biological absorption and metabolism. Being practically insoluble in water delivery of Resveratrol to the cells is fraught with many uncertainties. Buccal delivery (by chewing in the mouth) is supposed to be some what better and based on this finding by some scientists, chewing gum formulations containing Resveratrol are already in some markets. Oral ingestion is supposed to be very inefficient with not even 5% of the administered quantity ending up in the blood stream. Both small intestine and liver are known to conjugate Resveratrol into glucuronate and sulfonate, both inactive in any way. Synthetic versions and bio-technologically made products are available but due to uncertainty about the real effect of Resveratrol in human body, no approved drug formulations have been marketed though some major drug companies are reported to be investing in this area with the hope of coming out with a successful product eventually. If they succeed humanity may have an effective drug that can counteract many diseases including cancers, severe inflammation, diabetes and cardiovascular aberrations. 

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

AFLATOXIN MENACE-THE 'CURSE' OF PEANUTS

Though peanut is considered a wholesome food rich in proteins, fats and many nutrients vital to the body, it was shunned for some time by the international buyers, because of the presence of mycotoxins, the hazardous metabolic product of the mold belonging to Aspergillus species which contaminates the crop mostly in the field due to improper drying. Its good thermal stability at high temperatures make it hard to destroy during processing and mold infected raw material if used will taint the final product also. Non-availability of an acceptable process to decontaminate peanuts and bring down the aflatoxin content to safe levels is a constraint coming in the way of development of this agricultural crop, competing effectively against soybean, considered its rival in the international market. While decorticated nut is a versatile food material for humans both for direct consumption as well as for providing edible oil, the protein rich deoiled residues are much sought after as an ingredient for animal feeds. In contrast soybean is mostly used for oil extraction, soy flour and processed products based it and as a component in animal feeds.

Peanut seeds can be blanched to remove cuticles if white kernel is desired or can be roasted, boiled, fried or coated to get different consumer products. Peanut butter, a highly popular product in western countries is made by grinding decuticled and roasted kernels through a process that ensures no separation of oil during packing and storage. Nutritionally shelled peanut seeds contain good quality oil to the extent of 50% while its protein content is around 25%. Bold seeds are in good demand and hand picked bold seeds fetch premium price in the export market. In India peanuts are processed in oil mills using ghani type rotary presses, screw expellers and solvent extraction plants to recover as much oil as possible. Since oil recovery is the major goal, very little attention is paid to the quality of the deoiled residue which generally contains high levels of husk and cuticles besides other undesirable contaminants. Edible quality peanut cake can be made if the seeds are precleaned before pressing for oil and during nineteen fifties and sixties, peanut protein isolate made from the deoiled cake was touted as a concentrated protein source with 90-93% protein content. Deficiency of amino acid lysine is considered as a drawback when peanut protein isolate is compared with that from soybean. Even a milk like product was developed from the peanut 4 decades ago in India as a cheap substitute to dairy milk.

Aspergillus flavus and Aspergillus parasiticus, the two organisms that grow on moist peanut seeds containing more than 7% moisture, excrete aflatoxins of different types which if consumed have been found to cause acute hepatic necrosis, liver cirrhosis and eventually carcinoma. There are 13 different types of aflatoxins identified so far and the most potent is aflatoxin B1. Global standards do not permit aflatoxin presence in peanut or any preparations derived from it beyond 4-20 parts per billion (ppb) and unless very high precaution is taken it will not be possible to restrict the aflatoxin to the stringent standard that exists to day. However in a country like USA, aflatoxin up to 300 ppb is permitted in domestic corn for feeding beef cattle, swines and mature poultry birds. It was in 1960 that the first out break of aflatoxin poisoning was encountered in UK killing more than 1 lakh turkey poults and subsequently several such incidences were reported from different parts of the world due to feeding aflatoxin contaminated feeds.

Aflatoxins belong to the difurocoumarolactone group of chemicals with molecular weights ranging from 312 to 346 with melting points in the range of 190-299C. Neither heat processing as encountered in frying or baking nor any other known method can destroy the toxin very significantly. Toxins present in oil fraction are not affected by the conventional alkali refining process but special filtration system can remove the particulates of aflatoxin satisfactorily. Ammoniation (0.5-2% ammonia) at room temperature or at elevated temperature and pressure can bring down the toxin level considerably but whether it can be deployed commercially is not certain. Use of Flavobacterium auranatiacum bacteria to destroy aflatoxin has been found to be technically feasible but the limitation is that such biological system can work only in aqueous medium calling for expensive process technologies and long processing time. Gamma irradiation at a level of 5-20kGy dose has been reported to be effective in detoxification but limited facilities available for irradiation makes this technology impractical on a large scale.

