peanut meals , peanut by-products
The introduction of peanut (Arachis hypogaea L.) cultivation coincides with the expansion of the Mediterranean civilizations. Peanut is an important crop grown in the worldwide, originating in South American, the peanut spreads beyond the Mediterranean, such as China, Africa, Indian, Japan and United States of America. Most peanuts grown in the world are used for oil production, peanut butter, confections, roasted peanuts and snack products, extenders in meat product formulations, soups and desserts (Rustom et al. 1996). The substantial amounts of by-products are generated in the process of peanut harvest and peanut oil extraction, which are potential pollutants. However, only a few in these by-products is used as animal feed, and treated as a fertilizer. A large portion of peanut meals, skins, hulls, and vines is regarded as the agriculture wastes. At present, many researchers focus on the investigation of producing edible oil and kernel. Thus, very little attention is given to the by products of peanut. Especially, no report has been found on examining the possibility of peanut vine utilization. These peanut byproducts easily lead to environmental contamination. Therefore, if the nutritional compositions of peanut by-products are recovered and recycled, it can represent a significant economic and social benefit (Nepote et al. 2002; Yu et al. 2005).Recently, the nutritional composition application of peanut by-products with market demands has been changed. During the last 20 years, new scientific research is focused on as following. Firstly, the value of peanut by-products is optimized. Secondly, the peanut proteins, peanut phenolic compounds, peanut edible fibre and their potential effects in the diet are characterized and quantified. Thirdly, the effects of nutritional composition from peanut by-products on human performance and product quality in food processing are studied. The information is essential in order to optimize the utilization of vegetable by-products in food processing. The special interest indicates that the peanut nutritional value may affect the human health. But the topics require further investigation.
The land area occupied by peanut has increased in recent years, largely in response to the worldwide rise in peanut oil consumption. Globally peanut and peanut oil production was shown Table 1 in 2000/01-2010/12 (FAS-USDA web, 2011). As shown Table 1, peanut is an important crop grown on over 20 million ha in worldwide, ranking second with respect to planting area after rapeseed in oil plants. The peanut production in world is about 33 million tons per annual since 2000/01 (FAS-USDA web, 2011). The production range of peanut oil was from 4.52 to 5.14 million metric tons in 2000–2010, the average production was 4.86 million metric tons. The world production of peanut oil has risen from 4.53 million metric tons in 2000 to 4.91 in 2010. Production across the countries of the world, where China (44%), Indian (20%), and Nigeria (11%) are the largest producers, is expected to account for almost 75% of the world’s peanut oil (FAS-USDA 2011). In China, the plant area (4.45 million hectares) is only in the second place, the production of peanut is the maximum in the world, second to annual production of soybeans and above 14.34 million metric tons per year (FAS-USDA 2011).
By-products derived from the harvested peanut and peanut oil extractions are generally known as “peanut by-products”. The different by-products considered in this review are defined as follows.
is a food paste or spread made from ground, dry-roasted peanuts. It often contains additional ingredients that modify the taste or texture, such as salt, sweeteners, or emulsifiers. Peanut butter is popular in many countries. The United States is a leading exporter of peanut butter and itself consumes $800 million of selling peanut butter annually, and peanut butter is served as a spread on bread, toast, or crackers, and used to make sandwiches (notably the peanut butter and jelly sandwich). It is also used in a number of breakfast dishes and desserts, such as peanut-flavored granola, smoothies, crepes, cookies, brownies, or croissants. It is similar to other nut butters such as cashew butter and almond butter.
also known as groundnut oil or arachis oil, is a vegetable oil derived from peanuts. The oil has a strong peanut flavor and aroma. It is often used in American, Chinese, South Asian and Southeast Asian cuisine, both for general cooking, and in the case of roasted oil, for added flavor.
is a product of peanuts used in sauces, cookies, crackers (and other baked goods), breakfast cereals and ice cream, and peanut paste is the main ingredient in some peanut butter recipes?
Dried fruit is fruit from which the majority of the original water content has been removed either naturally, through sun drying, or through the use of specialized dryers or dehydrators. Dried fruit has a long tradition of use dating back to the fourth millennium BC in Mesopotamia, and is prized because of its sweet taste, nutritive value, and long shelf life.Today, dried fruit consumption is widespread. Nearly half of the dried fruits sold are raisins, followed by dates, prunes, figs, apricots, peaches, apples and pears. These are referred to as “conventional” or “traditional” dried fruits: fruits that have been dried in the sun or in heated wind tunnel dryers. Many fruits such as cranberries, blueberries, cherries, strawberries and mango are infused with a sweetener (e.g. sucrose syrup) prior to drying. Some products sold as dried fruit, like papaya, kiwi fruit and pineapple are most often candied fruit, dried fruits retain most of the nutritional value of buying fresh fruits. The specific nutrient content of the different dried fruits reflects their fresh counterpart and the processing method.