In spite of 4 decades of scientific endeavor a satisfactory method of detoxification is still eluding the peanut industry. Preempting development of mold infection through prompt drying of the crop to less than 7% moisture, careful handling and storage at low temperature and humidity may be the best option. Use of electronic sorters to sort the seeds based on color development caused by the growth of the mold was explored without success. Considering the practical constraints in changing the prevalent agricultural practices, the best way to eliminate aflatoxin problem seems to be manual sorting of the seeds which has been accepted by many importing countries.

V.H.POTTY
http://vhpotty.blogspot.com/

PEANUTS-WHY UNFAIRLY JUDGED!

There was a time when every American kid symbolized three food products-Potato Chips, Cola Drink and Peanut Butter and they had dominated the markets all over the world as consumer crazy commercial products. Both cola drinks and chips faced enormous odds in the market now and then, being castigated as unhealthy and it is tribute to the sagacity, marketing muscle and technological prowess on the part of the manufacturers to weather the storms as when they blew across their turf. Now it is the turn of Peanut Butter which is facing the flak from the very consumers who courted them as one of their favorite snack items, who are raising a big hue and cry about the safety of this material for their children. What a turn around in a brief span of a decade? Currently peanut butter is banned in many schools and peanut free zones are being created in some other schools in that country. Even thorough hand washing is being enforced to prevent allergy molecules from peanut causing problems to others! 25% of parents do believe that their children are peanut allergic though statistically only 4% of school going kids are vulnerable to this syndrome. Probably the scientific correlation between peanut allergy and other allergies like asthma makes parents nervous about use of peanut products in general.

An adverse immune response to a food protein is responsible for allergy. Millions of people are affected by food allergies of various types, USA alone accounting for 12 million cases. About 1 in 15 children suffers from some form of allergy while 1 in 25 adults has the same affliction. Since most of the allergy cases are reported from western countries where hospital facilities are excellent, only 100-200 deaths occur each year. Other important allergic foods include shell fish,tree nuts,fish, eggs, soybean and wheat. The symptoms manifesting as angioedema, appears within a few seconds to one hour in the form of soft tissue swelling in areas near eyes, face, lips,tongue, larynx, trachea causing difficulties in breathing. Itching of mouth, throat, eyes and the skin, nausea, vomiting, stomach cramps, abdominal pain, nasal congestion, wheezing are other symptoms of allergy.

An allergic reaction to food involves the various components of the immune system. One component is a type of protein, an anti body called immunoglobulin (IgE) which circulates through the blood. Another component is the mast cells, a specialized cell that is found in all tissues in the body. These cells are common in nose, throat, lungs, skin and GI tract which are typical sites of allergic reactions. The allergen stimulates lymphocytes to produce IgE anti body that is specific to the allergen. This IgE attaches itself to the surface of the mast cells in different tissues of the body. When ever the food containing the allergen is eaten, it provokes the mast cells to release of chemicals like histamine and the consequent reaction.

Is the peanut allergy so serious as to warrant its total elimination from the diets in whole of the world? The present label warning system ensures that foods processed in machines commonly used for peanuts is declared on the label and separate cautionary warning is included for foods containing peanut as an ingredient for the benefits of allergic consumers. The health benefits of peanuts for a vast majority of the population far outweigh the relatively few allergy risks for some sensitive people. It is well known that consumption of a handful of peanuts twice a week halves the risk of heart attacks. Being a food product with very low glycemic index, peanut is strongly recommended for people vulnerable to sugar compromised conditions like diabetes. With high proteins in the kernel, peanut is an excellent wholesome food material for both children and adults. Breast feeding of children at least for the first four months is believed to be capable of preventing or delaying onset of peanut allergy. Indians are fortunate in that very few cases of peanut allergy are reported officially though possibility of many others going unreported cannot be ruled out. The nutrition monitoring bureau of the Ministry of Health must include data collection on food allergies also if, as a nation, we have to prevent epidemic forms of allergic manifestations in future. Unless reliable data base is established, no worthwhile national contingency strategy can be formulated for counter acting such incidences as and when they become a serious health challenge in the country.

V.H.POTTY
http://vhpotty.blogspot.com/