Given that the production of peanut by-products is seasonal their use in food processing or animal feeding over the whole year requires adequate preservation and storage. Drying may preserve peanut skins, peanut hulls and peanut vines but excess drying may decrease intake and nutritive value. Conversely, the main constraints to preserve peanut meals are water and oil contents. According to previous mycological surveys, peanuts are frequently contaminated by the fungal species Aspergillus flayus link, which can produce the aflatoxin (Achar et al. 2009). This infection can occur during transportation or storage of peanut meals. Aflatoxins are highly toxic and carcinogenic secondary metabolites of concern in food safety (Achar et al. 2009). In addition, it is well recognised that oxidation of the lipid fraction of peanut meals is a major cause of deterioration in fatty peanuts due to the high degree of fatty acid unsaturation (Talcott et al. 2005). Polyunsaturated fatty acids, specifically linoleic and linolenic acids, are very susceptible to oxidation even under mild ambient conditions and are easily incorporated into the chain mechanism of lipid peroxidation, to yield free and peroxy radicals (Talcott et al. 2005). Lipid oxidation is usually implicated as the primary cause of decreased shelf life, adverse tastes, loss of nutrients and generation of undesirable aromas during extended storage of peanut meals (Reed et al. 2002). So, it is important to develop preservation methods for the peanut meal. At present, no information about the preservation of peanut meals is available. The current study concerned storage of peanut meals in world where poor storage practice leads to heavy deterioration caused by fungi and fatty acid oxidation. However, silage storage may be a simple, cheap, and efficient procedure to preserve peanut meals. The inclusion of peanut meals, even those with moisture and oil, into multi-nutrient blocks has proved to be a promising way for their utilization (Yu et al. 2007; Jamdar et al. 2010).
Most peanuts grown in world are primarily used to produce edible oil. After the peanut oil is extracted, the protein content in the cake could reach 50%. The increasing demand for animal proteins (milk and meat) around the world has promoted the search for new sources of proteins. Peanut proteins constitute an interesting alternative due to their high nutritional value, functional properties and low cost. The latter is critically needed in many developing countries, because animal protein is more expensive and is getting beyond the reach of many people in developing countries. The abundant proteins of peanut are a cheap source of proteins, and can meet the requirements of many people.The peanut proteins had good emulsifying activity, emulsifying stability, foaming capacity, excellent water retention and high solubility, and would also provide a new high protein food ingredient for product formulation and protein fortification in food industry (Wu et al. 2009). Therefore, the peanut proteins can be regarded as one of the most attractive and promising vegetable proteins. Among plant proteins, the functional properties of soy proteins are the most extensively studied (Hua et al. 2005). Many investigations had been carried the functional properties of soy protein fractions, chemical and biochemical modified soy proteins (Jung et al. 2005). Adequate modification on proteins may improve their functional properties, so detailed investigation of peanut proteins is necessary to elucidate the functional properties of peanut proteins. Similar process was also found to enhance the solubility and other functional properties of peanut proteins. Yu et al. (2007) reported that the peanut flour by fermented treatment and peanut protein concentrate (PPC) could enhance the functional properties of peanut proteins and peanut flour. Functional properties of many other plant protein concentrates/isolates produced from peas and beans were also studied by a number of investigators (Lawal 2004). Functional properties of peanut protein have been the subject of limited studies (Yu et al. 2007; Wu et al. 2009). Among plant proteins, the nutritional value of peanut proteins is lower than soy proteins, but the anti-nutritional factor content of peanut proteins is less than that of soy proteins. So it is important to study the functional properties of protein concentrates/isolates.
Although there were previous studies on the functional components and properties in peanut meals, skins, hulls and vines, commercial products of by-products are absent in food, feed, medicine and chemistry industry. It can be seen that within field of endeavor, the state of knowledge is not yet strong. From this discussion we can see that there are components of knowledge that origins in food or material science. The by-products of peanut industry can be processed by separation and purification technique or mechanical engineering. There is a need to grasp the developments of defects in peanut by-products, which will provide the basis of coursework for process engineering. However, the case histories reviewed should indicate the great interest and activity to study processing technology of peanut by-products. With modern techniques and ideas, there should certainly be an impetus from industry to help grapple with the difficult issues. Once the companies first gain an effective understanding of a process to make a product, they will have an opportunity to gain a significant advantage. The challenges and future directions of research for by-products of peanut to investigate the potential as food or feed additives are as follows. Firstly, initiating strong programs investigate the underlying functional components and properties of peanut by-products. Secondly, it is the most interesting in the potential applications of by-products with modern technology (such as superfine grinding technology, microwave-assisted and ultrasound-assisted technology, reverse micelle technology et al.) both directly as food or feed supplements for animal and human consumption, and indirectly, as potentially health-promoting byproducts in the meat supply, to offset and replace the carcinogenic effects of chemical food additives.Most of us are familiar with the problems of hunger and malnutrition across the world, especially in developing countries. Problems with the world food supply remain a serious matter. It is receiving increasing attention by the WHO and other international aid agencies these days are an issue called the “epidemiological transition” by public health scientists. The epidemiological transition refers to a now well-established phenomenon that, as countries develop economically, there is a predictable shift in the leading causes of morbidity and mortality, from infectious diseases to chronic diseases, from diseases like malaria, cholera, polio and tuberculosis, to chronic diseases like cardiovascular heart disease, cancer, stroke and diabetes. With that as background, the development of by-products from peanut industry will make a significant contribution in all these areas in the years to come.